MAX17596 Evaluation Kit
Evaluates: MAX17596
General Description
The MAX17596 evaluation kit (EV kit) is a fully assembled
and tested circuit board that demonstrates an isolated
20W fly-back DC-DC converter. The circuit uses the
device’s peak current-mode controller in a 16-pin TQFN
package with an exposed pad. The EV kit demonstrates
the IC’s cycle-by-cycle current limit, soft-start, and EN/
UVLO features.
The EV kit circuit output is configured for an isolated +24V
and provides up to 833mA of output current. The EV kit
is configured to operate at a 200kHz switching frequency.
An optocoupler, along with the transformer, provides
galvanic isolation between the input and output, up to
1500V
RMS
.
Quick Start
Recommended Equipment
●
●
●
●
●
●
●
●
Electronic load
Four digital multimeters (DMM)
MAX17596 24V EVKITB#
Do not turn on the power supply until all connections
are completed.
Wear protective eye gear at all times.
Do not touch any part of the circuit with bare hands
or conductive materials when powered up.
Make sure all high-voltage capacitors are fully
discharged before handling. Allow 5 minutes after
disconnecting input power source before touching
circuit parts.
Set the power supply to +24VDC. Disable the power
supply output.
Connect the positive terminal of the power supply to
the VIN PCB pad and the negative terminal to the
nearest PGND PCB pad. Connect the positive terminal
of the electronic load to the VOUT PCB pad and the
negative terminal to the nearest GND0 PCB pad.
Set the electronic load to constant-current mode and
disable the electronic load.
Connect a DMM configured in voltmeter mode
across the VOUT PCB pad and the nearest GND0
PCB pad.
Connect another DMM configured in voltmeter mode
across the VOUT PCB pad and the GND0 PCB pad.
Enable the power supply.
Enable the load and adjust the current to 833mA.
Verify that the output voltmeter displays 24V
If required, vary the input voltage from 18V to 36V,
the load current from 0mA to 833mA, and verify that
the output voltage is 24V.
One 18V–36V DC, 2A power supply
Warning:
Features
● 18V to 36V Input Range
● Isolated Output: 24V DC at 20W
● Cycle-by-Cycle Current Limit
● Resistor Programmable UVLO/OVI Threshold
● Low-Cost Flyback Design
● Galvanic Isolation Up to 1500V
RMS
● Proven PCB Layout
● Fully Assembled and Tested
3)
4)
Ordering Information
appears at end of data sheet.
Equipment Setup and Test Procedure
1)
2)
5)
6)
7)
8)
9)
19-7708; Rev 0; 7/15
MAX17596 Evaluation Kit
Evaluates: MAX17596
Detailed Description
The MAX17596 EV kit provides a proven design to evaluate
the high-efficiency, DC-DC, flyback converter in a space-
saving, 16-pin TQFN package. The EV kit is configured
for a 24V output voltage that can supply up to 840mA
of current. The EV kit features a 200kHz fixed switching
frequency for optimum efficiency and component size.
This EV kit uses the peak-current-mode, pulse-width-
modulating (PWM) controller IC in a 16-pin TQFN
package with an exposed pad. This PWM controller
varies the duty cycle to compensate for the variation
in input voltage (V
IN
) and the output load to maintain a
constant output voltage. The duty cycle determines the
on/off duration of the MOSFET (Q1).
The detailed description of flyback design methodology
and the calculations for component value selection are
described in Application Note 5504:
Designing Flyback
Converters Using Peak-Current-Mode Controllers.
The
details of soft-start time programming, programming output
voltage, peak-current-limit setting, switching frequency
setting, and the EN/UVLO,OVI settings are described in
the MAX17595/MAX17596/MAX17597 IC data sheet.
Note:
The EV kit is shipped with the frequency dithering
disabled and the DITHER/SYNC pin shorted to SGND by
a 0Ω resistor. To set the desired frequency dither, replace
resistor R23 with a capacitor of appropriate value, as
detailed in the MAX17595/MAX17596/MAX17597 IC
data sheet. The DITHER/SYNC PCB pad is available for
monitoring the signal at the DITHER/SYNC pin.
EV Kit Performance Report
100
90
80
60
50
40
30
20
10
0
0
70
EFFICIENCY vs. LOAD CURRENT
toc1
24.05
24
OUTPUT VOLTAGE
vs.
LOAD CURRENT
toc2
V
IN
= 18V
V
IN
= 36V
OUTPUT VOLTAGE (V)
EFFICIENCY (%)
V
IN
= 24V
23.95
23.9
23.85
23.8
23.75
V
IN
= 18V V
IN
= 24V
V
IN
= 36V
100
200
300
400
500
600
700
800
0
100
200
300
400
500
600
700
800
LOAD CURRENT (mA)
LOAD CURRENT (mA)
LOAD TRANSIENT RESPONSE
(LOAD CURRENT STEPPED
FROM 400 TO 833mA)
toc3
BODE PLOT
toc4
V
OUT
(AC)
500mV/div
F
CR
= 5.954KHz,
PHASE MARGIN = 77.65°
500mA/div
PHASE
I
OUT
4.00mS/div
www.maximintegrated.com
Maxim Integrated │ 2
Electronics Design Contest
京公网安备 11010802033920号
EEWORLD
