MAX17497AEVKIT# Maxim Integrated, MAX17497AEVKIT# Datasheet - Page 3

• Manufacturer Part Number: MAX17497AEVKIT#
• Description: Power Management IC Development Tools MAX17497 Eval Kit
• Manufacturer: Maxim Integrated

Specifications of MAX17497AEVKIT#

• Rohs: yes

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The EV kit is fully assembled and tested. Follow the steps
below to verify board operation. Warning: Exercise
caution when connecting and measuring offline
voltages.
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The MAX17497A EV kit is a 5.58W, nonisolated fly-
back DC-DC converter that provides dual outputs of
+12V/300mA and +3.3V/600mA at VOUT1 and VOUT2,
respectively. The circuit can be powered from a +85V AC
to +265V AC power source connected at the LINE and
NEUTRAL PCB pads.
The transformer secondary +12V output (VOUT1) is used
as the input source for the IC integrated regulator, which
provides +3.3V at VOUT2.
The EV kit circuit VOUT1 voltage is set to +12V using
the transformer T1 secondary output and feedback
resistors R17 and R16. Capacitor C5 sets VOUT1 soft-
Maxim Integrated
Detailed Description of Hardware
MAX17497A EV kit
AC source (+85V AC to +265V AC)
Three voltmeters
300mA load
600mA load
Connect the first voltmeter to the VOUT1 and PGND
PCB pads.
Connect the second voltmeter to the VOUT2 and
PGND PCB pads.
Connect the 300mA load to VOUT1 and PGND PCB
pads.
Connect the 600mA load to VOUT2 and PGND PCB
pads.
Connect the +85V AC to +265V AC power supply to
the LINE and NEUTRAL PCB pads.
Turn on the AC power supply.
Verify that the voltmeter at VOUT1 reads approxi-
mately +12V.
Verify that the voltmeter at VOUT2 reads approxi-
mately +3.3V.
Required Equipment
Quick Start
Procedure
start to 5.6ms. VOUT2 uses the IC integrated step-down
regulator, whose output is internally set to +3.3V. The
VOUT2 step-down converter output has an internal 2ms
soft-start time.
The IC IN pin circuit preregulation circuitry consists of
transistor Q1, resistors R5–R8, capacitors C4 and C5,
and diode D2 and allows the startup of the converter.
During startup, when the input voltage is applied, the
R5–R8 startup resistors charge the C4 and C5 startup
capacitors, causing the voltage at the IN pin to increase
towards the rising IN UVLO threshold (+20V typ). During
this time, the IC draws a low startup current through the
resistors. When the voltage at IN reaches the rising IN
UVLO threshold, the IC commences switching operations
and drives external MOSFET N1, whose drain is con-
nected to the IC LXF input. Since this current cannot be
supported by the current through the startup resistors, IN
is bootstrapped by VOUT1. VOUT1 then provides power
to IN upon reaching its regulated +12V output. If the IN
voltage falls below its UVLO falling threshold (+4.5V, typ)
before VOUT1 is energized, the controllers turn off and
reinitiate the startup process.
The EV kit provides cycle-by-cycle primary-side cur-
rent-limit protection using MOSFET N1 and the IC LXF
input. Resistor R15 sets the current limit to 548mA .The
surface-mount transformer provides galvanic isolation up
to +1500V for VOUT1. The EV kit features zener clamp
snubber network (D6 and D3) to minimize leakage-ener-
gy ringing and clamp the voltage at the drain of MOSFET
N1 during switching.
The EV kit provides VOUT1 and VOUT2 PCB pads for
monitoring the circuit’s outputs and various PCB pads for
monitoring the circuit’s inputs and outputs.
The EV kit’s VOUT1 voltage is set to +12V using the T1
secondary output and feedback resistors R17 and R16.
VOUT2 is set internally to +3.3V by the IC and uses
VOUT1 as it input power source.
Refer to the Programming the Output Voltage of the
Flyback/Boost Converter (SSF) section in the MAX17497A/
MAX17497B IC data sheet for additional information on
setting the VOUT1 voltage.
Evaluates: MAX17497A
Output Voltages (VOUT1, VOUT2)
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