Functional Diagram

TLH7768 – 9

Timing Diagram

TLH7768 – 10

Pin Function Description

One of the main features of the LM122 is its great versatility

Since this device is unique a description of the functions

and limitations of each pin is in order This will make it much

easier to follow the discussion of the various applications

presented in this note

V

a

is the positive supply terminal of the LM122 When us-

ing a single supply this terminal may be driven by any volt-

age between 45V and 40V The effect of supply variations

on timing period is less than 0005%V so supplies with

high ripple content may be used without causing pulse width

but may be necessary when driving highly reactive loads

25 mA independent of the supply voltage Of course addi-

tional current will be drawn if the reference is externally

loaded

enced to the ground pin Up to 50 mA can be drawn from

this pin for driving external networks In most applications

situations where a more linear charging current is required

The regulated voltage is very useful in applications where

the LM122 is not used as a timer such as switching regula-

tors variable reference comparators and temperature con-

5