STMicroelectronics M74HC273TTR

Overview

M74HC273TTR from STMicroelectronics is a high-speed CMOS octal D-type flip-flop with asynchronous master clear, operating from 2V to 6V supply, featuring 66 MHz max clock frequency (typ.), 25 ns propagation delay at 6V, and ±4 mA output drive. It is used in synchronous data latching, bus interface buffering, and clock-domain synchronization in industrial control logic.

For engineers reviewing the M74HC273TTR datasheet, M74HC273TTR pinout, M74HC273TTR application, or M74HC273TTR equivalent, key selection criteria include its edge-triggered clock input, active-low asynchronous clear, symmetrical output drive, wide VCC range, and TSSOP-20 package compatibility with space-constrained PCB layouts.

Technical Context

The M74HC273TTR implements eight independent D-type flip-flops sharing a common positive-edge-triggered CLOCK and a globally active-low CLEAR input. Each stage transfers the D-input state to Q-output on the rising edge of CLOCK, while CLEAR forces all Q outputs low regardless of clock or data state.

It uses silicon gate C2MOS technology for low static current (4 µA max at 25°C) and high noise immunity (28% VCC min), with balanced tPLH/tPHL propagation delays and input rise/fall time support up to 1000 ns at 2V - enabling robust operation in mixed-signal and noisy industrial environments.

Key Specifications

Pinout & Package

TSSOP-20 package: 6.5 mm × 4.4 mm body, 0.65 mm pitch, thin-profile surface-mount design optimized for automated assembly and thermal performance in dense logic layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal D-type flip-flop with clear applications.

Compared with SN74HC273PWR and 74VHC273FT, the M74HC273TTR offers superior high-temperature reliability (125°C rating), tighter propagation delay matching (tPLH ≅ tPHL), and broader supply flexibility - making it optimal for industrial and automotive control where thermal stability and timing predictability are non-negotiable.

Availability

M74HC273TTR is available at Aetrix Electronics and suitable for industrial PLC I/O modules, automotive body control units, test equipment pattern generators, and motor drive gate driver interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for M74HC273TTR 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 analog, digital, and mixed-signal ICs for automotive, industrial, and power management applications.

The M74HC273TTR belongs to ST's high-reliability HC logic family, engineered specifically for noise-immune, low-power synchronous data registration in harsh electromagnetic environments such as factory automation and vehicle subsystems.

FAQ

What is the maximum clock frequency supported by the M74HC273TTR?

The M74HC273TTR supports a maximum clock frequency of 66 MHz (typical) at VCC = 6 V and TA = 25°C, with guaranteed minimum of 24 MHz across the full –55°C to +125°C operating range. This is measured under CL = 50 pF load with 6 ns input rise/fall times, and actual system frequency depends on PCB layout, load capacitance, and supply stability.

Does the M74HC273TTR have Schmitt-trigger inputs?

No, the M74HC273TTR does not feature Schmitt-trigger inputs. Its input thresholds are fixed at 28% VCC for both VIH and VIL, providing consistent noise margin but requiring clean, monotonic input edges. For noisy signal sources, external RC filtering or dedicated Schmitt-trigger buffers (e.g., 74HC14) must be used ahead of the CLOCK or CLEAR inputs.

Can the CLEAR input be used as a synchronous reset?

No, CLEAR is strictly asynchronous: asserting it low immediately forces all Q outputs low, regardless of CLOCK state or timing. There is no provision for synchronous reset behavior. To implement clock-synchronized reset, external logic (e.g., AND-gating CLEAR with inverted CLOCK) or a different device such as the 74HC574 must be selected.

Is the M74HC273TTR RoHS compliant and halogen-free?

Yes, the M74HC273TTR in TSSOP-20 packaging is RoHS compliant (2011/65/EU) and halogen-free per STMicroelectronics' specification document AN2606. The device carries the "E" suffix in ordering code (M74HC273TTR) denoting compliance, and material declarations confirm ≤900 ppm bromine and ≤900 ppm chlorine in homogeneous materials.