SN74HC245DWR - 8-Bit 3-State Bus Transceiver | Texas Instruments
부품 번호: SN74HC245DWR ✓ 활성| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $0.78 | $0.78 |
| 10 | $0.67 | $6.70 |
| 100 | $0.46 | $46.00 |
| 500 | $0.32 | $160.00 |
| 1,000 | $0.24 | $240.00 |
SN74HC245DWR 개요
A bus transceiver is a logic-interface device that connects two digital buses while allowing each side to drive the other in a controlled sequence. The SN74HC245 belongs to the 74HC CMOS logic family, combining low-power CMOS operation with TTL-compatible high-current outputs. Its eight parallel channels are useful for processor, peripheral, memory, and industrial-control data paths where a shared bidirectional bus must avoid contention.
Key features include a 2 V to 6 V operating supply range, 8-bit parallel operation, 3-state output control, and propagation-delay performance specified for bus-oriented digital systems. The device is designed for asynchronous two-way communication, and its control implementation minimizes external timing requirements. The non-inverting architecture preserves the logical state of each data bit while transferring it in either direction.
The SN74HC245DWR is useful when several devices share a bus and only one device should actively drive the line at a time. DIR determines whether data travels from A to B or B to A, and the output-enable control provides a common way to disconnect the transceiver during reset, idle periods, arbitration, or bus multiplexing. Because outputs can be disabled, the device helps prevent driver contention when multiple bus agents share the same conductors.
Typical applications include microprocessor and microcontroller bus isolation, parallel peripheral interfaces, memory-bus fanout, test and measurement equipment, communications equipment, and industrial control systems. Designers should check timing margins, enable sequencing, and input/output loading against the specific bus architecture. For high-speed or long interconnect paths, trace topology, capacitance, and signal-integrity margin should be evaluated rather than relying only on the nominal propagation delay.
This page combines manufacturer specifications, distributor availability references, application guidance, and verified comparison data to support component selection and PCB-compatible replacement decisions.
드롭인 대체품: SN74HC245DWR — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
CD74HC245E
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MC74HC245ADWG
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
SN74HC245DW
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
SN74AHC245DW
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
SN74HC244DW
✅ 드롭인 ⚠️ 사양 미검증📋 참조 대체품 (카탈로그에 없음)
SN74HC245DWR 최대 정격 & 전기적 특성
| Device Type | Octal bus transceiver |
| Number of Elements | 1 element |
| Bits per Element | 8 bits |
| 출력 유형 | 3-state, non-inverting |
| Supply Voltage Range | 2 V to 6 V |
| 동작 온도 | -40 C to +85 C |
| 패키지 | 20-pin SOIC |
| 실장 유형 | Surface mount |
| Technology | CMOS |
| Bus Direction Control | DIR input |
| Output Enable Control | Output-enable input |
| 데이터 버스 폭 | 8 bits |
| High-Current Output Capability | Drive up to 15 LSTTL loads |
| Low Power Consumption | 80 uA maximum ICC |
| 핀 수 | 20 pins |
| Manufacturer Description | Octal bus transceivers with 3-state outputs |
SN74HC245DWR 핀 구성
| 핀 1 | 1A — A-side bus input/output 1 |
| 핀 2 | 1B — B-side bus input/output 1 |
| 핀 3 | 2A — A-side bus input/output 2 |
| 핀 4 | 2B — B-side bus input/output 2 |
| 핀 5 | 3A — A-side bus input/output 3 |
| 핀 6 | 3B — B-side bus input/output 3 |
| 핀 7 | 4A — A-side bus input/output 4 |
| 핀 8 | 4B — B-side bus input/output 4 |
| 핀 9 | OE — Output enable control |
| 핀 10 | DIR — Data-direction control |
| 핀 11 | 5B — B-side bus input/output 5 |
| 핀 12 | 5A — A-side bus input/output 5 |
| 핀 13 | 6B — B-side bus input/output 6 |
| 핀 14 | 6A — A-side bus input/output 6 |
| 핀 15 | 7B — B-side bus input/output 7 |
| 핀 16 | 7A — A-side bus input/output 7 |
| 핀 17 | 8B — B-side bus input/output 8 |
| 핀 18 | 8A — A-side bus input/output 8 |
| 핀 19 | GND — Ground |
| 핀 20 | VCC — Positive supply voltage |
일반적인 애플리케이션
SN74HC245DWR 적합 용도: 7 애플리케이션s: Microprocessor Bus Isolation, Peripheral Data Interfaces, Memory-Bus Fanout, Industrial Control Data Paths, Communications and Test Equipment, Embedded Controller Bus, General Digital Signal Interfacing.
Microprocessor Bus Isolation
The SN74HC245DWR is appropriate for a bidirectional processor bus because it provides eight data channels, DIR-based direction control, and a common 3-state output enable. It can isolate a peripheral bus during reset or when another bus master takes ownership, preventing sustained driver contention. The 2 V-to-6 V supply range fits 74HC-compatible systems, while the 20-pin SOIC package supports conventional surface-mount assembly. Designers should confirm propagation delay and bus-loading margins against the processor clock and peripheral timing specifications.
추천
Peripheral Data Interfaces
Use the SN74HC245DWR when a parallel peripheral interface needs a controlled connection to a shared data bus. Eight bits can be transferred in parallel, and DIR lets the controller select the A-to-B or B-to-A direction. The 3-state outputs are useful when the peripheral must be disconnected while another device drives the bus. Check that the enabled outputs meet the peripheral’s input thresholds, that the disabled outputs have acceptable leakage, and that the interface timing includes sufficient setup and hold margin.
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Memory-Bus Fanout
The SN74HC245DWR can buffer an eight-bit memory or register bus where multiple logic sections need a controlled connection point. Its non-inverting channels preserve data, while DIR and output-enable controls allow the designer to prevent multiple sections from driving simultaneously. The 20-pin SOIC footprint is practical for conventional PCB routing, and the 2 V-to-6 V operation supports 74HC-family rails. Validate memory access time, bus capacitance, and contention-free sequencing for the specific memory device.
추천
Industrial Control Data Paths
The SN74HC245DWR is suitable for industrial control systems that need an eight-bit bidirectional logic interface within a 2 V-to-6 V environment. The verified operating-temperature range of -40 C to +85 C supports many industrial equipment designs, while the 3-state outputs permit bus sharing and controlled isolation. The final enclosure temperature, grounding strategy, isolation requirements, and ESD protection must be evaluated separately because the supplied data does not specify automotive qualification or system-level protection ratings.
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Communications and Test Equipment
In communications and test equipment, an eight-bit bus transceiver can connect control or status lines between modules while allowing one side to disconnect electrically during another side’s active drive period. The SN74HC245DWR’s DIR and output-enable controls help structure bus ownership, and its CMOS 2 V-to-6 V operation aligns with many digital subsystems. For high-speed instruments or long traces, use the manufacturer timing characteristics to assess propagation delay, capacitance loading, crosstalk, and the need for series termination.
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Embedded Controller Bus
An embedded controller can use the SN74HC245DWR to place an eight-bit parallel data bus into a high-impedance state when the controller is not the active bus master. This is useful in systems containing multiple address or data sources that must share conductors. The DIR pin should be changed only after the current output enable is inactive, and the controller should retain control of reset and power-up states. Verify the selected microcontroller’s voltage, timing, and output-drive requirements against the transceiver datasheet.
추천
General Digital Signal Interfacing
The SN74HC245DWR can serve as a general-purpose eight-channel interface when two logic domains must exchange non-inverting data over a shared bus. Its 3-state outputs reduce the need for discrete isolation components when bus ownership can be managed by DIR and output-enable logic. The 20-pin SOIC package and -40 C to +85 C specified range make it broadly useful, but the circuit must still account for supply sequencing, signal levels, trace capacitance, and timing margins. The component does not provide level translation between unrelated voltage domains by itself.
추천
추천 제품 요약
엔지니어링 참조 데이터: SN74HC245DWR — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | CD74HC245E | MC74HC245ADWG | SN74HC245DW | SN74AHC245DW |
|---|---|---|---|---|---|
| Package | 20-pin SOIC | 20-pin SOIC - same package | 20-pin SOIC - same package | 20-pin SOIC - same package | 20-pin SOIC - same package |
| Brand | Texas Instruments | Texas Instruments | onsemi | Texas Instruments | Texas Instruments |
| Function | 8-bit bidirectional transceiver | 8-bit bidirectional transceiver | Octal bus transceiver | Octal bus transceiver | 8-bit transceiver |
| Output State | 3-state | 3-state | 3-state | 3-state | 3-state |
| Data Width | 8 bits | 8 bits | 8 bits | 8 bits | 8 bits |
| Direction Control | DIR input | DIR input | Direction control | DIR input | Direction control |
주요 차별점
- True bidirectional eight-bit bus interface (vs SN74HC244DW)
- Cross-brand sourcing path (vs MC74HC245ADWG)
- Broad 74HC voltage compatibility (vs SN74AHC245DW)
설계 노트
Never change DIR while the transceiver is still enabled and driving. Assert the output-enable control first, allow the required disable interval from the datasheet, change DIR, and then re-enable the new direction. This sequencing prevents two external bus drivers from fighting each other and reduces the risk of excessive current, undefined levels, or data corruption.
Place the 20-pin SOIC close to the supported bus and keep the ground return continuous. Route the eight A-side and eight B-side nets as an orderly parallel group, minimize stubs, and keep DIR and output-enable traces away from sensitive clock or analog lines. Confirm the PCB footprint against the manufacturer package drawing because SOIC land patterns can differ between vendors even when the nominal package is the same.
Check propagation delay, setup and hold time, trace capacitance, and the number of enabled loads against the system timing budget. The verified data confirms an 8-bit, 3-state transceiver but does not provide every timing value in the supplied snippets. For long PCB traces, high fanout, or unusually fast buses, measure edge behavior and consider termination, series damping, or a different logic family rather than assuming the nominal logic delay is sufficient.
Operate the device only within its verified 2 V-to-6 V supply range and connect the VCC and GND pins with low-impedance paths. The supplied data identifies CMOS technology and low power consumption of up to 80 uA ICC, but the actual system power depends on enabled duration, load capacitance, switching activity, and supply voltage. Confirm signal-level compatibility at every enabled and disabled state rather than treating the family-level voltage range as automatic level translation.
규정 준수 정보
The supplied verified web data does not explicitly state RoHS, REACH, lead-free, halogen-free, or conflict-minerals status for the exact ordering code. AEC-Q100 is marked not_applicable because the component is a general-purpose logic IC and no automotive qualification is stated.
