Current Sources and Voltage References

Using the LM134 as a temperature sensor

Using Monolithic IC Current Sources and Mirrors

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The circuit in Figure 10.9 shows the LM134/334 being used as a precision ramp gen-

erator, where its constant current is used to linearly charge a timing capacitor, C

1

. The

2N7000 small-signal DMOS FET is used as a fast reset switch.

In Figure 10.10, the LM334 is being used as a stable reference for the level settings of

a quad comparator IC, in a classic window comparator circuit. Compensating the

LM334 for a near-zero temperature coefficient helps improve the overall accuracy of

the window comparator.

10.3 Using the LM134 as a temperature sensor

In addition ...