ADP2230

Data Sheet

Rev. A | Page 12 of 18

THEORY OF OPERATION

Figure 31. Internal Block Diagram

OVERVIEW

The ADP2230 contains two, high efficiency, step-down, dc-to-

dc converters that use a proprietary, high speed, current mode,

constant frequency, PWM control scheme for excellent stability

and transient response. To ensure long battery life, the

ADP2230 also has a PSM mode that reduces the switching

frequency under light load conditions. The architecture ensures

smooth transitions between PWM mode and PSM, and

maintains high efficiencies at light loads.

The ADP2230 operates with an input voltage between 2.3 V and

6.5 V and buck to output voltages between 0.8 V and 6 V.

The ADP2230 buck outputs operate out of phase to reduce the

input current ripple. All versions include an internal power

switch, synchronous rectifier, and internal compensation for

minimal external part count. The ADP2230 also includes

internal protection features such as precision enable, soft start,

UVLO, TSD, and short-circuit protection.

The ADP2230 also includes an integrated, 200 Ω, switched

resistor, quick output discharge (QOD) function that

automatically discharges the output when the device is disabled.

The following sections describe the operating conditions, the

modes of operation, and the features of the ADP2230.

OPERATING CONDITIONS

Input Voltage

The ADP2230 operates with an input voltage between 2.3 V and

6.5 V. The VIN1 and VIN2 pins cannot be controlled separately.

VIN1 and VIN2 must be tied together and powered from a

single source.

Output Voltage

The ADP2230 step-down, dc-to-dc converter is available with

adjustable output voltages that can be set between 0.8 V and

6 V. The ADP2230 is also available in three fixed output voltage

pair options: 1.2 V/1.8 V, 1.2 V/3.3 V, or 1.8 V/3.3 V. For

additional output voltage options, contact a local sales or

distribution representative.

SLOPE COMP

OSCILLATOR

CONTROL

LOGIC

SOFT

START

1.0V

EN1

VIN2

FB2

SYNC

1.2V

STANDBY

PRECISION

EN1

VIN

UVLO

PWM

PSM

0.808V

0.8V

1.2A

2.25V

0.8V

150°C

135°C

H = PWM ONLY

L = PWM/PSM

THSD

–0.5A – (PWM)

0A – (PSM)

SLOPE COMP

CONTROL

LOGIC

SOFT

START

VIN1

SW1

PGND

FB1

PWM

PSM

0.808V

0.8V

1.2A

0.8V

–0.5A – (PWM)

0A – (PSM)

VTO I

V TO I

AGND

1.0V

EN2

1.2V

STANDBY

PRECISION

EN1

FIXED

ONLY

FIXED

ONLY

SW2