
www.austriamicrosystems.com
Revision 1.10
32 - 86
AS3542 3v2
Data Sheet, Strictly Confidential - D e ta 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
μ
F. 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: