ADI ADP2118 高效同步降压 DC-DC 转换方案关键词：电源管理 ,DC/DC 转换器,PWMADI 公司的 ADP2118 是 3A 高效同步降压 DC-DC 转换器, 采用电流模式恒定频率 PWM 控制方案 ,有极好的稳定性和瞬态响应, 输入电压丛 2.3V 到 5.5V,输出电压从 0.6V 到输入电压(VUN),可连续输出 3A 电流, 广泛应用在DSP/FPGA/ASIC 内核电源,通信和网络设备,PDA 和掌上电脑以及音频/ 视频消费类电子产品.本文介绍了 ADP2118 的主要特性, 方框图和典型应用电路,包括强迫连续导通模式, 使能 PFM 模式, 和 1MHz 外接时钟的相位同步以及和1MHz 外接时钟的 180 度相位同步的降压稳压器电路图.ADP2118: 3A, 1.2 MHz/600 kHz High Efficiency Synchronous Step-Down DC-to-DC ConverterThe ADP2118 is a low quiescent current, synchronous, step-down, dc-to-dc converter in a compact 4mm 4mm LFCSP_WQ package. It uses a current mode, constant frequency pulse-width modulation (PWM) control scheme for excellent stability and transient response. Under light loads, the ADP2118 can be configured to operate in pulse frequency modulation (PFM) mode that reduces switching frequency to save power. The ADP2118 runs from input voltages of 2.3 V to 5.5 V. The output voltage of the ADP2118ACPZ-R7 is adjustable from 0.6 V to input voltage (VIN), and the ADP2118ACPZ-x.x-R7 are 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 ADP2118 requires minimal external parts and provides a high efficiency solution with its integrated power switch, synchronous rectifier, and internal compensation. The IC draws less than 3 A 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).ADP2118 主要特性: 3 A continuous output current 75 m and 40 m integrated FET 1.5% output accuracy Input voltage range from 2.3 V to 5.5 V Output voltage from 0.6 V to VIN 600 kHz or 1.2 MHz fixed switching frequency Synchronizable between 600 kHz and 1.4 MHz Selectable synchronize phase shift: 0o or 180o Selectable PWM or PFM mode operation Current mode architecture Precision enable input Power good output Voltage tracking input Integrated soft start Internal compensation Starts up into a precharged output UVLO, OVP, OCP, and thermal shutdown Available in 16-lead 4mm 4mm LFCSP_WQ package ADP2118 应用: DSP/FPGA/ASIC core power Telecommunication/networking equipment PDAs and palmtop computers Audio/video consumer electronics图 1.ADP2118 功能方框图图 2.ADP2118 典型应用电路图 3. 1.2 V, 3 A, 1.2 MHz 降压稳压器(强迫连续导通模式)图 4.2.5 V, 3 A, 1.2 MHz 降压稳压器(使能 PFM 模式)AO-Electronics 傲壹电子 官网：www.aoelectronics.com 中文网：www.aoelectronics.cn图 5.1.8 V, 3 A 降压稳压器(和 1MHz 外接时钟的相位同步) 图 5.1.5 V, 3 A 降压稳压器(和 1MHz 外接时钟的 180 度相位同步) 图 6.3.3 V, 3 A, 1.2 MHz 降压稳压器(跟踪模式)