The document describes the features and characteristics of the 74HC/HCT5555 programmable delay timer with oscillator. It features positive and negative edge triggering, retriggerable or non-retriggerable modes, programmable delay with a minimum of 100ns, and a divide-by range of 2 to 224. The device has a direct reset function to terminate output pulses, Schmitt trigger action on trigger inputs, direct drive for a power transistor, low power consumption, and high precision digital timing. It is suitable for applications such as motor control, delay circuits, automotive applications, etc.
The Philips 74HC/HCT5555 is a high-speed monostable Si-gate CMOS device designed as a precision programmable delay timer. It is pin-compatible with low-power Schottky TTL (LSTTL) and complies with JEDEC standard no. 7A. The device integrates oscillator control logic, a 24-stage binary counter, and an integrated oscillator that supports RC, crystal, or external timing components.
| Minimum delay time | 100 ns |
|---|---|
| Divide-by range | 2 to 224 |
| Output capability | 20 mA |
The device supports three oscillator operating modes: RC oscillator, crystal oscillator, and external oscillator.
Yes, the direct reset terminates the output pulse, and an asynchronous overriding master reset (MR) can also reset all flip-flop stages.
Yes, the device is retriggerable or non-retriggerable, selectable via the RTR/RTR input.