VIPER12A-E

Rectangular U-I output characteristics

Doc ID 11977 Rev 2

7/21

4

Rectangular U-I output characteristics

Figure 4.

Rectangular U-I output characteristics for battery charger

A complete regulation scheme can achieve combined and accurate output characteristics.

Figure 4. presents a secondary feedback through an optocoupler driven by a TSM101. This

device offers two operational amplifiers and a voltage reference, thus allowing the regulation

of both output voltage and current. An integrated OR function performs the combination of

the two resulting error signals, leading to a dual voltage and current limitation, known as a

rectangular output characteristic. This type of power supply is especially useful for battery

chargers where the output is mainly used in current mode, in order to deliver a defined

charging rate. The accurate voltage regulation is also convenient for Li-ion batteries which

require both modes of operation.