HEF4538BT-Q100

The HEF4538B-Q100 is a dual retriggerable-resettable monostable multivibrator. Each multivibrator has an active LOW trigger/retrigger input (nA) and an active HIGH trigger/retrigger input (nB). It has an overriding active LOW direct reset input (nCD) and an output (nQ) together with its complement (nQ). There are also two pins for connecting the external timing components C_ext and R_ext. These pins, nREXT/CEXT, and nCEXT, are always connected to ground. Typical pulse width variation over the specified temperature range is ±0.2 %.

Either the positive or the negative edges of the input pulse can trigger the multivibrator. The trigger produces an accurate output pulse with a pulse width range of 10 μs to infinity. The external timing components C_ext and R_ext determine the duration and accuracy of the output pulse. The output pulse width (t_W) is equal to R_ext x C_ext. The linear design techniques in LOCMOS (Local Oxide CMOS) guarantee precise control of the output pulse width. A LOW level at nCD terminates the output pulse immediately. The Schmitt trigger action of the trigger inputs, makes the circuit highly tolerant of slower rise and fall times.

It operates over a recommended V_DD power supply range of 3 V to 15 V referenced to V_SS (usually ground). Unused inputs must be connected to V_DD, V_SS, or another input.

This product has been qualified to the Automotive Electronics Council (AEC) standard Q100 (Grade 1) and is suitable for use in automotive applications.