FN7605 Rev 2.00

Page 1 of 17

February 9, 2015

FN7605

Rev 2.00

February 9, 2015

ISL9305

3MHz Dual Step-Down Converters and Dual Low-Input LDOs with I2C Compatible

Interface

DATASHEET

The ISL9305 is an integrated mini Power Management IC

(mini-PMIC) ideal for applications of powering low-voltage

microprocessor or multiple voltage rails with battery as input

sources, such as a single Li-ion or Li-Polymer. ISL9305

integrates two high-efficiency 3MHz synchronous step-down

converters (DCD1 and DCD2) and two low-input, low-dropout

linear regulators (LDO1 and LDO2).

The 3MHz PWM switching frequency allows the use of very small

external inductors and capacitors. Both step-down converters can

enter skip mode under light load conditions to further improve the

efficiency and maximize the battery life. For noise sensitive

to operate in forced PWM mode regardless of the load current

the output voltage from 0.825V to 3.6V at 25mV/step size for

dynamic power saving. Each step-down converter can supply up to

800mA load current. The default output voltage can be set from

version, or the ISL9305 can be ordered in factory pre-set voltage

options from 0.9V to 3.6V in 50mV step.

The ISL9305 also provides two 300mA low dropout (LDO)

regulators. The input voltage range is 1.5V to 5.5V allowing

them to be powered from one of the on-chip step-down

converters or directly from the battery. The default LDO

power-up output comes with factory pre-set fixed output

voltage options between 0.9V to 3.3V.

The ISL9305 is available in a 4mmx4mm 16 Ld TQFN package.

Related Literature

• ISL9305H Data Sheet

• AN1564 “ISL9305 and ISL9305H Evaluation Boards”

Features

• Dual 800mA, Synchronous Step-down Converters and Dual

300mA, General-purpose LDOs

• Input Voltage Range

- DCD1/DCD2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3V to 5.5V

- LDO1/LDO2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5V to 5.5V

Between the Host Controller and the ISL9305

• Adjustable Output Voltage

- At 25mV/Step . . . . . . . . . . . . . . . . . . . . . . . . 0.825V to 3.6V

- At 50mV/Step . . . . . . . . . . . . . . . . . . . . . . . . . . 0.9V to 3.6V

for each Enabled LDO

Voltages

Load or Forced Fixed Switching Frequency PWM Mode

• Small, Thin, 4mmx4mm TQFN Package

Applications

• Cellular Phones, Smart Phones

• PDAs, Portable Media Players, Portable Instruments

• Single Li-ion/Li-Polymer Battery-Powered Equipment

•DSP Core Power

FIGURE 1. TYPICAL APPLICATION DIAGRAM

*

*

ISL9305

SDAT

VINDCD1

VINLDO1

VINLDO2

SW1

FB1

SW2

FB2

VOLDO2

2.3V TO 5.5V

800mA

800mA

1.5V TO 5.5V

1.5V TO 5.5V

GNDDCD1

300mA

300mA

GNDDCD2

SCLK

VOLDO1

GNDLDO

PG

VINDCD2

*Only for adjustable output version. For fixed output version, directly

connect the FB pin to the output of the buck converter.

1µF

1µF

10µF

1µF

1µF

4.7µF

4.7µF