Data Sheet Rev. 1.1

3

2000-10-11

TLE 4307

Figure 2

Block Diagram

Circuit Description

The TLE 4307 consists of 2 stages, the charge pump and the very low drop voltage

regulator.

Charge Pump

The power stage is used as a switching element, that is driven by a buffer. A current

source keeps the power stage on. When the output C of the charge pump reaches

V

the power stage is switched off. It is active clamped, when the input I reaches

V

Optional, an external capacity can be connected between pin SL and I to limit the slew

rate at the input, when an inductive load drives the IC. Saturation control as a function of

the load current prevents any over-saturation of the power element. The regulator is

additionally protected against overload and overtemperature.

Very Low Drop Regulator

The control amplifier compares a reference voltage, made highly accurate by resistance

balancing, with a voltage proportional to the output voltage and drives the base of the

series PNP transistor via a buffer. Saturation control as a function of the load current

prevents any over-saturation of the power element. The regulator is additionally

protected against overload and overtemperature.

AES02793

Power

Charge

Pump

Very

Low-Drop

Regulator

TLE 4307

4

1

5

SL

I

23

C

GND

Q