原标题：ST L6738单相降压电源转换解决方案

　　ST公司的L6738是集成了大电流驱动器的单相降压电源控制器,VIN输入电压可低至1.5V,电源电压从5V到12V,轻负载效率优化,集成了0.8V基准电压,输出电压精度±0.5%,主要用在存储器和终端电源,子系统电源(MCH, IOCH, PCI),CPU和DSP电源,分布式电源和通用DC/DC转换器.本文介绍了L6738主要特性,框图,典型应用电路以及评估板STEVAL-ISA075V1主要特性,电路图和材料清单.

　　The L6738 is a single-phase step-down controller with integrated high-current drivers that provides complete control logic and protection to realize a DC-DC converter.

　　The device flexibility allows the management of conversions with power input VIN as low as 1.5 V and the device supply voltage ranging from 5 V to 12 V bus.

　　The L6738 features a proprietary algorithm that allows light-load efficiency optimization, boosting efficiency without compromising the output voltage ripple.

　　The integrated 0.8 V reference allows the generation of output voltages with ±0.5% accuracy over line and temperature variations.

　　The oscillator is programmable up to 600 kHz. The L6738 provides a programmable dual-level overcurrent protection and overvoltage protection. The current information is monitored across the inductor DCR.

　　The L6738 is available in a VFQFPN 16 3x3 mm package.

　　L6738主要特性:

　　■ Flexible power supply from 5 V to 12 V bus

　　■ Power conversion input as low as 1.5 V

　　■ Light-load efficiency optimization

　　■ Embedded bootstrap diode

　　■ VIN detector

　　■ 0.8 V internal reference

　　■ 0.5% output voltage accuracy

　　■ Remote GND recovery

　　■ High-current integrated drivers

　　■ Sensorless and programmable precise-OC sense across inductor DCR

　　■ OV protection

　　■ Programmable oscillator up to 600 kHz

　　■ LS-less to manage pre-bias startup

　　■ Adjustable output voltage

　　■ Disable function

　　■ Internal soft-start

　　■ VFQFPN 16 3x3 mm package

　　L6738应用:

　　■ Memory and termination supply

　　■ Subsystem power supply (MCH, IOCH, PCI)

　　■ CPU and DSP power supply

　　■ Distributed power supply

　　■ General DC-DC converter

　　图1. L6738框图

　　图2. L6738快速保护的典型应用电路图

　　图3. L6738典型应用电路图

　　评估板STEVAL-ISA075V1

　　High efficiency DC-DC converter - compact solution based on L6738

　　The STEVAL-ISA075V1 product evaluation board is a compact solution designed for testing the performance of the L6738.

　　The L6738 is a single-phase step-down controller with integrated high-current drivers that provides complete control logic and protection for DC-DC converters.

　　评估板STEVAL-ISA075V1主要特性:

　　Compact size (25.4 mm x 14.6 mm)

　　4 layers

　　VIN< 6 V

　　VOUTup to 3.5 V

　　IOUTup to 8 A (depending on VOUT)

　　FSW= 600 KHz

　　Dual power MOS option (2 x STL 3x3 or 1 x Dual SO8)

　　CIN= 2 x GRM21BR60J226ME39 (22 uF,6.3 V, 0805)

　　COUT= 2 or 3 x GRM31CC70G226KE01 (22 uF, 4 V, 1206)

　　Dual choke options (WE 744310095 or VITEC 59Px8970)

　　RoHS compliant

　　图4. 评估板STEVAL-ISA075V1外形图

　　评估板STEVAL-ISA075V1材料清单: