FAN5078 Datasheet, PDF (5/16 Pages) Fairchild Semiconductor – DDR/ACPI Regulator Combo

Pin Configuration
SBUSB#
S4ST#
SBSW
5V MAIN
VTT SNS
VTT OUT
24 23 22 21 20 19
P1 = GND
7 8 9 10 11 12
EN
S3#I
S3#O
3.3 ALW
VCC
PGOOD
FAN5078MP 5x5mm MLP package (θ_JA = 38°C/W)
Note: Connect P1 pad to GND.
Pin Definitions
Pin #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Pin
SBUSB#
S4ST#
SBSW
5V MAIN
VTT SNS
VTT OUT
VDDQ IN
BOOT
HDRV
SW
ISNS
LDRV
PGOOD
VCC
Pin Function Description
USB Standby. Pulls low with constant current to limit slew rate in S3 if S4ST# is high. Drives a P-
Channel MOSFET to connect 5VSB to 5V USB.
S4_STATE# Connect to system logic signal that enables 5V USB power in S3.
Standby Switch. Drives the P-Channel MOSFET to power 5V DUAL from 5VSB when in S3. High in
S0 and S5.
5V MAIN. When this pin is below 4.5V, transition from S3 to S0 is inhibited.
VTT remote sense input.
VTT regulator power output.
VDDQ Input from PWM. Connect to VDDQ output voltage. This is the VTT Regulator power input.
Boot. Positive supply for the upper MOSFET driver. Connect as shown in Figure 1. IC contains a boot
diode to VCC.
High-Side Drive. High-side (upper) MOSFET driver output. Connect to gate of high-side MOSFET.
Switching Node. Return for the high-side MOSFET driver and a current sense input. Connect to
source of high-side MOSFET and low-side MOSFET drain.
Current Sense Input. Monitors the voltage drop across the lower MOSFET or external sense resistor
for current feedback and current limiting.
Low-Side Drive The low-side (lower) MOSFET driver output. Connect to gate of low-side MOSFET.
Power Good Flag. An open-drain output that pulls LOW when FB is outside of a ±10% range of the
0.9V reference or the VTT output is < 80% or > 110% of its reference. PGOOD goes low when the IC
is in the S5 state. The power-good signal from the PWM regulator enables the VTT regulator.
VCC. Provides IC bias and gate drive power. The IC is held in standby until this pin is above the UVLO
threshold.
© 2006 Fairchild Semiconductor Corporation
5
FAN5078 Rev. 1.0.0 • 05/11/06
www.fairchildsemi.com