Document
NCP81172
2-Phase Synchronous Buck
Controller with Integrated
Gate Drivers and PWM VID
Interface
The NCP81172, a general−purpose two−phase synchronous buck controller, integrates gate drivers and PWM VID interface in a QFN−24 package and provides a compact−footprint power management solution for new generation computing processors. It receives power save command (PSI) from processors and operates in 1−phase diode emulation mode to obtain high efficiency in light−load condition. Operating in high switching frequency up to 800 kHz allows employing small size inductor and capacitors. The part is able to support all−ceramic−capacitor applications.
Features
4.5 V to 24 V Input Voltage Range Output Voltage up to 2.0 V with PWM VID Interface Differential Output Voltage Sense Integrated Gate Drivers 200 kHz ~ 800 kHz Switching Frequency Power Saving Interface (PSI) Power Good Output Programmable Over Current Protection Over Voltage Protection Under Voltage Protection Temperature Sense and Alert Output Thermal Shutdown Protection QFN−24, 4 x 4 mm, 0.5 mm Pitch Package This is a Pb−Free Device
Typical Applications
GPU and CPU Power Graphics Card Applications Desktop and Notebook Applications
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1 24 QFN24 CASE 485L
MARKING DIAGRAM
81172 ALYWG
G
81172 A L Y W
G
= Specific Device Code = Assembly Location = Wafer Lot = Year = Work Week
= Pb−Free Package
PINOUT
18 17 16 15 14 13
BST2 HG2 PGOOD VCC TALERT# TSNS
19 PH2 20 LG2 21 PVCC 22 PGND 23 LG1 24 PH1
25 GND
COMP 12 FB 11
FBRTN 10 FS 9
VREF 8 REFIN 7
BST1 HG1 EN PSI VID VIDBUF
123456
(Top View)
ORDERING INFORMATION
Device
Package
Shipping†
NCP81172MNTXG QFN24 (Pb−Free)
4000 / Tape & Reel
†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specification Brochure, BRD8011/D.
Semiconductor Components Industries, LLC, 2013
April, 2013 − Rev. 1
1
Publication Order Number: NCP81172/D
NCP81172
+5 V
+3.3 V
EN PSI
PG TALT VID
15 VCC
PVCC 21
25 GND
PGND 22
3 EN
4 PSI
16 PGOOD 14 TALERT#
NCP81172
5 VID
13 TSNS
HG1 2 BST1 1
PH1 24 LG1 23
HG2 17 BST2 18
PH2 19 LG2 20
8 VREF 7 REFIN 6 VIDBUF 9 FS
FBRTN 10 FB 11
COMP 12
+5 V VIN
VIN
Figure 1. Typical Application Circuit with PWM−VID Interface
VOUT
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NCP81172
+5 V
+3.3 V
EN PSI
PG TALT
15 VCC
PVCC 21
25 GND
PGND 22
3 EN
4 PSI
16 PGOOD 14 TALERT#
NCP81172
5 VID
13 TSNS
HG1 2 BST1 1
PH1 24 LG1 23
HG2 17 BST2 18
PH2 19 LG2 20
8 VREF 7 REFIN 6 VIDBUF 9 FS
FBRTN 10 FB 11
COMP 12
+5 V VIN
VIN
Figure 2. Typical Application Circuit without PWM−VID Interface
VOUT
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NCP81172
15 VCC 3 EN 16 PGOOD
UVLO &
PGOOD
13 TSNS Thermal
14 TALERT# Management
FAULT
PWM1
Gate Drive 1
4 PSI
PSI Control
9 FS
Ramp Generator
VREF 8
Reference Voltage
5 VID
6 VIDBUF
7 REFIN
11 FB
10 FBRTN
25 GND
12 COMP
RAMP1 PH1 RAMP2
2/1 Phase PWM Control &
Protections (.