MAX6765, MAX6766, MAX6767, MAX6768, MAX6769, MAX6770, MAX6771, MAX6772, MAX6773, MAX6774

MAX6765, MAX6766, MAX6767, MAX6768, MAX6769, MAX6770, MAX6771, MAX6772, MAX6773, MAX6774

19-0657; Rev 3; 9/07

EVALUATION KIT

AVAILABLE

Automotive Micropower Linear Regulators with Supervisor

General Description

The MAX6765–MAX6774B are low-quiescent-current, high-voltage linear regulators that operate from 4V to 72V and deliver up to 100mA of load current. These lowpower devices consume only 31µA of quiescent current, making them ideal for always-on automotive modules.

These devices are offered with fixed standard output options of 5.0V, 3.3V, 2.5V, and 1.8V, or can be adjusted from 1.8V to 11V with two external resistors.

The MAX6765–MAX6774B feature a push-pull or opendrain, active-low RESET output with either fixed or adjustable thresholds. Whenever the regulator’s output falls below the reset threshold, the RESET output asserts and remains asserted for at least the minimum reset timeout period after the output voltage exceeds its threshold. The minimum reset timeout period is offered with fixed values from 75µs to 200ms or can be adjusted externally with a small capacitor.

These devices provide three regulator enable modes to accommodate several power-on schemes. The

MAX6765/MAX6766/MAX6769/MAX6770/MAX6773/

MAX6773B/MAX6774/MAX6774B feature a single traditional enable input (ENABLE) to turn on and off the regulator. The MAX6771/MAX6772 provide dual enable inputs

(ENABLE1 and ENABLE2) to turn on and off the regulator either through an ignition switch or a bus transceiver. The

MAX6767/MAX6768 provide a hold input (HOLD) in addition to the enable input to allow for the implementation of a self-holding circuit without requiring external components.

Setting HOLD low after enabling the regulator forces the regulator to remain on even if ENABLE is subsequently set low. Releasing HOLD shuts down the regulator.

PART

Features

Low 31

µ

A Quiescent Current

4V to 72V Wide Input Voltage Range

100mA Output Current Capability

Dropout Voltage of 620mV with 5V Output

at 100mA

Fixed Output-Voltage Options: 5V, 3.3V, 2.5V,

and 1.8V

Watchdog Timer Option (1.6s (MAX6773/

MAX6774) and 50ms (MAX6773B/MAX6774B))

Adjustable Output Voltages from 1.8V to 11V

Open-Drain or Push-Pull RESET Output

Fixed or Capacitor-Adjustable Reset Timeouts

Small, Thermally Enhanced 1.9W, 3mm x 3mm

TDFN Package

Overtemperature and Short-Circuit Protection

Fully Specified from -40°C to +125°C

Ordering Information

TEMP

RANGE

PIN-

PACKAGE

PKG

CODE

The MAX6773/MAX6773B/MAX6774/MAX6774B also include a watchdog input that monitors a pulse train from the microprocessor (µP) and generates a reset pulse if the watchdog input remains high or low for a duration longer than the 1.6s (typ) (MAX6773/MAX6774) or 50ms

(typ) (MAX6773B/MAX6774B) watchdog timeout period.

The MAX6765–MAX6774B are available in a small, thermally enhanced 3mm x 3mm TDFN package that can dissipate up to 1.951W, thereby supporting continuous regulator operation during high ambient temperatures, high battery voltage, and high load-current conditions.

MAX6765TT_D_+ -40°C to +125°C 6 TDFN-EP* T633-2

MAX6766TT_D_+ -40°C to +125°C 6 TDFN-EP* T633-2

Ordering Information continued at end of data sheet.

The first “_” is a placeholder for the voltage output and reset threshold. The 2nd “_” designates the fixed reset-timeout option.

See Tables 1 and 2 for details. For example, the MAX6765TTLD4 has a 5V output, a reset threshold of 4.65V, and a 200ms typical reset timeout.

+Denotes lead-free package.

*EP = Exposed paddle.

For tape-and-reel orders add a “T” after the “+” symbol to complete the part number. Tape-and-reel orders are available in

2.5k increments. Nonstandard versions require a 10k minimum order quantity.

TOP VIEW

6

Pin Configurations

5 4

The MAX6765–MAX6774B are fully specified for a -40°C to +125°C operating temperature range.

Applications

Automotive

Industrial

Telecom

Typical Application Circuit and Selector Guide appear at end of data sheet.

+

1

MAX6765

MAX6766

2 3

TDFN

Pin Configurations continued at end of data sheet.

________________________________________________________________ Maxim Integrated Products 1

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Automotive Micropower Linear Regulators with Supervisor

ABSOLUTE MAXIMUM RATINGS

(All pins referenced to GND, unless otherwise noted.)

V

IN

..........................................................................-0.3V to +80V

OUT ................................................-0.3V to min (12V, IN + 0.3V)

ENABLE, ENABLE1, ENABLE2 .....................-0.3V to (IN + 0.3V)

RESET (open-drain output), TIMEOUT, WDI,

RESETIN, SET ......................................................-0.3V to 12V

RESET (push-pull output), HOLD ..............-0.3V to (OUT + 0.3V)

Maximum Current (all pins except IN and OUT).................50mA

Continuous Power Dissipation (T

A

= +70°C)

6-Pin TDFN 3mm x 3mm

(derate 23.8mW/°C above +70°C) ...........................1904.8mW

8-Pin TDFN 3mm x 3mm

(derate 24.4mW/°C above +70°C) ...........................1951.2mW

Operating Temperature Range .........................-40°C to +125°C

Junction Temperature ......................................................+150°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

ELECTRICAL CHARACTERISTICS

(V

IN

= 14V, C

IN

= 0.1µF, C

OUT

= 10µF, T

A

= T

J

= -40°C to +125°C, unless otherwise noted. Typical values are at T

A

= T

J

= +25°C.)

(Note 1)

PARAMETER

Supply Voltage Range

Supply Current

(MAX6765–MAX6772) (Note 2)

Supply Current

(MAX6773/MAX6773B/

MAX6774/MAX6774B)

(Note 2)

Shutdown Supply Current

Output Voltage

Adjustable Output Voltage Range

SET Threshold Voltage

(MAX6767–MAX6774)

SYMBOL

V

IN

CONDITIONS

I

SHDN

ENABLE , ENABLE1, ENABLE2 = GND

L/M, I

LOAD

= 1mA

L/M, 1mA ≤ I

LOAD

≤ 100mA, V

IN

= 11V

T/S, I

LOAD

= 1mA

V

OUT

T/S, 1mA ≤ I

LOAD

≤ 100mA, V

IN

= 9.3V

Z/Y, I

LOAD

= 1mA

Z/Y, 1mA ≤ I

LOAD

≤ 100mA, V

IN

= 8.5V

W/V, I

LOAD

= 1mA

W/V, 1mA ≤ I

LOAD

≤ 100mA, V

IN

= 7.8V

V

OUT

I

LOAD

= 0

I

LOAD

= 50mA

I

LOAD

= 100mA, V

IN

= 14V

I

LOAD

= 0, V

IN

= 42V

I

LOAD

= 10mA, V

IN

= 42V

I

LOAD

= 0

I

LOAD

= 50mA

I

LOAD

= 100mA

I

LOAD

= 0, V

IN

= 42V

I

LOAD

= 10mA, V

IN

= 42V

V

SET

I

LOAD

= 1mA

MIN

4

4.925

4.850

3.251

3.201

2.463

2.425

1.773

1.746

1.8

1.20

TYP

3.3

5

5

3.3

3.3

2.5

2.5

1.8

1.8

31

35

37

35

37

38

42

44

42

44

1.233

7

5.075

5.150

3.350

3.399

2.538

2.575

1.827

1.854

11.0

MAX

72

45

50

55

50

55

50

55

60

55

60

1.26

UNITS

V

µA

µA

µA

V

V

V

Dual Mode™ SET Threshold

SET rising

SET falling

116

58 mV

Dual Mode is a trademark of Maxim Integrated Products, Inc.

2 _______________________________________________________________________________________

Automotive Micropower Linear Regulators with Supervisor

ELECTRICAL CHARACTERISTICS (continued)

(V

IN

= 14V, C

IN

= 0.1µF, C

OUT

= 10µF, T

A

= T

J

= -40°C to +125°C, unless otherwise noted. Typical values are at T

A

= T

J

= +25°C.)

(Note 1)

PARAMETER

SET Input Current

(MAX6767–MAX6774)

SYMBOL

I

SET

V

SET

= 1.5V, V

CONDITIONS

IN

= 11V

Dropout Voltage (Note 3) ∆V

DO

L/M, 5V output option, I

LOAD

= 10mA

L/M, 5V output option, I

LOAD

= 50mA

L/M, 5V output option, I

LOAD

= 100mA

T/S, 3.3V output option, I

LOAD

= 100mA

Guaranteed Output Current

(Note 4)

Output Current Limit

Thermal-Shutdown Temperature

Thermal-Shutdown Hysteresis

Line Regulation

Load Regulation

(MAX6767–MAX6774)

Power-Supply Rejection Ratio

Startup Response Time

Output shorted to GND, V

IN

= 14V t

6.5V ≤ V

IN

≤ 72V, I

LOAD

= 1mA

I

OUT

= 1mA to 100mA,

V

IN

= V

OUT(NOM)

+ 6V

PSRR I

LOAD

= 10mA, f

IN

= 100Hz, 500mV

P-P

START

From ENABLE high to OUT,

I

LOAD

= 100mA

Output Overvoltage Protection

Threshold

OV

TH

I

SINK

= 1mA (from OUT)

Output Overvoltage Protection

Maximum Sink Current

OUT = OUT

LOGIC INPUT (ENABLE, ENABLE1, ENABLE2,

HOLD)

(NOM)

x 1.15

Input Low Voltage

Input High Voltage

V

IL

V

IH

ENABLE, ENABLE1, ENABLE2

ENABLE, ENABLE1, ENABLE2

ENABLE, ENABLE1, ENABLE2

Input Pulldown Current

ENABLE, ENABLE1, ENABLE2 are internally pulled down to GND

V

IL

1.8V ≤ V

OUT

≤ 11V

HOLD Input Threshold Voltage

V

IH

1.8V ≤ V

OUT

≤ 11V

HOLD Input Pullup Current

RESET OUTPUT

HOLD is internally pulled up to OUT

RESET Threshold

SET = GND,

RESET falling

L

M

Z

Y

T

S

W

V

MIN

-100

100

150

1.07 x

V

OUT

5

1.4

OUT -

0.4

4.500

4.250

2.970

2.805

2.250

2.125

1.620

1.530

TYP

60

300

620

866

250

160

20

70

180

1.1 x

V

OUT

10

0.6

1.8

4.625

4.375

3.053

2.888

2.313

2.188

1.665

1.575

4.750

4.500

3.135

2.970

2.375

2.250

1.710

1.620

MAX

+100

130

630

1200

1600

1

1.5

1.13 x

V

OUT

0.4

0.4

UNITS

nA mV mA mA

°C

°C

%

% dB

µs

V mA

V

V

µA

V

µA

V

_______________________________________________________________________________________ 3

Automotive Micropower Linear Regulators with Supervisor

ELECTRICAL CHARACTERISTICS (continued)

(V

IN

= 14V, C

IN

= 0.1µF, C

OUT

= 10µF, T

A

= T

J

= -40°C to +125°C, unless otherwise noted. Typical values are at T

A

= T

J

= +25°C.)

(Note 1)

PARAMETER

RESET Threshold (Adjustable

Output Voltage)

RESETIN Input Current

RESETIN Threshold

OUT to RESET Delay

RESETIN To RESET Delay

RESET Timeout Period (TIMEOUT

Connected to OUT)

TIMEOUT Ramp Current

TIMEOUT Ramp Threshold

SYMBOL CONDITIONS

L/T/Z/W, SET = resistive divider, RESET falling

M/S/Y/V, SET = resistive divider, RESET falling

RESETIN = GND or 12V

V

TH

= 87.5% of V

SET

(M/S/Y/V),

RESET falling

V

TH

= 92.5% of V

SET

(L/T/Z/W),

RESET falling

V

OUT

falling

RESETIN falling

V

OUT

rising

D0

D1

D2

D3

D4

MIN

V

OUT

x

0.9

V

OUT

x

0.85

-100

1.057

1.118

2.187

8.75

35

140

800

1.160

V

TYP

V

OUT

x

0.925

OUT

x

0.875

1.085

1.147

0.3

35

75

3.125

12.5

50

200

1000

1.22

MAX

V

OUT

x

0.950

V

OUT

x

0.900

+100

1.112

1.176

4.063

16.25

65

260

1200

1.259

UNITS

V nA

V

µs

µs

µs ms nA

V

RESET Output-Voltage Low

(Open Drain or Push-Pull)

V

OL

V

OUT

≥ 1.8V, I

SINK

= 50µA,

RESET asserted

V

OUT

≥ 1.8V, I

SINK

= 3.2mA,

RESET asserted

V

OUT

≥ 1.8V, I

SOURCE

= 250µA,

RESET not asserted

0.3

0.4

V

RESET Output-Voltage High

(Push-Pull)

RESET Open-Drain Leakage

Current

Watchdog Minimum Input Pulse

Watchdog Input Low Voltage

V

OH

RESET not asserted, RESET = 12V

0.8 x

V

OUT

100

V nA t

WDI

V

IL

1.8V ≤ V

OUT

≤ 11V

1.8V ≤ V

OUT

≤ 11V

1

0.4

µs

V

Watchdog Input High Voltage V

IH

1.8V ≤ V

OUT

≤ 11V

V

OUT

- 0.4V

V

Watchdog Input Low Voltage

Watchdog Input Current

Watchdog Timeout Period

I t

V

IL

WDI

WD

1.8V ≤ V

OUT

≤ 11V

WDI = 0V or WDI = 12V

MAX6773/MAX6774

MAX6773B/MAX6774B

-1

1.12

40

1.6

50

0.4

+1

2.08

60

V

µA s ms

Note 1: Production tested at T

A

= +25°C. Overtemperature limits are guaranteed by design.

Note 2: Device tested at internally set voltage.

Note 3: Dropout voltage for L/M versions is defined as (V

IN

- V

OUT

) when V

OUT equals 98% of the nominal value of V

OUT when

V

IN

= 11V. For T/S versions, dropout voltage is defined as (V

IN

- V

OUT

) when V

OUT equals 98% of the nominal value of V

OUT when V

IN

= 9.3V.

Note 4: Observe the absolute maximum power dissipation limits.

4 _______________________________________________________________________________________

Automotive Micropower Linear Regulators with Supervisor

Typical Operating Characteristics

(V

IN

= 14V, C

OUT

= 10µF, C

IN

= 0.1µF, T

A

= +25°C, unless otherwise noted.)

44

42

40

38

36

34

32

30

28

26

24

4

SUPPLY CURRENT vs. INPUT VOLTAGE

12

I

LOAD

= 100mA

V

OUT

= 3.3V

LIMITED BY POWER

DISSIPATION

I

LOAD

= 0

20 28 36 44 52 60 68

INPUT VOLTAGE (V)

SUPPLY CURRENT vs. TEMPERATURE

47

45

43

41

39

37

I

LOAD

= 100mA

I

LOAD

V

= 50mA

OUT

= 5V

35

33

31

I

LOAD

= 1mA

29

I

LOAD

= 0

27

-40 -25 -10 5 20 35 50 65 80 95 110 125

TEMPERATURE (°C)

SHUTDOWN SUPPLY CURRENT vs. TEMPERATURE

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

-40 -25 -10 5 20 35 50 65

TEMPERATURE (°C)

80 95 110 125

SHUTDOWN SUPPLY CURRENT vs. INPUT VOLTAGE

4.5

4.0

3.5

3.0

2.5

6.0

5.5

5.0

2.0

1.5

1.0

0.5

0

4 12 20 28 36 44

INPUT VOLTAGE (V)

52 60 68

OUTPUT VOLTAGE vs. LOAD CURRENT

5.20

5.15

V

OUT

= 5V

5.10

5.05

5.00

4.95

4.90

4.85

4.80

0 10 20 30 40 50 60 70

LOAD CURRENT (mA)

80 90 100

1.004

1.003

1.002

NORMALIZED RESETIN THRESHOLD VOLTAGE vs. TEMPERATURE

1.001

1.000

0.999

0.998

0.997

0.996

0.995

0.994

0.993

0.992

-40 -25 -10 5 20 35 50 65 80 95 110 125

TEMPERATURE (°C)

DROPOUT VOLTAGE vs. LOAD CURRENT

600

550

500

450

400

350

300

250

200

150

100

50

0

0

V

OUT

= 5V

10 20 30 40 50 60 70

LOAD CURRENT (mA)

80

OUTPUT VOLTAGE vs. LOAD CURRENT

V

OUT

= 3.3V

3.34

3.32

3.30

3.28

3.26

3.24

3.22

3.20

0 10 20 30 40 50 60 70

LOAD CURRENT (mA)

80 90 100

90 100

_______________________________________________________________________________________

5

Automotive Micropower Linear Regulators with Supervisor

Typical Operating Characteristics (continued)

(V

IN

= 14V, C

OUT

= 10µF, C

IN

= 0.1µF, T

A

= +25°C, unless otherwise noted.)

OUTPUT VOLTAGE vs. LOAD CURRENT

1.85

1.84

1.83

1.82

1.81

1.80

1.79

1.78

1.77

1.76

1.75

0

V

OUT

= 1.8V

10 20 30 40 50 60 70

LOAD CURRENT (mA)

80 90 100

160

140

120

100

80

60

40

20

0

0

RESET TIMEOUT PERIOD vs. CAPACITOR VALUE

25 50 75

CAPACITOR VALUE (nF)

100 125

NORMALIZED RESET TIMEOUT PERIOD vs. TEMPERATURE

1.10

1.08

1.06

1.04

1.02

1.00

0.98

0.96

0.94

-40 -25 -10 5 20 35 50 65

TEMPERATURE (°C)

80 95 110 125

NORMALIZED WATCHDOG TIMEOUT vs. TEMPERATURE

1.06

1.04

1.02

1.00

0.98

0.96

0.94

0.92

0.90

-40 -25 -10 5 20 35 50 65

TEMPERATURE (°C)

80 95 110 125

42

41

40

39

38

37

36

SUPPLY CURRENT vs. WATCHDOG INPUT FREQUENCY

V

OUT

= 5V

35

34

0.001

0.01

0.1

1 10

WATCHDOG INPUT FREQUENCY (kHz)

100

RESET OUTPUT vs. SINK CURRENT

4.0

3.5

V

OUT

= 5V

3.0

2.5

2.0

1.5

1.0

0.5

0

0 5 10 15 20 25 30 35 40

SINK CURRENT (mA)

4.0

3.5

3.0

2.5

2.0

5.5

5.0

4.5

1.5

1.0

0.5

0

0

RESET OUTPUT vs. SOURCE CURRENT

2

OUT AND HOLD vs. ENABLE

4 6 8 10 12

SOURCE CURRENT (mA)

MAX6765 toc16

20ms/div

(SEE TEST CIRCUIT FOR ENABLE AND HOLD)

ENABLE

5V/div

GATE

5V/div

HOLD

5V/div

OUT

5V/div

V

OUT

= 5V

14 16

6 _______________________________________________________________________________________

Automotive Micropower Linear Regulators with Supervisor

Typical Operating Characteristics (continued)

(V

IN

= 14V, C

OUT

= 10µF, C

IN

= 0.1µF, T

A

= +25°C, unless otherwise noted.)

-40

-60

-80

-100

40

20

0

-20

-120

-140

-160

-180

0.1

POWER-SUPPLY REJECTION RATIO vs. FREQUENCY

1 10 100 1k 10k 100k

FREQUENCY (Hz)

1M

1.0020

1.0015

1.0010

1.0005

1.0000

0.9995

0.9990

0.9985

0.9980

4

NORMALIZED OUT VOLTAGE vs. INPUT VOLTAGE

V

OUT

= 3.3V

12 20 28 36 44 52 60 68

INPUT VOLTAGE (V)

LOAD-TRANSIENT RESPONSE

MAX6765 toc19

V

OUT

= 5V

OUT

(AC-COUPLED)

200mV/div

LINE-TRANSIENT RESPONSE

MAX6765 toc20

V

OUT

= 5V

OUT

(AC-COUPLED)

1V/div

I

OUT

100mA/div

V

IN

10V/div

100ms/div

LINE-TRANSIENT RESPONSE

MAX6765 toc21

V

OUT

= 5V

OUT

(AC-COUPLED)

1V/div

400µs/div

V

IN

20V/div

400µs/div

5

4

3

2

1

0

7

6

10

9

8

11

OUTPUT CAPACITOR SERIES RESISTANCE vs. LOAD CURRENT

STABLE OPERATING

REGION

0 20 40 60 80 100

LOAD CURRENT (mA)

_______________________________________________________________________________________

7

Automotive Micropower Linear Regulators with Supervisor

Enable and Hold Test Circuit

V

IN

OUT OUT

IN

MAX6767

MAX6768

GND

ENABLE

ENABLE

HOLD

N

GATE

HOLD

TEST CIRCUIT FOR OUT AND HOLD VS. ENABLE

Pin Description

MAX6765/

MAX6766

MAX6767/

MAX6768

PIN

MAX6769/

MAX6770

MAX6771/

MAX6772

MAX6773/

MAX6773B/

MAX6774/

MAX6774B

1 1 1 1 1

2

3

4

5

6

2

3

5

7

8

2

3

5

7

8

2

5

7

8

2

3

5

7

8

NAME FUNCTION

IN

GND

ENABLE

Regulator Input. Bypass IN to GND with a capacitor with a minimum value of 0.1µF.

Ground

Active-High Enable Input. Drive ENABLE high to turn on the regulator. ENABLE is internally connected to

GND through a 0.6µA current sink.

RESET

TIMEOUT

OUT

Active-Low, Open-Drain/Push-Pull Reset Output.

For the MAX6769/MAX6770, RESET asserts when

RESETIN is below the internal V

TH

and deasserts when RESETIN is above the internal V

TH

threshold.

For all other versions, RESET remains low while OUT is below the reset threshold. For all versions, RESET remains low for the duration of the reset timeout period after the reset conditions end.

Reset Timeout Adjust Input. Connect TIMEOUT to

OUT for the internally fixed timeout period. For an adjustable timeout, connect a capacitor from

TIMEOUT to GND. See the Selecting Timeout

Capacitor section.

Regulator Output. The MAX6765/MAX6766 provide a fixed output (+1.8V, +2.5V, +3.3V, or +5V). The

MAX6767–MAX6774 provide a fixed output voltage of +1.8V, +2.5V, +3.3V, or 5V, or adjust the output from +1.8V to +11V. Bypass to GND with a 10µF capacitor (min).

8 _______________________________________________________________________________________

Automotive Micropower Linear Regulators with Supervisor

Pin Description (continued)

MAX6765/

MAX6766

MAX6767/

MAX6768

PIN

MAX6769/

MAX6770

MAX6771/

MAX6772

MAX6773/

MAX6773B/

MAX6774/

MAX6774B

EP

4

6

EP

6

4

EP

6

3

4

EP

6

4

EP

NAME FUNCTION

HOLD

SET

Active-Low Regulator Hold Input. When HOLD is forced low, OUT remains on even if ENABLE is pulled low. To shut down the regulator, release HOLD after

ENABLE is pulled low. Connect HOLD to OUT or leave unconnected if unused. HOLD is internally connected to OUT through a 1.8µA current source.

Feedback Input for Setting the Output Voltage.

Connect SET to GND to select the preset output voltage. Connect to an external resistive divider for adjustable output operation.

RESETIN

ENABLE1

ENABLE2

WDI

Adjustable Reset Threshold Input. Connect to a resistive divider to set the desired threshold.

Active-High Enable Input 1. Drive ENABLE1 high to turn on the regulator. ENABLE1 is internally connected to ground through a 0.6µA current sink.

Active-High Enable Input 2. Drive ENABLE2 high to turn on the regulator. ENABLE2 is internally connected to ground through a 0.6µA current sink.

Watchdog Timer Input. If WDI remains high or low for longer than the watchdog timeout period, the internal watchdog timer expires and the reset output asserts for the reset timeout period. The internal watchdog timer clears whenever a reset is asserted or WDI sees a rising or falling edge. The watchdog timer cannot be disabled. Do not leave WDI unconnected.

Exposed Paddle. EP is internally connected to GND.

Connect EP to the ground plane to provide a low thermal-resistance path from the IC junction to the

PCB. Do not use as the electrical connection to GND.

Detailed Description

The MAX6765–MAX6774B low-quiescent-current, highvoltage linear regulators operate from a 4V to 72V input voltage and deliver more than 100mA of load current.

The MAX6765–MAX6774B include an integrated µP reset circuit that monitors the regulator output voltage and asserts a reset output when OUT falls below a threshold limit, and includes an internally fixed or adjustable reset timeout using a capacitor from TIME-

OUT to ground. All devices are available in a preset output-voltage option of +1.8V, +2.5V, +3.3V, and +5V. The output voltage of the MAX6767–MAX6774B is adjustable from +1.8V to +11V using a resistive divider at SET. The

MAX6773/MAX6774 include a watchdog timer (WDI) with a 1.6s (typ) watchdog timeout period and the

MAX6773B/MAX6774B include a watchdog timer with a

50ms (typ) watchdog timeout period. The MAX6769/

MAX6770 feature an adjustable reset threshold using a resistive divider between the monitored voltage,

RESETIN, and GND; see the Functional Diagrams.

The MAX6771/MAX6772 provide dual enable inputs

(ENABLE1 and ENABLE2) to turn on and off the regulator either through an ignition switch or a bus transceiver.

_______________________________________________________________________________________ 9

Automotive Micropower Linear Regulators with Supervisor

Functional Diagrams

IN

THERMAL

PROTECTION

MAX6765/MAX6766

OVERCURRENT

PROTECTION

OUT

ENABLE

CONTROL

LOGIC

1.147V

1.233V

OR

1.085V

RESET

TIMEOUT

RESET

TIMEOUT

GND

10 ______________________________________________________________________________________

Automotive Micropower Linear Regulators with Supervisor

Functional Diagrams (continued)

IN

THERMAL

PROTECTION

MAX6767/MAX6768

OUT

OVERCURRENT

PROTECTION

ENABLE

HOLD

CONTROL

LOGIC

1.147V

1.233V

OR

1.085V

116mV

RESET

TIMEOUT

SET

RESET

TIMEOUT

GND

______________________________________________________________________________________ 11

Automotive Micropower Linear Regulators with Supervisor

Functional Diagrams (continued)

IN

THERMAL

PROTECTION

MAX6769/MAX6770

OVERCURRENT

PROTECTION

OUT

ENABLE

CONTROL

LOGIC

1.233V

1.147V

OR

1.085V

GND

RESETIN

116mV

RESET

TIMEOUT

SET

RESET

TIMEOUT

12 ______________________________________________________________________________________

Automotive Micropower Linear Regulators with Supervisor

Functional Diagrams (continued)

IN

THERMAL

PROTECTION

MAX6771/MAX6772

OUT

OVERCURRENT

PROTECTION

ENABLE1

ENABLE2

CONTROL

LOGIC

1.233V

1.147V

OR

1.085V

116mV

RESET

TIMEOUT

SET

RESET

TIMEOUT

GND

______________________________________________________________________________________ 13

Automotive Micropower Linear Regulators with Supervisor

Functional Diagrams (continued)

IN

THERMAL

PROTECTION

MAX6773/MAX6773B

MAX6774/MAX6774B

OUT

OVERCURRENT

PROTECTION

ENABLE

CONTROL

LOGIC

1.233V

1.147V

OR

1.085V

GND

116mV

RESET

TIMEOUT

SET

RESET

TIMEOUT WDI

14 ______________________________________________________________________________________

Automotive Micropower Linear Regulators with Supervisor

Regulator

The regulator accepts an input voltage from +4V to +72V.

All of the devices feature fixed output-voltage options of

+1.8V, +2.5V, +3.3V, and +5V. The MAX6767-MAX6774B feature an adjustable output voltage set with an external resistive-divider network connected between OUT, SET, and GND. See Figure 1.

Enable and Hold Inputs

(MAX6767/MAX6768)

The MAX6767/MAX6768 support two logic inputs,

ENABLE (active-high) and HOLD (active-low), making these devices “automotive friendly.” For example, when the ignition key signal drives ENABLE high, the regulator turns on and remains on even if ENABLE goes low, as long as HOLD is forced low and kept low before

ENABLE goes low. In this state, releasing HOLD turns the regulator output (OUT) off. This feature makes it possible to implement a self-holding circuit without external components. Forcing ENABLE low with HOLD high (or unconnected) places the MAX6767/MAX6768 into shutdown mode, drawing 3.3µA (typ) of supply current.

Table 3 shows the state of the regulator output with respect to the voltage level at ENABLE and HOLD.

Connect HOLD to OUT or leave it unconnected to allow the ENABLE input to act as a standard enable/shutdown switch for the regulator output (OUT).

Reset Output

The reset output is typically connected to the reset input of a µP. A µP’s reset input starts or restarts the µP in a known state. The MAX6765–MAX6774B supervisory circuits provide the reset logic to prevent code-execution errors during power-up, power-down, and brownout conditions (see the Typical Application

Circuit). RESET changes from high to low whenever the monitored voltage drops below the reset threshold voltages. Once the monitored voltage exceeds its respective reset threshold voltage(s), RESET remains low for the reset timeout period, then goes high. See Table 1.

RESETIN Threshold (MAX6769/MAX6770)

The MAX6769/MAX6770 monitor the voltage on RESETIN using an adjustable reset threshold (V

RESETIN

) set with an external resistive voltage-divider and the internal reset threshold V

TH

. See Table 2.

V

IN

IN

OUT

MAX6767–MAX6774B

SET

GND

R1

R2

Figure 1. Setting the Output Voltage Using a Resistive Divider

Table 1. Preset Timeout Period

PART NUMBER

SUFFIX (_)

D0

D1

D2

D3

D4

TIMEOUT

PERIOD

75µs

3.125ms

12.5ms

50ms

200ms

Table 2. Preset Output Voltage and Reset

Threshold

PART NUMBER

SUFFIX (_)

Z

Y

W

T

S

L

M

V

OUTPUT

VOLTAGE (V)

5

5

3.3

3.3

2.5

2.5

1.8

1.8

RESET

THREHOLD (V)

4.625

4.375

3.053

2.888

2.313

2.188

1.665

1.575

______________________________________________________________________________________ 15

Automotive Micropower Linear Regulators with Supervisor

Table 3. ENABLE/HOLD Truth Table/State Table

OPERATING

STATE

ENABLE

HOLD

REGULATOR

OUTPUT

COMMENT

Initial State

Turn-On State

Hold

Setup State

Hold State

Off-State

Low

High

High

Low

Low

Don’t care

Don’t care

Low

Low

High

(floats high)

Off

On

On

On

Off

Watchdog Timer (MAX6773/MAX6773B/

MAX6774/MAX6774B)

The MAX6773/MAX6774 include a watchdog timer that asserts RESET if the watchdog input (WDI) does not toggle within the watchdog timeout period t

WD

(1.6s

(typ) for the MAX6773/MAX6774 and 50ms (typ) for the

MAX6773B/MAX6774B). RESET remains low for the reset timeout period, t

RP

. If the watchdog is not updated for lengthy periods of time, the reset output appears as a pulse train, asserted for the reset timeout period and deasserted for the watchdog timeout period, until

WDI is toggled again. When RESET asserts, it stays low for the entire reset timeout period ignoring any WDI transitions. To prevent the watchdog from asserting

RESET, toggle WDI with a valid rising or falling edge prior to t

WD

(min). The watchdog counter clears when

WDI toggles prior to t

WD or when RESET asserts. The watchdog resumes counting after RESET deasserts.

The watchdog timer cannot be disabled.

ENABLE is pulled to GND through an internal pulldown. HOLD is floating (pulled up to OUT). Regulator output is disabled.

ENABLE is externally driven high turning the regulator output on.

HOLD is pulled up by OUT.

HOLD is externally pulled low while ENABLE remains high (latches

HOLD state).

ENABLE is driven low (or allowed to float low by an internal pulldown).

HOLD remains externally pulled low keeping the regulator output on.

HOLD is driven high (or allowed to float high by an internal pullup) while ENABLE is low. Regulator output is shut off and ENABLE/

HOLD logic returns to the initial state.

voltage mode. In preset voltage mode, internal trimmed feedback resistors set the internal linear regulator to

+1.8V, +2.5V, +3.3V, or +5V (see Table 2). Select preset-voltage mode by connecting SET to ground. In adjustable mode, select an output voltage between

+1.8V and +11V using two external resistors connected as a voltage-divider to SET (see Figure 1). Set the output voltage using the following equation:

V

OUT

= V

SET

(1 + R1 / R2) where V

SET

= 1.233V and the recommended value for

R2 is 50kΩ (maximum 100kΩ).

RESETIN Threshold Selection

The MAX6769/MAX6770 feature an adjustable reset threshold to monitor the voltage on RESETIN using a resistive divider between the monitored voltage,

RESETIN and GND. See Figure 2. Use the following formula to set the desired reset threshold:

V

MON

= V

TH

(1 + R3 / R4) where V

TH is 1.085V for the M/S/Y/V versions and

1.147V for L/T/Z/W versions.

Thermal Protection

When the junction temperature exceeds T

J

= +160°C

(typ), an internal thermal sensor signals the shutdown logic that turns off the pass transistor and allows the IC to cool. The thermal sensor turns the pass transistor on again after the IC’s junction temperature cools by 20°C

(typ), resulting in a cycled output during continuous thermal-overload conditions. Thermal protection protects the MAX6765–MAX6774B in the event of a fault condition. Never exceed the absolute maximum junction temperature rating of T

J

= +150°C. See Figures 3 and 4 for the safe operating area.

R3

V

MON

V

IN

IN

MAX6769

MAX6770

RESETIN RESET

Applications Information

R4

GND

Output Voltage Selection

The MAX6767–MAX6774B feature dual-mode operation: these devices operate in either a preset or adjustable

Figure 2. RESETIN Threshold Selection

16 ______________________________________________________________________________________

Automotive Micropower Linear Regulators with Supervisor

Available Output-Current Calculation

The MAX6765–MAX6774B provide up to 100mA of load current. Package power dissipation limits the amount of output current available for a given input/output voltage and ambient temperature. Figures 3 and 4 depict the maximum power dissipation curve for the MAX6765/

MAX6766 and MAX6767–MAX6774B, respectively. The graph assumes that the exposed metal pad of the device package is soldered to a solid 1in

2 section of

2oz. PCB copper (JESD51-3 AND JESD51-5). Use

Figure 4 to determine the allowable package dissipation for a given ambient temperature. Alternately, use the following formula to calculate the allowable package dissipation:

PD

MAX

= Max. Power Dissip = 1.951W, for T

A

≤ +70°C

PD

MAX

= Max. Power Dissip = [1.9W - 0.0244W x

(T

A

- 70°C)], for +70°C < T

A

≤ +125°C where 0.0244W is the MAX6767–MAX6774B package thermal derating in W/°C and T

A is the ambient temperature in °C, under the same conditions used for Figure 4.

After determining the allowable package dissipation, calculate the maximum output current using the following formula:

PD < PD

MAX where PD = [(V

IN

- V

OUT

) x I

OUT

]

Also, I

OUT should be ≤ 100mA in any case.

Selecting Timeout Capacitor

The reset timeout period is adjustable to accommodate a variety of µP applications. Adjust the reset timeout period by connecting a capacitor between TIMEOUT and GND.

t

RP

= C

TIMEOUT x 1.22 x 10

6

Ω where t

RP is in seconds and C

TIMEOUT is in Farads.

Connect TIMEOUT to OUT to select the internally fixed timeout period. C

TIMEOUT must be a low-leakage

(< 10nA) type capacitor. Ceramic capacitors are recommended; do not use capacitor values lower than

100pF to avoid the influence of parasitic capacitances.

Capacitor Selection and

Regulator Stability

For stable operation over the full temperature range and with load currents up to 100mA, use a 10µF (min) output capacitor with an ESR < 0.5Ω. To reduce noise and improve load-transient response, stability, and powersupply rejection, use larger output-capacitor values.

Some ceramic dielectrics exhibit large capacitance and ESR variation with temperature. For dielectric capacitors such as Z5U and Y5V, use more capacitance to ensure stability at low temperatures. With X7R or X5R dielectrics, 10µF should be sufficient at all operating temperatures. For higher-ESR tantalum capacitors, use larger capacitor values to maintain stability. To improve power-supply rejection and transient response, use a larger capacitor than the minimum

0.1µF capacitor between IN and GND.

2.2

2.0

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0

0

1.904W

20

SAFE OPERATING

AREA

40 60

DERATE 23.8mW/°C

ABOVE +70°C

80 100

TEMPERATURE (°C)

120 140 160

Figure 3. Maximum Power Dissipation vs. Temperature

(MAX6765/MAX6766)

2.2

2.0

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0

0

1.951W

SAFE OPERATING

AREA

20 40 60

DERATE 24.4mW/°C

ABOVE +70°C

80 100

TEMPERATURE (°C)

120 140 160

Figure 4. Maximum Power Dissipation vs. Temperature

(MAX6767–MAX6774B)

______________________________________________________________________________________ 17

Automotive Micropower Linear Regulators with Supervisor

Ensuring a Valid

RESET Output Down to

V

IN

= 0V (MAX6766/MAX6768/MAX6770/

MAX6772/MAX6774/MAX6774B)

When V

IN falls below 1V, RESET current-sinking capabilities decline drastically. High-impedance CMOSlogic inputs connected to RESET can drift to undetermined voltages. This presents no problems in most applications, since most µPs and other circuitry do not operate with supply voltages below 1V. In those applications where RESET must be valid down to 0V, adding a pulldown resistor between RESET and ground sinks any stray leakage currents, holding RESET low

(Figure 5). The value of the pulldown resistor is not critical; 100kΩ is large enough not to load RESET and small enough to pull RESET to ground. Open-drain

RESET versions are not recommended for applications requiring valid logic for V

IN down to 0V.

V

IN

IN

MAX6766

MAX6768

MAX6770

MAX6772

MAX6774

MAX6774B

RESET

GND

Figure 5. Ensuring RESET Valid to V

IN

= 0V

Table 4. Standard Version Part Numbers

PART

MAX6765TTLD2+T

MAX6765TTSD2+T

MAX6766TTLD2+T

MAX6766TTSD2+T

MAX6767TALD2+T

MAX6767TASD2+T

MAX6768TALD2+T

MAX6768TASD2+T

MAX6769TALD2+T

MAX6769TASD2+T

MAX6770TALD2+T

MAX6770TASD2+T

MAX6771TALD2+T

MAX6771TASD2+T

MAX6772TALD2+T

MAX6772TASD2+T

MAX6773TALD2+T

MAX6773TASD2+T

MAX6773BTALD2+T

MAX6773BTASD2+T

MAX6774TALD2+T

MAX6774TASD2+T

MAX6774BTALD2+T

MAX6774BTASD2+T

OUTPUT

VOLTAGE (V)

3.3

5

3.3

5

3.3

5

3.3

5

3.3

5

3.3

5

3.3

5

3.3

5

3.3

5

3.3

5

3.3

5

3.3

5

RESET TIMEOUT

PERIOD (ms)

12.5

12.5

12.5

12.5

12.5

12.5

12.5

12.5

12.5

12.5

12.5

12.5

12.5

12.5

12.5

12.5

12.5

12.5

12.5

12.5

12.5

12.5

12.5

12.5

RESET THRESHOLD

(V)

4.625

2.888

4.625

2.888

4.625

2.888

4.625

2.888

4.625

2.888

4.625

2.888

4.625

2.888

4.625

2.888

4.625

2.888

4.625

2.888

4.625

2.888

4.625

2.888

18 ______________________________________________________________________________________

TOP MARK

+BEQ

+APY

+BGC

+BBG

+AQE

+BHK

+BHU

+BCS

+BDC

+BIY

+BJI

+AQB

+AQL

+ARO

+ARZ

+AVI

+AVS

+AVZ

+AXE

+AYH

+AYQ

+AZS

+BAC

+BEG

PART

MAX6765

MAX6766

MAX6767

MAX6768

MAX6769

MAX6770

MAX6771

MAX6772

MAX6773

MAX6773B

MAX6774

MAX6774B

Automotive Micropower Linear Regulators with Supervisor

Selector Guide

RESET

OUTPUT

Open drain

Push-pull

Open drain

Push-pull

Open drain

Push-pull

Open drain

Push-pull

Open drain

Open drain

Push-pull

Push-pull

TYPICAL

WATCHDOG

TIMEOUT

1.6s

50ms

1.6s

50ms

OUTPUT

VOLTAGE

Fixed

Fixed

Fixed/Adj

Fixed/Adj

Fixed/Adj

Fixed/Adj

Fixed/Adj

Fixed/Adj

Fixed/Adj

Fixed/Adj

Fixed/Adj

Fixed/Adj

RESETIN

THRESHOLD

ENABLE

INPUTS

Single

Single

Single

Single

Single

Single

Dual

Dual

Single

Single

Single

Single

HOLD INPUT

Typical Application Circuit

12V

BATTERY

OUT

IN

GND

MAX6766

TIMEOUT

ENABLE

RESET

V

CC

µC

RESET

I/O

TXD

RXD

XCVR

LIN

______________________________________________________________________________________ 19

Automotive Micropower Linear Regulators with Supervisor

Pin Configurations (continued)

TOP VIEW TOP VIEW

8 7 6 5 8 7 6 5

MAX6767

MAX6768

+

1 2 3 4

TDFN

MAX6769

MAX6770

+

1 2 3 4

TDFN

TOP VIEW TOP VIEW

8 7 6 5

MAX6771

MAX6772

+

1 2 3 4

TDFN

8 7 6 5

MAX6773

MAX6773B

MAX6774

MAX6774B

+

1 2 3 4

TDFN

20 ______________________________________________________________________________________

Automotive Micropower Linear Regulators with Supervisor

Chip Information

Ordering Information (continued)

PART

TEMP

RANGE

PIN-

PACKAGE

PKG

CODE

MAX6767TA_D_+ -40°C to +125°C 8 TDFN-EP* T833-2

MAX6768TA_D_+ -40°C to +125°C 8 TDFN-EP* T833-2

MAX6769TA_D_+ -40°C to +125°C 8 TDFN-EP* T833-2

MAX6770TA_D_+ -40°C to +125°C 8 TDFN-EP* T833-2

MAX6771TA_D_+ -40°C to +125°C 8 TDFN-EP* T833-2

MAX6772TA_D_+ -40°C to +125°C 8 TDFN-EP* T833-2

MAX6773TA_D_+

-40°C to +125°C 8 TDFN-EP* T833-2

MAX6773BTA_D_+ -40°C to +125°C 8 TDFN-EP* T833-2

MAX6774TA_D_+ -40°C to +125°C 8 TDFN-EP* T833-2

MAX6774BTA_D_+ -40°C to +125°C 8 TDFN-EP* T833-2

The first “_” is a placeholder for the voltage output and reset threshold. The 2nd “_” designates the fixed reset-timeout option.

See Tables 1 and 2 for details. For example, the MAX6765TTLD4 has a 5V output, a reset threshold of 4.65V, and a 200ms typical reset timeout.

+Denotes lead-free package.

*EP = Exposed paddle.

For tape-and-reel orders add a “T” after the “+” symbol to complete the part number. Tape-and-reel orders are available in

2.5k increments. Nonstandard versions require a 10k minimum order quantity.

PROCESS: BiCMOS

______________________________________________________________________________________ 21

Automotive Micropower Linear Regulators with Supervisor

Package Information

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.)

22 ______________________________________________________________________________________

Automotive Micropower Linear Regulators with Supervisor

Package Information (continued)

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.)

L k

A2

D

E

A1

COMMON DIMENSIONS

SYMBOL MIN.

MAX.

A 0.70

0.80

2.90

2.90

0.00

3.10

3.10

0.05

0.20

0.40

0.25 MIN.

0.20 REF.

PACKAGE VARIATIONS

PKG. CODE

T633-2

T833-2

T833-3

T1033-1

T1033-2

T1433-1

T1433-2

8

8

10

N

6

10

14

14

D2

1.50±0.10

1.50±0.10

1.50±0.10

1.50±0.10

1.50±0.10

1.70±0.10

1.70±0.10

E2

2.30±0.10

2.30±0.10

2.30±0.10

2.30±0.10

2.30±0.10

2.30±0.10

2.30±0.10

e

0.95 BSC

0.65 BSC

0.65 BSC

0.50 BSC

0.50 BSC

0.40 BSC

0.40 BSC

JEDEC SPEC

MO229 / WEEA

MO229 / WEEC

MO229 / WEEC

MO229 / WEED-3 b

0.40±0.05

0.30±0.05

0.30±0.05

0.25±0.05

MO229 / WEED-3 0.25±0.05

- - - - 0.20±0.05

- - - - 0.20±0.05

[(N/2)-1] x e

1.90 REF

1.95 REF

1.95 REF

2.00 REF

2.00 REF

2.40 REF

2.40 REF

Revision History

Pages changed at Rev 1: 1, 21, 23

Pages changed at Rev 2: 1, 4, 8, 9, 14, 16, 18–23

Pages changed at Rev 3: 1, 7, 23

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________

23

© 2007 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.

Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement