Texas Instruments CD74ACT109M

Overview

CD74ACT109M from Texas Instruments is a dual J-K positive-edge-triggered flip-flop with independent clear (CLR) and preset (PRE) inputs, operating over –55°C to 125°C, supporting 100 MHz clock frequency, ±24 mA output drive, and TTL-voltage-compatible inputs. It performs toggle or D-type functions in digital control logic, synchronous counters, and state machines.

For engineers reviewing the CD74ACT109M datasheet, CD74ACT109M pinout, CD74ACT109M application, or CD74ACT109M equivalent, key selection criteria include its bipolar-speed CMOS process, balanced propagation delays (2.6–10.3 ns), SCR-latchup resistance, 2-kV ESD rating, and SOIC-16 packaging for high-reliability industrial timing and control systems.

Technical Context

The CD74ACT109M implements two independent edge-triggered J-K flip-flops with asynchronous active-low CLR and PRE inputs. Its logic diagram confirms direct gating of J/K/CLK signals through transmission gates and cross-coupled inverters, enabling predictable toggling and latching behavior on the rising clock edge.

It uses an SCR-latchup-resistant CMOS process with TTL-compatible input thresholds (VIH = 2 V, VIL = 0.8 V at VCC = 4.5–5.5 V), operates across full military temperature range, and meets MIL-STD-883 ESD requirements (≥2 kV). Propagation delay symmetry (tPLH ≈ tPHL) ensures minimal skew in dual-channel applications.

Key Specifications

Pinout & Package

CD74ACT109M is housed in a 16-pin SOIC (D) package with 1.27 mm pitch, JEDEC MS-012 compliant, and moisture sensitivity level 1 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual J-K flip-flop applications.

Compared with SN74ACT109N and CD74HC109M, the CD74ACT109M uniquely combines military-grade temperature range, TTL-compatible drive strength, and 100 MHz performance in a surface-mount SOIC package-making it the only option for high-reliability, high-speed, extended-temperature digital control.

Availability

CD74ACT109M is available at Aetrix Electronics and suitable for industrial PLC logic modules, satellite telemetry state machines, military radar pulse generators, and downhole oilfield instrumentation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CD74ACT109M 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 founded in 1930, specializing in analog, embedded processing, and logic solutions for industrial, automotive, and aerospace markets.

The CD74ACT109M belongs to TI's Advanced CMOS Technology (ACT) logic family, designed specifically for high-speed, low-power, TTL-compatible digital control in harsh-environment applications demanding military-grade reliability.

FAQ

What is the maximum clock frequency supported by CD74ACT109M across its full temperature range?

The CD74ACT109M supports a guaranteed maximum clock frequency of 100 MHz over its full operating range of –55°C to 125°C, as specified in the timing characteristics table of the SCHS327 datasheet. At 25°C, it achieves up to 114 MHz, but system designs targeting extended temperature operation must use the 100 MHz limit for timing closure and margin assurance. This value is measured under standard load conditions (CL = 50 pF, VCC = 5 V ± 0.5 V).

Does CD74ACT109M require external pull-up or pull-down resistors on unused J, K, CLR, or PRE inputs?

Yes - all unused inputs of the CD74ACT109M must be held at a valid logic level (VCC or GND) to prevent floating nodes that could cause excessive ICC current, metastability, or unintended toggling. The TI application report SCBA004 explicitly mandates this practice. Leaving inputs unconnected violates recommended operating conditions and may result in unpredictable output behavior or increased power consumption in the CD74ACT109M.

Is CD74ACT109M pin-compatible with CD74HC109M or SN74ACT109N?

No - while CD74ACT109M, CD74HC109M, and SN74ACT109N share identical pinouts (SOIC-16 and PDIP-16 variants follow the same 16-pin dual J-K flip-flop layout), they are not functionally interchangeable without design validation. The CD74ACT109M differs in drive strength (±24 mA vs. ±7.8 mA), speed (100 MHz vs. 60 MHz), and temperature rating (–55°C to 125°C vs. –40°C to 85°C), so direct substitution requires full electrical and thermal requalification of the CD74ACT109M in the target application.

What is the meaning of "SCR-latchup-resistant" in the CD74ACT109M datasheet?

"SCR-latchup-resistant" means the CD74ACT109M uses a specialized CMOS fabrication process and circuit layout that suppresses parasitic silicon-controlled rectifier (SCR) formation between n-well and p-substrate regions. This prevents destructive high-current latchup events triggered by transient overvoltage, ESD, or supply bounce - a critical reliability feature confirmed per MIL-PRF-38535 requirements and validated in the CD74ACT109M's absolute maximum ratings testing.

Can CD74ACT109M be used as a divide-by-two counter, and how is it configured?

Yes - the CD74ACT109M can function as a divide-by-two counter by connecting J = VCC and K = GND for one flip-flop, then feeding its Q output back to the CLK input of the second flip-flop. Alternatively, grounding K and tying J high on a single section configures it as a toggle flip-flop (T-FF), producing Q = Q̅ on each clock edge - delivering clean 50% duty-cycle division. This configuration is explicitly validated in the CD74ACT109M function table and logic diagram.