Specifications
| Type | Description |
|---|---|
| Part Number | SN74LS245 |
| Manufacturer | Texas Instruments |
| Product Type | Operational Amplifier |
| Category | Signal Chain |
| Package / Case | 20-pin CDIP J 24.20 mm x 6.92 mm; CFP W 7.02 mm x 13.72 mm; LCCC FK 8.89 mm x 8.89 mm; SSOP DB 7.20 mm x 5.30 mm; SOIC DW 12.80 mm x 7.50 mm; PDIP N 24.33 mm x 6.35 mm; SO NS 12.60 mm x 5.30 mm |
| Number of channels | 8; octal bus transceiver |
| Output type | 3-state outputs; outputs drive bus lines directly and can be disabled |
| Direction control | DIR low = Bx to Ax; DIR high = Ax to Bx; positive logic function |
| Output enable polarity | Active low; OE low = all channels active; OE high = all channels disabled/high impedance |
| Supply voltage absolute maximum | 7 V max; all voltage values with respect to GND |
| Input voltage absolute maximum | 7 V max; all voltage values with respect to GND |
| Operating virtual junction temperature absolute maximum | 150 °C max; over operating free-air temperature range |
| Storage temperature | -65 to 150 °C; absolute maximum rating |
| HBM ESD rating | ±2500 V; ANSI/ESDA/JEDEC JS-001 |
| CDM ESD rating | ±1500 V; JEDEC JESD22-C101 |
| Recommended supply voltage, SN74LS245 | 4.75 V min, 5 V nom, 5.25 V max |
| Recommended supply voltage, SN54LS245 | 4.5 V min, 5 V nom, 5.5 V max |
| High-level output current | -15 mA; SN74LS245 recommended operating condition |
| Low-level output current | 24 mA; SN74LS245 recommended operating condition |
| Operating free-air temperature | 0 to 70 °C; SN74LS245 |
| High-level input voltage | 2 V min; over recommended operating free-air temperature range |
| Low-level input voltage | 0.8 V max; SN74LS245 |
| Input clamp voltage | -1.5 V max; VCC = min, II = -18 mA |
| Bus input hysteresis | 0.2 V typ, 0.4 V max; A or B inputs, VCC = min, VT+ - VT- |
| High-level output voltage, IOH = -3 mA | 2.4 V min, 3.4 V typ; VCC = min, IOH = -3 mA, VIL = VIL(max) |
| High-level output voltage, IOH = max | 2 V min; VIH = 2 V, IOH = max |
| Low-level output voltage, IOL = 12 mA | 0.4 V max; VCC = min, IOL = 12 mA, VIH = 2 V, VIL = VIL(max) |
| Low-level output voltage, IOL = 24 mA | 0.5 V max; SN74LS245, IOL = 24 mA, VIH = 2 V, VIL = VIL(max) |
| Off-state output current high | 20 µA max; VCC = max, OE at 2 V, VO = 2.7 V |
| Off-state output current low | -200 µA max; VCC = max, OE at 2 V, VO = 0.4 V |
| Input current at maximum input voltage, A or B input | 0.1 mA max; VCC = max, VI = 5.5 V |
| Input current at maximum input voltage, DIR or OE input | 0.1 mA max; VCC = max, VI = 7 V |
| High-level input current | 20 µA max; VCC = max, VIH = 2.7 V |
| Low-level input current | -0.2 mA max; VCC = max, VIL = 0.4 V |
| Short-circuit output current | -40 mA typ, -225 mA max; VCC = max; not more than one output shorted at a time for max 1 second |
| Supply current outputs high | 48 mA typ, 70 mA max; VCC = max, outputs open, total outputs high |
| Supply current outputs low | 62 mA typ, 90 mA max; VCC = max, outputs open, total outputs low |
| Supply current outputs high-Z | 64 mA typ, 95 mA max; VCC = max, outputs open, outputs at high impedance |
| Propagation delay low-to-high | 8 ns typ, 12 ns max; VCC = 5 V, TA = 25°C, CL = 45 pF, RL = 667 ohm |
| Propagation delay high-to-low | 8 ns typ, 12 ns max; VCC = 5 V, TA = 25°C, CL = 45 pF, RL = 667 ohm |
| Output enable time to low level | 27 ns typ, 40 ns max; VCC = 5 V, TA = 25°C, CL = 45 pF, RL = 667 ohm |
| Output enable time to high level | 25 ns typ, 40 ns max; VCC = 5 V, TA = 25°C, CL = 45 pF, RL = 667 ohm |
| Output disable time from low level | 15 ns typ, 25 ns max; VCC = 5 V, TA = 25°C, CL = 5 pF, RL = 667 ohm |
| Output disable time from high level | 15 ns typ, 28 ns max; VCC = 5 V, TA = 25°C, CL = 5 pF, RL = 667 ohm |
| Junction-to-ambient thermal resistance, DB SSOP | 91.7 °C/W; DB SSOP 20-pin package |
| Junction-to-ambient thermal resistance, DW SOIC | 79.0 °C/W; DW SOIC 20-pin package |
| Junction-to-ambient thermal resistance, N PDIP | 46.1 °C/W; N PDIP 20-pin package |
| Junction-to-ambient thermal resistance, NS SO | 74.2 °C/W; NS SO 20-pin package |
| Datasheet Status | request_only |
Product Overview
The SN74LS245 is a Texas Instruments octal bus transceiver for Logic interfaces requiring bidirectional 8-channel bus transfer. Its 3-state outputs can drive bus lines directly and can also be disabled for high-impedance operation. Direction is controlled by DIR: a low DIR level transfers Bx to Ax, while a high DIR level transfers Ax to Bx.
Output enable is active low. With OE low, all channels are active; with OE high, all channels are disabled and placed in high impedance. The SN74LS245 recommended supply range is 4.75 V to 5.25 V with 5 V nominal operation, while the related SN54LS245 range is 4.5 V to 5.5 V. Input thresholds include 2 V minimum high-level input voltage and 0.8 V maximum low-level input voltage for SN74LS245.
Package options include 20-pin CDIP, CFP, LCCC, SSOP, SOIC, PDIP, and SO formats. Thermal resistance values are specified for DB SSOP, DW SOIC, N PDIP, and NS SO packages. Timing data at VCC = 5 V and TA = 25 °C includes 8 ns typical low-to-high and high-to-low propagation delays.
Key Features
- 8-channel octal bus transceiver architecture
- 3-state outputs for direct bus-line drive
- Active-low OE controls all-channel enable state
- DIR low transfers Bx inputs to Ax outputs
- DIR high transfers Ax inputs to Bx outputs
- SN74LS245 supports 4.75 V to 5.25 V supply
- 0 to 70 °C SN74LS245 free-air operation
- 8 ns typical propagation delay at 5 V
- Output enable time specified to 40 ns maximum
- Multiple 20-pin package formats listed
Typical Applications
- Bidirectional digital bus interfaces
- 8-bit data bus buffering
- Shared bus isolation
- Microprocessor peripheral buses
- TTL logic signal transfer
- 3-state bus control
- Direction-controlled parallel data paths
Procurement Notes
When requesting a quote for SN74LS245, 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 MCU, processor and logic IC sourcing, package, operating voltage, temperature grade, speed or frequency grade, firmware or mask version, lifecycle status and programming requirements should be checked before approval.
FAQ
What type of device is the SN74LS245?
The SN74LS245 is a Texas Instruments octal bus transceiver in the Signal_Chain category. It provides 8 channels with 3-state outputs that can drive bus lines directly or be disabled into a high-impedance state.
How is bus direction controlled on the SN74LS245?
Direction is set by the DIR input using positive logic. When DIR is low, data transfers from Bx to Ax. When DIR is high, data transfers from Ax to Bx.
What supply range is recommended for SN74LS245 operation?
For SN74LS245, the recommended supply voltage is 4.75 V minimum, 5 V nominal, and 5.25 V maximum. The specified operating free-air temperature range is 0 to 70 °C.
What happens when OE is high on the SN74LS245?
OE is active low. When OE is low, all channels are active. When OE is high, all channels are disabled and the outputs are placed in a high-impedance state.
What package options are available for the SN74LS245?
The SN74LS245 is available in multiple 20-pin package formats including CDIP (Ceramic DIP), CFP (Ceramic Flat Pack), LCCC (Leadless Ceramic Chip Carrier), SSOP (Shrink Small Outline Package), SOIC (Small Outline IC), PDIP (Plastic DIP), and SO (Small Outline) packages, providing flexibility for various PCB design requirements.
What is the typical application of the SN74LS245?
The SN74LS245 octal bus transceiver is commonly used in memory bus interfacing, microprocessor system buses, TTL logic signal transfer between subsystems, 3-state bus control, and bidirectional parallel data communication in industrial control, computing, and telecommunications equipment.
Technical Review & Sourcing Note
Prepared by LDeepAI Component Sourcing Team. Reviewed for RFQ, documentation and alternative sourcing use. Last updated: June 30, 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.