TPS65252RHDR.B中文资料德州仪器数据手册PDF规格书

1FEATURES

• Wide Input Supply Voltage Range

(4.5 V - 16 V)

• Output Range 0.8 to ~VIN - 1 V

• Fully Integrated Dual Buck,

3.5-A/2.5-A Maximum Current,

3-A/2-A Continuous Operation

• High Efficiency

• Switching Frequency:

300 kHz - 2.2 MHz Set By External Resistor

• External Enable/Sequencing Pins

• Adjustable Cycle-By-Cycle Current Limit Set

By External Resistor

• Soft Start Pins

• Current Mode Control With Simple

Compensation Circuit

• Power Good and Reset Generator

• Low Power Mode Set By External Signal

• One Current Adjustable USB Switch With Over

Current Protection

• Supervisory Circuit

• QFN Package, 28-Pin 5 mm x 5 mm RHD

APPLICATIONS

• DTV

• DSL Modems

• Cable Modems

• Set Top Boxes

• Car DVD Players

• Home Gateway and Access Point Networks

• Wireless Routers

DESCRIPTION/ORDERING INFORMATION

The TPS65252 features two 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 5-, 9- or 12-V systems and have integrated power transistors. The output voltage

can be set externally using a resistor divider to any value between 0.8 V and the input supply minus 1 V. Each

converter features enable pin that allows a delayed start-up for sequencing purposes, soft start pin that allows

adjustable soft-start time by choosing the soft-start capacitor, and a current limit (RLIMx) pin that enables

designer to adjust current limit by selecting an external resistor and optimize the choice of inductor. The COMP

pin allows optimizing transient versus dc accuracy response with a simple RC compensation.

The switching frequency of the converters can be set with an external resistor connected to ROSC pin. The

switching regulators are designed to operate from 300 kHz to 2.2 MHz. The converters operate with 180° phase

between them to minimize the input filter requirements.

TPS65252 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.

The USB switch provides up to 1-A of current as required by downstream USB devices. When the output load

exceeds the current-limit threshold selected with an external resistor or a short is present, the PMU limits the

output current to a safe level by switching into a constant-current mode and pulling the over current logic output

low. When continuous heavy overloads and short-circuits increase the power dissipation in the switch, causing

the junction temperature to rise, a thermal protection circuit shuts off the switch to allow continuous noninterrupted

operation the buck converters.

The TPS65252 features a supervisor circuit that monitors both converters and provides a PGOOD signal (End of

Reset) with a 256-ms timer.

TPS65252 is packaged in a small, thermally efficient 28-pin QFN package.