RT8202/A/B
1
DS8202/A/B-03 April 2010 www.richtek.com
Ordering Information
Pin Configurations
(TOP VIEW)
WQFN-16L 4x4/WQFN-16L 3x3
Note :
Richtek Pb-free and Green products are :
` RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
` Suitable for use in SnPb or Pb-free soldering processes.
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area, otherwise visit our website for detail.
Single Synchronous Buck Controller
General Description
The RT8202/A/B 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 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 RT8202/A/B 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. The buck conversion allows this device
to directly step down high voltage batteries for the highest
possible efficiency. The RT8202/A/B is intended for CPU
core, chipset, DRAM, or other low voltage supplies as
low as 0.75V. RT8202 is available in WQFN-16L 4x4,
RT8202A is available in WQFN-16L 3x3 and RT8202B is
available in WQFN-14L 3.5x3.5 packages.
Features
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Ultra-High Efficiency
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z Resistor Programmable Current Limit by Low Side
R
DS(ON)
Sense (Lossless Limit) or Sense Resistor
(High Accuracy)
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z Quick Load Step Response within 100ns
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z 1% V
OUT
Accuracy over Line and Load
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z Adjustable 0.75V to 3.3V Output Range
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z 4.5V to 26V Battery Input Range
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z Resistor Programmable Frequency
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z Over/Under Voltage Protection
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z 2 Steps Current Limit During Soft-Start
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z Drives Large Synchronous-Rectifier FETs
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z Power Good Indicator
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z RoHS Compliant and 100% Lead (Pb)-Free
Applications
z Notebook Computers
z CPU Core Supply
z Chipset/RAM Supply as Low as 0.75V
PGOOD
FB
VOUT
VDD
UGATE
PHASE
VDDP
OC
NC
PGND
GND
LGATE
TON
EN/DEM
BOOT
NC
12
11
10
9
13141516
1
2
3
4
8765
GND
17
WQFN-14L 3.5x3.5
13
12
11
10
141
2
3
4
5
87
FB
VDD
TON
VOUT
UGATE
PHASE
VDDP
OC
GND
PGND
EN/DEM
BOOT
GND
15
96
PGOOD LGATE
RT8202/A/B
Package Type
QW : WQFN-16L 4x4 (W-Type) (RT8202)
QW : WQFN-16L 3x3 (W-Type) (RT8202A)
QW : WQFN-14L 3.5x3.5 (W-Type) (RT8202B)
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
