MAX5052AEVKIT Maxim Integrated Products, MAX5052AEVKIT Datasheet - Page 3

• Manufacturer Part Number: MAX5052AEVKIT
• Description: EVAL KIT FOR MAX5052
• Manufacturer: Maxim Integrated Products

Specifications of MAX5052AEVKIT

• Main Purpose: DC/DC, Step Down
• Outputs And Type: 2, Isolated
• Voltage - Output: 5V, 15V
• Current - Output: 1.5A, 100mA
• Voltage - Input: 36 ~ 72V
• Regulator Topology: Buck
• Frequency - Switching: 262kHz
• Board Type: Fully Populated
• Utilized Ic / Part: MAX5052A
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

The MAX5052A EV kit is fully assembled and tested.
Follow these steps to verify board operation. Do not
turn on the power supply until all connections are
completed.
1) Connect a voltmeter to the VOUT1 pad and SGND.
2) Connect a second voltmeter to the VOUT2 pad and
3) Connect a 750mA load to VOUT1 and a 50mA load
4) Verify that a shunt is not installed across the pins of
5) Connect a +36V to +72V power supply to the +VIN
6) Turn on the power supply above +36V and verify
7) Verify that the voltmeter at VOUT2 reads approxi-
The maximum current for each output should be limited
to less than 1.5A for VOUT1 and 100mA for VOUT2. For
instructions on selecting the feedback resistors for
other output voltages, see the Evaluating Other Output
Voltages, Current Limits, and UVLO section.
DESIGNATION
SGND.
to VOUT2.
jumper JU1
pad. Do not exceed 100V input voltage. Connect
the power supply’s ground to the -VIN pad.
that the voltmeter at VOUT1 reads approximately
+5V.
mately +15V.
U1
T1
—
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Component List (continued)
(SHDN).
QTY
1
1
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35µH, 10W transformer
(10-pin Gull Wing)
Cooper-Coiltronics CTX03-16034
MAX5052AEUA (8-pin µMAX)
Shunt (JU1)
MAX5052A PC board
DESCRIPTION
Quick Start
Outputs
MAX5052A Evaluation Kit
The MAX5052A EV kit is a 9W, isolated flyback DC-to-DC
converter that provides +5V and +15V outputs. The
+5V output, VOUT1, can provide up to 1.5A and the
+15V output, VOUT2, can provide up to 100mA. The
circuit can be powered from a +36VDC to +72VDC or a
-36VDC to -72VDC source. The user must supply at
least 22µF of bulk-storage capacitance at the input
terminals (+VIN, -VIN). The capacitor should be rated
for 100V and be able to carry approximately 200mA of
ripple current.
The flyback DC-to-DC converter achieves up to 83%
efficiency. The single-transistor topology and primary-
side regulation provide for a low-cost design by elimi-
nating the need for an optocoupler and shunt reference
on the secondary side. The MAX5052 EV kit provides
cycle-by-cycle, primary-side current-limit protection.
The current-sense resistor, R5, senses the current
through the transformer’s (T1) primary winding.
Switching transistor (N1) turns off when the trip level of
291mV is reached. The surface-mount transformer pro-
vides galvanic isolation up to 1500V for both outputs.
The MAX5052A EV kit features PC board pads for an
RCD snubber network (R8, C10, D3) to minimize leak-
age-energy ringing and to clamp the voltage at the
drain of MOSFET (N1) during switching (with most
MOSFETs, this snubber circuit can be eliminated).
Primary-side regulation through feedback resistors R1,
R2, rectifier D6, and the T1 tertiary winding provides
±5% regulation for the outputs. R7 and R12 are adjusted
to preload the tertiary winding for the +5V ±5% output
regulation. UVLO provides controlled turn-on and shut-
down during brownouts when powering up or powering
down. The UVLO settings can be changed by replacing
R4. Startup resistor R6 and reservoir capacitor C16
enable the MAX5052A to start up within approximately
500ms. The digital soft-start allows the output voltage to
slowly ramp up in a controlled manner within 60ms. The
MAX5052A controller switches at a fixed 262kHz fre-
quency and the duty cycle is varied to control energy
transfer to the isolated outputs. The maximum duty cycle
is 50% for the MAX5052A EV kit’s discontinuous current-
mode flyback design.
Detailed Description
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