®
RT6541A
High Efficiency Single Synchronous Buck PWM Controller
General Description
The RT6541A PWM controller provides high efficiency,
excellent transient response, and high DC 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 RT6541A supports on chip voltage programming
function between 0.8V and 1.05V by controlling GX digital
inputs.
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.
The RT6541A 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 and enter diode emulation mode at
light load condition. The buck conversion allows this device
to directly step down high voltage batteries at the highest
possible efficiency. The RT6541A is intended for CPU core,
chipset, DRAM, or other low voltage supplies as low as
0.8V.
The RT6541A is available in a WDFN-14L 3x2 package.
Features
Intel SKL VR support
Built-in 1% Reference Voltage
2-Bit Programmable Output Voltage with Integrated
Transition Support
Support Intel LPM (Low-Power Mode) Feature
°
4700ppm/°C Programmable Current Limit by Low-
Side R
DS(ON)
Sensing
3V to 26V Battery Input Range
Internal Voltage Ramp Soft-Start Control
Drives Large Synchronous Rectifier FETs
Integrated Boost Switch
Over/Under-Voltage Protection
Thermal Shutdown
Power Good Indicator
RoHS Compliant and Halogen Free
Tiny 14-Lead WDFN Package
Applications
Notebook Computers
CPU/GPU Core Supply
Chipset/RAM Supply
Generic DC-DC Power Regulator
Simplified Application Circuit
RT6541A
V
CC
C
BYPASS
V
IN
VCC
UGATE
BOOT
R4
R3
Q1
C
IN
R2
C1
PGOOD
PHASE
EN
R
CS
L
OUT
V
OUT
R5*
Q2
C2*
C
OUT
LGATE
LPM
RGND
FB
G0
G1
CS
GND
MODE
Copyright
©
2019 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS6541A-02
September 2019
www.richtek.com
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
