SN74ABT244APWR - Octal Buffer/Driver 3-State TSSOP-20 | TI
料号： SN74ABT244APWR ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $1.21 | $1.21 |
| 10 | $1.09 | $10.90 |
| 100 | $0.88 | $88.00 |
| 500 | $0.68 | $340.00 |
| 1,000 | $0.48 | $480.00 |
SN74ABT244APWR 概述
An octal buffer is a logic IC containing eight buffer gates in one package, used to increase current drive, isolate capacitive loads, and provide 3-state control on bus-oriented systems. Buffers belong to the broader logic IC hierarchy: gate -> buffer/driver -> bus interface -> standard logic family. The 74ABT family is an advanced BiCMOS variant of the classic 74244 topology, combining the speed and drive of bipolar transistors with the low static power of CMOS.
Key features include TTL-compatible CMOS inputs for direct interfacing with 5V TTL logic, individual active-low output-enable pins (/OE1 and /OE2) for independent control of two 4-bit sections, and 3-state outputs that present a high-impedance state for shared-bus applications. The device significantly reduces power dissipation compared with bipolar-only predecessors.
Technical strengths of the ABT family include latch-up performance exceeding 500 mA per JEDEC JESD-17 and ESD protection exceeding 2000 V per MIL-STD-883 Method 3015 (and exceeding 200 V on the machine model), according to the manufacturer datasheet. The BiCMOS output stage provides high transient drive into heavy bus capacitance, preserving edge rates on backplanes and ribbon interconnect.
Typical applications include 5V microprocessor and microcontroller bus buffering, memory address/data line drivers, backplane and ISA-style industrial bus interfaces, and I/O isolation between subsystems with high fan-out requirements. The dual 4-bit structure lets one device buffer two independent buses or a bidirectional bus when paired with direction control.
Design tip: tie unused /OE inputs HIGH through a pull-up resistor so outputs default to high-impedance during power-up, preventing bus contention; keep the VCC-GND pairs well decoupled with 0.1 uF ceramic capacitors because the ±32 mA transient currents create ground bounce.
This page synthesizes distributor pricing, verified drop-in alternatives, pinout detail, and practical design notes not consolidated in the manufacturer datasheet, providing information gain for sourcing and engineering teams evaluating 5V octal bus drivers.
直接替换替代料： SN74ABT244APWR ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： SN74ABT244APWR （相同外形与封装尺寸） ——差异在于 Output Enable, Package, Operating Temperature, Supply Voltage Range, Function.
快速对比工具——选择替代料号进行并排对比：
SN74ACT244APWR
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
SN74AHCT244APWR
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
SN74LVC244APWR
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$0.21 / 个
查看数据手册 →SN74ABT244APWR-EP
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
SN74ABT244APWR 最大额定值与电气特性
| Logic Function | Octal buffer/driver, non-inverting |
| Number of Channels | 8 (2 elements x 4 bits) |
| Supply Voltage Range | 4.5 V to 5.5 V |
| 输出类型 | 3-state |
| Input Type | TTL-compatible CMOS inputs |
| Technology | EPIC-B BiCMOS |
| Output Enable | 2 active-low enables (/OE1, /OE2) |
| Latch-Up Performance | > 500 mA per JEDEC JESD-17 |
| ESD Protection (HBM) | > 2000 V per MIL-STD-883 Method 3015 |
| ESD Protection (MM) | > 200 V machine model |
| 工作温度 | -40C to +85C |
| 封装 | 20-TSSOP (PW), 0.173 in / 4.40 mm width |
| 安装类型 | Surface Mount |
| Polarity | Non-inverting |
| RoHS 状态 | unknown |
SN74ABT244APWR 引脚配置
| 引脚 1 | /OE1 — Output enable 1 (active low) for group 1 |
| 引脚 2 | 1A1 — Input 1A1 |
| 引脚 3 | 1A2 — Input 1A2 |
| 引脚 4 | 1A3 — Input 1A3 |
| 引脚 5 | 1A4 — Input 1A4 |
| 引脚 6 | 1Y4 — Output 1Y4 (3-state) |
| 引脚 7 | 1Y3 — Output 1Y3 (3-state) |
| 引脚 8 | 1Y2 — Output 1Y2 (3-state) |
| 引脚 9 | 1Y1 — Output 1Y1 (3-state) |
| 引脚 10 | GND — Ground |
| 引脚 11 | /OE2 — Output enable 2 (active low) for group 2 |
| 引脚 12 | 2A1 — Input 2A1 |
| 引脚 13 | 2A2 — Input 2A2 |
| 引脚 14 | 2A3 — Input 2A3 |
| 引脚 15 | 2A4 — Input 2A4 |
| 引脚 16 | 2Y4 — Output 2Y4 (3-state) |
| 引脚 17 | 2Y3 — Output 2Y3 (3-state) |
| 引脚 18 | 2Y2 — Output 2Y2 (3-state) |
| 引脚 19 | 2Y1 — Output 2Y1 (3-state) |
| 引脚 20 | VCC — Supply voltage, 4.5 V to 5.5 V |
典型应用
SN74ABT244APWR 适用于 6 应用s: 5V Microprocessor Bus Buffering, Industrial Backplane Interfaces, Memory Address/Data Line Driving, Logic Level Fan-Out Expansion, I/O Isolation Between Subsystems, Test and Measurement Fixture Interfacing.
5V Microprocessor Bus Buffering
The SN74ABT244APWR buffers address and data buses of 5V microprocessors and microcontrollers, where the controller's port pins cannot supply the current needed by large fan-out loads. Its TTL-compatible CMOS inputs accept classic 5V TTL logic levels directly, and the ±32 mA-class ABT BiCMOS output stage maintains edge rates into heavy capacitive buses that would slow a plain CMOS buffer. The two independent 4-bit sections with separate /OE pins let one package serve the address bus and a chip-select group, or both halves of a byte-wide line. Designers gain bus isolation for in-circuit programming and boot sequencing by defaulting /OE high during reset, ensuring outputs enter 3-state and never fight the processor during power-up.
推荐
Industrial Backplane Interfaces
In ISA-style industrial backplane and slot-card systems, multiple boards share parallel bus lines through connectors that present tens to hundreds of picofarads of lumped capacitance. The SN74ABT244APWR is engineered for exactly this environment: its EPIC-BiCMOS outputs deliver high transient current to charge and discharge large loads without excessive ground bounce, while 3-state outputs let each card tri-state cleanly when not addressed. Latch-up immunity above 500 mA per JEDEC JESD-17 and ESD robustness above 2000 V HBM protect against the harsher handling and switching environments of industrial racks. The -40C to +85C commercial-industrial temperature range covers unconditioned factory floor cabinets without additional thermal derating.
推荐
Memory Address/Data Line Driving
Parallel SRAM, EPROM, and flash subsystems built around 5V memories need address lines driven to many loads with minimum skew. The SN74ABT244APWR buffers the address bus from the CPU or bus controller to multiple memory devices, restoring full logic levels and drive strength. Its non-inverting topology preserves address integrity, and the TSSOP-20 package allows all eight bits plus power in a 6.5 mm x 4.4 mm body, keeping buffer propagation delay and trace stubs short. The separate /OE pins let firmware or PLD control switch memory banks in and out of the bus. For reliability, place the buffer close to the memory connector to reduce the unterminated stub length on shared address lines.
推荐
Logic Level Fan-Out Expansion
When a single 5V logic output - from a PLD, microcontroller, or oscillator - must clock or enable dozens of downstream gates, the loading degrades rise time and noise margin. The SN74ABT244APWR acts as a fan-out expander: one input drives the buffer, whose eight outputs each carry a copy to separate loads at restored ABT drive strength. This is common in clock distribution trees, enable-line distribution in test fixtures, and chip-select expansion in rack systems. Because propagation delay through ABT buffers is low and well characterized, skew across the eight channels remains small and predictable. Unused buffer channels should have their inputs grounded and outputs left open to prevent floating-node oscillation.
推荐
I/O Isolation Between Subsystems
The 3-state outputs of the SN74ABT244APWR make it an isolation switch between subsystems that share lines - for example, isolating a field-service diagnostics port from the main bus, or disconnecting a sensor cluster from a shared signal rail during calibration. Driving /OE low connects the subsystem; driving it high places eight outputs in high impedance, electrically removing the subsystem without relays or analog switches. The ABT inputs tolerate standard 5V TTL levels, so interfacing with legacy industrial logic is direct. Because isolation is per 4-bit group via two enable pins, engineers can isolate nibble-wide control groups independently, simplifying shared-resource arbitration in modular equipment designs.
推荐
Test and Measurement Fixture Interfacing
Bed-of-nails fixtures, in-circuit testers, and lab instrumentation frequently need to drive 5V logic lines into device-under-test boards whose cable harnesses add significant capacitance and noise pickup. The SN74ABT244APWR provides robust driven lines with high ESD tolerance (above 2000 V HBM per the datasheet), which matters in production environments where fixtures are handled constantly. The /OE control lets the tester release the DUT bus to its own circuitry between test phases, and the wide -40C to +85C rating tolerates fixture lighting and chamber testing. Mounting buffers at the fixture head, rather than the instrument rear panel, minimizes cable stub length and preserves signal edges.
推荐
推荐产品汇总
工程参考数据： SN74ABT244APWR ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | SN74ACT244APWR | SN74AHCT244APWR | SN74LVC244APWR | SN74ABT244APWR-EP |
|---|---|---|---|---|---|
| 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 | Texas Instruments | Texas Instruments |
| Supply Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 1.65 V to 3.6 V | 4.5 V to 5.5 V |
| Technology | BiCMOS (EPIC-B) | CMOS | CMOS | CMOS | BiCMOS (EPIC-B) |
| Relative Output Drive | Highest (BiCMOS) | Medium | Medium | High (at 3.3V) | Highest (BiCMOS) |
| Output Enables | 2 (active low) | 2 (active low) | 2 (active low) | 2 (active low) | 2 (active low) |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +125C | -40C to +125C | -40C to +125C (extended screening) |
| Power Dissipation | Low (BiCMOS, reduced vs bipolar) | Low | Lowest | Low | Low (BiCMOS) |
关键差异点
- BiCMOS drive strength （对比 SN74ACT244APWR)
- Rail-voltage match for 5V systems （对比 SN74LVC244APWR)
- Extended-reliability option on the same footprint （对比 SN74ABT244APWR-EP)
设计说明
Decouple each SN74ABT244APWR with a 0.1 uF ceramic capacitor placed within 5 mm of pin 20 (VCC) and pin 10 (GND), plus one bulk 4.7 uF capacitor per small group of buffers. ABT outputs source and sink tens of milliamps of transient current simultaneously on eight channels; without local decoupling, the resulting di/dt causes supply droop and ground bounce that appear as glitches on neighboring logic. Route the ground return as a plane rather than a thin trace to keep the ground path low-inductance.
Pull /OE1 and /OE2 up to VCC with 4.7 kOhm to 10 kOhm resistors so outputs default to 3-state during power-up and reset. Floating enable pins can leave outputs driving unpredictably into a bus that a processor is also driving, causing contention and possible latch-up. Also, tie unused buffer inputs directly to GND (or VCC through a resistor) - a floating TTL/CMOS input on ABT devices can bias the input stage into its linear region, increasing supply current and radiating noise.
For buses longer than roughly 10 cm on FR-4, add 22 to 47 Ohm series termination resistors at the buffer outputs to damp reflections and reduce overshoot. Estimate: with ~30 pF total load per line and ABT-class edge rates, an unterminated stub can ring above VCC + 0.5 V, stressing the receiving devices. Keep the buffer close to the connector on backplane designs to shorten stubs, and assign one ground pin return path per group of four outputs where possible.
合规信息
Verified web data did not state RoHS/REACH/lead-free status. Confirm on TI.com product quality pages for the exact ordering suffix (SN74ABT244APWR) before production release.
