AS3543 datasheet(34/92 Pages) AMSCO

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AS3543 3v2

Data Sheet - D e t a i l e d D e s c r i p t i o n - P o w e r M a n a g e m e n t F u n c t i o n s

9.2

DCDC Step-Down Converter (2x)

9.2.1

General

These converters are meant to convert the battery voltage down to voltages which fit to the core and peripheral supply

voltage requirements for microprocessors.

input Voltage BVDDC1/2 (usually connected to the battery)

output Voltage CVDD1 & CVDD2

output voltage levels can be programmed independently form 0.61V to 3.35V

the default value at start-up is defined by VPRG1 and VPRG2 pin

DVM for both outputs with selectable timings

driver strength 250mA

under- and over-voltage detection

Figure 21. DCDC Step-Down Block Diagram

9.2.2

Functional Description

The step-down converter is a high efficiency fixed frequency current mode regulator. By using low resistance internal

PMOS and NMOS switches efficiency up to 97% can be achieved. The fast switching frequency allows using small

inductors, without increasing the current ripple. The unique feedback and regulation circuit guarantees optimum load

and line regulation over the whole output voltage range, up to an output current of 250mA, with an output capacitor of

only 10

µF. The implemented current limitation protects the DCDC and the coil during overload condition.

To achieve optimized performance in different applications, adjustable settings allow to compromise between high effi-

ciency and low input, output ripple:

AS3543 Datenblatt(PDF) 34 Page - ams AG