REV. A

ADM1052

–7–

APPLICATIONS INFORMATION

PCB LAYOUT

For optimum voltage regulation, the loads should be placed as

close as possible to the source of the output MOSFETs and

feedback to the sense inputs should be taken from a point as

close to the loads as possible. The PCB tracks from the loads

back to the sense inputs should be separate from the output

tracks and not carry any load current.

Similarly, the ground connection to the ADM1052 should be

made as close as possible to the ground of the loads, and the

ground track from the loads to the ADM1052 should not carry

load current. Correct and incorrect layout practice is illustrated

in Figure 3.

12V SUPPLY

THRESHOLD

POR THRESHOLD

6V – 9V

GATE DRIVE TO

EXTERNAL MOSFET

MOSFET GATE

THRESHOLD

3.3V SUPPLY

TO EXTERNAL

MOSFET DRAIN

CHANNEL 1

OR CHANNEL 2

OUTPUT VOLTAGE

NORMAL OUTPUT VOLTAGE

FAULT

REMOVED

OUTPUT < 0.8

CHANNEL 1

OR CHANNEL 2

OUTPUT CURRENT

HICCUP MODE

HOLD-OFF TIME

2 AMPS

DEVICE

ENTERS

HICCUP MODE

FAULT

CURRENT

1:40 DUTY CYCLE

OFF

ON

Figure 2. Power-On Reset and Hiccup Mode

LOAD 1

LOAD 2

3.3V

FORCE 1

FORCE 2

SENSE 1

SENSE 2

GND

12V

LOAD 1

LOAD 2

3.3V

FORCE 1

FORCE 2

SENSE 1

SENSE 2

GND

12V

VOLTAGE DROP

IN GROUND LEAD

VOLTAGE DROP

BETWEEN OUTPUT

AND LOAD

CORRECT

INCORRECT

Figure 3. Correct and Incorrect Layout Practice