Charger schematic examples

AN417

14/21

Doc ID 2074 Rev 2

6

Charger schematic examples

6.1

Block diagram

The charger is a power supply operating as a constant current source. Such a current

source can be made with a SMPS working from the AC mains or from a DC voltage source.

Figure 11 and Figure 12 give block diagrams of an offline SMPS charger and a DC to DC

charger.

Figure 11.

Block diagram of an off-line SMPS charger

Figure 12.

Block diagram of a DC/DC charger

AC mains

SMPS

MCU

ST6210

PWM

current

mode

UC3845

NiMH

or

NiCd

battery

temperature

voltage

DC voltage

SMPS

MCU

ST6210

PWM

current

mode

UC3843

NiMH

or

NiCd

battery

temperature

voltage