TS1052

Constant Voltage and Constant Current Controller

For Battery Chargers and Adaptors

5/8

Version: A12

Principle of Operation and Application Hints (continues)

Compensation

The voltage control trans-conductance operational amplifier can be fully compensated. Both of its output and

negative input are directly accessible for external compensation components.

And example of a suitable compensation network is shown in typical application circuit. It consists of a capacitor

Cvc1=2.2nF and a resistor Rcv1=470K

Ω in series, connected in parallel with another capacitor Cvc2=22pF.

The current control trans-conductance operational amplifier can be fully compensated. Both of its output and

negative input are directly accessible for external compensation components. An example of suitable

compensation network is shown in typical application circuit. It consists of a capacitor Cic1=2.2nF and resistor

Ric1=22K

Ω in series. When the Vcc voltage reaches 18V it could be interesting to limit the current coming through

the output in the aim to reduce the dissipation of the device and increase the stability performances of the whole

application. An example of suitable Rout value could be 330

Ω in series with the optocoupler in case Vcc=12V.

Start Up and Short Circuit Conditions

The TS1052 is not provided with a high enough supply voltage in under start-up or short-circuit conditions. This is

due to the fact that the chip has its power supply line in common with the power supply line of the system.

Therefore, the current limitation can only be ensured by the primary PWM module, which should be chosen

accordingly. If the Primary current limitation is considered not to be precise enough for the application, then a

sufficient supply for the TS1052 has to be ensured under any condition. It would then be necessary to add some

circuitry to supply the chip with separate power line. This can be achieved in numerous ways, including an

additional winding on the transformer. The following schematic shows how to realize a low-cost power supply for

the TS1052 (with no additional windings). Please pay attention to the fact that in the particular case presented here,

this low-cost power supply can reach voltages as high as twice the voltage of the regulated line. Since the absolute

maximum rating of the TS1052 supply voltage is 18V, this low-cost auxiliary power supply can only be used in

applications where the regulated line voltage does not exceed 9V.

TS1052