SN74LVC244APWR - Octal Buffer 3-State 24mA | TI | Bus Driver
MPN: SN74LVC244APWR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.42 | $0.42 |
| 10 | $0.38 | $3.80 |
| 100 | $0.31 | $31.00 |
| 500 | $0.26 | $130.00 |
| 1,000 | $0.21 | $210.00 |
SN74LVC244APWR Overview
A buffer/line driver is a digital logic IC that provides signal amplification, isolation, and fan-out between system blocks. Within the logic IC hierarchy, it belongs to the standard logic family alongside transceivers, latches, and flip-flops. The 3-state output feature lets the device disconnect from a shared bus, enabling multiple drivers to share a common data line without bus contention.
Key features include a wide 1.65-V to 3.6-V supply range covering both 1.8-V and 3.3-V logic domains, inputs that tolerate voltages up to 5.5 V for mixed-voltage systems, and +/-24 mA output drive at 3.3 V. The Ioff partial-power-down circuitry prevents damaging backflow current when VCC is removed, and latch-up performance exceeds 100 mA per JESD 78 Class II. ESD protection exceeds 2000-V HBM (JESD 22 A114-A) and 1000-V CDM.
Fabricated in advanced CMOS, the SN74LVC244A achieves a typical propagation delay of 4.3 ns at 3.3 V while maintaining low static power consumption, balancing speed and efficiency for bus-interface timing budgets.
Typical applications include memory address buffering, clock distribution, and general-purpose I/O expansion for microcontrollers, FPGAs, and DSPs, plus level shifting between 1.8-V and 3.3-V domains in industrial control and telecommunications equipment.
Design tip: decouple VCC with a 0.1-uF ceramic capacitor placed close to the pin, tie unused OE pins to a defined logic level, and keep traces short for high-speed signals.
Drop-in alternatives for SN74LVC244APWR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with SN74LVC244APWR (same form factor and footprint) — differing in Output Enable, Package, Supply Voltage Range, Logic Function, Output Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
SN74LVC244AQPWRQ1
✅ Drop-In📋 Reference alternative (not in catalog)
SN74LV244APW
✅ Drop-In📋 Reference alternative (not in catalog)
SN74LVC540APWR
⚡ Same Package📋 Reference alternative (not in catalog)
74LVC244APW,118
✅ Drop-In📋 Reference alternative (not in catalog)
MC74LCX244DT
✅ Drop-In📋 Reference alternative (not in catalog)
74LVC244APW-13
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
SN74LVC244APWR Maximum Ratings & Electrical Characteristics
| Function | Octal buffer/driver with 3-state outputs |
| Output Polarity | Non-inverting |
| Configuration | 2 elements, 4 bit per element |
| Supply Voltage Range | 1.65 V to 3.6 V |
| Input Voltage Tolerance | Up to 5.5 V |
| Output Drive Current | +/-24 mA at 3.3 V |
| Propagation Delay | 4.3 ns typical at 3.3 V |
| Output Type | 3-state |
| Output Enable | 2 active-low OE pins (one per nibble) |
| Ioff Partial Power Down | Yes |
| ESD Protection | 2000 V HBM (JESD 22 A114-A), 1000 V CDM |
| Latch-up Performance | Exceeds 100 mA (JESD 78 Class II) |
| Operating Temperature | -40C to +125C |
| Package | TSSOP (PW), 20 pins |
| Mounting Type | Surface Mount |
| Technology | LVC CMOS |
| RoHS Status | Compliant |
SN74LVC244APWR Pin Configuration
| Pin 1 | OE1 — Output enable 1, active low (3-state control for Y1 outputs) |
| Pin 2 | 1A1 — Data input, buffer 1, bit 1 |
| Pin 3 | 1Y1 — 3-state output, buffer 1, bit 1 |
| Pin 4 | 1A2 — Data input, buffer 1, bit 2 |
| Pin 5 | 1Y2 — 3-state output, buffer 1, bit 2 |
| Pin 6 | 1A3 — Data input, buffer 1, bit 3 |
| Pin 7 | 1Y3 — 3-state output, buffer 1, bit 3 |
| Pin 8 | 1A4 — Data input, buffer 1, bit 4 |
| Pin 9 | 1Y4 — 3-state output, buffer 1, bit 4 |
| Pin 10 | GND — Ground |
| Pin 11 | 2Y1 — 3-state output, buffer 2, bit 1 |
| Pin 12 | 2A1 — Data input, buffer 2, bit 1 |
| Pin 13 | 2Y2 — 3-state output, buffer 2, bit 2 |
| Pin 14 | 2A2 — Data input, buffer 2, bit 2 |
| Pin 15 | 2Y3 — 3-state output, buffer 2, bit 3 |
| Pin 16 | 2A3 — Data input, buffer 2, bit 3 |
| Pin 17 | 2Y4 — 3-state output, buffer 2, bit 4 |
| Pin 18 | 2A4 — Data input, buffer 2, bit 4 |
| Pin 19 | OE2 — Output enable 2, active low (3-state control for Y2 outputs) |
| Pin 20 | VCC — Power supply, 1.65 V to 3.6 V |
Typical Applications
SN74LVC244APWR is suitable for 6 applications: Microcontroller and FPGA I/O Expansion, Memory Address and Data Bus Buffering, Mixed-Voltage Level Shifting (5-V to 3.3-V), Industrial Control and PLC I/O, Clock and Signal Distribution, Telecommunications Line-Card Logic Buffering.
Microcontroller and FPGA I/O Expansion
The SN74LVC244APWR extends the drive capability of microcontroller and FPGA I/O banks where native pins cannot source enough current or must be protected from bus loading. Its +/-24 mA drive at 3.3 V fans out clock or control lines to multiple peripheral loads, while the 4.3 ns typical propagation delay adds negligible timing margin cost. The two independent 4-bit halves let one package buffer both a data nibble and control group with separate enables. Place the device adjacent to the host I/O pins with 0.1-uF decoupling to keep reflections controlled on short traces.
Recommended
Memory Address and Data Bus Buffering
In systems with SRAM, flash, or memory-mapped peripherals, the SN74LVC244APWR buffers address lines to reduce capacitive loading on the CPU bus. Its 3-state outputs release the bus when another master drives it, and the Ioff feature prevents backfeed during partial-power-down when the memory domain is unpowered. At 3.3 V the 4.3 ns delay fits typical 50-100 ns memory cycle budgets easily. Using two packages, one per address bank with independent OE control, enables bus parking and reduces dynamic power on long backplane traces.
Recommended
Mixed-Voltage Level Shifting (5-V to 3.3-V)
Because its inputs tolerate up to 5.5 V regardless of VCC, the SN74LVC244APWR converts legacy 5-V TTL or 5-V CMOS signals down to clean 3.3-V logic levels while running from a 3.3-V rail. This suits designs mixing legacy 5-V peripherals, sensors, or modules with modern 3.3-V MCUs and FPGAs. Per TI datasheet, VIH/VIL thresholds accommodate both 5-V TTL and 5-V CMOS drivers at 3.3-V VCC. Note the device translates down only; for bidirectional up-translation use the SN74LVC8T245 instead.
Recommended
Industrial Control and PLC I/O
Industrial controllers operating from -40C to +125C ambient benefit from the SN74LVC244APWR's full temperature rating and 2000-V HBM / 1000-V CDM ESD robustness in electrically noisy factory environments. It buffers limit-switch inputs, relay drive commands, and status signals between field wiring and the logic core. Latch-up performance exceeding 100 mA per JESD 78 Class II provides resilience against transient overloads. The 3-state outputs let a service processor take over shared status lines during diagnostics without contention with the main controller.
Recommended
Clock and Signal Distribution
The SN74LVC244APWR repowers clock lines degraded by fan-out, distributing a single clock source to multiple ICs while restoring fast edges thanks to CMOS output drive. Each 4-bit half can carry an independent clock tree branch with its own OE for power-managed clock gating. With 4.3 ns typical delay and low output skew within the package, it suits 20-50 MHz clock distribution where added delay is calibrated out. Keep traces impedance-controlled and add series termination at the driver output to control ringing on longer lines.
Recommended
Telecommunications Line-Card Logic Buffering
Line cards densely packed with processors, PHYs, and FPGAs use the SN74LVC244APWR to buffer inter-chip control buses across backplane connectors. The Ioff partial-power-down feature is essential in telecom shelves where individual cards hot-swap or power up independently - it prevents damaging backflow current through unpowered device inputs. The wide 1.65-V to 3.6-V range accommodates 1.8-V and 3.3-V legacy sections on the same card. Operating temperature up to 125C supports constrained shelf airflow conditions.
Recommended
Recommended Products Summary
Engineering reference data for SN74LVC244APWR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | SN74LVC244AQPWRQ1 | SN74LV244APW | 74LVC244APW,118 | MC74LCX244DT |
|---|---|---|---|---|---|
| Package | TSSOP-20 (PW) | TSSOP-20 (PW) - same | TSSOP-20 (PW) - same | TSSOP-20 (PW) - same | TSSOP-20 (PW) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Nexperia | onsemi |
| Supply Voltage Range | 1.65 V to 3.6 V | 1.65 V to 3.6 V | 3 V to 5.5 V (LV family) | 1.65 V to 3.6 V | 2.0 V to 3.6 V |
| Input Tolerance | 5.5 V | 5.5 V | 7 V (5-V family) | 5.5 V | 5.5 V |
| Output Drive | +/-24 mA | +/-24 mA | +/-24 mA | +/-24 mA | +/-24 mA |
| Automotive Grade (AEC-Q100) | No | Yes (Q1) | No | No | No |
| Output Polarity | Non-inverting | Non-inverting | Non-inverting | Inverting | Non-inverting |
| Operating Temperature | -40C to +125C | -40C to +125C | -40C to +125C | -40C to +125C | -40C to +85C |
| Ioff Partial Power Down | Yes | Yes | No | Yes | Yes |
Key Differentiators
- 5.5-V tolerant inputs at any VCC (vs SN74LV244APW)
- Ioff partial-power-down protection (vs SN74LV244APW)
- Lower-cost non-Q1 option for industrial designs (vs SN74LVC244AQPWRQ1)
- True non-inverting drop-in family (vs SN74LVC540APWR)
Design Notes
Decouple VCC with a 0.1-uF ceramic capacitor placed within 3 mm of pin 20, plus one bulk 4.7-uF capacitor per few buffers on the rail. Simultaneous switching of eight outputs into capacitive loads produces ground bounce; keep the GND return path (pin 10) low-inductance with a via directly to the ground plane. Limit dV/dt-controlled loading if driving high-capacitance buses.
Never leave OE1 (pin 1) or OE2 (pin 19) floating - both are active-low 3-state controls and floating enables cause outputs to enter indeterminate Hi-Z states or oscillate. Tie each OE to GND through a 10-kOhm pull-down (or drive it) to guarantee defined bus behavior at power-up. Note the SN74LVC540A is inverting: swapping in that family variant requires logic-polarity review.
For bus lines longer than about 10 cm, add 22-33 ohm series termination resistors at each driver output to damp reflections; the 24-mA CMOS output drive has low output impedance that over-drives unterminated traces. Keep A-input and Y-output trace stubs short and route away from clock aggressors. When buffering clocks, skew between channels within one package is minimal, but add the 4.3 ns typical delay to your timing budget.
The TSSOP-20 (PW) has 0.65-mm pin pitch; use a standard 20-pin TSSOP land pattern per the TI datasheet mechanical section. The APWR suffix is tape-and-reel (2000 units/reel) - for prototypes order cut tape. If AEC-Q100 qualification may be needed later, consider laying out for the SN74LVC244AQPWRQ1 which is footprint-identical.
Compliance Information
RoHS compliant per TI product page. AEC-Q100 version available as SN74LVC244AQPWRQ1. Halogen-free status not stated in provided data.
