CD4536BPW | Texas Instruments

Programmable Timer, CD4536BPW, Texas Instruments

The CD4536BPW is a programmable timer consisting of 24 ripple-binary counter stages. The salient feature of this device is its flexibility. The device can count from 1 to 224 or the first 8 stages can be bypassed to allow an output, selectable by a 4-bit code, from any one of the remaining 16 stages. It can be driven by an external clock or an RC oscillator that can be constructed using on-chip components. Input IN1 serves as either the external clock input or the input to the on-chip RC oscillator. OUT1 and OUT2 are connection terminals for the external RC components. In addition, an on-chip monostable circuit is provided to allow a variable pulse width output. Various timing functions can be achieved using combinations of this capability.

A logic 1 on the 8-BYPASS input enables a bypass of the first 8 stages and makes stage 9 the first counter stage of the last 16 stages. Selection of one of 16 outputs is accomplished by the decoder and the BCD inputs A, B, C, and D. MONO IN is the timing input for the on-chip monostable oscillator. Grounding of the MONO IN terminal through a resistor of 10K ohms or higher disables the one-shot circuit and connects the decoder directly to the DECODE OUT terminal. A resistor to VDD and a capacitor to ground from the MONO IN terminal enables the one-shot circuit and controls its pulse width.

Features

• On-chip RC oscillator provision
• Clock inhibit input
• Schmitt-trigger in clock line permits operation with very long rise and fall times
• On-chip monostable output provision
• Test mode allows fast test sequence
• Standardized, symmetrical output characteristics