SCLSA03 March   2024 SN74AHC257

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6.   6
  7.   7
  8. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Switching Characteristics
    7. 5.7 Noise Characteristics
    8. 5.8 Typical Characteristics
  9. 6 Parameter Measurement Information
  10. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Balanced CMOS 3-State Outputs
      2. 7.3.2 Standard CMOS Inputs
      3. 7.3.3 Clamp Diode Structure
    4. 7.4 Device Functional Modes
  11. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
    3. 8.3 Design Requirements
      1. 8.3.1 Power Considerations
      2. 8.3.2 Input Considerations
      3. 8.3.3 Output Considerations
    4. 8.4 Detailed Design Procedure
    5. 8.5 Application Curve
    6. 8.6 Power Supply Recommendations
    7. 8.7 Layout
      1. 8.7.1 Layout Guidelines
      2. 8.7.2 Layout Example
  12. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  13. 10Revision History
  14. 11Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

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

6 Parameter Measurement Information

Phase relationships between waveforms were chosen arbitrarily for the examples listed in the following table. All input pulses are supplied by generators having the following characteristics: PRR ≤ 1MHz, ZO = 50Ω, tt < 2ns.

The outputs are measured individually with one input transition per measurement.

TEST S1 S2 RL CL ΔV VCC
tPLH, tPHL OPEN OPEN — 15pF, 50pF — ALL
tPLZ, tPZL CLOSED OPEN 1kΩ 15pF, 50pF 0.15V ≤ 2.5V
tPHZ, tPZH OPEN CLOSED 1kΩ 15pF, 50pF 0.15V ≤ 2.5V
tPLZ, tPZL CLOSED OPEN 1kΩ 15pF, 50pF 0.3V > 2.5V
tPHZ, tPZH OPEN CLOSED 1kΩ 15pF, 50pF 0.3V > 2.5V

GUID-EB3CF292-AF1E-41A1-A556-76EDB85F7F6F-low.gif
(1) CL includes probe and test-fixture capacitance.
Figure 6-1 Load Circuit for 3-State Outputs
GUID-20230721-SS0I-8DSF-V0ZP-LHHGHP0QG4NS-low.svg
(3) The greater between tPZL and tPZH is the same as ten.
(4) The greater between tPLZ and tPHZ is the same as tdis.
Figure 6-3 Voltage Waveforms Propagation Delays
GUID-20230721-SS0I-VJQB-BMGP-K0S1JW76FHMX-low.svg
Noise values measured with all other outputs simultaneously switching.
Figure 6-5 Voltage Waveforms, Noise
GUID-535BFE0F-9D7B-4CA6-85AB-D09CD11F52EA-low.gif
(1) The greater between tPLH and tPHL is the same as tpd.
Figure 6-2 Voltage Waveforms Propagation Delays
GUID-20200713-CA0I-ZTM5-PTJB-WD0LZ8VNG7PG-low.gif
(1) The greater between tr and tf is the same as tt.
Figure 6-4 Voltage Waveforms, Input and Output Transition Times