Step-Down Converter. RT2853B Datasheet


RT2853B Converter. Datasheet pdf. Equivalent


Part Number

RT2853B

Description

Synchronous Step-Down Converter

Manufacture

Richtek

Total Page 23 Pages
Datasheet
Download RT2853B Datasheet


RT2853B
®
RT2853A/B
3A, 18V, 650kHz, ACOTTM Synchronous Step-Down Converter
General Description
The RT2853A/B are high-performance 650kHz 3A step-
down regulators with internal power switches and
synchronous rectifiers. They feature quick transient
response using their Advanced Constant On-Time
(ACOTTM) control architecture that provides stable
operation with small ceramic output capacitors and without
complicated external compensation, among other benefits.
The input voltage range is from 4.5V to 18V and the output
is adjustable from 0.765V to 7V.
The proprietary ACOTTM control improves upon other fast-
response constant on-time architectures, achieving nearly
constant switching frequency over line, load, and output
voltage ranges. Since there is no internal clock, response
to transients is nearly instantaneous and inductor current
can ramp quickly to maintain output regulation without
large bulk output capacitance. The RT2853A/B are stable
with and optimized for ceramic output capacitors.
With internal 110mΩ switches and 30mΩ synchronous
rectifiers, the RT2853A/B display excellent efficiency and
good behavior across a range of applications, especially
for low output voltages and low duty cycles. Cycle-by-
cycle current limit, input under-voltage lock-out, externally-
adjustable soft-start, output under- and over-voltage
protection, and thermal shutdown provide safe and smooth
operation in all operating conditions.
The RT2853A and RT2853B are each available in
WQFN-16L 3x3 package, with exposed thermal pads.
Simplified Application Circuit
Features
z Fast Transient Response
z Steady 650kHz Switching Frequency
z Enhanced Efficiency at Light Load (RT2853A)
z Advanced Constant On-Time (ACOTTM) Control
z Optimized for Ceramic Output Capacitors
z 4.5V to 18V Input Voltage Range
z Internal 110mΩ Switch and 30mΩ Synchronous
Rectifier
z 0.765V to 7V Adjustable Output Voltage
z Externally-adjustable, Pre-biased Compatible Soft-
Start
z Cycle-by-Cycle Current Limit
z Optional Output Discharge Function
z Output Over- and Under-voltage Shut-down
` Latched (RT2853ALGQW/RT2853BLGQW Only)
` With Hiccup Mode (RT2853AHGQW/
RT2853BHGQW Only)
Applications
z Industrial and Commercial Low Power Systems
z Computer Peripherals
z LCD Monitors and TVs
z Point of Load Regulation for High-Performance DSPs,
FPGAs, and ASICs
Fast-Transient Response
RT2853B
VOUT
(50mV/Div)
VIN
Power Good
VREG5
Input Signal
RT2853A/B
VIN SW
VCC
BOOT
PGOOD
VS
EN FB
SS VREG5
GND PGND
VOUT
IOUT
(1A/Div)
VIN = 12V, VOUT = 1.05V, IOUT = 0 to 3A
Time (100μs/Div)
Copyright ©2013 Richtek Technology Corporation. All rights reserved.
DS2853A/B-01 July 2013
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
1

RT2853B
RT2853A/B
Ordering Information
Pin Configurations
RT2853A/B
(TOP VIEW)
Package Type
QW : WQFN-16L 3x3 (W-Type)
Lead Plating System
G : Green (Halogen Free and Pb Free)
H : Hiccup Mode OVP & UVP
L : Latched OVP & UVP
A : Enhanced Light Load Efficiency
B : Continuous Switching Mode
16 15 14 13
FB
VREG5
SS
GND
1
2
3
4
GND
17
12 BOOT
11 SW
10 SW
9 SW
5 678
Note :
Richtek products are :
` RoHS compliant and compatible with the current require-
WQFN-16L 3x3
ments of IPC/JEDEC J-STD-020.
` Suitable for use in SnPb or Pb-free soldering processes.
Marking Information
RT2853AHGQW
2K=YM
DNN
2K= : Product Code
YMDNN : Date Code
RT2853BHGQW
2H=YM
DNN
2H= : Product Code
YMDNN : Date Code
RT2853ALGQW
2J=YM
DNN
2J= : Product Code
YMDNN : Date Code
RT2853BLGQW
2G=YM
DNN
2G= : Product Code
YMDNN : Date Code
Copyright ©2013 Richtek Technology Corporation. All rights reserved.
www.richtek.com
2
is a registered trademark of Richtek Technology Corporation.
DS2853A/B-01 July 2013


Features ® RT2853A/B 3A, 18V, 650kHz, ACOTTM Sy nchronous Step-Down Converter General Description The RT2853A/B are high-perf ormance 650kHz 3A stepdown regulators w ith internal power switches and synchro nous rectifiers. They feature quick tra nsient response using their Advanced Co nstant On-Time (ACOTTM) control archite cture that provides stable operation wi th small ceramic output capacitors and without complicated external compensati on, among other benefits. The input vol tage range is from 4.5V to 18V and the output is adjustable from 0.765V to 7V. The proprietary ACOTTM control improve s upon other fastresponse constant on-t ime architectures, achieving nearly con stant switching frequency over line, lo ad, and output voltage ranges. Since th ere is no internal clock, response to t ransients is nearly instantaneous and i nductor current can ramp quickly to mai ntain output regulation without large b ulk output capacitance. The RT2853A/B a re stable with and optimized for ceramic output capacitors. With.
Keywords RT2853B, datasheet, pdf, Richtek, Synchronous, Step-Down, Converter, T2853B, 2853B, 853B, RT2853, RT285, RT28, Equivalent, stock, pinout, distributor, price, schematic, inventory, databook, Electronic, Components, Parameters, parts, cross reference, chip, Semiconductor, circuit, Electric, manual, substitute




@ 2014 :: Datasheetspdf.com :: Semiconductors datasheet search & download site (Privacy Policy & Contact)