APW8871 Datasheet, PDF (9/27 Pages) Anpec Electronics Coropration – DDR4 TOTAL POWER SOLUTION (VPP/VDDQ/VTT) SYNCHRONOUS DC/DC CONVERTER for NB/MB

APW8871
SMBus Serial Control Port Operation(cont.)
SMC
VI
H
V_IL
tLOW tR
SMV_ID
H
VIL
tHD_STA
tBUF
P
S
tHD_DAT
t_F
tHIGH
tSU_STA
tS U_ DAT
S
Figure1. SMCand SMD Timing
tSU _ STO
P
Pin Description
NO.
1
2
3
4
5
6
7, 8
9 ~12
13~15
16
17
18
19
20
21
22
23
24
25
26
NAME
PMAX
FB2
SMD
SMC
VCC
PVCC
LX2
VIN
LX1
PGND
BOOT
LDOIN
VDDQSNS
VTTREF
VTT
VTTSNS
AGND
S5
S3
POK
FUNCTION
Open drain indicator. When total power is larger than setting values, then this pin will assert to PCH
or CPU.
VPP PWM output voltage feedback pin. This pin is connected the resistor divider to set the desired
output voltage.
Serial data. This pin must be connected to AGND if not used.
Serial clock. This pin must be connected to AGND if not used.
Filtered 5V power supply input for internal control circuitry.
VPP Power input stage pin. This pin supply voltage for internal high side power MOSFET.
VPP Junction point of the high-side MOSFET Source, output filter inductor and the low-side
MOSFET Drain for VPP PWM Converter.
VDDQ Power input stage pin. This pin supply voltage for internal high side power MOSFET.
Junction point of the high-side MOSFET Source, output filter inductor and the low-side MOSFET
Drain for VDDQ PWM Converter.
Power ground for internal low side power MOSFET source.
Supply Input for the internal UGATE gate driver and an internal level-shift circuit. Connect to an
external capacitor and diode to create a boosted voltage suitable to drive an internal logic-level
N-channel MOSFET.
Supply voltage input for the VTT LDO.
Reference input for VTT and VTTREF. Power supply for the VTTREF. Discharge current sinking
terminal for VDDQ discharge. Output voltage feedback input for VDDQ output if VDDQSET pin is
connected to VCC or GND.
VTTREF buffered reference output.
Power output for the VTT LDO.
Voltage sense input for the VTT LDO. Connect to plus terminal of the VTT LDO output capacitor.
Signal ground for PWM controller and VTT LDO.
S5 signal input.
S3 signal input.
Power-okay output pin. POK is an open drain output used to Indicate the status of the output
voltage. When VDDQ/VPP output voltage is within the target range, it is in high state.
C opyright © ANPEC Electronics C orp.
9
Rev. A.1 - Sep., 2015
www.anpec.com.tw