AS1302

5V/30mA Adaptive Inductorless Boost Converter

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Revision 1.02

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Datasheet

1 General Description

The AS1302 is a 30mA inductorless boost converter

using a double H-bridge charge-pump topology with two

external flying capacitors. The AS1302 charge pump

features 1:2 and 2:3 operation modes as well as a 1:1

operation mode where the input is directly connected to

the output.

The AS1302 runs on a 1.2MHz fixed frequency and is

utilized with a low noise regulation scheme to allow

usage together with sensitive RF circuitry from the same

battery supply. Additionally to increase efficiency the

AS1302 switches to 49kHz at light loads.

Designed to reside in portable and space limited

equipment the 1.2MHz charge pump converts a 2.9V to

5.15V input to regulated 5V output with 3% accuracy.

The shutdown function reduces the supply current to

<1µA and disconnects the load from the output. The

integrated soft-start circuitry prevents high inrush

currents being drawn from the battery during start-up.

The AS1302 includes built-in under-voltage lockout,

short circuit-, and thermal protection circuitry.

The AS1302 is available in TDFN (3x3x0.8mm) 10-pin

and an extremely small 1.2x1.2mm WL-CSP 8-bumps

package with 0.4mm pitch.

2 Key Features

!

Up to 90% Efficiency

!

2.9V to 5.15V Input Voltage

!

Regulated 5V Output

!

Automatic Mode Switching

!

<1µA Shutdown Current

!

Startup with Full Load (within 1ms)

!

Up to 30mA Load Current

!

Short Circuit Protection

!

Output Disconnected During Shutdown

!

Soft-Start

!

No Inductor Required

!

Small External Components Required

!

Low Noise Fixed Frequency (1.2MHz, 49kHz)

Charge Pump:

- 1:1 Battery Feed Through Mode

- 2:3 Single Phase Mode

- 1:2 Single Phase Mode

!

Package Options:

- TDFN (3x3x0.8mm) 10-pin

- WL-CSP 8-bumps with 0.4mm Pitch

3 Applications

The device is ideal for two or three AA cells or a single

Li-Ion battery cell to 5V conversion, mobile phones,

portable instruments, microprocessor based systems

and remote data-acquisition systems.

Figure 1. AS1302 - Typical Application Diagram

AS1302

2.2µF

VBATT

EN

GND

VOUT

C1+

C1-

C2+

C2-

2.2µF

On

Off

2.9V to 5.15V

220nF

220nF