DCDC变换器ADP2119特性及应用
ADP2119/ADP2120是ADI公司的2A/1.25A低静态电流同步降压DC/DC电源稳压器,采用3 mm × 3 mm LFCSP_WD封装.两种器件采用恒流模式恒频PWM控制方案,具有极好的稳定性和瞬态响应.轻负载下可工作在脉冲频率调制(PFM)模式,以降低开关频率,节省功耗.输入电压从2.3V到5.5V,输出电压从0.6V到VIN,输出精度±1.5%,主要用在POL负载,通信和网络设备,工业和仪表,消费类电子和医疗设备.本文介绍了ADP2119/ADP2120主要特性, 功能方框图以及多种典型应用电路和所用元件.
The ADP2119/ADP2120 are low quiescent current, synchronous, step-down dc-to-dc regulators in a compact 3 mm × 3 mm LFCSP_WD package. Both devices use a current mode, constant frequency pulse-width modulation (PWM) control scheme for excellent stability and transient response. Under light load conditions, they can be configured to operate in a pulse frequency modulation (PFM) mode, which reduces switching frequency to save power.
The ADP2119/ADP2120 support input voltages from 2.3 V to 5.5 V. The output voltage can be adjusted from 0.6 V up to the input voltage (VIN) for the adjustable version, whereas the fixed output version is available in preset output voltage options of 3.3 V, 2.5 V, 1.8 V, 1.5 V, 1.2 V, and 1.0 V. The ADP2119/ADP2120 require minimal external parts and provide a high efficiency solution with their integrated power switches, synchronous rectifiers, and internal compensation. Each IC draws less than 2 μA current from the input source when it is disabled. Other key features include undervoltage lockout (UVLO), integrated soft start to limit inrush current at startup, overvoltage protection (OVP), overcurrent protection (OCP), and thermal shutdown (TSD).
ADP2119/ADP2120主要特性:
Continuous output current
ADP2119: 2 A
ADP2120: 1.25 A
145 mΩ and 70 mΩ integrated MOSFETs
Input voltage range from 2.3 V to 5.5 V
Output voltage from 0.6 V to VIN
±1.5% output accuracy
1.2 MHz fixed switching frequency
Synchronizable between 1 MHz and 2 MHz
Selectable PWM or PFM mode operation
Current mode architecture
Precision threshold enable input
Power-good flag
Voltage tracking
Integrated soft start
Internal compensation
Startup with precharged output
UVLO, OVP, OCP, and thermal shutdown
10-lead, 3 mm × 3 mm LFCSP_WD package
ADP2119/ADP2120应用:
Point of load conversion
Communications and networking equipment
Industrial and instrumentation
Consumer electronics
Medical applications
图1.ADP2119/ADP2120功能方框图