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Evaluates: MAX17552/MAX17552B (TDFN)

in 5V Output Voltage Applications

MAX17552 5V Output

Evaluation Kit (TDFN)

Detailed Description

The MAX17552 5V EV kit (TDFN) is a fully assembled and

tested circuit board that demonstrates the performance of

the MAX17552 60V, 100mA ultra-small, high-efficiency,

synchronous step-down DC-DC converter in a 10-pin

TDFN package. The EV kit operates over a wide input

voltage range of 6V to 60V and provides up to 100mA

load current at 5V output. It draws only 26µA supply cur-

rent under no-load conditions (EN/UVLO connected to

VIN). The EV kit is programmed to switch at a frequency

of 220kHz and delivers a peak efficiency of 93% with the

supplied components. The device is simple to use and

easily configurable with minimal external components.

It features cycle-by-cycle peak current limit protection,

undervoltage lockout, and thermal shutdown.

The EV kit includes an EN/UVLO PCB pad and jumpers

JU1 and JU2 to enable control of the converter output.

The MODE PCB pad and jumper JU3 are provided

for selecting the mode of operation of the converter. A

RESET

PCB pad is available for monitoring the RESET

output. The RT/SYNC PCB pad can be used to synchro-

nize the EV kit switching frequency to an external clock

frequency.

Enable Control (JU1, JU2)

The EN/UVLO pin on the EV kit serves as an on/off control

while also allowing the user to program the input undervolt-

age lockout (UVLO) threshold. Jumpers JU1 and JU2 con-

figure the EV kit’s output for turn-on/turn-off control. See

Table 1 for proper JU1, JU2 jumper configurations.

Additionally, resistors R1 and R2 are included to set the

UVLO to a desired turn-on voltage. Refer to the Setting

the Input Undervoltage-Lockout Level section in the

MAX17552 IC data sheet for additional information on

setting the UVLO threshold voltage.

RESET Output

The EV kit provides a PCB pad to monitor the status of

the RESET output. RESET goes high and when the out-

put voltage rises above 95% (typ) of its nominal regulated

output voltage. RESET goes low when output voltage falls

below 92% (typ) of its nominal regulated voltage.

PFM or Forced-PWM Mode (MODE)

The EV kit includes a jumper (JU3) to select the mode

of operation of the converter. Install a shunt across JU3

before powering up the EV kit to enable the forced-PWM

operation. Keep JU3 open to enable the light-load PFM

operation. See Table 2 for proper JU3 settings.

Soft-Start

The EV kit offers a fixed 5ms soft-start time. Connect the

following equation to determine the soft-start capacitance

value (CSS).

External Synchronization (RT/SYNC)

The EV kit provides a PCB pad to synchronize the EV

kit switching frequency to an external clock frequency.

Apply the external clock to the RT/SYNC PCB pad

though an AC-coupling capacitor. Refer to the External

Synchronization section in the MAX17552 IC data sheet

for additional information on configuring the external

clock and selecting the AC-coupling capacitor.

Table 1. Enable Control (EN/UVLO) (JU1, JU2)

Table 2. MODE Control (JU3)

*Default position.

*Default position.

SHUNT POSITION

EN/UVLO PIN

VOUT OUTPUT

JU1

JU2

1-2

Open

Connected to VIN

Enabled

Open

1-2

Connected to GND

Disabled

1-2*

1-2

Connected to midpoint of R1, R2 resistor-divider

Enabled at VIN ≥ 6V

SHUNT POSITION

MODE PIN

MODE OF OPERATION

1-2

Connected to GND

Forced PWM

Open*

Unconnected

PFM