ADI ADP174x 2A LDO线性稳压方案

ADI 公司的ADP1740/ADP1741是低压降( LDO)CMOS线性稳压器,工作电压从1.6V到3.6V,输出电流高达2A, 2A负载电流时的压降为160mV,可调输出电压从0.75V到3.0V,关断电流仅为2uA,初始精度±1%,负载,线路和温度的调整精度为±2%,1kHz时的PSRR为65dB,主要应用于服务器计算机,存储器部件,通信设备,DSP/FPGA/微处理器电源以及仪器仪表/数据采集系统.本文介绍了ADP1740/ADP1741的主要特性,方框图以及评估板电路图和所用元器件.

The ADP1740/ADP1741 are low dropout (LDO) CMOS linear regulators that operate from 1.6 V to 3.6 V and provide up to 2 A of output current. These low VIN/VOUT LDOs are ideal for regulation of nanometer FPGA geometries operating from 2.5 V down to 1.8 V I/O rails, and for powering core voltages down to 0.75 V. Using an advanced, proprietary architecture, the ADP1740/ ADP1741 provide high power supply rejection ratio (PSRR) and low noise, and achieve excellent line and load transient response with only a small 4.7 μF ceramic output capacitor. The ADP1740 is available in seven fixed output voltage options. The ADP1741 is an adjustable version that allows output voltages ranging from 0.75 V to 3.0 V via an external divider. The ADP1740/ADP1741 allow an external soft start capacitor to be connected to program the startup. A digital power-good output allows power system monitors to check the health of the output voltage. The ADP1740/ADP1741 are available in a 16-lead, 4 mm × 4 mm LFCSP, making them not only very compact solutions, but also providing excellent thermal performance for applications that require up to 2 A of output current in a small, low profile footprint.

ADP174x 主要特性:

Maximum output current: 2 A

Input voltage range: 1.6 V to 3.6 V

Low shutdown current: 2 μA

Low dropout voltage: 160 mV @ 2 A load

Initial accuracy: ±1%

Accuracy over line, load, and temperature: ±2%

7 fixed output voltage options with soft start: 0.75 V to 2.5 V (ADP1740)

Adjustable output voltage options with soft start: 0.75 V to 3.0 V (ADP1741)

High PSRR

65 dB @ 1 kHz

65 dB @ 10 kHz

54 dB @ 100 kHz

23 μV rms at 0.75 V output

Stable with small 4.7 μF ceramic output capacitor

Excellent load and line transient response

Current-limit and thermal overload protection

Power-good indicator

Logic-controlled enable

Reverse current protection

ADP174x应用:

Server computers

Memory components

Telecommunications equipment

Network equipment

DSP/FPGA/microprocessor supplies

Instrumentation equipment/data acquisition systems



图1.ADP1740 内部方框图



图2.ADP1741 内部方框图

ADP1740/ADP1741评估板

The ADP1740/ADP1741 evaluation board is used to demon-strate the functionality of the ADP1740/ADP1741 series of linear regulators.

Simple device measurements, such as line and load regulation, dropout, and ground current, can be demonstrated with just a single voltage supply, a voltmeter, a current meter, and load resistors.

ADP1740/ADP1741评估板主要特性:

Input voltage range: 1.6 V to 3.6 V

Output current range: 500 μA to 2 A

Output voltage accuracy: ±2%

Operating temperature range: −40℃ to +125℃



图3.ADP1740/ADP1741评估板外形图



图4.ADP1740/ADP1741评估板电路图

ADP1740/ADP1741评估板硬件元件: