PWM Controller. RT8228B Datasheet


RT8228B Controller. Datasheet pdf. Equivalent


Part Number

RT8228B

Description

Single Synchronous Buck PWM Controller

Manufacture

Richtek

Total Page 15 Pages
Datasheet
Download RT8228B Datasheet


RT8228B
®
RT8228B
Single Synchronous Buck PWM Controller
General Description
The RT8228B 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-onresponse to load transients while maintaining
a relatively constant switching frequency.
The RT8228B 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 RT8228B is intended for CPU core,
chipset, DRAM, or other low voltage supplies as low as
0.5V. The RT8228B is available in a WQFN-12L 2x2
package.
Ordering Information
RT8228B
Package Type
QW : WQFN-12L 2x2 (W-Type)
Lead Plating System
G : Green (Halogen Free and Pb Free)
Z : ECO (Ecological Element with
Halogen Free and Pb free)
Note :
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.
Features
z Built in 1% 0.5V Reference Voltage
z Adjustable 0.5V to 3.3V Output Range
z Support Pure MLCC Output Capacitor
z Quick Load Step Response within 100ns
z 4700ppm/°C Programmable Current Limit by Low
Side RDS(ON) Sensing
z 4.5V to 26V Battery Input Range
z Resistor Programmable Frequency
z Internal Ramp Current Limit Soft-Start Control
z Drives Large Synchronous Rectifier FETs
z Integrated Boost Switch
z Over/Under Voltage Protection
z Thermal Shutdown
z Power Good Indicator
z RoHS Compliant and Halogen Free
Applications
z Notebook Computers
z CPU Core Supply
z Chipset/RAM Supply as Low as 0.5V
z Generic DC/DC Power Regulator
Pin Configurations
(TOP VIEW)
12 11 10
LGATE
PHASE
UGATE
1
2
3
GND
13
9 PGOOD
8 EN
7 MODE
4 56
WQFN-12L 2x2
Copyright ©2014 Richtek Technology Corporation. All rights reserved.
DS8228B-06 January 2014
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
1

RT8228B
RT8228B
Marking Information
RT8228BGQW
44 : Product Code
44W
W : Date Code
RT8228BZQW
44 : Product Code
44W
W : Date Code
Typical Application Circuit
VDDP
R2
100k
PGOOD
Chip Enable
RTON
360k
11
TON
RT8228B
BOOT 4
5 VCC
C2
4.7µF
UGATE 3
PHASE 2
LGATE 1
R4
0
R5
0
VIN
4.5V to 26V
C4
10µF
C3
0.1µF
Q1 L1
1µH
Q2 R7*
9 PGOOD
10 CS
R6
8 EN
FB 6
MODE 7
To 5V : DEM
To GND : FCCM
GND 12, 13 (Exposed Pad)
C7*
* : Optional
C5* C6*
R8
10k
C1
22µF
C8
22µF
VOUT
1V
C9 C10
22µF 22µF
R9
10k
Copyright ©2014 Richtek Technology Corporation. All rights reserved.
www.richtek.com
2
is a registered trademark of Richtek Technology Corporation.
RT8228B-06 January 2014


Features ® RT8228B Single Synchronous Buck PWM Controller General Description The RT8 228B PWM controller provides high effic iency, excellent transient response, an d high DC output accuracy needed for st epping down high voltage batteries to g enerate low voltage CPU core, I/O, and chipset RAM supplies in notebook comput ers. The constant on-time PWM control s cheme handles wide input/output voltage ratios with ease and provides 100ns instant-on” response to load transie nts while maintaining a relatively cons tant switching frequency. The RT8228B a chieves high efficiency at a reduced co st by eliminating the current sense res istor found in traditional current mode PWMs. Efficiency is further enhanced b y its ability to drive very large synch ronous rectifier MOSFETs and enter diod e emulation mode at light load conditio n. The buck conversion allows this devi ce to directly step down high voltage b atteries at the highest possible effici ency. The RT8228B is intended for CPU core, chipset, DRAM, or other .
Keywords RT8228B, datasheet, pdf, Richtek, Single, Synchronous, Buck, PWM, Controller, T8228B, 8228B, 228B, RT8228, RT822, RT82, 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)