RT8289
5A, 32V, 500kHz Step-Down Converter
General Description
The RT8289 is a step-down regulator with an internal Power
MOSFET. It achieves 5A of continuous output current over
a wide input supply range with excellent load and line
regulation. Current mode operation provides fast transient
response and eases loop stabilization.
The RT8289 prorides protections such as cycle-by-cycle
current limiting and thermal shutdown. In shutdown mode,
the regulator draws 25A of supply current.
The RT8289 requires a minimum number of external
components, to proride a compact solution.
The RT8289 is available in a SOP-8 (Exposed Pad)
package.
Features
High Output Current up to 5A
Internal Soft-Start
100mΩ Internal Power MOSFET Switch
Ω
Internal Compensation Minimizes External Parts
Count
High Efficiency up to 90%
25μA Shutdown Current
μ
Fixed 500kHz Frequency
Thermal Shutdown Protection
Cycle-by-Cycle Over Current Protection
Wide 5.5V to 32V Operating Input Range
Adjustable Output Voltage from 1.222V to 26V
Available in an SOP-8 (Exposed Pad) Package
RoHS Compliant and Halogen Free
Ordering Information
RT8289
Package Type
SP : SOP-8 (Exposed Pad-Option 1)
Lead Plating System
G : Green (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.
Applications
Distributive Power Systems
LCD TV
DSL Modems
Pre-regulator for Linear Regulators
Battery Charger
Pin Configurations
(TOP VIEW)
BOOT
NC
NC
FB
2
3
4
8
SW
VIN
GND
EN
GND
9
7
6
5
SOP-8 (Exposed Pad)
Typical Application Circuit
V
IN
5.5V to 32V
7
C
IN
4.7µF x 2
5 EN
6, Exposed Pad (9)
FB 4
R2
3.16k
VIN
BOOT
RT8289
1
C
BOOT
L
10nF 10µH
D
B550C
R1
10k
V
OUT
5V/5A
C
OUT
47µFx2
(POSCAP)
SW 8
Chip Enable
Open
= Automatic Startup
GND
DS8289-01 March 2011
www.richtek.com
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
