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AS1332

Datasheet - D e t a i l e d D e s c r i p t i o n

8 Detailed Description

For driving RF power amplifiers in portable devices and battery powered RF devices the AS1332 is a very suitable DC-

DC converter. The AS1332 features current overload protection, thermal overload shutdown and soft start. Besides

these features the device also displays the following characteristics:

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Current-mode buck architecture with synchronous rectification for high efficiency.

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Operation at maximum efficiency over a wide range of power levels from a single Li-Ion battery cell.

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The maximum load capability of 650mA is provided in PWM mode, wherein the maximum load range may vary

depending on input voltage, output voltage and the selected inductor.

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Efficiency is of around 96% for a 400mA load with 3.16V output and 3.6V input.

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For longer battery life, the output voltage can be dynamically programmable from 1.3V (typ) to 3.16V (typ) by

adjusting the voltage on the control pin without the need for external feedback resistors.

Figure 30. AS1332 Block Diagram

AS1332 is fabricated using a 8-pin WL-CSP, which requires special design considerations for implementation. Its fine

bumppitch requires careful board design and precision assembly equipment. This package offers the smallest possible

size, for space-critical applications such as cell phones, where board area is an important design consideration. The

size of the external components is reduced by using a high switching frequency (2MHz). For implementation only three

external power components are required (see Figure 1 on page 1). The 8-pin WL-CSP package is appropriate for

opaque case applications, where its edges are not subject to high intensity ambient red or infrared light. Also the

system controller should set EN low during power-up and other low supply voltage conditions. See Shutdown Mode on

page 13.

Mosfet

Control

Logic

Shutdown

Control

Main Control

Clamp

Logic and

Soft Start

Oscillator

Current

Sense

PVIN

VDD

FB

VCON

EN

SW

AGND

PGND

AS1332