ADI 公司的ADP1853是宽输入电压DC/DC同步降压控制器,输入电压从3.3V到12V(高达20V),电压跟踪输入,输出电压0.6V到90%VIN,通常工作在电流模式以得到更快的响应速度.最大输出电流大于25A,输出电压对温度的精度±1%,可编频率200 kHz到1.5 MHz,主要用于中间总线和POL系统,通信基站和网络,工业和仪表,医疗和保健设备.本文介绍了ADP1853主要特性,方框图,典型应用电路图,15A电流模式和25A电压模式应用电路图,以及ADP1853评估板主要特性,电路图,材料清单和PCB元件布局图.

 The ADP1853 is a wide range input, dc-to-dc, synchronous buck controller capable of running from commonly used 3.3 V to 12 V (up to 20 V) voltage inputs. The device nominally operates in current mode with valley current sensing providing the fastest step response for digital loads. It can also be configured as a voltage mode controller with low noise and crosstalk for sensitive loads.

The ADP1853 can be used as a master synchronization clock for the power system and for convenient synchronization between controllers. The CLKOUT signal can synchronize other devices in the ADP185x family such that slave devices are phase-shifted from the master to reduce the input ripple current, improve EMI, and reduce the size of the input bulk capacitance. The ADP1853 can also be configured as a slave device for current sharing. Additionally, the ADP1853 includes accurate tracking, precision enable, and power good functions for sequencing. The ADP1853 provides a high speed, high peak current gate driving capability to enable energy efficient power conversion. The device can be configured to operate in power saving mode by skipping pulses, reducing switching losses and improving efficiency at light load and standby conditions.

The accurate current limit allows design within a narrower range of tolerances and can reduce overall converter size and cost. The ADP1853 can regulate down to 0.6 V output using a high accuracy reference with ±1% tolerance over the temperature range from −0℃ to 125℃.

With a wide range input voltage, the ADP1853 is designed to provide the designer with maximum flexibility for use in a variety of system configurations; loop compensation, soft start, frequency setting, power saving mode, current limit, and current sense gain can all be programmed using external components. In addition, the external RAMP resistor allows choosing optimal slope and VIN feedforward in both current and voltage mode for excellent line rejection. The linear regulator and the boot strap diode for the high-side driver are internal.

Protection features include undervoltage lock out, overvoltage, overcurrent/short circuit, and overtemperature.

ADP1853主要特性:

Input voltage range: 2.75 V to 20 V

Output voltage range: 0.6 V to 90% VIN

Maximum output current of more than 25 A

Current mode architecture with current sense input

Configurable to voltage mode

±1% output voltage accuracy over temperature

Voltage tracking input

Programmable frequency: 200 kHz to 1.5 MHz

Synchronization input

Internal clock output

Power saving mode at light load

Precision enable input

Power good with internal pull-up resistor

Adjustable soft start

Programmable current sense gain

Integrated bootstrap diode

Starts into a precharged load

Externally adjustable slope compensation

Suitable for any output capacitor

Overvoltage and overcurrent-limit protection

Thermal overload protection

Input undervoltage lockout (UVLO)

Available in 20-lead, 4 mm × 4 mm LFCSP

Supported by ADIsimPower™design tool

ADP1853应用:

Intermediate bus and POL systems requiring sequencing and tracking, including

Telecom base station and networking

Industrial and Instrumentation

Medical and healthcare

图1.ADP1853方框图

图2.ADP1853典型应用电路图

图3.ADP1853两相应用电路图

图4.ADP1853 15A电流模式应用电路图

图5.ADP1853 25A电压模式应用电路图

ADP1853降压DC/DC控制器评估板

This document describes the design, operation, and test results of the ADP1853-EVALZ. The input voltage range for this evaluation board is 9 V to 15 V, and the regulated output voltage VOUT is set to 3.3 V with the maximum output current up to 20 A. The switching frequency (fSW) of 300 kHz is set to achieve high efficiency.

ADP1853评估板主要特性:

Input voltage range: 9 V to 15 V

Output voltage: 3.3 V

Output current: up to 20 A

Switching frequency: 300 kHz

Operates in PWM or PSM

Designed for evaluation of the ADP1853 functionality

Flexible and easy to re-configure and modify

图6.ADP1853评估板外形图

图7.ADP1853评估板电路图
ADP1853评估板材料清单:


图8.ADP1853评估板元件布局图(顶层)
详情请见:
http://www.analog.com/static/imported-files/data_sheets/ADP1853.pdf
和
http://www.analog.com/static/imported-files/user_guides/UG-431.pdf