Detailed Description

The MAX5092 evaluation kit (EV kit) is a fully assem-

bled and tested surface-mount PCB demonstrating

the MAX5092B LDO with internal boost preregulator

IC. The EV kit operates from a 4V to 72V input voltage

and delivers up to 250mA from a preprogrammed 7V

boost preregulator output (BSOUT) and 5V LDO out-

put (VOUT).

VOUT can deliver up to 250mA total output current.

The voltage maintained at BSOUT depends upon the

input voltage and the programmed BSOUT regulation

above the BSOUT regulation voltage, causing

Both the LDO and boost preregulator output voltages

can be programmed using external resistors. The boost

selecting resistors R1 and R2. The LDO output voltage

resistors R4 and R5. See the

Evaluating Other Output

Voltages section for more details. If it is desired to pro-

IC. See the

Configuring for the MAX5093_ section for

more details.

The MAX5092_/MAX5093_ feature an internal voltage

regulator that is used to supply all internal low-voltage

blocks within the IC. An output on the EV kit (VL) is pro-

is not intended to supply an external load.

The MAX5092 EV kit utilizes two jumpers (JU1 and JU2)

to control the ENABLE and

HOLD functions of the

MAX5092 IC. See Table 1 for jumper descriptions. Shunt

pins 2-3 of jumper JU1 to enable the MAX5092. Shunt

pins 1-2 of jumper JU1 to disable the MAX5092. Shunt

pins 1-2 of jumper JU2 to enable

HOLD mode. Shunt

pins 2-3 of jumper JU2 to disable

HOLD mode. Enabling

HOLD prevents the IC from shutting down if EN is

brought low. The ENABLE function is also controlled by

an external voltage source by connecting the external

source to the ENABLE pad on the EV kit. When control-

ling ENABLE from an external source, ensure the shunt

on jumper JU1 is removed. Refer to the MAX5092A/

MAX5092B/MAX5093A/MAX5093B data sheet for a

more detailed description of the ENABLE and

HOLD

timing functions.

The MAX5092 contains a power-on-reset output

(

RESET) that indicates when the LDO output voltage

above 92% of the programmed regulation threshold,

period. Capacitor C5 sets the

RESET timeout period.

See the

Adjusting the

RESET Timeout Period section

for more details.

The MAX5092A IC (3.3V LDO output) can be used with

this EV kit. Refer to the MAX5092/MAX5093 IC data

sheet for operation. The MAX5092 EV kit can be config-

ured for the MAX5093_ IC using an external Schottky

diode. Use the MAX5093_ for higher boost voltage

applications up to 12V or to lower package power dissi-

pation. See the

Configuring for the MAX5093_ to modify

the MAX5092 EV kit for use with the MAX5093_.

Customizing the MAX5092 EV Kit

Evaluating Other Output Voltages

The MAX5092_/MAX5093_ feature Dual Mode™ opera-

tion for regulating the boost-converter output voltage.

These devices operate in either preset output-voltage

mode or adjustable output-voltage mode. In preset

to a fixed 7V. The default EV kit is configured for the

BSOUT preset mode by directly connecting BSFB to

can be programmed up to 11V for the MAX5092_ (or

up to 12V for the MAX5093_) by selecting resistors R1

and R2. Note that the current drawn by these resistors

adds to the quiescent current and the shutdown current

of the IC. Use the adjustable output mode only if

MAX5092 Evaluation Kit

4

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Table 1. JU1 and JU2 Jumper Positions

JUMPER

POSITION

FUNCTION

1-2

Sets ENABLE low (disables IC)

JU1

2-3

Sets ENABLE high (enables IC)

1-2

Sets

HOLD low (enables HOLD)

JU2

2-3

Sets

HOLD high (disables HOLD)

Dual Mode is a trademark of Maxim Integrated Products, Inc.