Key facts
- Brand
- Philips
- Model
- HCT42
- Category
- Other Electronics
- Documents
- 2
- Languages
- EN
- Last added
- 2012-07-02
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PHILIPS 74HC/HCT42 BCD to decimal decoder (1-of-10) handbook
The 74HC/HCT42 is a high-speed Si-gate CMOS device that is pin compatible with low power Schottky TTL (LSTTL). It accepts four active HIGH BCD inputs and provides 10 mutually exclusive active LOW outputs, facilitating the addressing of other MSI circuits. The logic design ensures that all outputs remain HIGH when binary codes greater than nine are applied to the inputs.
The device features mutually exclusive outputs and a 1-of-8 demultiplexing capability. The most significant input (A3) can be used as a useful inhibit function when used as a 1-of-8 decoder, or as a data input in an 8-output demultiplexer application. The document provides typical symbol parameters, ordering information, pin descriptions, function tables, and AC/DC characteristics for both HC and HCT variants.
Philips HCT42 specifications
| Logic Family | High-speed Si-gate CMOS |
|---|---|
| TTL Compatibility | Pin compatible with LSTTL |
| Inputs | Four active HIGH BCD inputs |
| Outputs | 10 mutually exclusive active LOW outputs |
Source: PHILIPS 74HC/HCT42 BCD to decimal decoder (1-of-10) handbook
All Philips HCT42 documents by type
Ratings, dimensions and ordering codes, for selection and design work.
Questions answered in these manuals
What happens to the outputs when binary codes greater than nine are applied?
All outputs remain HIGH when binary codes greater than nine are applied to the inputs.
From: PHILIPS 74HC/HCT42 BCD to decimal decoder (1-of-10) handbook
Can the A3 input be used for demultiplexing?
Yes, the A3 input can be used as the data input in an 8-output demultiplexer application.
From: PHILIPS 74HC/HCT42 BCD to decimal decoder (1-of-10) handbook
What is the formula for calculating the output pulse width?
The typical output pulse width is defined as tw = 0.45 x Rext x Cexr.
From: Philips 74HC/HCT423 Dual Retriggerable Monostable Multivibrator Datasheet
Can the device be triggered via the reset input?
No, the '423' variant cannot be triggered via the reset input.
From: Philips 74HC/HCT423 Dual Retriggerable Monostable Multivibrator Datasheet