8-bit synchronous down counter with asynchronous reset
The Texas Instruments CD74HCT40103M is an 8-stage synchronous down counter from the 74HCT logic family, designed for frequency division, timing generation, and event counting in 5 V systems. It counts down on each positive clock edge and clears asynchronously when the reset input is asserted. The part is housed in a 16-SOIC surface-mount package and operates across the full military temperature range of -55°C to 125°C, making it suitable for avionics, satellite, downhole instrumentation, and industrial control where wide temperature tolerance is required.
14 MHz count rate — timing budget for 5 V systems
The 14 MHz maximum count rate sets the upper frequency for reliable down-counting. In a typical divide-by-N application, the input clock must stay below this limit to avoid missing edges. At 5 V ± 0.5 V supply, the HCT family provides LSTTL-compatible inputs and CMOS outputs, so it interfaces directly with 5 V microcontrollers and legacy TTL logic without level translation. The positive-edge trigger simplifies synchronization with most clock sources.
Military temperature grade — deployment context
Rated for -55°C to 125°C operating temperature, this counter is qualified for extreme environments: engine bay electronics, satellite payloads, downhole drilling tools, and military ground vehicles. The 16-SOIC package (3.90 mm body width) is a standard footprint for automated assembly and rework, and the surface-mount format suits high-density PCB layouts where through-hole parts would consume more board area.
Active lifecycle — no end-of-life risk
The CD74HCT40103M carries an Active product status with ROHS3 compliance. There is no last-time-buy notice or obsolescence risk for current designs. For volume requirements or scheduled releases, the part can be quoted to order with confirmed lead time and pricing at the time of RFQ.