Texas Instruments 8409001CA

Overview

8409001CA from Texas Instruments is a high-speed CMOS quad-bus transceiver with three-state outputs, designed for bidirectional asynchronous data bus communication between systems operating at 2 V to 6 V (HC logic family). It features 7 ns typical propagation delay (V_CC = 5 V, C_L = 15 pF), ±35 mA output drive capability, and operates across -55°C to +125°C - enabling use in military-grade avionics backplanes and ruggedized industrial controllers.

For engineers reviewing the 8409001CA datasheet, 8409001CA pinout, 8409001CA application, or 8409001CA equivalent, this device serves as a radiation-tolerant, wide-temperature-range bus interface IC with buffered inputs, LSTTL-load compatibility (15 loads), and precise direction control via dual enable inputs (OEA/OEB).

Technical Context

The 8409001CA implements four independent noninverting bidirectional channels, each controlled by shared OEA and OEB inputs that jointly determine both data direction (A→B or B→A) and three-state output enable/disable state. Its silicon-gate CMOS architecture delivers low ICC (≤160 µA at 6 V) while maintaining TTL-compatible switching thresholds only in HCT variants - this part is HC-type, requiring 2–6 V supply and exhibiting 30% noise immunity (NIL/NIH) at 5 V.

Propagation delay is balanced across A→B and B→A paths, and transition times are tightly matched (t_PLH/t_PHL ≤ 27 ns max at 6 V, -55°C to +125°C), ensuring deterministic timing in synchronous bus arbitration schemes. Input capacitance is 10 pF, and three-state output capacitance is 20 pF - critical for minimizing bus loading in high-density backplane designs.

Key Specifications

Pinout & Package

Ceramic Dual-In-Line Package (CDIP, J-body), 14-pin, hermetically sealed with 19.55 mm × 6.71 mm body size and 5.08 mm maximum height - compliant with MIL-STD-1835 GDIP1-T14 and rated for harsh-environment deployment.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bus transceiver applications.

Compared with CD54HC243F (identical functionality, alternate marking) and CD74HC243E (plastic PDIP, reduced temp range), the 8409001CA provides guaranteed hermetic reliability and full military temperature compliance - making it the sole choice for safety-critical, long-lifecycle avionics and defense systems.

Availability

8409001CA is available at Aetrix Electronics and suitable for aerospace data bus interfaces, industrial PLC backplanes, and military avionics subsystems requiring stable component supply across extended product lifecycles.

Supply support for 8409001CA includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and high-reliability logic solutions for aerospace, industrial, and automotive markets.

The CDx4HC243 family was engineered specifically for high-integrity bidirectional bus communication in extreme-environment systems - emphasizing radiation tolerance, wide temperature operation, and deterministic timing for mission-critical control applications.

FAQ

What is the supply voltage range supported by the 8409001CA?

The 8409001CA operates from 2 V to 6 V DC, consistent with HC-series CMOS logic. This allows interoperability between 3.3 V microcontrollers and 5 V legacy peripherals without level shifters. Operation below 2 V or above 6 V violates absolute maximum ratings and may cause permanent damage. The 8409001CA maintains specified timing and drive strength across the full 2–6 V range, with propagation delay decreasing as V_CC increases.

Does the 8409001CA support true bidirectional data flow on each channel?

Yes, the 8409001CA supports true bidirectional data flow per channel using shared OEA and OEB control inputs. When OEA = low and OEB = high, data flows A→B; when OEA = high and OEB = low, data flows B→A; both high places all outputs in high-Z. The 8409001CA does not auto-detect direction - external logic must assert the correct enable combination before data transfer begins.

Is the 8409001CA pin-compatible with other CDx4HC243 variants?

The 8409001CA uses the CDIP (J) 14-pin package and shares identical pinout with CD54HC243F and CD54HC243F3A. It is not pin-compatible with PDIP (N) or SOIC (D) variants due to differing physical dimensions and leadforms - though logic function and electrical behavior are identical. PCB layout must match the 19.55 mm × 6.71 mm ceramic DIP footprint for 8409001CA.

What is the maximum capacitive load the 8409001CA can drive while maintaining specified timing?

The 8409001CA is characterized up to 50 pF load capacitance in switching specifications, with 7 ns typical propagation delay measured at 15 pF. Driving >50 pF increases t_pd nonlinearly and may violate setup/hold windows in high-speed systems. For loads exceeding 50 pF, TI recommends adding series termination or using multiple 8409001CA devices in parallel - the 8409001CA's ±35 mA drive supports this scaling without external buffers.

How does the 8409001CA handle unused input pins?

Unused inputs on the 8409001CA - including A1–A4, B1–B4, OEA, and OEB - must be terminated to V_CC or GND via ≤1 MΩ resistors to prevent floating states that cause excessive ICC or metastability. TI explicitly warns against leaving any input unconnected. The 8409001CA's internal structure lacks weak pull-ups/downs, so external biasing is mandatory for reliable operation across -55°C to +125°C.