MAX17681EVKITB# Datasheet - Maxim Part Number Search

MAX17681EVKITB# Datasheet - Maxim Part Number Search
MAX17681 Evaluation Kit
General Description
The MAX17681EVKITB is a fully assembled and tested
circuit board that demonstrates the performance of the
MAX17681 high-efficiency, iso-buck DC-DC converter.
The EV kit operates over a wide input-voltage range of
17V to 36V and uses primary-side feedback to regulate
the output voltage. The EV kit has two output configurations.
In configuration one the output is programmed to
±[email protected], with ±8% output voltage regulation. The
second configuration uses a post regulator, MAX17651 to
produce ±[email protected] with < ±3% regulation.
The EV kit comes installed with the MAX17681 in a 10-pin
(3mm x 2mm) TDFN package and MAX17651 in a 6-lead
TSOT package.
Features
●● 17V to 36V Input Voltage Range
●● ±7V, 100mA or ±5V, 50mA Continuous Current
●● EN/UVLO Input
●● 200kHz Switching Frequency
●● 87.5% Peak Efficiency
●● Overcurrent Protection
●● No Optocoupler
●● Delivers up to 1.4W Output Power
●● Overtemperature Protection
●● Proven PCB Layout
Ordering Information appears at end of data sheet.
Evaluates: MAX17681 for Isolated ±7V
or ±5V Output Configuration
Quick Start
Recommended Equipment
●● One 15V–60V DC, 0.5A power supply
●● Two resistive loads of 50mA to 100mA sink capacity
●● Four digital multimeters (DMM)
Caution: Do not turn on the power supply until all connections
are completed.
Procedure
The EV kit comes with the default output configuration
programmed to ±7V.
Test Procedure for ±7V Output
1) Verify that the J1 is open.
2) Verify that the R17, R18, and R19 are not installed.
3) Set the power supply output to 24V. Disable the
power supply.
4) Connect the positive terminal of the power supply
to the VIN PCB pad and the negative terminal to
the nearest PGND PCB pad. Connect a 100mA
resistive load across the +7V PCB and GND0 PCB
pads. Connect another 100mA resistive load across
the GND0 PCB and -7VPCB pads.
5) Connect a DMM, configured in voltmeter mode,
across the +7V PCB pad and the nearest GND0 PCB
pad. Connect another DMM configured in voltmeter
mode across the -7V PCB pad and the nearest GND0
PCB pad.
6) Enable the input power supply.
7) Verify that output voltages are at ±7V (with allowable
tolerance of ±8%) with respect to GND0.
8) If required, vary the input voltage from 17V to 36V, the
load current from 0mA to 100mA, and verify that output
voltages are ±7V (with allowable tolerance of ±8%).
19-8443; Rev 1; 5/16
MAX17681 Evaluation Kit
Evaluates: MAX17681 for Isolated ±7V
or ±5V Output Configuration
Test Procedure for ±5V Output
The iso-buck is a synchronous-buck-converter-based
topology, useful for generating isolated outputs at low
power level without using an optocoupler. The detailed
procedure for setting the soft-start time, ENABLE/
UVLO divider, primary output voltage (VPRI) selection,
adjusting the primary output voltage, primary inductance
selection, turns-ratio selection, output capacitor selection,
output diode selection and external loop compensation
are given in the MAX17681 IC data sheet. The post
regulator, MAX17651 output voltage setting and the
related additional information are detailed in MAX17651
IC data sheet.
1) Verify that J1 is open
2) Remove R16 and R10. Place 0Ω resistors in R18
and R19.
3) Set the input power supply output to 24V. Disable the
power supply.
4) Connect the positive terminal of the power supply
to the VIN PCB pad and the negative terminal to the
nearest PGND PCB pad. Connect a 50mA resistive
load across the +5V PCB pad and the GND0 PCB
pad. Connect another 50mA resistive load across the
GND0 PCB pad and the -5VPCB pad.
5) Connect a DMM, configured in voltmeter mode,
across the +5V PCB pad and the nearest GND0
PCB pad. Connect another DMM, configured in
voltmeter mode, across the -5V PCB pad and the
nearest GND0 PCB pad.
6) Enable the input power supply.
7) Verify that output voltages are at ±5V (with allowable
tolerance of ±3%) with respect to GND0.
8) If required, vary the input voltage from 17V to 36V, the
load current from 0mA to 50mA, and verify that output
voltages are ±5V (with allowable tolerance of ±3%).
Detailed Description
The MAX17681EVKITB EV kit is a fully assembled and
tested circuit board that demonstrates the performance
of the MAX17681 high-efficiency, iso-buck, DC-DC
converter designed to provide an isolated power up
to 1.4W. The EV kit generates either ±7V, 100mA
or ±5V, 50mA output, from a 17V to 36V input
supply. The EV kit features a forced PWM control scheme
that provides constant switching-frequency of 200kHz
operation at all load and line conditions.
The EV kit includes an EN/UVLO PCB pad to monitor
and program the EN/UVLO pin of the MAX17681. The
VPRI PCB pad helps measure the regulated primary
output voltage (VPRI). An additional RESET PCB pad is
available for monitoring the health of primary output
voltage (VPRI). RESET is pulled low if the FB voltage
drops below 92.5% of its set value. RESET goes high
1024 clock cycles after the FB voltage rises above 95.5%
of its set value. The programmable soft-start feature
allows users to reduce the input inrush current.
www.maximintegrated.com
Enable Control (J1)
The EN/UVLO pin on the device serves as an on/
off control while also allowing the user to program the
input undervoltage-lockout (UVLO) threshold. Jumper J1
configures the EV kit’s output for turn-on/turn-off control.
Install a shunt across J1 pins 2-3 to disable VOUT. See
Table 1 for proper J1 configurations.
Table 1. Enable Control (EN/UVLO) (J1)
Jumper Settings
SHUNT
POSITION
EN/UVLO PIN
VOUT OUTPUT
1-2
Connected to VIN
Always Enabled
2-3
Connected to GND
Always Disabled
Open*
Connected to
midpoint of R1, R2
resistor-divider
Enabled at VIN ≥
15.5V
J1
*Default position.
NOTE 1: The secondary output diodes D1, D2 are rated to carry
short-circuit current only for a few hundredths of a millisecond
and are not rated to carry the continuous short-circuit current.
NOTE 2: The iso-buck converter typically needs 10% minimum
load to regulate the output voltage. In this design, when both
+7V and -7V rails are healthy, the U4 sinks the minimum load
current required to regulate the output voltages within ±8%
regulation. When a short is applied on any one of the output
rails with no-load on other healthy rail, the healthy rail voltage
can be as high as 16V.
Maxim Integrated │ 2
Evaluates: MAX17681 for Isolated ±7V
or ±5V Output Configuration
MAX17681 Evaluation Kit
EV Kit Performance Report
EFFICIENCY vs. LOAD CURRENT
toc1
90
70
OUTPUT VOLTAGE (V)
EFFICIENCY (%)
+7V output
7.8
80
VIN = 36V
60
VIN = 24V
50
VIN = 17V
40
30
20
7.6
VIN = 17V
7.4
VIN = 24V
VIN = 36V
7.2
7.0
10
0
OUTPUT VOLTAGE vs. LOAD CURRENT
8.0
toc2
100
±7V output
0
10
20
30
40
50
60
70
80
6.8
90 100
0
20
OUTPUT VOLTAGE vs. LOAD CURRENT
-6.8
60
80
100
OUTPUT VOLTAGE vs. LOAD CURRENT
5.01
+5V OUTPUT
5.005
-7
toc4
toc3
-7V OUTPUT
40
LOAD CURRENT (mA)
LOAD CURRENT (mA)
VIN = 17V
-7.4
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
5
-7.2
VIN = 24V
VIN = 36V
-7.6
-7.8
-8
VIN = 36V
4.985
4.98
4.975
0
20
40
60
80
100
4.97
10
20
30
40
50
LOAD TRANSIENT RESPONSE (LOAD
CURRENT FROM 50mA TO 100mA ON +7V,
-7V LOADED WITH 100mA )
-4.985
+7V OUTPUT
VOUT
(AC)
-4.99
toc6
toc5
-5V OUTPUT
-4.98
0
LOAD CURRENT (mA)
OUTPUT VOLTAGE vs. LOAD CURRENT
-4.975
OUTPUT VOLTAGE (V)
VIN = 17V
4.99
LOAD CURRENT (mA)
200mV/div
VIN = 36V
-4.995
VIN = 24V
-5
-5.005
50mA/div
VIN = 17V
IOUT
-5.01
-5.015
VIN = 24V
4.995
0
10
20
30
40
50
1mS/div
LOAD CURRENT (mA)
www.maximintegrated.com
Maxim Integrated │ 3
MAX17681 Evaluation Kit
Evaluates: MAX17681 for Isolated ±7V
or ±5V Output Configuration
Component Suppliers
Ordering Information
SUPPLIER
WEBSITE
Wurth Electronik
www.we-online.com
Murata Americas
www.murata.com
Panasonic Corp.
www.panasonic.com
PART
TYPE
MAX17681EVKITB#
EV Kit
#Denotes RoHS compliant.
Note: Indicate that you are using the MAX17681 when contacting
these component suppliers.
Component List, PCB Layout, and
Schematic
See the following links for component information, PCB
files, and schematic.
●● MAX17681B EV BOM
●● MAX17681B EV PCB Layout
●● MAX17681B EV Schematic
www.maximintegrated.com
Maxim Integrated │ 4
Evaluates: MAX17681 for Isolated ±7V
or ±5V Output Configuration
MAX17681 Evaluation Kit
Revision History
REVISION
NUMBER
REVISION
DATE
0
2/16
Initial release
1
5/16
Updated General Description section
DESCRIPTION
PAGES
CHANGED
—
1, 2
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
© 2016 Maxim Integrated Products, Inc. │ 5
S NO Designation Qty Description
1
Murata
GRM31CR71H105KA61
KEMET
C1206C105K5RAC
Murata
GRM31MR71H105KA88
1
1µF±10% 16V X7R Ceramic
capacitor (0603)
Murata
GRM188R71C105KA12
KEMET
C0603C105K4RAC
TDK C1608X7R1C105K
1
33nF±10%,25V, X7R ceramic Murata
capacitor (0402)
GRM155R71E333KA88
1
0.082uF±10%,16V, X7R
ceramic capacitor (0402)
1
820pF±5%,50V,COG ceramic
KEMET
capacitor (0402)
Murata GRM1555C1H821J C0402C821J5GAC
1
10uF±10%,16V, X7R ceramic Murata
capacitor (1206)
GRM31CR71C106KAC7
2
4.7uF±10%,50V, X7R ceramic Murata
capacitor (1206)
GRM31CR71H475KA12
2
2.2uF±10%,50V, X7R
ceramic capacitor (1206)
1
C11
1000PF ±10%,1500V, X7R
ceramic capacitor (1206)
C12, C13
2
0.1uF±10%, 25V, X7R
ceramic capacitor(0402)
AVX 1206SC102KAT
Murata
GRM155R71E104KE14
1
0.01uF±10%, 50V, X7R
ceramic capacitor (0402)
Murata
GRM155R71H103KA88
1
22uF, 20%, 50V, ALUMINUM
ELECTROLYTIC CAPACITOR
6.60*6.60mm,
3
C3
4
C4
5
C5
6
C6
7
C7, C8
8
C9, C10
9
11
C14
12
C15
13
14
Manufacturer
Partnumber-3
1µF±10%, 50V,X7R Ceramic
capacitor (1206)
C2
10
Manufacturer
Partnumber-2
1
C1
2
Manufacturer
Partnumber-1
D1, D2
J1
KEMET
Murata C0402C823K4RAC C0402C823K4RAC
Murata
GRM31CR71H225KA88
Panasonic EEEFK1H220P
2
100V/1A, PowerDI®123
1
3-pin headers
Diode Inc. DFLS1100-7
SULLINS ELECTRONICS
CORP PEC03SAAN
TAIYO YUDEN
UMK316B7225K
KEMET
C0402C103K5RAC
Manufacturer
Partnumber-4
TAIYO YUDEN
EMK107B7105KA
15
16
17
18
19
20
21
22
23
24
25
R1
R2
R3
R4
R5
R6
R7, R9
R8
R10
R11
R12, R14
26
1
1
1
3.01M Ohm±1% resistor
(0402)
261K Ohm±1% resistor
(0402)
78.7K Ohm±1% resistor
(0402)
1
10.5kΩ ±1% resistor (0402)
1
4.02kΩ ±1% resistor (0402)
1
100kΩ ±5% resistor (0402)
2
22kΩ ±1% resistor (0402)
1
115kΩ ±1% resistor (0402)
1
22Ω ±1% resistor (0402)
1
604kΩ ±1% resistor (0402)
2
432kΩ ±1% resistor (0402)
2
59kΩ ±1% resistor (0402)
1
0Ω ±5% resistor (0805)
R13, R15
27
R16
VISHAY DALE
CRCW04023M01FK
VISHAY DALE
CRCW0402261KFK
VISHAY DALE
CRCW040278K7FK
PANASONIC ERJ-2RKF1052
VISHAY DALE
PANASONIC ERJCRCW04024K02FK
2RKF4021X
PANASONIC ERJ-2GEJ104X
VISHAY DALE
CRCW040222K0FK
VISHAY DALE
CRCW0402115KFK
VISHAY DALE
CRCW040222R0FK
PANASONIC ERJ2RKF6043X
VISHAY DALE
CRCW0402432KFK
VISHAY DALE
CRCW040259K0FK
YAGEO PHYCOMP
RC0805JR-070RL
28
R17
1
OPEN (0402)
29
R18, R19
2
OPEN (0402)
30
T1
1
EP7, 8-pin SMT, 50µH,1.2A,
(1-4):(5-6):(7-8) = 1:1
WURTH ELECTRONICS INC.
750342779
31
U1
1
MAX17681 TDFN10 3*2mm
Iso buck DC-DC converter
MAX17681ATB+
32
U2,U3
1
MAX17651 TSOT LDO
MAX17651AZT+
33
U4
1
Shunt regulator SOT25
Diode Inc. TL431BW5
VENKEL LTD
CR0402-16W5902FT
8
7
6
5
4
3
1
2
+7V
D
A
D1
VPRI
OPEN
C7
C12
0.1UF
R9
R10
4.7UF
22K
22
T1
U1
1UF
1
+
22UF
VIN
VIN
EN/UVLO
C2
3.01M
2
3
J1
C14
0.01UF
VCC
1UF
R2
1
PGND
2
VIN
3
LX
GND
EN/UVLO
4
VCC
5
FB
RESET
10
261K
1
VCC
8
COMP
7
SS
6
R6
RESET
R5
C5
C6
100K
4.02K
820PF
6
7
6
7
8
8
10UF
R3
78.7K
OUT
2
GND PGOOD
5
1
EN
6
FB
+5V
R12
432K
C9
2.2UF
MAX17651AZT+
59K
GND0
R16
GND0
GND0
GND0
R19
R17
C8
OPEN
4.7UF
2
1
R11
C4
C
D2
C13
604K
U4
R7
4
C
U3
OPEN
0.082UF
C3
IN
4
R13
750342779
9
EP
11
1
R1
1
MAX17681ATB+
5
3
C1
C15
C
5
22K
5
2
PGND
4
3
GND0
0
4
D
U2
R18
C
0.1UF
3
IN
OUT
4
2
GND PGOOD
5
EN
6
1
FB
C10
R14
2.2UF
432K
MAX17651AZT+
R8
R15
115K
59K
A
-5V
R4
0.033UF
10.5K
B
B
-7V
SGND
EN/UVLO
EN/UVLO
C11
1000PF
RESET
RESET
SGND
PGND
PGND
GND0
A
A
PROJECT TITLE:
DRAWING TITLE:
SIZE
MAX17681B EVKIT
DATE:
HARDWARE NUMBER:
B <HARDWARE_NUMBER>
ENGINEER:
06/22/15
DRAWN BY:
REV:
TEMPLATE REV:
1.5
8
7
6
5
4
3
2
A
SHEET 2 OF 2
1
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