RT8256 Datasheet, PDF (1/12 Pages) Richtek Technology Corporation – 2A, 22V, 400kHz Step-Down Converter

RT8256
2A, 22V, 400kHz Step-Down Converter
General Description
The RT8256 is an as high voltage buck converter that can
support the input voltage range from 4.75V to 22V and the
output current can be up to 2A. Current Mode operation
provides fast transient response and eases loop
stabilization.
The chip provides protection functions such as cycle-by-
cycle current limiting and thermal shutdown protection.
In shutdown mode, the regulator draws 25uA of supply
current. The RT8256 is available in a SOP-8 surface mount
package.
Ordering Information
RT8256
Package Type
S : SOP-8
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.
Typical Application Circuit
Features
z Wide Operating Input Range : 4.75V to 22V
z Adjustable Output Voltage Range : 1.22V to 16V
z Output Current up to 2A
z 25uA Low Shutdown Current
z Power MOSFET : 0.18Ω
z High Efficiency up to 95%
z 400kHz Fixed Switching Frequency
z Stable with Low ESR Output Ceramic Capacitors
z Thermal Shutdown Protection
z Cycle-By-Cycle Over Current Protection
z RoHS Compliant and Halogen Free
Applications
z Distributive Power Systems
z Battery Charger
z DSL Modems
z Pre-regulator for Linear Regulators
Pin Configurations
(TOP VIEW)
NC
BOOT 2
VIN
3
SW
4
8
EN
7 COMP
6
FB
5
GND
SOP-8
V_IN
4.75V to 22V
Chip Enable
C_IN
10µF
3 _VIN
BOOT ²
RT8256
SW ⁴
8 _EN
FB ⁶
5 _GND
COMP ⁷
C_B
L1
10nF 15µH
D1
B230
R1
17k
R_C
10k
C_C
1.5nF
R2
10k
V_OUT
3.3V/2A
C_OUT
22µF
C_P
NC
DS8256-01 March 2011
www.richtek.com
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