RT7274 Datasheet, PDF (1/22 Pages) Richtek Technology Corporation – 2A, 18V, 700kHz ACOTTM Synchronous Step-Down Converter

®
RT7274/79/80/81
2A, 18V, 700kHz ACOT^TM Synchronous Step-Down Converter
General Description
The RT7274/79/80/81 is a synchronous step-down DC/
DC converter with Advanced Constant On-Time (ACOT^TM)
mode control. It achieves high power density to deliver up
to 2A output current from a 4.5V to 18V input supply. The
proprietary ACOT^TM mode offers an optimal transient
response over a wide range of loads and all kinds of ceramic
capacitors, which allows the device to adopt very low ESR
output capacitor for ensuring performance stabilization. In
addition, RT7274/79/80/81 keeps an excellent constant
switching frequency under line and load variation and the
integrated synchronous power switches with the ACOT^TM
mode operation provides high efficiency in whole output
current load range. Cycle-by-cycle current limit provides
an accurate protection by a valley detection of low side
MOSFET and external soft-start setting eliminates input
current surge during startup. Protection functions indude
thermal shutdown for RT7274/79/80/81; output under
voltage protection and output over voltage protection for
RT7279/80 only.
Features
z ACOT^TM Mode Enables Fast Transient Response
z 4.5V to 18V Input Voltage Range
z 2A Output Current
z High Efficient Internal N-MOSFET Optimized for
Lower Duty Cycle Applications
z 105mΩ Internal Low Side N-MOSFET
z Advanced Constant On-Time Control
z Allows Ceramic Output Capacitor
z 700kHz Switching Frequency
z Adjustable Output Voltage from 0.765V to 8V
z Adjustable and Pre-biased Soft-Start
z Cycle-by-Cycle Current Limit
z Input Under Voltage Lockout
z Thermal Shutdown
z RoHS Compliant and Halogen Free
Applications
z Industrial and Commercial Low Power Systems
z Computer Peripherals
z LCD Monitors and TVs
z Green Electronics/Appliances
z Point of Load Regulation for High-Performance DSPs,
FPGAs, and ASICs
Simplified Application Circuit
V_IN
Input Signal
Power Good
RT7274/79/80/81
VIN
SW
VINR*
EN
BOOT
FB
GND
PGOOD*
PVCC VOUT*
SS
PGND*
V_OUT
* : VINR pin for TSSOP-14 (Exposed Pad) only.
VOUT pin for TSSOP-14 (Exposed Pad) only.
PGND pin for TSSOP-14 (Exposed Pad) only.
PGOOD pin for TSSOP-14 (Exposed Pad) only.
Copyright ©2013 Richtek Technology Corporation. All rights reserved.
DS7274/79/80/81-01 February 2013
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
1