LTM2884 Isolated USB Transceiver with Isolated Power FeaTures

FeaTures

n

Isolated USB Transceiver: 2500V

RMS

for 1 Minute

n

USB 2.0 Full Speed and Low Speed Compatible n

Integrated Isolated DC/DC Converter, External or n

Bus Powered

Auto-Configuration of Bus Speed n

2.5W (500mA at 5V) Output Power from External n

Input Supply (V

CC

= 8.6V to 16.5V)

1W (200mA at 5V) Output Power from USB Bus n n

Supply (V

BUS

)

3.3V LDO Output Supply Signal References V

LO

, V

High Common Mode Transient Immunity: 30kV/μs

LO2 n

ESD: ±15kV HBM on USB Interface Pins n

15mm × 15mm × 5mm Surface Mount BGA Package

applicaTions

n

Isolated USB Interfaces n

Host, Hub, or Device Isolation n

Industrial/Medical Data Acquisition

L

, LT, LTC, LTM, Linear Technology, the Linear logo and µModule are registered trademarks of

Linear Technology Corporation. All other trademarks are the property of their respective owners.

LTM2884

Isolated USB Transceiver with Isolated Power

DescripTion

The LTM

®

2884 is a complete galvanically isolated USB

2.0 compatible μModule

®

(micromodule) transceiver.

An upstream supply powers both sides of the interface through an integrated, isolated DC/DC converter.

The LTM2884 is ideal for isolation in host, hub, bus splitter or peripheral device applications. It is compatible with

USB 2.0 full speed (12Mbps) and low speed (1.5Mbps) operation. Automatic speed selection configures integrated pull-up resistors on the upstream port to match those sensed on the downstream device.

The isolator µModule technology uses coupled inductors and an isolated power transformer to provide 2500V

RMS of isolation between the upstream and downstream USB interface. This device is ideal for systems requiring isolated ground returns or large common mode voltage variations.

Uninterrupted communication is guaranteed for common mode transients greater than 30kV/μs.

Enhanced ESD protection allows this part to withstand up to ±15kV (human body model) on the USB transceiver interface pins to local supplies and ±15kV through the isolation barrier to supplies without latch-up or damage.

Typical applicaTion

Powered 2.5W Isolated Hub Port

4.4V TO 16.5V

8.6V TO 16.5V

V

BUS

V

CC

V

LO

ON

LTM2884

PWR

SPNDPWR

HUB

µC

D1

+

D1

–

V

CC2

+

500mA AT 5V

V

BUS2

100µF

V

BUS

V

LO2

D2

+

DOWNSTREAM

USB PORT

D2

–

UPSTREAM

USB PORT

Bus Powered 1W Isolated Peripheral Device

200mA AT 5V

V

LO

ON

V

BUS

SPNDPWR

V

CC

LTM2884

PWR

V

CC2

PERIPHERAL

V

LO2

1.5k

D1

+

D1

–

D2

+

D2

–

15k 15k

GND GND2 GND GND2

2884 TA01b

GND

2884 TA01a

For more information www.linear.com/LTM2884

2884f

1

LTM2884

absoluTe MaxiMuM raTings

(Note 1)

Supply Voltages

V

CC

to GND ............................................ –0.3V to 18V

V

V

V

LO

V

LO2

BUS

CC2

to GND .......................................... –0.3V to 18V

to GND2 ....................................... –0.3V to 10V

to GND .................................................. –0.3V to 4V

to GND2 ............................................... –0.3V to 4V

ON, SPNDPWR to GND .................–0.3V to (V

D1

+

, D1

–

LO

+ 0.3V)

to GND ........................................ –0.3V to 5.3V

D2

+

, D2

–

to GND2 ..................................... –0.3V to 5.3V

Operating Ambient Temperature Range (Note 3)

LTM2884C ............................................... 0°C to 70°C

LTM2884I ............................................–40°C to 85°C

LTM2884H ......................................... –40°C to 105°C

Storage Temperature Range .................. –40°C to 125°C

Maximum Internal Operating Temperature ............ 125°C

Peak Body Reflow Temperature ............................ 245°C

pin conFiguraTion

1

D1

–

2

D1

3

TOP VIEW

4 5 6 7

ON V

LO

GND

V

BUS

8 9

V

CC

10 11

C

D

E

F

A

B

J

K

L

G

H

GND

GND2

D2

–

D2

+

GND2

V

LO2

GND2

V

CC2

BGA PACKAGE

44-LEAD (15mm × 15mm × 5mm)

PCB = DC1746A: θ

JA

= 33.5°C/W, θ

JCtop

HEAT FLOW: θ

JA

= NORMAL, θ

JCtop

WEIGHT = 2.4g

PCB = JESD51-9 2s2p: θ

JA

T

JMAX

= 18.7°C/W, θ

JCtop

= 125°C,

= 16°C/W, θ

JCbottom

= 5.7°C/W, θ

= 15.7°C/W, θ

= 100%, θ

JCbottom

= 6.1°C/W, θ

JCbottom

= 100%, θ

JB

= 5.6°C/W

JB

= 5.3°C/W

JB

= 100%

orDer inForMaTion

PART NUMBER

LTM2884CY#PBF

LTM2884IY#PBF

PAD OR BALL FINISH

SAC305 (RoHS) LTM2884Y

LTM2884HY#PBF

• Device temperature grade is indicated by a label on the shipping container.

• Pad or ball finish code is per IPC/JEDEC J-STD-609.

• Terminal Finish Part Marking: www.linear.com/leadfree

PART MARKING

DEVICE

• This product is not recommended for second side reflow. For more information, go to: www.linear.com/BGA-assy

FINISH CODE

e1

PACKAGE

TYPE

BGA

MSL

RATING

4

TEMPERATURE RANGE

0°C to 70°C

–40°C to 85°C

• Recommended BGA PCB Assembly and Manufacturing Procedures: www.linear.com/BGA-assy

–40°C to 105°C

• BGA Package and Tray Drawings: www.linear.com/packaging

• This product is moisture sensitive. For more information, go to: www.linear.com/BGA-assy

2884f

2

For more information www.linear.com/LTM2884

LTM2884

elecTrical characTerisTics

temperature range, otherwise specifications are at T

A

The

l

denotes the specifications which apply over the full operating

= 25°C. V

CC

= 5V, V

BUS

= 5V, GND = GND2 = 0V, ON = V

LO

, unless otherwise noted.

MIN TYP MAX UNITS

I

I

SYMBOL PARAMETER

Power Supply

V

CC

V

BUS

Operating Supply Range (Isolated Power Input)

V

CC

BUS

CC2

Operating Supply Range (USB Bus Power Input)

V

CC

Supply Current Power Off

V

CC

Supply Current Power On

V

BUS

Supply Current Power Off

V

BUS

Supply Current Power On

V

BUS

Supply Current Suspend Mode

Regulated V

CC2

Output Voltage, Loaded

V

LO

V

LO2

V

LO

Output Voltage Maximum Current

V

LO2

Regulated Output Voltage

V

LO2

Output Voltage Maximum Current

USB Input Levels (D1

+

, D1

–

, D2

+

, D2

–

)

Single-Ended Input High Voltage V

IH

V

IL

V

HYS

V

CC2

Source Current High Power Mode

V

CC2

Source Current Bus Power Mode

V

LO

Regulated Output Voltage

Single-Ended Input Low Voltage

Single-Ended Input Hysteresis

V

DIFF

V

CM

Differential Input Sensitivity

Common Mode Voltage Range

Logic Input Levels (ON, SPNDPWR)

CONDITIONS

ON = 0V, V

CC

= 4.4V to 16.5V

I

CC2

= 0mA, Figure 1

ON = 0V

I

VLO

= 0mA, Figure 1

SPNDPWR = 3.3V

USB Suspend Timeout

SPNDPWR = 0,

USB Suspend Timeout

V

CC

= 4.4V, I

CC2

V

CC

= 8.6V, I

CC2

= 200mA, Figure 1

= 500mA, Figure 1

V

CC

= 8.6V, Figure 1

V

CC

= V

BUS

= 4.4V, Figure 1

I

VLO

= 0mA to 10mA, Figure 1

Figure 1

I

VLO2

= 0mA to 10mA, Figure 1

Figure 1

|(D1

+

– D1

–

)| or |(D2

+

– D2

–

)|

V

IHL

V

ILL

I

INL

Logic Input High Voltage

Logic Input Low Voltage

Logic Input Current

V

HYSL

Logic Input Hysteresis

USB Output Levels (D1

+

, D1

–

, D2

+

, D2

–

)

V

OL

Output Low Voltage R

PU

= 1.5k to 3.6V, Figure 4

V

OH

V

CRS

Terminations

Output High Voltage

Differential Output Signal Cross-Point Voltage

R

PU

R

PD

= 15k to 0V, Figure 4

Bus Pull-Up Resistance on Upstream Facing Port D2

+

or D2

–

Pull-Up to 3.3V

Bus Pull-Down Resistance on Downstream Facing Port D2

+

and D2

–

Pull-Down to GND2 R

PD

Z

DRV

C

INUSB

USB Driver Output Resistance

USB Transceiver Pad Capacitance to GND (Note 2) l l l l l l l l l l l l l l l l l l l

|(D1

+

+ D1

–

)|/2 or |(D2

+

+ D2

–

)|/2 l l l l l l l l

4.4

4.4

4.75

4.75

500

200

3.15

3.15

2.0

0.2

0.8

2.0

0

2.8

1.3

1.425

14.25

28

12

5

100

50

10

6

1.5

5

5

3.3

3.3

200

200

10

3.45

10

3.45

10

16.5

16.5

500

100

100

9

500

2.0

5.25

5.25

0.8

2.5

0.8

±1

0.3

3.6

2.0

1.575

15.75

44 kΩ kΩ

Ω pF

µA mV

V

V mV

V

V

V

V

V

V

V mA

µA mA

µA mA

V

V

µA mA

V mA mA mA

V

V

V

For more information www.linear.com/LTM2884

2884f

3

LTM2884

swiTching characTerisTics

temperature range, otherwise specifications are at T

A

The

l

denotes the specifications which apply over the full operating

= 25°C. V

CC

= 5V, V

BUS

= 5V, GND = GND2 = 0V, ON = V

LO

, unless otherwise noted.

CONDITIONS MIN TYP MAX UNITS SYMBOL

Low Speed USB

t

LDR t

LR t

LF t

LPRR

, t

LPFF t

LDJ1 t

LDJ2

Full Speed USB

PARAMETER

Low Speed Data Rate

Rise Time

Fall Time

Propagation Delay

Differential Jitter

Differential Jitter t

FDR t

FR t

FF t

FPRR

, t

FPFF t

FDJ1

Full Speed Data Rate

Rise Time

Fall Time

Propagation Delay

Differential Jitter t

FDJ2

Differential Jitter

Power Supply Generator

V

CC2

– GND2 Supply Start-Up Time

(ON V

LO

, V

CC2

to 4.5V) t

WUSPND

Wake Up from Suspend Mode

ESD (HBM) (Note 2) Isolation Barrier

D1

+

, D1

–

, D2

+

, D2

–

C

L

= 50pF to 450pF (Note 4)

Figure 2, C

L

= 50pF to 600pF

Figure 2, C

L

= 50pF to 600pF

Figure 2, C

L

= 50pF to 600pF

To Next Transition (Note 2)

To Paired Transitions (Note 2)

C

L

= 50pF (Note 4)

Figure 3, C

L

= 50pF

Figure 3, C

L

= 50pF

Figure 3, C

L

= 50pF

To Next Transition (Note 2)

To Paired Transitions (Note 2)

R

LOAD

= 50Ω, C

LOAD

R

LOAD

= 10Ω, C

LOAD

= 100µF

= 100µF, V

CC

= 12V

Resume Signal, SPNDPWR = 0

GND to GND2

D1

+

D2

+

/D1

/D2

–

–

to GND, V

CC

, V

BUS

, or V

to GND2, V

CC2

, or V

LO2

LO

and l l l l l l l l l

75

75

4

4

60

1.5

200

12

80

2

1

2

3

0.25

±15

±15

300

300

300

±45

± 15

20

20

115

5

10

10 ms ms

µs kV kV

Mbps ns ns ns ns ns

Mbps ns ns ns ns ns

ON, SPNDPWR ±3 kV

isolaTion characTerisTics

T

A

= 25°C.

CONDITIONS SYMBOL PARAMETER

Isolation Barrier: GND to GND2

V

ISO

Rated Dielectric Insulation Voltage

(Notes 6, 7)

Common Mode Transient Immunity

V

IORM

Maximum Working Insulation Voltage

1 Minute (Derived from 1 Second Test)

1 Second (Note 5)

V

BUS

= V

CC

= 5V, ON = 3.3V, 1000V in 33ns

Transient Between GND and GND2 (Note 2)

(Notes 2, 5)

CTI

DTI

Partial Discharge

Comparative Tracking Index

Depth of Erosion

Distance Through Insulation

Input to Output Resistance

Input to Output Capacitance

Creepage Distance

V

PR

= 750V

RMS

(Note 5)

IEC 60112 (Note 2)

IEC 60112 (Note 2)

(Note 2)

(Notes 2, 5)

(Notes 2, 5)

(Notes 2, 5)

MIN

2500

3000

±30

560

400

600

TYP

10

12

0.017

0.1

13

9.48

MAX

<5

UNITS

V

RMS

V

RMS kV/µs

V

PEAK

V

RMS pC

V

RMS mm mm

Ω pF mm

2884f

4

For more information www.linear.com/LTM2884

LTM2884

elecTrical characTerisTics

Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute

Maximum Rating condition for extended periods may affect device reliability and lifetime.

Note 2: Guaranteed by design and not production tested.

Note 3: This µModule transceiver includes over temperature protection that is intended to protect the device during momentary overload conditions. Junction temperature will exceed 125°C when over temperature protection is active. Continuous operation above specified maximum operating junction temperature may result in device degradation or failure.

Note 4: Maximum data rate is guaranteed by other measured parameters and is not directly tested.

Note 5: Device considered a 2-terminal device. Measurement between groups of pins A1 through B11 shorted together and pins K1 through L11 shorted together.

Note 6: The rated dielectric insulation voltage should not be interpreted as a continuous voltage rating.

Note 7: In accordance with UL1577, each device is proof tested for the

2500V

RMS

rating by applying the equivalent positive and negative peak voltage multiplied by an acceleration factor of 1.2 for one second.

For more information www.linear.com/LTM2884

2884f

5

LTM2884

Typical perForMance characTerisTics

ON = 3.3V, unless otherwise noted.

100

Full Speed Propagation Delay vs Temperature

C

LOAD

= 120pF

95

250

Low Speed Propagation Delay vs Temperature

C

LOAD

= 120pF

T

A

= 25°C, V

CC

= 5V, V

BUS

= 5V, GND = GND2 = 0V,

Full Speed Differential Jitter

240

D1

–

D1

+

90

230

1V/DIV

85

D2

–

JITTER 1.4ns

P-P

80

220

D2

+

210

75

10ns/DIV 2884 G03

70

–50 –25 0 25 50 75

TEMPERATURE (°C)

100 125

2884 G01

200

–50 –25 0 25 50 75

TEMPERATURE (°C)

100 125

2884 G02

1V/DIV

Low Speed Differential Jitter

D1

+

D1

–

D2

+

D2

–

50ns/DIV

JITTER 7.5ns

P-P

2884 G04

450

V

CC vs V

Input Current

CC2

Output Current

400

350

300

250

200

150

100

50

0

0

V

CC

= 5V

V

CC

= 12V

0.2

0.4

0.6

OUTPUT CURRENT (A)

0.8

2884 G07

800

V

CC2

Output Current vs Temperature

V

CC2

= 4.75V

700

V

CC

= 12V

600

500

400

300

V

CC

= 5V

200

–50 –25 0 25 50 75

TEMPERATURE (°C)

100 125

2884 G05

5.25

V

CC2

Output Voltage vs Load Current

V

CC

= 8.1V

5.00

V

CC

= 12V

4.75

4.50

V

CC

= 4.4V

4.25

V

CC

= 5V

4.00

0 0.2

0.4

0.6

LOAD CURRENT (A)

0.8

1.0

2884 G08

0.55

0.50

0.45

0.40

0.35

0.30

0.25

0.20

0.15

0.10

0.05

0

25

70

V

CC

Loss

to V

CC2

Efficiency and Power

V

CC

= 5V

EFFICIENCY

60

V

CC

= 12V

1.4

1.2

1.0

50

0.8

40

V

CC

= 5V

V

CC

= 12V

0.6

30

POWER LOSS 0.4

20

0.2

0

0 0.2

0.4

I

OUT

(A)

0.6

0.8

0

2884 G06

Derating for 125°C Maximum

Internal Operating Temperature

35

V

V

BUS

BUS

V

BUS

– V

– V

V

BUS

– V

– V

CC

= 5V

CC

= 8.6V

CC

= 12V

CC

= 16.5V

45 55 65 75 85 95

TEMPERATURE (°C)

105 115 125

2884 G09

2884f

6

For more information www.linear.com/LTM2884

LTM2884

Typical perForMance characTerisTics

ON = 3.3V, unless otherwise noted.

I

V

CC2

CC2

Ripple, V

= 200mA

CC

= 5V,

I

V

CC2

CC2

Ripple, V

= 500mA

CC

= 12V,

T

A

= 25°C, V

CC

= 5V, V

BUS

= 5V, GND = GND2 = 0V,

V

CC2

Start-Up Ramp

V

CC2

100mV/DIV 100mV/DIV

1V/DIV

ON

2µs/DIV 2884 G10 2µs/DIV 2884 G11

500µs/DIV 2884 G12

200mA/DIV

500mV/DIV

V

CC2

= Load Step Response,

0mA to 500mA (V

CC

= 12V)

I

CC2

V

CC2

100µs/DIV

1V/DIV

V

CC2

Droop/Plug-In Response

V

CC

V

CC2

200µs/DIV

2884 G13

2884 G16

200mA/DIV

500mV/DIV

V

CC2

= Load Step Response,

0mA to 200mA (V

I

CC2

V

CC2

CC

= 5V)

100µs/DIV 2884 G14

70

I

CC

vs Temperature

I

CC2

= 0mA

60

V

CC

= 4.4V

50

V

CC

= 5V

40

30

20

V

CC

= 8.1V

V

CC

= 12.5V

V

CC

= 16.5V

10

0

–50 –25 0 25 50 75 100

TEMPERATURE (°C)

125

2884 G15

Upstream V

BUS

Droop During

Plug-In with C

LOAD

= 100µF

HOST V

BUS

1V/DIV

PLUG IN TO HOST

ISOLATED V

CC2

500mV/DIV

Full Speed Data Start of Packet

D2

+

D2

–

500µs/DIV 2884 G16 100ns/DIV 2884 G17

For more information www.linear.com/LTM2884

2884f

7

LTM2884

pin FuncTions

Upstream Side (V

CC

, V

BUS

, V

LO

, GND)

D1

–

(A1): USB Data Bus Upstream Facing Negative

Transceiver Pin. A 1.5k pull-up resistor is automatically configured to indicate the idle condition of the D2

–

pin.

D1

+

(A2): USB Data Bus Upstream Facing Positive

Transceiver Pin. A 1.5k pull-up resistor is automatically configured to indicate the idle condition of the D2

+

pin.

SPNDPWR (A3): Suspend Power Control. A high input enables the DC/DC converter shutdown control if the USB bus is suspended. A low input (GND) disables the shutdown control to the DC/DC converter maintaining power to the isolated downstream side during suspend mode.

The recovery time from suspend mode may be equivalent to the power supply start-up time if the DC/DC converter was shut down. The SPNDPWR pin is referenced to V

LO and GND.

ON (A4): Enable for Power and Data Communication

Through the Isolation Barrier. If ON is high, the part is enabled. If ON is low, the upstream side is held in reset and the isolated side is unpowered by the DC/DC converter.

The ON pin is referenced between V

LO

and GND.

V

LO

(A5): Internally Regulated 3.3V Logic Voltage Output.

The V

LO

pin is used as a positive reference for the ON and

SPNDPWR pins and can source up to 10mA of surplus current. Internally bypassed to GND with 2.2µF. Output supply, no external connection necessary.

GND (A6, B1-B11): Upstream Circuit Ground.

V

BUS

(A7): Voltage Supply Input to USB Transceiver. The operating range is 4.4V to 16.5V. Connect to the USB

V

BUS

supply or an external source. Internally bypassed to GND with 2.2µF.

V

CC

(A8-A11): Voltage Supply Input to DC/DC Converter.

The operating range is 4.4V to 16.5V. Connect to an external supply greater than 8.6V for 500mA on V

CC2 the USB V

BUS

V

BUS

for up to 200mA on V

CC2

. Connect to

. Connect V source. Internally bypassed to GND with 4.7µF.

CC

to

when the peripheral device has an external power

Isolated Downstream Side (V

CC2

, V

LO2

, GND2)

GND2 (K1-K11, L3, L4, L6, L7): Downstream Circuit

Ground.

D2

–

(L1): USB Data Bus Downstream Facing Negative

Transceiver Pin. The pin has a 15k pull-down resistor to

GND2.

D2

+

(L2): USB Data Bus Downstream Facing Positive Transceiver Pin. The pin has a 15k pull-down resistor to GND2.

V

LO2

(L5): Internally Regulated 3.3V Logic Voltage Output.

The V

LO2

pin can source up to 10mA of surplus current.

Internally bypassed to GND2 with 2.2µF. Output supply, no external connection necessary.

V

CC2

(L8-L11): Isolated Voltage Supply Output from DC/

DC Converter. Output voltage is 5V and can support up to

500mA of peripheral device current referenced to GND2.

Output current is dependant on input supply voltage and current limit. Internally bypassed to GND2 with 22µF.

Output supply, no external connection necessary.

2884f

8

For more information www.linear.com/LTM2884

LTM2884

block DiagraM

V

BUS

2.2µF

V

CC

3.3V

REG

4.7µF

DC/DC

V

LO

2.2µF

ISOLATED COMMUNICATION

INTERFACE

ON

1.5k

1.5k

D1

+

UPSTREAM

PORT

D1

–

SPNDPWR

= UPSTREAM SIDE COMMON

GND

3.3V

REG

ISOLATED COMMUNICATION

INTERFACE

V

CC2

22µF

V

LO2

2.2µF

GND2

= DOWNSTREAM SIDE COMMON

15k 15k

D2

+

D2

–

DOWNSTREAM

PORT

2884 BD

For more information www.linear.com/LTM2884

2884f

9

LTM2884

TesT circuiTs

I

CC

I

BUS

+–

V

CC

+–

V

BUS

I

VLO

V

CC

V

BUS

V

LO

LTM2884

V

CC2

V

LO2

GND GND2

Figure 1. Power Supply Loads

2884 F01

I

VLO2

I

CC2

10

For more information www.linear.com/LTM2884

2884f

LTM2884

TesT circuiTs

D1

+

OR D2

+

D1

–

OR D2

–

D2

+

OR D1

+

C

L

3.6V

D2

–

OR D1

–

1.5k

C

L

3.3V

D1

–

OR D2

–

0V

D1

+

OR D2

+

3.3V

D2

–

OR D1

–

0V

D2

+

OR D1

+ t

LPRR

10% t

LR

90%

Figure 2. Low Speed Timing Measurements

t

LPFF

10% t

LF

90%

2884 F02

D1

+

OR D2

+

D1

–

OR D2

–

D2

+

OR D1

+

C

L

D2

–

OR D1

–

C

L

3.3V

D1

+

OR D2

+

0V

D1

–

OR D2

–

3.3V

D2

+

OR D1

+

0V

D2

–

OR D1

– t

FPFF

10% t

FF

90%

Figure 3. Full Speed Timing Measurements

t

FPRR

10% t

FR

90%

2884 F03

For more information www.linear.com/LTM2884

2884f

11

LTM2884

FuncTional Table

USB Transceiver Functional Table

MODE

Full Speed (Idle)

Low Speed (Idle)

D1

+

1.5k Pull-Up

Host Pull-Down

D1

–

Host Pull-Down

1.5k Pull-Up

AUTOMATIC PULL-UP

CONNECTION

D1

+

D1

–

D2

+

D2

–

Peripheral Pull-Up 15k Pull-Down

15k Pull-Down Peripheral Pull-Up

Disconnected (Idle) Host Pull-Down Host Pull-Down None 15k Pull-Down 15k Pull-Down

Suspend (Idle >3ms) Set at Device Connect Set at Device Connect Set at Device Connect Peripheral or 15k Peripheral or 15k

Set at Device Connect Set at Device Connect Set at Device Connect 15k Pull-Down 15k Pull-Down Suspend No Power

(Idle >3ms)

D1 to D2 Data

D2 to D1 Data

IN

+

OUT

+

IN

–

OUT

–

Set at Device Connect

Set at Device Connect

OUT

IN

+

+

OUT

IN

–

–

SPNDPWR

X

X

X

0

3.3V

X

X

Power Functional Table

MODE

Off

On

On, Suspend (Idle >3ms)

On, Suspend (Idle >3ms), Power Off

On, USB Transceiver Only Power Off

ON

0

3.3V

3.3V

3.3V

3.3V

SPNDPWR

X

X

0

3.3V

X

V

CC

X

>4.4V

>4.4V

>4.4V

0

V

BUS

X

>4.4V

>4.4V

>4.4V

>4.4V

DC/DC CONVERTER

OFF

ON

ON

OFF

OFF

12

For more information www.linear.com/LTM2884

2884f

LTM2884

operaTion

The LTM2884 µModule transceiver provides a galvanically isolated robust USB interface, powered by an integrated, regulated DC/DC converter, complete with decoupling capacitors. This flexible device can support a variety of

USB configurations, either bus powered or externally powered. Applications include isolation in hosts, hubs, peripherals, or standalone inline bus splitters. Automatically configured pull-up resistors are included to represent the condition of the isolated downstream USB bus to the upstream USB bus. The LTM2884 is ideal for use in USB connections where grounds between upstream hub/host and downstream devices can take on different voltages.

Isolation in the LTM2884 blocks high voltage differences and eliminates ground loops and is extremely tolerant of common mode transients between ground potentials. Error free operation is maintained through common mode events exceeding 30kV/µs providing excellent noise isolation.

The LTM2884 contains a fully integrated DC/DC converter including the transformer, so that no external components are necessary in many configurations. The upstream side contains a flyback converter that regulates the downstream output voltage through primary sensing techniques. The internal power solution is sufficient to support the transceiver interface and supply up to 500mA at 5V through

V

CC2

to an attached device dependent on the supply voltage and available current on V

CC

.

The integrated USB transceivers on both sides of the isolation barrier support full and low speed modes defined in the USB 2.0 specification. The communication through the isolation barrier for USB is bidirectional and as such the

LTM2884 determines data flow direction based on which side a start of packet (SOP) begins first. The direction of data is maintained until an end of packet (EOP) pattern is observed or a timeout occurs due to a lack of activity.

The USB interface maintains a consistent propagation delay representative of a hub delay and transfers all data.

Pull-up resistors integrated in the upstream interface automatically indicate device connections and disconnections. A downstream device connection automatically selects the proper pull-up resistor at the upstream facing port after sensing the idle state of the downstream device at connection time. Disconnection of a downstream device automatically releases the pull-up resistor on the upstream facing port allowing the upstream 15k pull-down resistors to pull the bus signals to a disconnect condition. This function makes the LTM2884 ideal for host, hub, bus splitter, or peripheral device integration.

Isolator µModule Technology

The LTM2884 utilizes isolator µModule technology to translate signals and power across an isolation barrier.

Signals on either side of the barrier are encoded into pulses and translated across the isolation boundary using differential signaling through coreless transformers formed in the µModule substrate. This system, complete with data refresh, error checking, safe shutdown on fail, and extremely high common mode immunity, provides a robust solution for bidirectional signal isolation. The

µModule technology provides the means to combine the isolated signaling with a USB transceiver and powerful isolated DC/DC converter in one small package.

USB Transceiver Pin Protection

The LTM2884 USB transceiver pins D1

D2

–

+

, D1

–

, D2

+

, and

have protection from ESD and short-circuit faults.

The transceiver pins withstand ±15KV HBM ESD events.

Overcurrent circuitry on the transceiver pins monitor fault conditions from D1

+

and D1

–

D2

+

and D2

–

to GND, V

LO

, or V

BUS

to GND2, V

LO2

, or V

CC2

40mA for greater than 600ns. The V

and from

. A current detection circuit disables the transceiver pin if the pin sinks about

LO

and V

LO2

output supplies protect the USB transceiver pins from shorts to GND or GND2 respectively with a 40mA current limit.

For more information www.linear.com/LTM2884

2884f

13

LTM2884

applicaTions inForMaTion

USB Connectivity

The LTM2884 µModule transceiver connects directly to

USB ports on the upstream side and the downstream side without the addition of external components. The transceiver passes through all data and does not act as a hub or intelligent device. The bus lines are monitored for idle conditions, start of packet, and end of packet conditions to properly maintain bus speed and data direction. The series resistance, pull-up, and pull-down resistors are built into the LTM2884. The upstream facing USB port contains automatically configured 1.5k pull-up resistors which are switched in or out based on the downstream side peripheral device configuration. This implementation allows upstream reporting of the downstream bus speed and connection/disconnection conditions. Built-in 15k pulldown resistors are included from the D2

+

and D2

–

signals to GND2 supporting the downstream bus configuration.

Monitoring the USB data pins, the LTM2884 detects a

K-state to begin a data packet and set the data direction.

The data is monitored for an end of packet signature and a finishing J-state before the bus is released. The data payload between the K-state and J-state is transferred through the LTM2884 isolator with a delay of approximately 80ns.

Idle State Communication and Automatic Speed

Selection

The LTM2884 µModule transceiver maintains the conditions of the USB bus idle state by monitoring the downstream side bus idle condition and refreshing the state across the isolation barrier at a consistent rate. Furthermore, the LTM2884 monitors the speed of the downstream peripheral once connected and sets its own operation to match. Figure 4 shows the abbreviated circuitry of the automatic monitoring and reporting of the bus speeds.

The D2

+

or D2 pull-ups on D2

–

signals are monitored for a connection to

+

or D2

–

and the result is processed as full speed or low speed, otherwise disconnect. The idle state is communicated to the upstream side through a refresh transmission. The switches SW1 or SW2 are controlled based on the received information. SW1 is closed if D2

+ is detected to have a pull-up and D2 closed if D2

–

–

was open. SW2 is

is detected to have a pull-up and D2

+

was open. Both SW1 and SW2 are opened if the downstream

USB bus is disconnected. During a USB suspend, the pullup resistor will maintain the condition prior to detecting the suspend command.

15k 15k

UPSTREAM CONNECTION

V

LO

DOWNSTREAM CONNECTION

LTM2884

3.3V

3.3V

D1

+

D1

–

R

SW1

PU

1.5k

SW2

R

PU

1.5k

REFRESH R

PD

15k

FULL

SPEED

LOW

SPEED

1.5k

1.5k

D2

+

D2

–

R

PD

15k

OR

OR DISCONNECTED

2884 F04

Figure 4. Idle State Automatic Resistor Setting

2884f

14

For more information www.linear.com/LTM2884

LTM2884

applicaTions inForMaTion

Suspend Mode

When the upstream USB bus is idle for greater than 3ms, the LTM2884 enters suspend mode. The power savings and behavior in suspend mode depend on the state of the

SPNDPWR pin, as summarized in Table 1.

Table 1. Suspend Mode Operation

SPNDPWR V

CC2

High Off

I

BUS

< 500µA V

I

CC

CC

/45k

Low On 1.5mA

50mA

WAKE-UP

Resume

Resume or

Remote Wake-Up

WAKE-UP

TIME

3ms

10µs

The biggest power savings in suspend mode comes when

SPNDPWR is high. In this case, the DC/DC converter is disabled, shutting down power to the isolated side, while the current draw on V

CC

and V

BUS

are minimized. However, in this mode, if a downstream device is connected or disconnected from the bus or remote wake-up functionality is configured, it will not be recognized by the LTM2884 and will not be relayed to the host. A resume command at the upstream side will wake up the LTM2884 and a renumeration by the host will be required. Recovery time is about 3ms from the start of the resume command on the upstream side.

If SPNDPWR is low in suspend mode, the LTM2884 operates in a low power mode but maintains a higher functional state with the DC/DC converter on and the downstream transceiver powered. The V

1.5mA and V

CC

BUS

current is reduced to

current is about 50mA when there is no external draw on V

CC2

. Wake-up is initiated with disconnects, reconnects, or a remote wake-up command from a downstream device or a resume command from the host.

Recovery time from suspend mode is about 10µs from when the first state change is detected.

During suspend mode DC current drawn from V

LO external circuits will be supplied from V

BUS the limits set in the USB specification.

into

and may exceed

DC/DC Power Supply

The internal DC/DC converter converts the input power from the V to the V

CC2

CC

pin to the V

CC2

output. The power delivered

pin is regulated and current limited to protect against overcurrent conditions. The voltage supply, V

CC before USB specifications are exceeded. Connecting the V

CC and V

BUS

, is sensed to limit the maximum current that can be delivered before V

supply pins to the USB V

BUS

pin (4.4V to 5.5V) limits the maximum downstream side supply current to 200mA

CC2

supply degradation. When V

CC

is connected to a high voltage external DC source (8.6V to 16.5V) the current limit is increased so that 500mA is sourced from V

CC2

.

If a downstream device sinking current from V

CC2 more than 25mA, the input current on V

CC

100mA, the USB single unit load specification for low power devices. The LTM2884 does not enforce a 100mA current limit for low power peripherals.

draws

may exceed

V

CC2

is internally decoupled to GND2 with a 22µF capacitor. Add an additional low ESR 100µF capacitor to V meet the V

BUS

CC2

to

downstream supply decoupling minimum specification of 120µF when supporting device plug in.

Locate the additional 100µF capacitor adjacent to the downstream USB connector. Additional capacitance may not be necessary when the LTM2884 is used in a peripheral device, or upstream hub application.

V

LO

and V

LO2

Supplies

The V

LO

and V

LO2

output supply pins are available for use as low current 3.3V supplies on both sides of the isolation barrier. They also serve as supplies for the USB interface circuitry. An internal linear regulator maintains 3.3V on

V

LO

from the V

BUS

input supply. A separate linear regulator maintains 3.3V on V

LO2

from V

CC2

. The current is limited to 10mA for external applications. Exceeding this limit may cause degradation in the V

LO

or V

LO2

supplies and undesirable operation from the USB isolator. Connection of signals ON or SPNDPWR to V

LO

will not cause a significant change in the available V

LO

current. These supplies are available to support interface logic to the isolated USB port.

In order to meet the suspend mode current limit, minimize the DC current of external applications on the V

LO

output supply. V

LO

and V

LO2

are protected from overcurrent and overtemperature conditions.

For more information www.linear.com/LTM2884

2884f

15

LTM2884

applicaTions inForMaTion

Supply Current

Loading the multiple output supply pins of the LTM2884 affects the supply current on V

BUS

and V

CC

. The V

BUS

input supplies current to the the upstream side of the transceiver and to the V

CC2

and V

LO

pin. The V

CC

input supplies power

LO2

through an isolated DC/DC converter. to V

The efficiency (η) of the DC/DC converter is shown in the

Typical Performance Characteristics section for 5V and

12V inputs from V

CC

to V

CC2

.

Supply Current Equations

Operating:

I

BUS

= 6mA + I

VLO

I

CC

=

V

CC2

(

η • V

Suspend: SPNDPWR = 0

CC2

CC

+ I

VLO2

)

I

BUS

= 1.5mA + I

VLO

I

CC

=

V

CC2

(

CC2

+ I

VLO2

η • V

CC

)

Suspend: SPNDPWR = V

LO

I

BUS

= 0.45mA + I

VLO

I

CC

=

V

CC

45k

Off:

I

BUS

= 10µA

I

CC

=

V

CC

45k

USB 2.0 Compatibility

The LTM2884 µModule transceiver is compatible with the

USB 2.0 specification of full and low speed operation. Some characteristics and implementations may not support full compliance with the USB 2.0 specification. Three specific cases exist within the LTM2884 µModule transceiver and the integrated DC/DC power converter.

First, the propagation delay for full speed data of 80ns exceeds the specification for a single hub of 44ns plus the attached cable delay of 26ns. This is due to driving the signal to the 3.3V rail prior to a K-state transition to maintain balanced crossover voltages equivalent to the cross over voltages of the successive data transitions.

USB ports commonly drive the idle state bus to the 3.3V rail prior to the k-state start of packet transition.

Second, setting SPNDPWR = V

LO

will cause the DC/DC power converter to turn off during a bus suspend. V

CC2 will lose power causing the downstream device to lose enumeration. Remote wake-up, disconnect, and reconnect events are ignored. A resume command from the host or upstream hub will start the DC/DC converter and wake up the downstream device. The downstream device will require re-enumeration, which causes a failure in USB compliance testing. After a resume command initiates, a delay of 3ms will elapse before the isolated device is fully powered. When SPNDPWR = 0V, the DC/DC power converter remains on during suspend, therefore power and enumeration information is retained. The V consumes 50mA to support the isolated power during suspend. Separate the V with the 2.5mA USB 2.0 V

BUS

BUS

and V

CC

CC

supply

supplies to comply

suspend current specification.

Third, when connecting a low power device to the downstream side of the LTM2884 and V

BUS

and V

CC are connected together, the input current is higher due to the operating current and the efficiency of the DC/DC converter. The operating current of the DC/DC converter and the USB transceiver function is 46mA. The efficiency of the converter is approximately 55%, resulting in a 1/0.55 increase in the input current due to the load current on

V

CC2

. A 100mA load on V

CC2

+ operating current at V

BUS

appears as a 181mA load

and V

CC

. In order to meet a

100mA input current, the V

CC2

load current must be less than 25mA. This characteristic of an isolated supply may limit the use of the LTM2884 in bus powered hub applications or downstream connection to a bus powered hub.

Connect V

CC

to an external supply to mitigate this concern.

2884f

16

For more information www.linear.com/LTM2884

LTM2884

applicaTions inForMaTion

Hot Plug Protection

The V

CC

and V

BUS

inputs are bypassed with low ESR ceramic capacitors. During a hot plug event, the supply inputs can overshoot the supplied voltage due to cable inductance. When using external power supply sources greater than 10V that can be hot plugged, add an additional 2.2µF tantalum capacitor with greater than 1Ω of ESR, or a ceramic capacitor with a series 1Ω resistor to the V

CC

input to reduce the possibility of exceeding absolute maximum ratings. Refer to Application Note 88,

“Ceramic Capacitors Can Cause Overvoltage Transients,” for a detailed discussion of this problem.

PC Board Layout

The high integration of the LTM2884 makes PCB layout simple. However, to optimize its electrical isolation characteristics, EMI, and thermal performance, some layout considerations are necessary. The PCB layout in Figure 5 is a recommended configuration for a low EMI USB application. The following considerations optimize the performance of the LTM2884:

• Under loaded conditions, V

700mA, V

CC2

CC

and GND current exceed

and GND2 current is up to 500mA. Use sufficient copper on the PCB to ensure resistive losses do not cause the supply voltage to drop below the minimum allowed level. The heavy copper traces will also help to reduce thermal stress and improve thermal conductivity.

• Input and output decoupling is not required on peripheral or hub inputs. Add additional low ESR capacitance to reduce noise induction on the power supply connections. Hub/bus splitter outputs require an additional

100µF of low ESR capacitance.

• Do not place copper between the inner columns of pads on the top or bottom of the PCB. This area must remain open to withstand the rated isolation voltage and maintain the creepage distance.

RF, Magnetic Field Immunity

The isolator µModule technology used within the LTM2884 has been independently evaluated, and successfully passed the RF and magnetic field immunity testing requirements per European Standard EN 55024, in accordance with the following test standards:

EN 61000-4-3 Radiated, Radio-Frequency,

Electromagnetic Field Immunity

EN 61000-4-8 Power Frequency Magnetic

Field Immunity

EN 61000-4-9 Pulsed Magnetic Field Immunity

Tests were performed using an unshielded test card designed per the data sheet PCB layout recommendations.

Specific limits per test are detailed in Table 2.

Table 2. Test Frequency Field Strength

EN 61000-4-3, Annex D, 80MHz to 1GHz

1.4MHz to 2GHz

2GHz to 2.7GHz

EN61000-4-8, Level 4 50Hz and 60Hz

EN61000-4-8, Level 5 60Hz

EN61000-4-9, Level 5 Pulse

*Non IEC Method

10V/m

3V/m

1V/m

30A/m

100A/m*

1000A/m

EMI

Radiated emissions have been measured for the LTM2884 using a gigahertz transverse electromagnetic (GTEM) cell with and without a USB cable attached. The performance shown in Figure 6 was achieved with the layout structure in Figure 5. Results are corrected per IEC 61000-4-20.

For more information www.linear.com/LTM2884

2884f

17

LTM2884

applicaTions inForMaTion

TECHNOLOGY

DC1789a Demo Board

18

DC1789a Top

Figure 5. PC Board Layout

20

10

0

60

50

40

30

–10

–20

–30

0

CISPR 22 CLASS B LIMIT

DETECTOR = PEAK-HOLD

RBW = 120kHz

VBW= 300kHz

SWEEP TIME = 680ms

# OF POINTS = 501

100 200 300 400 500 600 700

FREQUENCY (MHz)

800 900 1000

2884 F06

Figure 6. EMI Plot

DC1789a Bottom

For more information www.linear.com/LTM2884

2884 F04

2884f

Typical applicaTions

V

BUS

100mA

OR 500mA

V

LO

V

BUS

ON

SPNDPWR

V

CC LTM2884

PWR

V

CC2

5V

25mA

OR

200mA

V

BUS2

100µF

UPSTREAM

USB PORT

D

+

D

–

D1

+

D1

–

GND

GND GND2

V

LO2

D2

+

D2

–

2884 F07

ISOLATED

DOWNSTREAM

USB PORT

D

+

D

–

GND2

Figure 7. Bus Powered Inline Bus Splitter

LTM2884

V

BUS

UPSTREAM TO

USB HOST

D

+

D

–

D1

+

D1

–

V

LO

ON

V

BUS

SPNDPWR

GND

GND

V

CC LTM2884

PWR

GND2

Figure 8. USB Hub Upstream Isolator

V

CC2

V

LO2

D2

+

D2

–

5V

USB HUB

CONTROLLER

DA

DA

+

–

DB

DB

+

–

DC

DC

+

–

4 USB

DOWNSTREAM

PORTS

DD

+

DD

–

2884 F08

GND2

For more information www.linear.com/LTM2884

2884f

19

LTM2884

Typical applicaTions

USB HOST

CONTROLLER

15k 15k

V

LO

V

BUS

ON

SPNDPWR

4.4V TO 16.5V

V

CC LTM2884

PWR

V

CC2

5V UP TO

200mA FOR V

500mA FOR V

CC

4.4V TO 5.5V

CC

8.6V TO 16.5V

V

BUS2

100µF

V

LO2

D1

D1

+

–

GND GND2

D2

D2

+

–

D

+

DOWNSTREAM

USB PORT

D

–

GND2

2884 F09

Figure 9. USB Host Integration

V

BUS

5V

V

BUS

V

LO

ON

SPNDPWR

V

CC LTM2884

PWR

V

CC2

PERIPHERAL

V

LO2

UPSTREAM

USB PORT

D

+

D

–

D1

+

D1

–

D2

+

D2

–

GND GND2

GND

2884 F10

Figure 10. Powered Peripheral Device with USB Isolation and Low Current Suspend

20

For more information www.linear.com/LTM2884

2884f

LTM2884

Typical applicaTions

V

BUS

SiA921EDJ

200mA FOR V

CC

500mA FOR V

CC

4.4V TO 5.5V

8.6V TO 16.5V

V

IN

GND

LTC4412

SENSE

GATE

CTL STAT

V

LO

ON

V

BUS

SPNDPWR

V

CC LTM2884

PWR

V

CC2

9V TO 16V (500mA)

V

PLUG

150k

4.99k

V

IN

SHDN

UV

OV

LTC4365

GATE

V

OUT

FAULT

GND

Si4230DY-TI-GE3

4.75k

OVERVOLTAGE = 16.7V

UNDERVOLTAGE = 8.1V

UPSTREAM

USB PORT

D

+

D

–

D1

+

D1

–

GND

GND GND2

V

LO2

D2

+

D2

–

Figure 11. Bus or Self Powered USB Isolation with Low Current Suspend and Power Plug Detection

PERIPHERAL

2884 F11

For more information www.linear.com/LTM2884

2884f

21

LTM2884

Typical applicaTions

V

PLUG

4.4V TO 16.5V (500mA)

V

CC

ON OFF

V

BUS

V

LO

ON

SPNDPWR

GND

D1

+

D1

–

GND

LTM2884

200mA FOR V

CC

500mA FOR V

CC

4.4V TO 5.5V

8.6V TO 16.5V

V

CC2

5V

PWR

V

LO2

D2

+

D2

–

GND2

2884 F12

Figure 12. Isolated 1W or 2.5W Power Supply

22

For more information www.linear.com/LTM2884

2884f

package DescripTion

Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.

LTM2884

NOTES: 1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994 6. SOLDER BALL COMPOSITION CAN BE 96.5% Sn/3.0% Ag/0.5% Cu

Y PIN 1 BEVEL

MOLD CAP

// bbb Z

PIN “A1” CORNER aaa Z

0.000

3.810

2.540

0.3175

0.3175

1.270

1.270

6.350

5.080

6.350

5.080

3.810

2.540

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.

However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-

For more information www.linear.com/LTM2884

2884f

23

LTM2884

Typical applicaTion

3.3V

V

+

3.3V

TUSB2046B

V

BUS

47k

91k

IN

MAX4594 SPST

NO

GND

COM

OVRCUR4

3.3V

51k

SN74LVC04

PWRON4

1.5k

27Ω

DP0

DM0

27Ω

DP0

DM0

DM4

DP4

27Ω

27Ω

LTC1154

STATUS

EN

SD

IN

V

S

DS

GATE

GND

PWRON_D

D4D

–

D4D

+

SN75240

A

B

C

D

15k 15k

12V

GND

4.7µF

3.3V LDO

LT1762-3.3

3.3V

4.7µF

EXTMEM

V

CC

XTAL1

OVRCUR3

PWRON3

DM3

DP3

3.3V

51k

27Ω

27Ω

LTC1154

STATUS

EN

SD

IN

V

S

DS

GATE

GND

PWRON_C

D3C

–

D3C

+

6MHz CLOCK

SIGNAL

15k 15k

XTAL2

SYSTEM

POWER-ON

RESET

RESET

OVRCUR2

PWRON2

DM2

DP2

3.3V

51k

27Ω

27Ω

LTC1154

STATUS

EN

SD

IN

V

S

DS

GATE

GND

PWRON_B

D2B

–

D2B

+

15k 15k

12V

12V

0.2Ω

V

CC

V

LO

V

BUS

ON

D1

–

D1

+

LTM2884

SPNDPWR

GND

12V

12V

0.2Ω

V

CC

V

LO

V

BUS

ON

D1

–

D1

+

LTM2884

12V

0.2Ω

SPNDPWR

GND

12V

V

CC

V

LO

V

BUS

ON

D1

–

D1

+

LTM2884

OVRCUR1

BUSPWR

PWRON1

DM1

EEDATA/

GANGED

DP1

3.3V

51k

27Ω

27Ω

LTC1154

STATUS

EN

SD

IN

V

S

DS

GATE

GND

PWRON_A

D1A

–

D1A

+

12V

0.2Ω

SPNDPWR

GND

12V

V

CC

V

LO

V

BUS

ON

D1

–

D1

+

LTM2884

GND

15k 15k

SPNDPWR

GND

Figure 13. Self Powered 4-Port Hub with Independent Isolation

PWR

V

CC2

V

BUSD

100µF

GND2

GNDD

V

LO2

D2

+

D2

–

USB PORT D

DD

+

DD

–

PWR

V

CC2

V

BUSC

100µF

GND2 GNDC

V

LO2

D2

+

D2

–

USB PORT C

DC

+

DC

–

PWR

V

CC2

V

BUSB

100µF

GND2 GNDB

V

LO2

D2

+

D2

–

USB PORT B

DB

+

DB

–

PWR

V

CC2

V

BUSA

100µF

GND2 GNDA

V

LO2

D2

+

D2

–

USB PORT A

DA

+

DA

–

2884 F13

relaTeD parTs

PART NUMBER DESCRIPTION

LTM2881

LTM2882

LTM2883

LTM2892

Complete Isolated RS485/RS422 µModule Transceiver + Power

Dual Isolated RS232 µModule Transceiver with Integrated DC/DC Converter

SPI or I

2

C µModule Isolator with Adjustable ±12.5V and 5V Regulated Power

SPI/Digital or I

2

C Isolated µModule

24

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

(408) 432-1900

●

FAX: (408) 434-0507

●

For more information www.linear.com/LTM2884

COMMENTS

2500V

RMS

2500V

RMS

2500V

RMS

3500V

RMS

Isolation in Surface Mount BGA or LGA

Isolation in Surface Mount BGA or LGA

Isolation in Surface Mount BGA

Isolation, 6 Channels

2884f

LT 514 • PRINTED IN USA



LINEAR TECHNOLOGY CORPORATION 2014