RT8259A Datasheet, PDF (1/11 Pages) Richtek Technology Corporation – The RT8259A is a monolithic step-down switch mode

RT8259A
1.5A, 24V, 1.4MHz Step-Down Converter
General Description
The RT8259A is a monolithic step-down switch mode
converter with a built-in power MOSFET. It achieves 1.5A
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
chip also provides protection functions such as cycle-by-
cycle current limiting and thermal shutdown protection.
Ordering Information
RT8259A
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.
Typical Application Circuit
Features
z 1.5A Output Current
z 0.3Ω Internal Power MOSFET Switch
z Stable with Low ESR Output Ceramic Capacitors
z Up to 92% Efficiency
z Fixed 1.4MHz Frequency
z Thermal Shutdown
z Cycle-By-Cycle Over Current Protection
z Wide 4.5V to 24V Operating Input Range
z Output Adjustable from 0.8V to 15V
z Available in SOP-8 Package
z RoHS Compliant and Halogen Free
Applications
z Distributed Power Systems
z Battery Charger
z Pre-Regulator for Linear Regulators
z WLEDDrivers
Pin Configurations
(TOP VIEW)
PHASE
VIN
2
NC
3
EN
4
8 BOOT
7 NC
6 GND
5 FB
SOP-8
4.5VVt^Io^N5.5V
1N4148
2 _{VIN BOOT} 8
C1
10µF/25V
RT8259A
PHASE ¹
Chip Enable _{4 EN}
Open =
Automatic Startup
GND
6
FB ⁵
CB L1
10nF 4.7µH
D1
B230A
V_OUT
3.3V
R1
49.9k
R2
16k
C2
22µF
6.3V
V_IN
5.5V to 24V
2 _{VIN BOOT} 8
C1
10µF/25V
RT8259A
PHASE ¹
Chip Enable _{4 EN}
Open =
Automatic Startup
GND
6
FB ⁵
CB L1
10nF 4.7µH
D1
B230A
V_OUT
3.3V
R1
49.9k
R2
16k
C2
22µF
6.3V
Figure 1. Input Voltage 4.5V to 5.5V
Figure 2. Input Voltage 5.5V to 24V
DS8259A-02 March 2011
www.richtek.com
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