Figure 1 : Components Connected to Pins 6 and 7 Determine the Load Current Waveshape.

COMPONENTS ON PINS 6 AND 7

LOAD CURRENT WAVEFORM

APPLICATION INFORMATION

Controlled by a logic input and an inhibit input (both

TTL compatible), the device drives the external dar-

lington(s) to produce a load current waveform as

shown in figure 4. This basic waveform shows that

the device produces an initial high level current in or-

der to ensure a fast opening, followed by a holding

level current as long as the input is active. Both

the peak and holding current are regulated by the

L584’s switchmode circuitry.

The duration of the high level current and the values

of the peak and the holding currents can be adjusted

by external components.

Moreover, by omitting C1, C2 or both it is possible

to realize single-level current control, a transitory

peak followed by a regulated holding current or a

simple peak (figure 1).

The peak and holding current values are always re-

L584

5/13