ADM1014

–10–

REV.

PrN 1/02

Figure 3. Typical Application Circuit

the capacitor on 12VG, the +3.3VAUX, 3.3V and 5V outputs

may not have exceeded their undervoltage thresholds by the

time the undervoltage comparators are enabled, and a false

undervoltage condition may be detected. For this reason it is

recommended to use the same value for all three gate capaci-

tors.

For PCI applications the minimum recommended value is

0.033µF. Smaller values may cause overcurrent faults at power-

up due to excessive charging currents drawn by decoupling

capacitors.

The maximum value of the gate capacitors is determined by the

need to discharge them quickly when turning off the outputs

under fault conditions. If the capacitors are too large the

ADM1014 may be unable to protect the power bus or the ex-

ternal MOSFETs. With 0.033µF capacitors, the turn-off time

will be less than 6µs.

APPLICATIONS INFORMATION

APPLICATION CIRCUIT

Figure 3 shows a typical circuit configuration for the ADM1014 in

a PCI application, controlling supply voltages of +3.3V at up to

7.6A, +5V at up to 5A, +12V at up to 0.5A and –12V at up to

0.1A. In this circuit, two external MOSFETs are connected in

parallel for the 3.3V and 5V outputs to minimise on-resistance.

OCSET GND

R5

C11

C12

M12VOB

M12GB

PWRONA

M12VINA

12VOB

12VINA

3VISENA

3VSA

3V5VGA

3VISENB

3VSB

3V5VGB

12VINB

M12VINB

5VSB

5VISENB

M12VOA

M12GA

12VGA

12VOA

5VSA

5VISENA

ADM1014

C2

C3

C4

C5

R1

R2

R3

R4

Q1

Q2

Q3

Q4

TO SYSTEM CONTROLLER

SLOT 2

5V

3.3V

C7

C8

SLOT 1

-12V

12V

AUXINA

AUXOA

AUXGA

C1

+3.3Vaux

3.3V

5V

-12V

12V

AUXINB

AUXOB

AUXGB

C6

+3.3Vaux

FLTNA

C10

12VGB

PWRONB

PAUXONA

PAUXONB

FAUXA

FLTNB

FAUXB

FROM

SYSTEM

CONTROLLER

R11

R12

C9

PRELIMINARY TECHNICAL DATA