ADIADP1853 output 20 ADC-DC conversion solution

Analog Devices’ ADP1853 is a wide input voltage DC/DC synchronous step-down controller with input voltages from 3.3V to 12V (up to 20V), voltage tracking input, and output voltages from 0.6V to 90% VIN, typically operating in current mode for better performance. Fast response speed. The maximum output current is greater than 25A, the accuracy of output voltage to temperature is ±1%, the frequency can be programmed from 200 kHz to 1.5 MHz, mainly used in intermediate bus and POL systems, communication base stations and networks, industrial and instrumentation, medical and Healthcare Equipment. This article describes the ADP1853 key features, block diagram, typical application Circuit diagram, 15A current mode and 25A voltage mode application circuit diagrams, as well as the ADP1853 evaluation board key features, circuit diagram, bill of materials, and PCB component layout.

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 °C.

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 main features:

Input voltage range: 2.75V to 20V

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 application:

Intermediate bus and POL systems requiring sequencing and tracking, including

Telecom base station and networking

Industrial and Instrumentation