MAX17682 Evaluation Kit D
Evaluates: MAX17682 for Isolated
±15V
Dual-Output Configuration
General Description
The MAX17682 EV kit is a fully assembled and tested
circuit board that demonstrates the performance of the
MAX17682 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 voltages. The EV kit has isolated dual output
voltages programmed to ±15V at 150mA, along with a
primary regulated +5V output voltage at 1A, with 10%
output voltage regulation.
The EV kit comes installed with the MAX17682 in a 20-pin
(4mm x 4mm) TDFN package.
Quick Start
Recommended Equipment
●
●
●
One 15V - 60V DC, 1A Power Supply
One resistive load of 5Ω,1A and two resistive loads
of 100Ω,150mA sink capacity
Three Digital Multimeters (DMM)
Caution: Do not turn on the power supply until all
connections are completed.
Procedure
1)
2)
3)
4)
Features
●
17V to 36V Input Voltage Range
● ±15V,150mA; +5V, 1A Continuous Current
● EN/UVLO Input
● 200kHz Switching Frequency
● 93% Peak Efficiency
● Overcurrent Protection
● No Optocoupler
● Delivers up to 10W Output Power
● Overtemperature Protection
● Proven PCB layout
5)
6)
7)
Ordering Information
appears at end of data sheet.
8)
Verify that J1 is open and J2 is connected to GND.
Set the power supply output to 24V. Disable the
power supply.
Connect the positive terminal of the power supply to
the VIN PCB pad and the negative terminal to the
nearest PGND PCB pad.
Connect one DMM configured in voltmeter mode
across the +5V PCB pad and the nearest PGND
PCB pad, and two DMMs across the ±15V PCB pad
and the corresponding nearest GND0 PCB pads.
Connect a 1A resistive load across the +5V PCB pad
and the nearest PGND PCB pad, and two 150mA
resistive loads across the ±15V PCB pads and the
corresponding nearest GND0 PCB pad.
Enable the input power supply.
Verify that the secondary output voltage is at ±15V
(with allowable tolerance of 10%) with respect to
GND0 and the primary output voltage is +5V with
respect to PGND.
If required, vary the input voltage from 17V to 36V,
the primary load current form 100mA to 1A and the
secondary load current from 15mA to 150mA, and
verify that the output voltages are within the toler-
ance limit.
319-100185; Rev 0; 4/18
MAX17682 Evaluation Kit D
Evaluates: MAX17682 for Isolated ±15V
Dual-Output Configuration
This EV Kit is protected against accidental primary and
secondary output short-circuit conditions. When a short-
circuit fault occurs at any of the secondary isolated output
terminals, the condition induces a negative current in
the primary winding of the transformer, which eventually
causes the current to hit the negative current limit
in MAX17682. The part enters hiccup mode after 16
consecutive events of hitting a negative current limit. If the
short circuit happens across the primary output terminals,
the MAX17682 enters HICCUP mode either when the
high-side switch current hits runaway current limit or when
the FB-pin voltage goes below 0.58V. In either case, the
part attempts to recover after 32,768 clock cycles.
Detailed Description
The MAX17682EVKITD evaluation kit (EV kit) is a fully
assembled and tested circuit board that demonstrates the
performance of the MAX17682 high-efficiency, iso-buck,
DC-DC converter designed to provide an isolated power up
to 10W. The EV kit generates isolated dual output of ±15
V, 150mA and a primary output of +5V, 1A from a 17V to
36V input supply. The EV kit features a forced-PWM control
scheme that provides constant switching-frequency of 200
kHz 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 MAX17682. The VPRI
PCB pad helps measure the regulated primary output volt-
age (V
PRI
). An additional RESETB PCB pad is available
for monitoring the health of primary output voltage (V
PRI
).
RESETB pulls low if FB voltage drops below 92%(typ)
of its set value and RESETB goes high impedance 1024
clock cycles after FB voltage rises above 95% of its set
value. The programmable soft-start feature allows users
to reduce the input inrush current.
The iso-buck is a synchronous-buck-converter-based
topology, useful for generating isolated outputs at low
power level without using an opto-coupler. The detailed
procedure for setting the soft-start time, ENABLE/UVLO
divider, primary output voltage (V
PRI
) 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 MAX17682 IC data sheet.
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
J1configures the EV kit’s output for turn-on/turn-off control.
Install a shunt across jumper J1 pins 2-3 to disable VOUT.
See
Table 1
for J1 jumper configurations.
External Synchronization (J2)
The SYNC pin on the device allows synchronization to
an external clock. Jumper J2 configures the frequency of
operation of the EV kit by selecting the internal clock with
frequency decided by the RT resistor value or the external
clock to synchronize. See
Table 2
for J2 jumper configurations.
Table 1. Enable Control (EN/UVLO) (J1) Jumper Settings
SHUNT POSITION
1-2
2-3
Open*
*Default
position.
EN/UVLO PIN
Connected to V
IN
Connected to GND
Connected to midpoint of R1, R2 resistor-divider
V
OUT
OUTPUT
Always Enabled
Always Disabled
Enabled at V
IN
≥ 15V
Table 2. External Synchroniztaion (SYNC) (J2) Jumper Settings
SHUNT POSITION
1-2
2-3*
Open
*Default
position.
Note 1:
The secondary output diodes are rated to carry short-circuit current only for 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 the ±15V rails
are healthy, U2 sinks the minimum load current required to regulate the output voltages within ±10% regulation.
SYNC PIN
Connected to SYNC
Connected to GND
Unconnected
CLOCK FREQUENCY
Uses external clock
Uses Internal clock set according to RT resistor
Not recommended
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│
2
MAX17682 Evaluation Kit D
Evaluates: MAX17682 for Isolated ±15V
Dual-Output Configuration
EV Kit Performance Report
EFFICIENCY vs. LOAD CURRENT
95
93
toc01
OUTPUT VOLTAGE vs. LOAD CURRENT
1.035
1.030
toc02
NORMALIZED OUTPUT VOLTAGE
91
1.025
1.020
1.015
1.010
1.005
1.000
0.995
0.990
V
SEC2
V
SEC1
V
PRI
EFFICIENCY (%)
89
87
85
83
81
79
77
75
0
10
20
30
40
50
60
70
80
90 100
V
IN
= 17V
V
IN
= 24V
V
IN
= 36V
0.985
0
LOAD CURRENT (% OF FULL LOAD)
10 20 30 40 50 60 70 80 90 100 110
LOAD CURRENT (% OF FULL LOAD)
SECONDARY LOAD TRANSIENT RESPONSE
(LOAD CURRENT STEPPED FROM
75mA TO 150mA)
toc03
PRIMARY LOAD TRANSIENT RESPONSE
(LOAD CURRENT STEPPED FROM 500mA TO 1A)
toc04
I
OUT
100mA/div
I
OUT
500mA/div
V
SEC1
(AC)
500mV/div
V
PRI
(AC)
50mV/div
V
SEC2
(AC)
500mV/div
400µs/div
400µs/div
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3
MAX17682 Evaluation Kit D
Evaluates: MAX17682 for Isolated ±15V
Dual-Output Configuration
EV Kit Performance Report (continued)
FULL LOAD SWITCHING WAVEFORMS
toc05
OUTPUT SHORT WAVEFORMS
toc06
V
PRI
(AC)
200mV/div
V
SEC1
V
PRI
20V/div
5V/div
20V/div
V
SEC1
(AC)
V
SEC2
(AC)
200mV/div
V
LX
200mV/div
I
LX
5A/div
V
LX
4µs/div
20V/div
20µs/div
RECOVERY AFTER
MOMENTARY OUTPUT SHORT
toc07
PERMANANT OUTPUT SHORT WAVEFORMS
toc08
V
GS
V
PRI
5/div
5V/div
V
GS
V
PRI
5V/div
5V/div
V
LX
20V/div
V
LX
20V/div
I
LX
5A/div
I
LX
5A/div
40ms/div
200ms/div
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4
MAX17682 Evaluation Kit D
Evaluates: MAX17682 for Isolated ±15V
Dual-Output Configuration
Component Suppliers
SUPPLIER
Wurth Electronik
Murata Americas
Panasonic Corp.
www.we-online.com
www.murataamericas.com
www.panasonic.com
WEBSITE
Note:
Indicate that you are using the MAX17682 when contacting these component suppliers.
Ordering Information
PART
MAX17682EVKITD#
#Denotes
RoHS compliant.
TYPE
EVKIT
MAX17682 EV Kit D Bill of Materials
S. No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
Designation
C1
C2
C3
C4
C5
C6
C7, C8
C9, C10
C11
C12
C13
C14
D1, D2
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10
R11
T1
U1
U2
JU1, JU2
SU1, SU2
Qty
1
1
1
1
1
1
2
2
1
1
1
0
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
2
Description
47µF±20%, 80V, Aluminium electrolytic cappacitor
10µF±10%, 50V X7R ceramic capacitor(1210)
0.1µF±10%, 100V X7R ceramic capacitor(0603)
470pF±5%, 25V X7R ceramic capacitor(0402)
0.039µF±10%, 25V X7R cermaic capacitor(0402)
.033µF±10%, 25V X7R ceramic capacitor(0402)
47µF±10%, 10V X7R ceramic capacitor(1210)
2.2µF±10%, 25V X7R ceramic capacitor(1210)
2.2µF±20%, 10V X7R ceramic capacitor(0603)
0.1µF±10%, 16V X7R ceramic capacitor(0402)
2700pF±10%, 3kV X7R ceramic capacitor(1812)
47µF±10%, 10V X7R ceramic capacitor(1210)
Diode, 400V/1A, SMT
3.3MΩ±1%
resistor(0603)
274kΩ±1% resistor(0603)
102kΩ±1%
resistor(0402)
4.42kΩ±1%
resistor(0402)
82kΩ±1% resistor(0402)
18kΩ±1%
resistor(0402)
10kΩ±1%
resistor(0402)
931kΩ±1%
resistor(0402)
82.5kΩ±1%
resistor(0402)
562Ω±1% resistor(0402)
0Ω±1%
resistor(0805)
EVKIT PART-TRANSFORMER; SMT-12; 3.2:1
MAX17682 TQFN10 4*4mm Iso buck DC-DC converter
Shunt regulator SOT-23
Jumper Headers
Jumper pins
Maufacturer Par#1
PANASONIC EEE-FK1K470P
MURATA GRM32ER71H106KA12L
MURATA GRM188R72A104KA35
KEMET C0402C393K3RAC7867
YAGEO AC0402KRX7R8BB471
MURATA GRM155R71E333KA88
MURATA GRM32ER71A476KE15
MURATA GRM32RR71E225KC01L
MURATA GRM188R71A225ME15
TDK C1005X7R1C104K050BC
AVX 1812HC272KAZ1A
MURATA GRM32ER71A476KE15
DIODES INCORPORATED DFLU1400
VISHAY DALE CRCW06033M30FK
PANASONIC ERJ-3EKF2743V
VISHAY DALE CRCW0402102KFK
PANASONIC ERJ-2RKF4421X
VISHAY DALE CRCW040282K0FK
VISHAY DALE CRCW040218K0FK
VISHAY DALE CRCW040210K0FK
VISHAY DALE CRCW0402931KFK
VISHAY DALE CRCW040282K5FK
PANASONIC ERJ-2RKF5620X
VISHAY DALE CRCW08050000ZS
WURTH ELECTRONICS INC 750343673
MAXIM MAX17682
DIODES INCORPORATED TL431BSA
SULLINS ELECTRONICS CORP. PEC03SAAN
SULLINS ELECTRONICS CORP. STC02SYAN
Maufacturer Par#2
SAMSUNG ELECTRONICS CL32B106KBJNNN
TDK CC0603KRX7R0BB104
AMERICAN TECHNICAL CERAMICS ATC530L104KT16
ROHM MCR01MZPF8202
YAGEO PHICOMP RC0402FR-0710K
BOURNS CR0402-FX-8252GLF
PANASONIC ERJ-6GEY0R00V
VIN, +5V, +15V, -
15V, GND0, PGND,
SGND, SYNC,
PGND1, GND0_1,
30 RESETB, EN/UVLO
12 Test Loops
WEICO WIRE 9020 BUSS
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│ 5
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