adm1014 Analog Devices, Inc., adm1014 Datasheet - Page 10

• Manufacturer Part Number: adm1014
• Description: Dual Pci Hot-plugtm Controller
• Manufacturer: Analog Devices, Inc.

ADM1014
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.
CONTROLLER
SYSTEM
FROM
12V
12V
-12V
-12V
+3.3Vaux
+3.3Vaux
C1
C2
C3
C4
C5
C6
R11
R12
Figure 3. Typical Application Circuit
AUXINA
AUXGA
AUXOA
12VGB
M12VINA
M12GA
M12VOA
M12VINB
M12GB
M12VOB
12VINA
12VGA
12VOA
12VINB
12VOB
AUXINB
AUXGB
AUXOB
PAUXONA
PWRONB
PAUXONB
PWRONA
FLTNA
C9
TO SYSTEM CONTROLLER
C10
FAUXA FLTNB
–10–
ADM1014
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.
SLOT 2
SLOT 1
C11
FAUXB
C12
R5
OCSET GND
5VISENA
5VISENB
3VISENA
3VISENB
3V5VGA
3V5VGB
5VSA
5VSB
3VSB
3VSA
C7
C8
3.3V
5V
Q1
Q2
Q3
Q4
R1
R2
R3
R4
5V
3.3V
REV. PrN 1/02