RT8270 Datasheet, PDF (1/12 Pages) Richtek Technology Corporation – 2A, 22V, 1.2MHz Step-Down Converter

RT8270
2A, 22V, 1.2MHz Step-Down Converter
General Description
The RT8270 is an asynchronous 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 25μA of supply
current. The RT8270 is available in a SOP-8 surface mount
package.
Ordering Information
RT8270
Package Type
S : SOP-8
Note :
Lead Plating System
G : Green (Halogen Free and Pb Free)
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.
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area, otherwise visit our website for detail.
Features
z Wide Operating Input Range : 4.75V to 22V
z Adjustable Output Voltage Range : 1.222V to 16V
z Output Current up to 2A
z 25μA Low Shutdown Current
z Power MOSFET : 0.18Ω
z High Efficiency up to 95%
z 1.2MHz 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)
BOOT
VIN
2
SW
3
GND
4
8
NC
7
EN
6
COMP
5
FB
SOP-8
Typical Application Circuit
V_IN
4.75V to 22V
Chip Enable
C_IN
10µF
2 _VIN
BOOT ¹
RT8270
SW ³
7 _EN
FB ⁵
4 _GND
COMP ⁶
C_B
L1
10nF 4.7µH
D1
B330
R1
17k
R_C
18k
C_C
1.8nF
R2
10k
V_OUT
3.3V/2A
C_OUT
22µF
C_P
NC
DS8270-01 March 2011
www.richtek.com
1