®
RT8126A/B/C
High Efficiency Single Synchronous Buck PWM Controller
General Description
Features
VCC Input Range : 4.5V to 13.2V
VOUT Operating Range : 0.6V to 5V
Power Stage Input Range : 2.5V to 24V
Shutdown Current <10μA
Operating Frequency : Fixed 300kHz
Diode Emulation Mode (RT8126A)
Audio Skipping Mode (RT8126B)
VIN Detection
The RT8126A/B/C PWM controller provides high efficiency,
excellent transient response, and highDC output accuracy
needed for stepping down high voltage batteries to
generate low voltage CPU core, I/O, and chipset RAM
supplies in notebook computers.
The constant on-time PWM control scheme handles wide
input/output voltage ratios with ease and provides 100ns
“instant-on” response to load transients while maintaining
a relatively constant switching frequency.
Pinless LGATE Over Current Setting (LGOCS)
Power Good Indication
The RT8126A/B/C achieves high efficiency at a reduced
cost by eliminating the current sense resistor found in
traditional current mode PWMs. Efficiency is further
enhanced by its ability to drive very large synchronous
rectifier MOSFETs. To eliminate noise in audio
applications, the RT8126B providesAudio-Skipping mode,
which maintains the switching frequency above 25kHz.
The buck conversion allows this device to directly step
down high voltage batteries at the highest possible
efficiency. The RT8126A/B/C is intended for CPU core,
chipset, DRAM, or other low voltage supplies as low as
0.6V.
Embedded Bootstrap Switch
Current Limit with Low Side Current Sense Scheme
1% High Accuracy Internal VREF = 0.6V
Enable Function
Differential Output Sense
OVP/UVP/OTP/Pre-OVP/OCP
Applications
Chipset/RAM Supply as Low as 0.6V
GenericDC/DC Power Regulator
Simplified Application Circuit
V
IN
RT8126A/B/C
VCC
UGATE
BOOT
VCC
V
OUT
4.7µF
PHASE
100k
LGATE/
OCSET
5V
PGOOD
EN
PGOOD
FB
Load
Enable
GND
FBG
Copyright 2017 Richtek Technology Corporation. All rights reserved.
©
is a registered trademark of Richtek Technology Corporation.
DS8126A/B/C-02 July 2017
www.richtek.com
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