STMicroelectronics 74ACT163TTR

Overview

74ACT163TTR from STMicroelectronics is a high-speed CMOS synchronous presettable 4-bit binary counter with synchronous clear, operating at up to 250 MHz (typ.) at 5 V, featuring 24 mA output drive, 50 Ω transmission line compatibility, and TTL-compatible input thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V). It supports four operational modes-synchronous reset, parallel load, count-up, and hold-via CLEAR, LOAD, PE, and TE control inputs, and is used in digital timing, address sequencing, and clock-domain synchronization circuits.

For engineers reviewing the 74ACT163TTR datasheet, 74ACT163TTR pinout, 74ACT163TTR application, or 74ACT163TTR equivalent, key selection criteria include propagation delay symmetry (tPLH ≅ tPHL), guaranteed 50 Ω line driving, ±24 mA balanced output current, and operation across –55°C to +125°C industrial temperature range.

Technical Context

The 74ACT163TTR implements a fully synchronous 4-bit binary counter using sub-micron C2MOS technology, with all state transitions triggered on the rising edge of CLOCK. Its mode selection logic prioritizes CLEAR (asynchronous override), then LOAD, followed by counting enabled only when both PE and TE are HIGH.

It delivers symmetrical output impedance (|IOH| = IOL = 24 mA min), balanced propagation delays (tPLH/tPHL ≤ 11 ns at VCC = 4.5 V), and operates within a strict 4.5–5.5 V supply range while maintaining 2 kV ESD immunity and latch-up robustness-enabling direct interfacing with TTL, NMOS, and CMOS systems without level-shifting.

Key Specifications

Pinout & Package

TSSOP-16 package: 4.9 × 6.4 mm body, 0.65 mm pitch, 1.1 mm height, lead-free and RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous 4-bit counter applications.

Compared with 74ACT163MTR and SN74ACT163PWR, the 74ACT163TTR offers the smallest TSSOP footprint (4.9 × 6.4 mm), best thermal performance among ST variants, and direct compatibility with ST's legacy 74ACT product documentation and SPICE models.

Availability

74ACT163TTR is available at Aetrix Electronics and suitable for industrial PLC timing modules, digital test equipment counters, and automotive body control units requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74ACT163TTR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power management ICs, sensors, and discrete components for industrial, automotive, and consumer markets.

The 74ACT163TTR belongs to ST's advanced high-speed CMOS logic family, engineered specifically for TTL-compatible, low-power, high-frequency digital control applications in harsh-environment systems.

FAQ

What is the minimum recommended VCC bypass capacitance for stable 74ACT163TTR operation?

A minimum 0.1 µF ceramic capacitor placed between VCC (pin 16) and GND (pin 8), located within 3 mm of the device, is required to suppress high-frequency supply noise. For systems with >100 MHz clock edges or multiple simultaneous output switches, add a 4.7 µF tantalum capacitor in parallel to handle bulk transient current demand.

Can 74ACT163TTR be used in asynchronous reset configurations?

No-the CLEAR input is asynchronous but only affects outputs on the next rising clock edge; it does not produce immediate output changes. True asynchronous reset behavior (glitch-free, zero-clock-latency) is not supported. For immediate reset, external gating of CLOCK or use of a dedicated asynchronous counter is required.

Does 74ACT163TTR support hot-swap or live-insertion?

No-74ACT163TTR lacks powered-off protection circuitry. Applying VCC before GND, or connecting inputs before supply stabilization, may cause latch-up or permanent damage. Power sequencing per ST's AN2012 guidelines (GND first, then VCC, then inputs) is mandatory for safe operation.

How is CARRY OUT generated, and what logic conditions activate it?

CARRY OUT goes HIGH when QA–QD = 1111 (all outputs HIGH) AND both PE and TE are HIGH. It remains LOW during parallel load, hold, or reset modes. The output is edge-triggered and synchronized to CLOCK, with propagation delay matching QA–QD outputs (tPLH/tPHL ≤ 13 ns).