®
RT2805A
5A, 36V, 500kHz Current Mode Asynchronous Step-Down
Converter
General Description
Features
z 5A Output Current
The RT2805Ais a current mode asynchronous step-down
converter that achieves excellent load and line regulation.
Over a wide input voltage range from 5.5V to 36V and
supports output current up to 5A. The Current mode
operation provides fast transient response and eases loop
stabilization.
z Wide Operating Input Range 5.5V to 36V
z Adjustable Output Voltage from 1.222V to 26V
z High Efficiency up to 90%
z Internal Compensation Minimizes External Parts
Count
z Internal Soft-Start
An adjustable soft-start reduces the stress on the input
source at startup. In shutdown mode, the regulator draws
only 25μA of supply current. The RT2805A requires a
minimum number of readily available external
components, providing a compact solution. The RT2805A
provides protection functions inducing input under voltage
lockout, cycle-by-cycle current limit, short circuit
protection and thermal shutdown protection.
z 110mΩ Internal Power MOSFET Switch
z 25μA Shutdown Mode
z Fixed 500kHz Frequency
z Thermal Shutdown
z Cycle-by-Cycle Current Limit
z Available In an SOP8 (Exposed Pad) Package
z RoHS Compliant and Halogen Free
The RT2805A is available in the SOP-8 (Exposed Pad)
package.
Applications
z Distributive Power Systems
z Battery Charger
Ordering Information
z DSL Modems
RT2805A
z Pre-regulator for Linear Regulators
Package Type
SP : SOP-8 (Exposed Pad-Option 2)
Marking Information
Lead Plating System
G : Green (Halogen Free and Pb Free)
RT2805AGSP : Product Number
RT2805A
Note :
YMDNN : Date Code
GSPYMDNN
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.
Simplified Application Circuit
VIN
BOOT
C
BOOT
V
IN
C
IN
L1
RT2805A
SW
FB
V
OUT
D1
Chip Enable
R1
R2
C
OUT
EN
GND
Copyright 2012 Richtek Technology Corporation. All rights reserved.
©
is a registered trademark of Richtek Technology Corporation.
DS2805A-00 November 2012
www.richtek.com
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