Resistors R14 and R15 set VOUT1 and VOUT2 source

110mV, respectively. The sink current-limit voltage

threshold is approximately half the source current-limit

voltage threshold. Use the following equation to recon-

figure the source current-limit voltage threshold:

Refer to the

Current-Limit Circuit (LIM_) and Setting the

Cycle-by-Cycle, Low-Side Source Peak Current Limit

sections in the MAX15023 IC data sheet for further

instructions on computing the MAX15023 EV kit source

and sink current limits.

Switching Frequency

The MAX15023 controller’s switching frequency is set

to 500kHz by resistor R17. Replace resistor R17 with

a new resistor value to program the switching fre-

quency between 200kHz and 1MHz. Use the following

equation to calculate R17 when reconfiguring the

switching frequency:

When reconfiguring the EV kit controller switching fre-

quency, it might be necessary to change compensation

network components to new values. Refer to the

Compensation section in the MAX15023 IC data sheet

for computing new compensation component values.

Power-Good Outputs

(PGOOD1, PGOOD2)

The MAX15023 EV kit provides power-good output test

points (TP1 and TP2) to monitor the PGOOD1 and

PGOOD2 signals. PGOOD1 and PGOOD2 are high

when VOUT1 and VOUT2, respectively, rise 92.5%

above their programmed output voltages. The PGOOD_

signals are pulled up to VCC by resistors R4 and R5.

When VOUT1 and VOUT2 drop below 89.5% of their

nominal regulated voltages, PGOOD1 and PGOOD2 are

pulled low, respectively.

Enable/Power-Supply Sequencing

(JU1, JU2)

Jumpers JU1 and JU2 configure the MAX15023 EV kit’s

VOUT1and VOUT2 outputs, respectively, for indepen-

dent turn-on/off control or power-supply sequencing.

Install shunts across pins 1-2 of jumpers JU1 and JU2

to enable VOUT1 and VOUT2 using the MAX15023

VCC linear regulator output or the DC voltage source

supplied at the VCC PCB pad.

The outputs can also be externally controlled, by plac-

ing independent voltage sources greater than 1.3V at

the EN1 and EN2 PCB pads, when shunts are not

installed at jumpers JU1 and JU2. Additional PCB resis-

tor pads R2 and R7 are included to set the individual

channel to a desired turn-on voltage. See Tables 2 and

3 for jumpers JU1 and JU2 settings.

Power-Supply Sequencing

The MAX15023 EV kit outputs can be configured for

power-supply sequencing by utilizing the PGOOD_ out-

puts and configuring jumpers JU1 and JU2 appropri-

ately. Place shunts across pins 1-2 of jumper JU1 and

pins 2-3 of jumper JU2 for power sequencing VOUT1,

and then VOUT2. Place shunts across pins 1-2 of

jumper JU2 and pins 2-3 of jumper JU1 for sequencing

VOUT2, and then VOUT1. See Table 4 for configuring

the outputs for power-supply sequencing operation.

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MAX15023 Evaluation Kit

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_______________________________________________________________________________________

SHUNT

POSITION

EN1 PIN

VOUT1 OUTPUT

1-2

Connected to VCC

Enabled

2-3*

Connected to

PGOOD2

Enabled (power-

supply sequencing)

Not installed

Pulled down to

GND through R8

Disabled

Table 2. JU1 Jumper Selection (EN1)

*See the

Power-Supply Sequencing section.

SHUNT

POSITION

EN2 PIN

VOUT2 OUTPUT

1-2

Connected to VCC

Enabled

2-3*

Connected to

PGOOD1

Enabled (power-

supply sequencing)

Not installed

Pulled down to

GND through R3

Disabled

Table 3. JU2 Jumper Selection (EN2)

*See the

Power-Supply Sequencing section.

SHUNT POSITION

JU1

JU2

OUTPUT SEQUENCE OPERATION

1-2

2-3

VOUT1, VOUT2

2-3

1-2

VOUT2, VOUT1

Table 4. Power-Supply Sequencing (JU1,

JU2)