5A, 18V, 650kHz, ACOTTM Synchronous Step-Down Converter
The RT7235/36/39/40 is a synchronous step-down DC/
DC converter with Advanced Constant On-Time (ACOTTM)
mode control. It achieves high power density to deliver up
to 5A output current from a 4.5V to 18V input supply. The
proprietary ACOTTM 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, RT7235/36/39/40 keeps an excellent constant
switching frequency under line and load variation and the
integrated synchronous power switches with the ACOTTM
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 include
thermal shutdown for RT7235/36/39/40, output Under
Voltage Protection (UVP) / Over Voltage Protection (OVP)
for RT7235/36. When the UVP/OVP is triggered, the device
will enter latch mode for TSSOP-14 (Exposed Pad), and
hiccup mode for WDFN-10L 3x3.
The RT7235/36 are available in TSSOP-14 (Exposed Pad)
and WDFN-10L 3x3 packages, and the RT7235 is operated
in forced continuous conduction mode.
The RT7239/40 are available in the SOP-8 (Exposed Pad)
package, and the RT7239 is operated in forced continuous
z ACOTTM Mode Enables Fast Transient Response
z 4.5V to 18V Input Voltage Range
z 5A Output Current
z 35mΩ Internal Low Site N-MOSFET
z Advanced Constant On-Time Control
z Support All Ceramic Capacitors
z Up to 95% Efficiency
z 650kHz Switching Frequency at all Load Current
z Discontinuous Operating Mode at Light Load
z Adjustable Output Voltage from 0.765V to 8V
z Adjustable Soft-Start
z Cycle-by-Cycle Current Limit
z Input Under Voltage Lockout
z Thermal Shutdown
z RoHS Compliant and Halogen Free
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
* : VCC pin for TSSOP-14 (Exposed Pad) only.
VS pin for TSSOP-14 (Exposed Pad) only.
GND pin for TSSOP-14 (Exposed Pad) only.
PGOOD pin for TSSOP-14 (Exposed Pad) and WDFN-10L 3x3 only.
Copyright ©2013 Richtek Technology Corporation. All rights reserved.
DS7235/36/39/40-00 March 2013
is a registered trademark of Richtek Technology Corporation.
Free Datasheet http://www.datasheet4u.com/