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 copact 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:
