SN74HC540 Octal Inverting Buffer Line Driver

Texas Instruments Signal_Chain — specifications, applications, sourcing support and RFQ.

SN74HC540 Octal Inverting Buffer Line Driver

RFQ Available Sourcing Support Alternative Matching RoHS
Part Number
SN74HC540
Manufacturer
Texas Instruments
Package
20-pin CDIP 26.92 mm x 6.92 mm; SOIC 12.80 mm x 7.50 mm; PDIP 25.40 mm x 6.35 mm; SO 15.00 mm x 5.30 mm; TSSOP 6.50 mm x 4.40 mm
Category
Signal Chain
Product Type
Operational Amplifier

Quick Sourcing Note

The SN74HC540 from Texas Instruments is a Signal_Chain octal inverting buffer line driver with inverting 3-state outputs. It operates from a recommended 2 to 6 V supply range, with SN74HC540 free-air operation specified from -40 to 85 °C. Package options include 20-pin CDIP, SOIC, PDIP, SO, and TSSOP formats. The device supports controlled output disable to high impedance when either OE input is high, making it applicable to signal buffering, line driving, and shared-bus output control. Key parameters include 0 to VCC input and output ranges, 3 pF typical input capacitance, 35 pF typical power dissipation capacitance per buffer/driver, and propagation delay values down to 8 ns typical at 6 V with 50 pF load.

Specifications

TypeDescription
Part NumberSN74HC540
ManufacturerTexas Instruments
Product TypeOperational Amplifier
CategorySignal Chain
Package / Case20-pin CDIP 26.92 mm x 6.92 mm; SOIC 12.80 mm x 7.50 mm; PDIP 25.40 mm x 6.35 mm; SO 15.00 mm x 5.30 mm; TSSOP 6.50 mm x 4.40 mm
Supply Voltage Range2 to 6 V
Supply Voltage Range-0.5 to 7 V
Operating Free-Air Temperature-55 to 125 °C
Operating Free-Air Temperature-40 to 85 °C
High-Level Input Voltagemin 1.5 V
High-Level Input Voltagemin 3.15 V
High-Level Input Voltagemin 4.2 V
Low-Level Input Voltagemax 0.5 V
Low-Level Input Voltagemax 1.35 V
Low-Level Input Voltagemax 1.8 V
Input Voltage Range0 to VCC
Output Voltage Range0 to VCC
Input Transition Rise/Fall Timemax 1000 ns
Input Transition Rise/Fall Timemax 500 ns
Input Transition Rise/Fall Timemax 400 ns
Input Clamp Current+/-20 mA
Output Clamp Current+/-20 mA
Continuous Output Current+/-35 mA
Continuous Current Through VCC or GND+/-70 mA
Junction Temperature150 °C
Storage Temperature Range-65 to 150 °C
Lead Temperature300 °C
High-Level Output Voltagemin 1.9 V, typ 1.998 V; SN54 min 1.9 V; SN74 min 1.9 V
High-Level Output Voltagemin 4.4 V, typ 4.499 V; SN54 min 4.4 V; SN74 min 4.4 V
High-Level Output Voltagemin 5.9 V, typ 5.999 V; SN54 min 5.9 V; SN74 min 5.9 V
High-Level Output Voltagemin 3.98 V, typ 4.3 V; SN54 min 3.7 V; SN74 min 3.84 V
High-Level Output Voltagemin 5.48 V, typ 5.8 V; SN54 min 5.2 V; SN74 min 5.34 V
Low-Level Output Voltagetyp 0.002 V, max 0.1 V; SN54 max 0.1 V; SN74 max 0.1 V
Low-Level Output Voltagetyp 0.001 V, max 0.1 V; SN54 max 0.1 V; SN74 max 0.1 V
Low-Level Output Voltagetyp 0.001 V, max 0.1 V; SN54 max 0.1 V; SN74 max 0.1 V
Low-Level Output Voltagetyp 0.17 V, max 0.26 V; SN54 max 0.4 V; SN74 max 0.33 V
Low-Level Output Voltagetyp 0.15 V, max 0.26 V; SN54 max 0.4 V; SN74 max 0.33 V
Input Currenttyp +/-0.1 nA; SN54 max +/-100 nA; SN74 max +/-1000 nA
Off-State Output Currenttyp +/-0.01 uA, max +/-0.5 uA; SN54 max +/-10 uA; SN74 max +/-5 uA
Supply Currenttyp 8 uA; SN54 max 160 uA; SN74 max 80 uA
Input Capacitancetyp 3 pF, max 10 pF
Propagation Delaytyp 35 ns, max 100 ns; SN54 max 149 ns; SN74 max 125 ns
Propagation Delaytyp 10 ns, max 20 ns; SN54 max 30 ns; SN74 max 25 ns
Propagation Delaytyp 8 ns, max 17 ns; SN54 max 25 ns; SN74 max 21 ns
Output Enable Timetyp 75 ns, max 150 ns; SN54 max 224 ns; SN74 max 188 ns
Output Enable Timetyp 15 ns, max 30 ns; SN54 max 45 ns; SN74 max 38 ns
Output Enable Timetyp 13 ns, max 26 ns; SN54 max 38 ns; SN74 max 32 ns
Output Disable Timetyp 40 ns, max 150 ns; SN54 max 224 ns; SN74 max 188 ns
Output Disable Timetyp 18 ns, max 30 ns; SN54 max 45 ns; SN74 max 38 ns
Output Disable Timetyp 17 ns, max 26 ns; SN54 max 38 ns; SN74 max 32 ns
Output Transition Timetyp 28 ns, max 60 ns; SN54 max 90 ns; SN74 max 75 ns
Output Transition Timetyp 8 ns, max 12 ns; SN54 max 18 ns; SN74 max 15 ns
Output Transition Timetyp 6 ns, max 10 ns; SN54 max 15 ns; SN74 max 13 ns
Propagation Delaytyp 60 ns, max 150 ns; SN54 max 224 ns; SN74 max 188 ns
Propagation Delaytyp 15 ns, max 30 ns; SN54 max 45 ns; SN74 max 38 ns
Propagation Delaytyp 13 ns, max 26 ns; SN54 max 38 ns; SN74 max 32 ns
Output Enable Timetyp 100 ns, max 200 ns; SN54 max 298 ns; SN74 max 250 ns
Output Enable Timetyp 20 ns, max 40 ns; SN54 max 60 ns; SN74 max 50 ns
Output Enable Timetyp 17 ns, max 34 ns; SN54 max 51 ns; SN74 max 43 ns
Output Transition Timetyp 45 ns, max 210 ns; SN54 max 315 ns; SN74 max 265 ns
Output Transition Timetyp 17 ns, max 42 ns; SN54 max 63 ns; SN74 max 53 ns
Output Transition Timetyp 13 ns, max 36 ns; SN54 max 53 ns; SN74 max 45 ns
Power Dissipation Capacitance Per Buffer/Drivertyp 35 pF
Output FunctionInverting 3-state outputs
Output Disable LogicHigh impedance when OE1=high or OE2=high
Function Table StateY=H
Function Table StateY=L
Function Table StateY=Z
Function Table StateY=Z
Bypass Capacitor Recommendation0.1 uF recommended; 0.1 uF and 1 uF commonly used in parallel
Unused Input HandlingTie unused inputs to VCC or GND
Datasheet Statusrequest_only

Product Overview

The recommended supply range for SN54HC540 and SN74HC540 operation is 2 to 6 V, with input and output voltage ranges from 0 to VCC. For SN74HC540, the recommended operating free-air temperature range is -40 to 85 °C. Logic thresholds are specified across 2 V, 4.5 V, and 6 V supplies, including VIH minimums of 1.5 V, 3.15 V, and 4.2 V and VIL maximums of 0.5 V, 1.35 V, and 1.8 V.

Key Features

  • Octal inverting buffer line driver function
  • Inverting 3-state outputs controlled by OE1 and OE2
  • Recommended 2 to 6 V supply operation
  • SN74HC540 free-air temperature range -40 to 85 °C
  • Input and output voltage ranges from 0 to VCC
  • High-impedance output when either output-enable input is high
  • Typical 3 pF input capacitance over 2 to 6 V
  • Typical 35 pF power dissipation capacitance per buffer/driver
  • Unused inputs must be tied to VCC or GND
  • 0.1 uF bypass capacitor recommended near VCC

Typical Applications

  • Inverting signal buffering
  • Line driver interfaces
  • Shared bus output control
  • High-impedance output gating
  • Digital signal routing
  • Buffered logic fanout
  • Controlled A-to-Y inversion

Procurement Notes

When requesting a quote for SN74HC540, buyers should confirm the manufacturer, package or case, required quantity, target date code, compliance documents, packing method, destination country and expected delivery schedule.

If alternatives are acceptable, buyers should share the approved vendor list, required electrical or optical limits, package constraints and qualification requirements. Any alternative part should be reviewed by the buyer's engineering team before production use.

For analog and signal-chain sourcing, supply voltage, bandwidth, accuracy, noise level, package, temperature grade, input/output configuration and qualification requirements should be verified before approval.

FAQ

What supply voltage range is specified for SN74HC540 operation?

The recommended supply voltage range for SN54HC540 and SN74HC540 operation is 2 to 6 V. The absolute maximum supply voltage range is specified separately as -0.5 to 7 V.

How are the SN74HC540 outputs enabled or disabled?

The outputs are inverting 3-state outputs. When OE1 and OE2 are both low, an A input is output at Y with inversion. If OE1 is high or OE2 is high, the Y output is high impedance.

What packages are listed for the SN74HC540?

The listed package options are 20-pin CDIP 26.92 mm x 6.92 mm, SOIC 12.80 mm x 7.50 mm, PDIP 25.40 mm x 6.35 mm, SO 15.00 mm x 5.30 mm, and TSSOP 6.50 mm x 4.40 mm.

How should unused inputs be handled on this device?

Unused inputs should be tied to VCC or GND. The datasheet fact states this is required to prevent floating inputs and undefined operational states.

Technical Review & Sourcing Note

Prepared by LDeepAI Component Sourcing Team. Reviewed for RFQ, documentation and alternative sourcing use. Last updated: July 21, 2026.

This page is based on manufacturer datasheet information and LDeepAI sourcing review. Specifications should be verified against the official manufacturer datasheet before final procurement or design approval. Final electrical, optical and reliability approval should be confirmed by the buyer's engineering team.

Request Quote Request Datasheet