Maxim Integrated │ 3

www.maximintegrated.com

Evaluates: MAXM17543 in 3.3V

Output-Voltage Application

MAXM17543 3.3V Output

Evaluation Kit

Mode Selection (MODE)

The device’s MODE pin can be used to select among the

PWM, PFM, or DCM modes of operation in advance of

constant frequency or high efficiency at light load. The

EN/UVLO voltage exceed the respective UVLO rising

thresholds and all internal voltages are ready to allow LX

switching. The changes on the MODE pin are ignored

during normal operation. Refer to the MAXM17543 IC

data sheet for more information on the PWM, PFM, and

DCM modes of operation. Table 2 shows EV kit jumper

settings that can be used to configure the desired mode

of operation.

External Clock Synchronization (SYNC)

The internal oscillator of the device can be synchronized

to an external clock signal to eliminate beat frequency

between regulators through the SYNC pin. The external

by R5. The minimum external clock high pulse width and

amplitude should be greater than 50ns and 2.1V, respectively.

The minimum external clock low pulse width should be

greater than 160ns, and the maximum external clock

low pulse amplitude should be less than 0.8V. Table 3

describes the connection of the SYNC pin.

at FB

The EV kit is preset for 3.3V and offers an adjustable

output voltage range as low as 0.9V up to 12V at 2.5A

maximum load. The adjustable output voltage can be

programmed by the set of resistor dividers R1 and R2.

Refer to the Table 1 (Selection Component Values) on

the MAXM17543 datasheet to select optimal component

values for each specific input voltage range from 4.5V

up to 42V and an output voltage from 0.9V up to 12V. To

obtain a different output voltage other than default setting

outputs in Table 1, only six component (R1, R2, C1, C2,

C3, and C8) values are needed to modify the equation

that described in the Setting the Output Voltage section in

the MAXM17543 IC data sheet.

Table 3. SYNC Description (JU3)

Table 2. MODE Description (JU2)

Default position.

Default position.

Table 1. UVLO Enable/Disable

Configuration (JU1)

Default position.

SHUNT

POSITION

SYNC PIN

MAXM17543_SYNC

1-2*

Connected to

SGND

SYNC feature unused

Not installed

Connected to test

loop on PCB

Frequency can be

synchronized with an

external clock

SHUNT

POSITION

MODE PIN

MAXM17543_ MODE

Not installed

Unconnected

PFM mode of operation

1-2

2-3*

Connected to GND PWM mode ofoperation

SHUNT

POSITION

EN PIN

MAXM17543_

OUTPUT

Installed

Connected to GND

Disable

Not installed*

Connected to VIN

Enable