SCHS169D November   1998  – March 2022 CD54HC251 , CD54HCT251 , CD74HC251 , CD74HCT251

PRODUCTION DATA  

  1. 1 Features
  2. 2 Description
  3. 3 Revision History
  4. 4 Pin Configuration and Functions
  5. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 Recommended Operating Conditions (1)
    3. 5.3 Thermal Information
    4. 5.4 Electrical Characteristics
    5. 5.5 Switching Characteristics
  6. 6 Parameter Measurement Information
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Device Functional Modes
  8. 8 Power Supply Recommendations
  9. 9 Layout
    1. 9.1 Layout Guidelines
  10. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • N|16
  • D|16
Thermal pad, mechanical data (Package|Pins)
Orderable Information

5.5 Switching Characteristics

Input tt = 6ns. Unless otherwise specified, CL = 50pF
PARAMETER VCC (V) 25°C -40°C to 85°C -55°C to 125°C UNIT
TYP MAX MAX MAX
HC TYPES
tpd Select to outputs 2 245 305 370 ns
4.5 21(1) 49 61 74
6 42 52 63
tpd Data to outputs 2 175 220 265 ns
4.5 12(1) 35 44 53
6 30 37 45
tpd Enable to high Z and enable from high Z 2 140 175 210 ns
4.5 11(1) 28 35 42
6 24 30 36
tt Output transition times 2 75 95 110 ns
4.5 15 19 22
6 13 16 19
Ci Input capacitance 10 10 10 pF
CO Three-state output capacitance 15 15 15 pF
Cpd(3)(4) Power dissipation capacitance 5 60(2) pF
HCT TYPES
tpd Select to outputs 4.5 18(1) 42 53 63 ns
tpd Data to outputs 4.5 12(1) 35 44 53 ns
tpd Enable to high Z and enable from high Z 4.5 12(1) 30 38 45 ns
tt Output transition times 4.5 15 19 22 ns
Ci Input capacitance 10 10 10 pF
Cpd(3)(4) Power dissipation capacitance 5 60(2) pF
(1) Typical value tested at 5V, CL = 15pF.
(2) Typical value tested at 5V.
(3) CPD is used to determine the dynamic power consumption, per channel.
(4) PD = VCC2fi(CPD + CL) where fi = input frequency, CL = output load capacitance, VCC = supply voltage.