CD74ACT163 - 4-Bit Sync Binary Counter 5V | Texas Instruments
MPN: CD74ACT163 β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.85 | $0.85 |
| 10 | $0.72 | $7.20 |
| 100 | $0.55 | $55.00 |
| 500 | $0.44 | $220.00 |
| 1,000 | $0.36 | $360.00 |
Drop-in alternatives for CD74ACT163 β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
CD74ACT163M
β Drop-Inπ Reference alternative (not in catalog)
CD74ACT163M96
β Drop-Inπ Reference alternative (not in catalog)
SN74ACT163D
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
CD74ACT163 Maximum Ratings & Electrical Characteristics
| Logic Function | 4-bit synchronous presettable binary counter with synchronous reset |
| Logic Family | ACT (Advanced CMOS, TTL-compatible inputs) |
| Supply Voltage | 5 V |
| Number of Elements | 1 |
| Number of Bits | 4 |
| Counting Mode | Synchronous, positive-edge triggered |
| Reset Type | Synchronous (CLR) |
| Parallel Load | Synchronous (LOAD, active-low) |
| Carry Look-Ahead | Internal, for fast counting |
| Cascading Output | RCO ripple carry output for n-bit cascading |
| Input Compatibility | TTL-voltage compatible |
| Operating Temperature | -40C to +85C (CD74ACT163M grade) |
| Package | SOIC-16 (16-pin small outline) |
| Mounting Type | Surface Mount |
CD74ACT163 Pin Configuration
| Pin 1 | CLR β Synchronous clear, active-low - resets all outputs on next clock edge |
| Pin 2 | CLK β Clock input, positive-edge triggered |
| Pin 3 | A β Data input A (parallel load, QA) |
| Pin 4 | B β Data input B (parallel load, QB) |
| Pin 5 | C β Data input C (parallel load, QC) |
| Pin 6 | D β Data input D (parallel load, QD) |
| Pin 7 | ENP β Count enable parallel input |
| Pin 8 | GND β Ground |
| Pin 9 | LOAD β Synchronous parallel load control, active-low |
| Pin 10 | ENT β Count enable trickle input (gates counting and RCO) |
| Pin 11 | QD β Counter output D (MSB) |
| Pin 12 | QC β Counter output C |
| Pin 13 | QB β Counter output B |
| Pin 14 | QA β Counter output A (LSB) |
| Pin 15 | RCO β Ripple carry output for n-bit cascading |
| Pin 16 | VCC β Power supply, 5 V nominal |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this digital IC. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
CD74ACT163 is suitable for 6 applications: Frequency Division, Digital Timers and Event Counting, Cascaded n-Bit Counters, Address Generation and Sequencing, Industrial Control Sequencing, Test and Measurement Counters.
Frequency Division
The CD74ACT163 divides an input clock frequency by an arbitrary integer from 2 to 16 using its synchronous LOAD and carry look-ahead architecture. Because all flip-flops clock simultaneously, the divided output has no ripple-induced glitches, making it safe to feed decoded division outputs into clock trees or PLL reference inputs. In a typical divide-by-N configuration, the Q outputs feed a comparator that asserts LOAD to reload the terminal count, and the internal carry look-ahead keeps the loop timing deterministic at high input frequencies. The 5V ACT family also provides TTL-level clock compatibility with legacy oscillator modules. Place 0.1uF decoupling at VCC to keep clock edges clean.
Recommended
Digital Timers and Event Counting
In timer and event-counting roles, the CD74ACT163 accumulates pulses from a sensor or clock source and presents a latched 4-bit count on QA-QD. The synchronous reset allows the host controller to clear the count on a clock boundary, guaranteeing no partial-count artifacts, while ENP/ENT enable gated counting so external gates can start and stop accumulation without extra gating logic. The internal carry look-ahead keeps counts accurate at high event rates where ripple counters would smear transitions. Multiple stages cascade through RCO-to-ENT wiring to extend the count range to 8, 12, or 16 bits. The 5V supply suits industrial panel environments with legacy TTL signal levels.
Recommended
Cascaded n-Bit Counters
The CD74ACT163 is purpose-built for cascading: wiring each stage's RCO to the next stage's ENT creates fully synchronous 8-, 12-, or 16-bit counters with a common clock, so all bits change on the same edge and decoded outputs are glitch-free. The internal carry look-ahead removes the need for external ripple delay compensation, and ENP/ENT gating allows conditional counting across the whole chain. This is the standard architecture for high-resolution position counters, batch counters, and time-of-day clocks in PLC-style designs. At 5V with TTL-compatible inputs, the chain interfaces directly with legacy processor buses. Keep the common clock short and star-routed to limit skew between stages.
Recommended
Address Generation and Sequencing
Using its synchronous parallel load inputs A-D and LOAD control, the CD74ACT163 generates programmable address or state sequences: load any starting value, count up synchronously, and reload to create circular address generators for memory scanning, lookup-table stepping, or display multiplexing. The synchronous reset gives a clean return to zero aligned to the clock, and carry look-ahead supports fast stepping in scan chains. Because outputs transition coincidentally, address decoders driving memory or peripheral selects see no transient spurious addresses, a common failure mode with ripple counters. The 5V ACT I/O matches legacy microprocessor and SRAM control signal levels directly, minimizing interface glue.
Recommended
Industrial Control Sequencing
On factory automation panels, the CD74ACT163 provides deterministic step sequencing for machinery state machines, stepper indexing, and batch process control. The 5V supply and TTL-compatible inputs integrate cleanly with 24V-referenced I/O once level-shifted through optocouplers or transistor buffers, and the synchronous LOAD/CLR functions let a PLC reload or zero the sequence on the next clock edge, avoiding mid-step partial states. The internal carry look-ahead supports rapid step rates for fast pick-and-place cycles, and RCO cascading extends sequences beyond 16 states. Its surface-mount SOIC-16 footprint suits both new SMD boards and retrofit adapters. pair with watchdog logic to reset stuck sequences.
Recommended
Test and Measurement Counters
Bench instruments and embedded diagnostic modules use the CD74ACT163 as a prescaler or event tally in frequency meters, pulse counters, and pattern generators. The positive-edge clock with simultaneous flip-flop switching yields clean count boundaries essential for measurement repeatability, and the synchronous parallel load supports arbitrary modulo-N presets from firmware. TTL-compatible inputs accept signals from standard probe and signal-generator levels at 5V, while the RCO output feeds higher-order counter stages for extended range. Because the device is fully synchronous, measurement uncertainty from internal propagation skew is eliminated, improving count accuracy at high input frequencies. Use short ground-return paths for the clock input.
Recommended
Recommended Products Summary
Engineering reference data for CD74ACT163 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | CD74ACT163M | CD74ACT163M96 | SN74ACT163D |
|---|---|---|---|---|
| Package | SOIC-16 | SOIC-16 - same | SOIC-16 - same | SOIC-16 - same |
| Brand | Texas Instruments | Texas Instruments (Rochester Electronics supply) | Texas Instruments | Texas Instruments |
| Logic Function | 4-bit sync presettable binary counter, sync reset | 4-bit sync presettable binary counter, sync reset | 4-bit sync presettable binary counter, sync reset | 4-bit sync presettable binary counter, sync reset |
| Supply Voltage | 5 V | 5 V | 5 V | 5 V |
| Reset Type | Synchronous | Synchronous | Synchronous | Synchronous |
| Input Compatibility | TTL-voltage compatible | TTL-voltage compatible | TTL-voltage compatible | TTL-voltage compatible |
| Carry Look-Ahead / RCO | Yes (internal look-ahead, RCO for cascading) | Yes | Yes | Yes |
| Sourcing / Lifecycle | Active (TI catalog) | Active via Rochester Electronics (DigiKey listing) | Active per TI.com part-details | [DATA_NEEDED] |
Key Differentiators
- Synchronous reset eliminates decoding glitches (vs CD74ACT161 (asynchronous reset version))
- Internal carry look-ahead for high-speed counting (vs Simpler ripple counters (e.g., CD4029-class parts))
- Continued availability via second-source channel (vs CD74ACT163M (Harris die via Rochester Electronics))
Design Notes
CLR and LOAD on the CD74ACT163 are synchronous: they take effect only on the next rising clock edge, not immediately. Hold the control signal low for at least one full clock period to guarantee the operation executes. Designs ported from asynchronous-clear counters (e.g., CD74ACT161 or 74161) will behave differently - a brief CLR pulse that would asynchronously clear a 161 will do nothing on a 163 if it does not overlap a clock edge. This is the single most common migration error.
Decouple the 5V rail with a 0.1uF ceramic capacitor placed within a few millimeters of pin 16 (VCC) and pin 8 (GND). ACT-family devices drive fast edges into TTL-level loads, and simultaneous switching of four outputs can inject supply noise that falsely clocks the counter. Add a bulk 4.7uF-10uF capacitor per counter cluster on boards with multiple cascaded stages. Avoid long shared ground returns between the clock source and the counter ground pin.
When cascading multiple CD74ACT163 stages, tie all CLK pins to a single clock net routed as a short star or daisy chain with matched lengths to minimize inter-stage clock skew; skew larger than a few nanoseconds can break the coincident-output property that makes the design glitch-free. Route RCO-to-ENT connections away from the clock net to avoid coupling. Keep decoded-output traces short since fast ACT edges can radiate.
Compliance Information
Compliance status varies by ordering suffix; verify on the TI CD74ACT163 product page (Ordering and quality section) for the exact suffix ordered.
