RT8208BGQW Datasheet, PDF (1/18 Pages) Richtek Technology Corporation – Resistor Programmable Output Voltage from 0.75V to 3.3V with Integrated Transition Support

RT8208A/B
Programmable Output Voltage Single Synchronous
Buck Controller
General Description
The RT8208A/B is a constant-on-time PWM controller
which provides four resistor programmable DC output
voltages by controlling the G0 and G1 digital input. The
output voltage is programmable from 0.75V to 3.3V. The
RT8208A/B offers the lowest total solution cost in systems
where need output voltage slewing. The RT8208A/B
provides an automatic masking power good output during
output voltage transition.
The constant-on-time PWM control scheme handles wide
input/output ratios with ease and provides 100ns “instant-
on” response to load transient while maintaining a
relatively constant frequency. It provides the high efficiency,
excellent transient response, and DC output accuracy
needed for stepping down high voltage batteries to
generate low voltage CPU core, graphics, I/O and chipset
RAM supplies in notebook computers.
The RT8208A/B achieves high efficiency at a reduced cost
by eliminating the current sense resistor 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 from high voltage batteries for the highest
possible efficiency. Additional features include soft-start,
under voltage protection, programmable over current
protection and non-overlapping gate drive. The RT8208A/
B is available in a WQFN-16L 3x3 package.
Pin Configurations
(TOP VIEW)
16 15 14 13
VOUT 1
VDD 2
FB 3
PGOOD 4
GND
17
12 UGATE
11 PHASE
10 CS
9 VDDP
5 678
WQFN-16L 3x3
Features
z Ultra-High Efficiency
z Resistor Programmable Output Voltage from 0.75V
to 3.3V with Integrated Transition Support
z Quick Load Step Response within 100ns
z 1% V_FB Accuracy over Line and Load
z 4.5V to 26V Battery Input Range
z Resistor Programmable Frequency
z Integrated Bootstrap Switch
z Resistor Programmable Positive Current Limit by
Low Side R_DS(ON) Sense (Lossless Limit)
z Negative Current Limiter
z Voltage Transient Overshoot Eliminator*
z Over Voltage Protection
z Under Voltage Protection
z 4 Steps Current Limit During Soft-Start
z Power Good Indicator
z RoHS Compliant and Halogen Free
* Paten Pending
Applications
z Notebook Computers
z System Power Supplies
z I/O Supplies
z Programmable-Output Power Supplies
Ordering Information
RT8208
Package Type
QW : WQFN-16L 3x3 (W-Type)
Lead Plating System
G : Green (Halogen Free and Pb Free)
Z : ECO (Ecological Element with
Halogen Free and Pb free)
Note :
Turn-on D0/D1 MOSFET
A : G0/G1 High
B : G0/G1 Low
Richtek 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.
DS8208A/B-04 May 2011
www.richtek.com
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