Data Sheet
CDx4HC147, CD74HCT147 High-Speed CMOS Logic 10- to 4-Line Priority Encoder
1 Features
- Buffered inputs and outputs
- Typical propagation delay: 13ns at VCC = 5V, CL = 15pF, TA = 25oC
- Fanout (over
temperature range)
- Bus driver outputs: 15 LSTTL loads
- Wide operating temperature range: -55oC to 125oC
- Balanced propagation delay and transition times
- Significant power reduction compared to LSTTL logic ICs
- HC types
- 2V to 6V Operation
- High noise immunity: NIL = 30%, NIH = 30% of VCC at VCC = 5V
- HCT types
- 4.5V to 5.5V Operation
- Direct LSTTL input logic compatibility, VIL= 0.8V (Max), VIH = 2V (Min)
- CMOS input compatibility, Il ≤ 1µA at VOL, VOH
2 Description
The CDx4HC147 and CD74HCT147 are 9-input priority encoders. These devices provide the 10-line to 4-line priority encoding function by use of the implied decimal “zero.”
Device Information
| PART NUMBER | PACKAGE(1) | BODY SIZE (NOM)(2) |
|---|---|---|
| CD54HC147 | J (CDIP, 16) | 21.34mm × 6.92mm |
| CD74HC147 | N (PDIP, 16) | 19.31mm × 6.35mm |
| D (SOIC, 16) | 9.90mm × 3.90mm | |
| PW (TSSOP, 16) | 5.00mm × 4.40mm | |
| CD74HCT147 | N (PDIP, 16) | 19.31mm × 6.35mm |
(1) For more information, see Mechanical, Packaging, and
Orderable Information.
(2) The body size (length × width) is a nominal value and does not include
pins.
Functional Block
Diagram3 Pin Configuration and Functions
CD54HC147 J Package;
CD74HC(T)147 N, D, or PW Package;16-Pin CDIP, PDIP, SOIC, or TSSOP
(Top View)
Table 3-1 Pin Functions
| PIN | I/O1 | DESCRIPTION | |
|---|---|---|---|
| NO. | NAME | ||
| 1 | I4 | I | Active low input 4 |
| 2 | I5 | I | Active low input 5 |
| 3 | I6 | I | Active low input 6 |
| 4 | I7 | I | Active low input 7 |
| 5 | I8 | I | Active low input 8 |
| 6 | Y2 | O | Active low output 2 |
| 7 | Y1 | O | Active low output 1 |
| 8 | GND | — | Ground |
| 9 | I0 | I | Active low input 0 |
| 10 | I9 | I | Active low input 9 |
| 11 | I1 | I | Active low input 1 |
| 12 | I2 | I | Active low input 2 |
| 13 | I3 | I | Active low input 3 |
| 14 | Y3 | O | Active low output 3 |
| 15 | NC | N/A | No internal connection |
| 16 | VCC | — | Positive supply |
- I = input, O = output, P = power, FB = feedback, GND = ground, N/A = not applicable