PIN FUNCTIONS

N

°

Name

Functions

1

Alternator Voltage

Sensing

Connection for voltage regulation sensing. The regulation sensitivity is a

function of R1 and is given by :

S=

∆ VA

∆ R1

= 0.5mV ⁄ Ω

2-3

Filter Capacitor

A capacitor connected between these two pins filters the feedback signal from

the regulated output. Typically the input impedance is 15K

Ω.

4

Alternator Overvoltage

Adjustment

When this pin is left open circuit the overvoltage threshold is a described in the

specification. Typically the warning lamp is switched on when the voltage at

this pin is greater than 3.5V. This threshold can be modified with a resistor

between either the ground or pin 2.

5

GND

This pin must be connected to ground.

6

Darlington Driver

to ground.

7-8-9

N.C.

These pins must be left floating.

10

IC Supply Voltage

Supply Voltage Input

A 7.5V (typical) Zener is present at the input.

11

Oscillator Capacitor

A capacitor connected to ground sets the frequency of the internal oscillator.

The frequency is given by :

fosc =

20 x 10

−6

8.4

12

GND

This pin must be connected to ground.

13

Lamp Driver

Current Driver for External Lamp for Diagnostics.

Internally protected agains short circuits (current limiting), load dump transients

and, by means of a zener, against low energy spikes.

14

NC

Not connected.

15

Phase Voltage Sensing.

Connection for no charge sensing from the alternator .

The internal low threshold is typically 2.4V. By means of the external divider

R3/R4 the threshold can be adjusted to give the required sensitivity.

16

Battery Voltage Sensing

Connection for Voltage Battery Sensing

This pin senses a failure of the alternator-battery lead as the voltage difference

L585

3/9