SN74ABT244APWRG4 - Octal 3-State Buffer 5V TSSOP-20 | TI
MPN： SN74ABT244APWRG4 ✓ 啟用中SN74ABT244APWRG4 概覽
A line driver or buffer is a logic device that strengthens digital signals for transmission across buses, long PCB traces, or cables where fan-out, capacitive loading, or noise would otherwise corrupt data. Buffers sit within the broader logic IC hierarchy: gate -> buffer/driver -> bus transceiver -> logic IC. The 244 family is the industry-standard octal buffer topology, splitting its eight channels into two independently enabled 4-bit groups so one device can serve two separate buses or provide bidirectional-by-direction-control buffering.
Key features of the SN74ABT244A include TTL-compatible CMOS inputs, 3-state outputs that tri-state for bus sharing, and a drive capability suited to heavily loaded backplanes. The device belongs to TI's BiCMOS ABT (Advanced BiCMOS Technology) family, which combines the low static power of CMOS with the high drive current and speed of bipolar output stages, significantly reducing power dissipation compared with older bipolar-only drivers.
Technically, the ABT family uses TI's EPIC-BiCMOS process, providing output current levels capable of driving 50 pF loads while keeping propagation delays in the nanosecond range, and includes livable latch-up immunity and partially powered operation behavior typical of ABT parts (driving outputs while VCC is absent is a classic ABT benefit for hot-insertion-style designs).
Typical applications include microprocessor and DSP address/data bus buffering, memory interface isolation, backplane driving in industrial control systems, and general 5V TTL logic level strengthening in instrumentation.
Design consideration: always decouple VCC with a 0.1uF ceramic capacitor close to pin 20, and use the two /OE pins to guarantee 3-state condition during power sequencing or bus arbitration.
This page adds value beyond the TI datasheet by synthesizing drop-in alternatives, pricing tiers, comparison tables, and practical design notes in one place.
直接替換替代品，適用於 SN74ABT244APWRG4 — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： SN74ABT244APWRG4 （相同外形與佔位） — 差異在於 Input Type, Package.
SN74ABT244APW
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
SN74ABT244APWE4
✅ 直接替換📋 參考替代品（不在目錄中）
SN74ABT244APWRE4
✅ 直接替換聯絡詢價
查看資料表 →SN74ABT244APWG4
✅ 直接替換📋 參考替代品（不在目錄中）
SN74ABT244APWRG4 最大額定值與電氣特性
| Logic Function | Octal buffer/line driver, non-inverting |
| 輸出類型 | 3-state |
| Supply Voltage Range | 4.5 V to 5.5 V |
| 通道數 | 8 (2 elements x 4 bit) |
| Input Type | TTL-compatible CMOS |
| Propagation Delay | 4.6 ns typical |
| Load Capacitance | 50 pF |
| Control Type | Enable LOW (/OE1, /OE2) |
| Output Polarity | Non-inverting |
| Temperature Grade | Industrial (-40C to +85C) |
| 封裝 | TSSOP-20 (PW), 20 terminals, gull wing |
| 安裝類型 | Surface Mount |
| Technology | ABT (Advanced BiCMOS, EPIC-B process) |
| RoHS 狀態 | Compliant |
SN74ABT244APWRG4 腳位配置
| 腳位 1 | /OE1 — Output enable 1, active LOW (3-state control for group 1) |
| 腳位 2 | 1A1 — Group 1 input 1 |
| 腳位 3 | 2Y1 — Group 2 output 1 |
| 腳位 4 | 1A2 — Group 1 input 2 |
| 腳位 5 | 2Y2 — Group 2 output 2 |
| 腳位 6 | 1A3 — Group 1 input 3 |
| 腳位 7 | 2Y3 — Group 2 output 3 |
| 腳位 8 | 1A4 — Group 1 input 4 |
| 腳位 9 | 2Y4 — Group 2 output 4 |
| 腳位 10 | GND — Ground |
| 腳位 11 | 2A1 — Group 2 input 1 |
| 腳位 12 | 1Y1 — Group 1 output 1 |
| 腳位 13 | 2A2 — Group 2 input 2 |
| 腳位 14 | 1Y2 — Group 1 output 2 |
| 腳位 15 | 2A3 — Group 2 input 3 |
| 腳位 16 | 1Y3 — Group 1 output 3 |
| 腳位 17 | 2A4 — Group 2 input 4 |
| 腳位 18 | 1Y4 — Group 1 output 4 |
| 腳位 19 | /OE2 — Output enable 2, active LOW (3-state control for group 2) |
| 腳位 20 | VCC — Supply voltage, 4.5 V to 5.5 V |
典型應用
SN74ABT244APWRG4 適用於 6 應用s: Microprocessor Bus Buffering, Industrial Control Backplanes, Memory Interface Isolation, Test and Measurement Instrumentation, Legacy 5V System Maintenance, Networking and Telecom Line Cards.
Microprocessor Bus Buffering
The SN74ABT244APWRG4 buffers address and data buses in 5V microprocessor and DSP systems where a CPU output cannot alone drive the fan-out and trace capacitance of a loaded backplane. Its 4.6 ns propagation delay at 50 pF adds minimal timing overhead even in systems with tens of nanoseconds of setup margin, while the ABT BiCMOS output stage supplies the peak current needed to charge heavy loads with clean edges. The two independent 4-bit groups with separate /OE pins let one package buffer two distinct buses or implement direction-controlled isolation. Place the device close to the bus connector to minimize stub lengths, and keep /OE de-asserted during power-up to avoid bus contention while supplies stabilize.
推薦
Industrial Control Backplanes
In factory automation and PLC backplanes, control and status signals travel long distances across several card slots, accumulating capacitance well beyond what a microcontroller pin can drive. The SN74ABT244APWRG4's industrial -40C to +85C temperature grade matches the operating envelope of industrial enclosures, and its bipolar-class output drive restores signal integrity on heavily loaded 5V TTL buses. The 3-state outputs allow multiple cards to share common backplane lines without contention, provided each card tri-states via /OE when not addressed. Its TTL-compatible inputs also tolerate the slower, degraded edges typical of long backplane runs, improving noise margin in electrically noisy motor-drive environments.
推薦
Memory Interface Isolation
When multiple SRAM, EPROM, or flash devices share a common data bus, each memory's output must be isolated until selected. The SN74ABT244APWRG4 sits between memory outputs and the bus, presenting 3-state outputs controlled by the memory select logic so unaddressed devices never fight the bus. Its 4.6 ns delay consumes little of the memory access-time budget, and its low input current minimally loads weak memory output drivers. In 5V legacy systems, the ABT family's drive strength ensures valid VOL/VOH levels even with the combined capacitance of several memory sockets. Use one /OE group per memory bank to simplify decode logic and keep enable routing short for clean switching.
推薦
Test and Measurement Instrumentation
Bench instruments, data-acquisition cards, and rack systems built on 5V TTL logic use the SN74ABT244APWRG4 to drive front-panel connectors, trigger buses, and inter-card signal lines. The ABT BiCMOS construction provides fast, monotonic edges required for clean timing in trigger chains, while 3-state outputs let a test controller take over shared measurement lines during calibration sequences. The industrial temperature range suits instruments used on factory floors, and the TSSOP-20 gull-wing package reflows reliably on standard assembly processes. Because the device adds only 4.6 ns of delay at 50 pF, trigger-loop timing budgets remain accurate without per-channel compensation.
推薦
Legacy 5V System Maintenance
Many deployed military, telecom, and industrial systems still run on 5V TTL logic and require replacement line drivers during repair and life-extension programs. The SN74ABT244APWRG4 is an active TI part that drops directly into these designs: the 244 pinout has been the de facto octal-buffer standard for decades, so boards designed around 74LS244, 74F244, or 74ALS244 footprints in TSSOP-20 accept the ABT244A without layout change. Its TTL-compatible input thresholds guarantee compatibility with older LS/F-family outputs, while the 3-state outputs preserve original bus-sharing behavior. This makes it the safest choice for sustaining engineering of heritage hardware.
推薦
Networking and Telecom Line Cards
Telecom line cards and network interface boards in 5V architectures use the SN74ABT244APWRG4 to drive backplane control lines, LED status signals, and relay-select lines from a central controller. The ABT output stage supplies sufficient sink current for multiple parallel loads such as LED indicators and optocoupler inputs without external buffering, simplifying the bill of materials. The two independently enabled 4-bit groups let a single device handle both transmit-direction and receive-direction control signals with separate tri-state control from the management controller. Its 4.6 ns delay is negligible relative to telecom signaling timing, and the industrial temperature grade covers outdoor-plant equipment enclosures.
推薦
推薦產品摘要
工程參考資料，適用於 SN74ABT244APWRG4 — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | SN74ABT244APW | SN74ABT244APWE4 | SN74ABT244APWRE4 | SN74ABT244APWG4 |
|---|---|---|---|---|---|
| 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 | 4.5 V to 5.5 V | 4.5 V to 5.5 V |
| Propagation Delay | 4.6 ns typical | 4.6 ns typical | 4.6 ns typical | 4.6 ns typical | 4.6 ns typical |
| Output Type | 3-state | 3-state | 3-state | 3-state | 3-state |
| Temperature Range | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| RoHS / Green | Yes (G4 green) | RoHS | RoHS (E4) | RoHS (E4) | Yes (G4 green) |
| Packing | Tape & Reel | Tube | Tube | Tape & Reel | Tube |
主要差異化特點
- Industrial temperature grade with green G4 packaging (對比SN74ABT244APW)
- Dual independent 4-bit enables (對比SN74ABT541APW)
- BiCMOS drive strength vs pure CMOS buffers (對比SN74LVC244APW)
設計說明
Decouple VCC with a 0.1uF ceramic capacitor placed within 5 mm of pin 20, plus one bulk 10uF capacitor per eight driver packages. The ABT BiCMOS output stage draws a substantial dynamic current shot when all four outputs of a group switch simultaneously; without local decoupling this shot creates ground bounce that can falsely clock adjacent TTL inputs. Estimated: eight simultaneous 50 pF load transitions at 5V can draw peak transient currents in the hundreds of milliamps for a few nanoseconds.
Never leave /OE1 or /OE2 floating - the ABT input structure interprets undefined levels unreliably and floating enables can release outputs onto a live bus during power-up. Terminate each /OE pin to VCC through a 10 kOhm pull-up (outputs disabled by default) or drive it from decoded logic. Additionally, do not exceed 5.5V on VCC; unlike some families, ABT parts do not tolerate 6V transients well, so verify supply regulation on backplanes with long harness runs.
Keep A-input and Y-output traces of the same channel short and, where possible, on adjacent layers to control loop area and crosstalk. For backplane driving, place the SN74ABT244APWRG4 within 15 mm of the connector and add 22-33 Ohm series resistors at outputs driving unterminated cables to damp reflections - the ABT output's fast 4.6 ns edges will otherwise ring on lines longer than roughly one-third of the signal rise time.
合規資訊
G4 suffix denotes TI green/RoHS-compliant packaging per TI ordering conventions. REACH, halogen-free, and conflict-minerals declarations not present in provided data - consult TI quality pages for the SN74ABT244A family.
