ADP1051

Preliminary Technical Data

Rev. PrA | Page 14 of 17

THEORY OF OPERATION

The ADP1051 is designed as a flexible, easy-to-use, digital power

supply controller. The ADP1051 integrates the typical functions

that are needed to control a power supply such as:

•

Output voltage sense and feedback

•

Voltage feed forward control

•

Digital loop filter compensation

•

PWM generation

•

Current, voltage, and temperature sense

•

•

Calibration and trimming

The main function of controlling the output voltage is performed

using the feedback ADCs, the digital loop filter, and the PWM

block.

The feedback ADCs use a multipath approach. There is a

combination of a high speed, low resolution (fast and coarse) ADC

and a low speed, high resolution (slow and accurate) ADC. The

ADC outputs combine to form a high speed and high resolution

feedback path. Loop compensation is implemented using the digital

filter. This PID (proportional, integral, derivative) filter is

implemented in the digital domain, allowing easy programming of

filter characteristics, which is of great value in customizing and

debugging designs. The PWM block generates up to six

programmable PWM outputs for control of FET drivers and

synchronous rectification FET drivers. This programmability

allows many traditional and specific switching topologies to be

realized.

Conventional power supply housekeeping features, such as remote

and local voltage sense and primary side current sense, are

included. An extensive set of protections are offered, including

overvoltage protection (OVP), over current protection (OCP), over

temperature protection (OTP), under voltage protection (UVP), SR

reverse current protection (RCP).

interface. This interface is also used for calibrations. Other

information, such as input current, output current, and fault flags,

is also available through this digital bus interface.

The internal EEPROM can store all programmed values and allows

standalone control without a microcontroller. A free, downloadable

ADP1051 GUI is available that provides all the necessary software

to program the ADP1051. To obtain the latest GUI software and a

user guide, visit http://www.analog.com/digitalpower.

The ADP1051 operates from a single 3.3V power supply and is

specified from -40°C to 125°C.

Figure 13. Functional Block Diagram

RTD

PG/ALT#

SDA

SCL

SYNI/FLGI

SR2

SR1

OUTD

OUTC

ADD

VCORE

AGND

RES

PWM

ENGINE

ADC

OSC

DIGITAL CORE

VREF

PMBus

8kB

EEPROM

VS-

VS+

OVP

CS1

OUTA

OUTB

VF

CS2-

CS2+

CTRL

VDD

UVLO

LDO

0.25V

1.2V

DAC