STMicroelectronics 74VHC157TTR

Overview

74VHC157TTR from STMicroelectronics is a quad 2-channel non-inverting digital multiplexer in TSSOP-16 package, operating from 2V to 5.5V, with 4.1 ns typical propagation delay at 5V, ±8 mA output drive, and 4 µA max quiescent current. It routes A/B inputs to Y outputs under common SELECT/STROBE control and supports 5V-to-3V interfacing.

For engineers reviewing the 74VHC157TTR datasheet, 74VHC157TTR pinout, 74VHC157TTR application, or 74VHC157TTR equivalent, key selection criteria include propagation delay symmetry (tPLH ≅ tPHL), input overvoltage tolerance (0–7V independent of VCC), power-down input protection, and ESD immunity (2 kV HBM).

Technical Context

The 74VHC157TTR implements four independent 2:1 multiplexers sharing one SELECT line and one active-high STROBE that forces all Y outputs low when high. Its C2MOS process enables rail-to-rail input tolerance and latch-up immunity without external clamping.

It operates as a non-inverting data selector: when STROBE = L, Yn = An if SELECT = L, or Yn = Bn if SELECT = H. All inputs feature diode-based ESD protection and accept voltages up to 7V regardless of VCC, enabling mixed-voltage system interfacing.

Key Specifications

Pinout & Package

TSSOP-16 package: 4.4 mm × 5.0 mm body, 0.65 mm pitch, 1.2 mm height, lead-free and RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LV157APWR and 74HC157D,653, the 74VHC157TTR uniquely combines 7 V input tolerance, 4.1 ns speed at 5 V, and 4 µA quiescent current-making it optimal for robust, mixed-supply industrial interfaces where reliability and timing precision are co-prioritized.

Availability

74VHC157TTR is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, automotive body control modules, and test equipment signal routing requiring stable component supply and long-term lifecycle support.

Supply support for 74VHC157TTR 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 ICs, sensors, and analog/mixed-signal products for industrial, automotive, and consumer markets.

The 74VHC logic family targets high-speed, low-power, mixed-voltage digital interfacing-specifically engineered for seamless integration between legacy 5 V and modern 3.3 V/2.5 V systems without external level shifters.

FAQ

Can the 74VHC157TTR operate with VCC = 2.5 V while accepting 5 V inputs?

Yes. The device supports VCC from 2 V to 5.5 V and tolerates input voltages from −0.5 V to +7.0 V regardless of supply voltage. At VCC = 2.5 V, inputs up to 5 V are safely clamped internally, enabling direct connection to higher-voltage sources without external protection.

What happens to outputs when STROBE is high?

When STROBE is high, all four Y outputs are forced low (logic 0), irrespective of SELECT state or A/B input values. This overrides normal multiplexer behavior and provides a synchronous disable function useful for bus arbitration or test mode isolation.

Is the 74VHC157TTR pin-compatible with the 74LS157?

Yes. Pin numbering, signal names (SELECT, STROBE, A/B inputs, Y outputs), and logic function match the 74LS157 exactly. However, the 74VHC157TTR draws significantly less current, operates over a wider voltage range, and offers superior noise immunity and input voltage tolerance.

Does the 74VHC157TTR require external pull-up or pull-down resistors on unused inputs?

No. Unused inputs may be left floating only if STROBE is held low and SELECT is fixed-otherwise, unconnected inputs risk metastability or increased ICC. For robust operation, tie unused SELECT or STROBE to VCC or GND; unused A/B inputs should be terminated to avoid noise coupling, though internal protection diodes prevent damage.