SMH4046 Datasheet, PDF (6/51 Pages) List of Unclassifed Manufacturers – Hot-Swap, Active DC Output Control (ADOCTM) Power Manager with I2C lnterface

SMH4046
Preliminary Information
PIN DESCRIPTIONS (CONTINUED)
Symbol
VMB
TRIMB
TRIM_CAPB
VMC
TRIMC
TRIM_CAPC
1VREF
CARD_5V
CARD_3V
VCC3V
FILT_CAP
PUPC
PUPB
PUPA
ADC_CAPC
ADC_CAPB
ADC_CAPA
VGG_CAP
DRVREN#
VGATE5V
VGATE3V
Pin Type Description
18 I Positive converter sense line for DC/DC converter B
19 O Output voltage used to control the output of DC/DC converter B.
20 I External sample and hold capacitor input used to set the voltage on the TRIMB pin.
21 I Positive converter sense line for DC/DC converter C
22 O Output voltage used to control the output of DC/DC converter C.
23 I External sample and hold capacitor input used to set the voltage on the TRIMC pin.
24
O
This output provides a 1V reference for pre-charging the CompactPCI bus signal
pins.
25
I
5V card side supply input. This input is monitored for power integrity. If it falls below
the 5V sense threshold, the CARD_V_VLD signal is de-asserted.
26
I
3.3V monitor input from the line card. This input is monitored for power integrity. If it
falls below the 3.3V sense threshold, the CARD_V_VLD signal is de-asserted.
27 I 3.3V host side supply input. This input is monitored for power integrity.
28 I External capacitor input used to filter VMX inputs
29
O
Programmable active high/low open drain converter enable output for DC/DC
converter C.
30
O
Programmable active high/low open drain converter enable output for DC/DC
converter B.
31
O
Programmable active high/low open drain converter enable output for DC/DC
converter A.
32 I External capacitor input used to filter the VMC input to the 10-bit ADC.
33 I External capacitor input used to filter the VMB input to the 10-bit ADC.
34 I External capacitor input used to filter the VMA input to the 10-bit ADC.
This pin supplies power for the high-side drivers. An external 1uF ceramic charge
pump capacitor should be connected to VGG_CAP. VGG_CAP is a charge storage
35
O
connection for the internal charge pump of the SMH4046. This capacitor should be
of sufficient size to provide current to the VGATE outputs high side drivers under
varying load conditions. For most applications this can be tied to a 1.0 µF ceramic
capacitor.
36
O
High-side driver enable used to switch on the 12V supply. Pulldown current of
100µA when on.
37
O
5V gate output. Slew rate limited high side driver output for the 5V external Power
FET gate. Alternatively this can be used as a PUP output.
38
O
3.3V gate output. Slew rate limited high side driver output for the 3.3V external
Power FET gate. Alternatively, this can be used as a PUP output.
Summit Microelectronics, Inc
2082 1.7 08/23/04
6