STMicroelectronics M74HCT157RM13TR

Overview

M74HCT157RM13TR from STMicroelectronics is a high-speed CMOS quad 2-channel multiplexer with TTL-compatible inputs, 16 ns typical propagation delay at 4.5 V, 4 µA max quiescent current at 25°C, and symmetrical 4 mA output drive. It routes A/B data sources to four Y outputs under common SELECT and STROBE control in digital logic systems such as address/data bus switching and signal routing in industrial controllers.

For engineers reviewing the M74HCT157RM13TR datasheet, M74HCT157RM13TR pinout, M74HCT157RM13TR application, or M74HCT157RM13TR equivalent, key selection criteria include propagation delay matching (tPLH/tPHL ≈ 16–38 ns), STROBE-enabled output disable functionality, TSSOP-16 package thermal profile, and HCT-series 5 V logic compatibility with legacy TTL interfaces.

Technical Context

The M74HCT157RM13TR implements four independent 2:1 digital multiplexers sharing one SELECT line and one active-low STROBE input that forces all Y outputs low when high. Its C2MOS silicon gate process enables rail-to-rail output swing and low static power consumption while maintaining TTL-level input thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V).

Propagation delays are balanced across input types: A/B-to-Y delay is 16 ns (typ.) at VCC = 4.5 V, SELECT-to-Y is 19 ns (typ.), and STROBE-to-Y is 17 ns (typ.). Output drive capability is symmetrical-|IOH| = |IOL| = 4 mA (min) at VCC = 4.5 V-ensuring consistent rise/fall times and noise margin in mixed-logic systems.

Key Specifications

Pinout & Package

TSSOP-16 package: 4.9–5.1 mm width, 6.2–6.6 mm length, 1.2–1.05 mm height, 0.65 mm pitch, lead-free, RoHS-compliant surface-mount outline with exposed pad not present.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad 2:1 multiplexer applications.

Compared with SN74HCT157DR and 74VHC157M, the M74HCT157RM13TR uniquely combines TSSOP-16 miniaturization, guaranteed 5 V TTL interoperability, and industrial temperature range-all within ST's qualified automotive-grade manufacturing flow.

Availability

M74HCT157RM13TR is available at Aetrix Electronics and suitable for industrial PLC I/O multiplexing, legacy system bus interface, and automotive body control module designs requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for M74HCT157RM13TR 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, designing and manufacturing microcontrollers, power management ICs, sensors, and analog/mixed-signal devices for industrial, automotive, and consumer markets.

The M74HCT series targets high-reliability 5 V logic interfacing, delivering TTL-compatible performance with CMOS power efficiency for legacy system upgrades and industrial control applications.

FAQ

Is M74HCT157RM13TR pin-compatible with 74LS157?

Yes-M74HCT157RM13TR uses identical pin numbering and logic function mapping as 74LS157, including SELECT (pin 1), STROBE (pin 15), and Y outputs (pins 4,7,9,12). Its TTL-compatible input thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V) ensure direct substitution without circuit modification.

What is the maximum clock frequency supported by M74HCT157RM13TR?

The device supports data rates up to approximately 62 MHz, derived from its 16 ns typical propagation delay (tPD) at VCC = 4.5 V. For reliable operation, maximum toggle frequency should be limited to fMAX = 1/(2 × tPD_max) = 13.2 MHz under worst-case conditions (tPD = 38 ns at –55°C to +125°C).

Does M74HCT157RM13TR require external pull-up or pull-down resistors on SELECT or STROBE?

No-SELECT and STROBE inputs have no internal biasing and must be actively driven to valid logic levels. Floating inputs are undefined and may cause erratic output behavior; external pull-downs (to GND) are recommended only if firmware cannot guarantee state during reset or power-up sequences.

Can M74HCT157RM13TR operate reliably at 3.3 V supply?

No-it is specified only for VCC = 4.5–5.5 V. At 3.3 V, VIH and VIL thresholds become noncompliant (VIH min drops below 2.0 V), output drive degrades significantly, and propagation delay increases beyond specification. Use 74VHC157 or 74LVC157 for 3.3 V systems.