EVB_RT7273GQW: 1.2V @ 3.5A, 1.8V and 3.3V @ 2.5A, 4.5 ~ 18V in

Summary

The RT7273 features three synchronous wide input range high efficiency Buck converters. The converters are designed to simplify its application while giving the designer the option to optimize their usage according to the target application. The converters can operate in 5V, 9V or 12V systems and have integrated power transistors. The output voltage can be set externally using a resistor divider to any value between 0.8V and the input supply minus 1V.

Each converter features an enable pin that allows a delayed start-up for sequencing purposes, a soft-start pin that allows adjustable soft-start time by choosing the softstart capacitor, and a current limit pin (RLIMx) to adjust current limit by selecting an external resistor. The COMP pin allows optimizing transient versus dc accuracy response with a simple RC compensation.

The switching frequency of the converters can either be set with an external resistor connected to ROSC pin or be synchronized to an external clock connected to SYNC pin if needed. The switching converters are designed to operate from 300kHz to 2.2MHz. The converters operate with 180° phase between CH 1 and CH 2, CH 3 (CH 2 and CH 3 ran in phase) to minimize the input filter requirements. The RT7273 also features a low power mode enabled by an external signal, which allows for a reduction on the input power supplied to the system when the host processor is in stand-by (low activity) mode.

Features:

Wide Input Supply Voltage Range : 4.5V to 18V
Output Range : 0.8V to (VIN @ 1V)
Maximum Current 3.5A/2.5A/2.5A
Continuous Operation 3A/2A/2A
Current Mode Control with Simple Compensation Circuit

Specifications

Manufacturer	Richtek USA Inc.
Category	AC/DC and DC/DC Conversion
Sub-Category	DC/DC SMPS - Multi Output
Eval Board Part Number	EVB_RT7273GQW-ND
Eval Board Supplier	Richtek USA Inc.
Eval Board	Board not Stocked
Topology	Step Down
Outputs and Type	3 Non-Isolated
Voltage Out: Highest Current First	1.2V, 1.8V, 3.3V
Current Out	3.5A, 2.5A, 2.5A
Voltage In	4.5 ~ 18 V
Efficiency @ Conditions	>90%, 12V in, 3.3V @ 0.5 ~ 2 A >85%, 12V in, 1.8V @ 0.5 ~ 1.5 A >80%, 12V in, 1.2V @ 0.5 ~ 2 A
Voltage Out Range	0.8 ~ Vin (-1V)
Features	Current Limit (Adj. or Fixed) Light Load Mode Power Good Output Shutdown, Enable, Standby Soft Start Synchronizable
Switching Frequency	300 kHz ~ 2.5 MHz
Standby Current [Typical]	1.3 mA
Quiescent Current [Typical]	20 mA
Component Count + Extras	50 + 37
Internal Switch	Yes
Design Author	Richtek USA Inc.
Application / Target Market	Automotive DVD/Blu-ray Players Security IP Camera Set-Top Boxes
Standby Current [Maximum]	- Not Given
Quiescent Current [Maximum]	- Not Given
Main I.C. Base Part	RT7273
Date Created By Author	2016-04
Date Added To Library	2019-04