Texas Instruments SN74LVC157APWT

Overview

SN74LVC157APWT from Texas Instruments is a quadruple 2-line to 1-line data selector/multiplexer in TSSOP-16 package, operating from 1.65V to 3.6V supply, with 5.2ns max propagation delay at 3.3V, 5.5V-tolerant inputs, and –40°C to 125°C temperature range. It routes four independent 2:1 data paths under common address (A/B) and strobe (G) control for bus selection in mixed-voltage digital systems.

For engineers reviewing the SN74LVC157APWT datasheet, SN74LVC157APWT pinout, SN74LVC157APWT application, or SN74LVC157APWT equivalent, key selection criteria include its 16-pin TSSOP footprint, 3.3V/5V I/O compatibility, low ground bounce (<0.8V), output undershoot margin (>2V), and latch-up immunity exceeding 250mA per JESD17.

Technical Context

The SN74LVC157APWT implements true (non-inverting) 2:1 multiplexing across four parallel channels, each selecting between A and B inputs based on the shared A/B select line. All outputs are simultaneously enabled or disabled via active-low G (strobe) input - when G is high, all Y outputs drive low regardless of A/B or data inputs.

Its CMOS design supports mixed-voltage interfacing: inputs tolerate up to 5.5V independent of VCC, enabling direct connection to 5V logic while powered from 1.65–3.6V supplies. Propagation delay varies with voltage (e.g., 5.2ns typ at 3.3V, 7.4ns max at 2.7V), and output drive strength scales with VCC (±24mA at 3V, ±12mA at 2.7V).

Key Specifications

Pinout & Package

TSSOP-16 (PW) package: 5.00 mm × 6.4 mm body size, 0.65 mm lead pitch, exposed thermal pad optional (not electrically connected unless tied to GND).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LV157APW and 74LVC1G157GW,125, the SN74LVC157APWT uniquely balances 1.65V operation, 5.5V-tolerant inputs, quad integration, and 5.2ns speed - making it optimal for compact, mixed-voltage embedded systems requiring minimal layout change.

Availability

SN74LVC157APWT is available at Aetrix Electronics and suitable for industrial automation, automotive control units, and communications infrastructure requiring stable component supply, extended temperature support, and RoHS-compliant packaging.

Supply support for SN74LVC157APWT 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and logic solutions with over 50 years of innovation in high-reliability digital ICs.

The SN74LVC157APWT belongs to TI's LVC logic family, designed specifically for low-voltage, high-speed, mixed-signal interfacing in space- and power-constrained applications across automotive, industrial, and communications markets.

FAQ

What is the maximum operating frequency supported by the SN74LVC157APWT?

The SN74LVC157APWT does not specify a maximum clock frequency directly, but its 5.2ns maximum propagation delay at 3.3V implies reliable operation up to approximately 100MHz for data path switching. Actual system frequency depends on setup/hold timing margins, load capacitance, and PCB routing - design validation using TI's recommended 30pF load and 50Ω source impedance is advised for high-speed use cases involving the SN74LVC157APWT.

Can the SN74LVC157APWT interface safely with 5V logic inputs while powered from a 3.3V supply?

Yes, the SN74LVC157APWT supports 5.5V-tolerant inputs, meaning all data and control pins (1A–4B, A/B, G) accept voltages up to 5.5V regardless of VCC level. When powered from 3.3V, it correctly interprets 5V TTL or CMOS logic levels as valid HIGH/LOW signals without damage or level-shifting circuitry - a key feature confirmed in the absolute maximum ratings and functional description sections of the official SN74LVC157APWT datasheet.

What is the function of the G (strobe) pin on the SN74LVC157APWT?

The G pin on the SN74LVC157APWT is an active-low output enable/strobe. When G is driven HIGH, all four Y outputs (1Y–4Y) are forced LOW irrespective of A/B select state or input data. When G is LOW, the device operates normally: each Y output reflects the selected A or B input per the A/B control line. This enables synchronized disabling of all multiplexer outputs - useful for bus contention avoidance or power-gated subsystem control in the SN74LVC157APWT.

Does the SN74LVC157APWT require external pull-up or pull-down resistors on unused inputs?

Yes, all unused inputs of the SN74LVC157APWT must be held at a defined logic level - either VCC or GND - to prevent floating states that cause increased ICC, erratic output behavior, or ESD susceptibility. TI explicitly recommends this in Section 4.4 of the SN74LVC157APWT datasheet. Leaving inputs unconnected violates recommended operating conditions and may compromise reliability, especially in high-noise or wide-temperature environments where the SN74LVC157APWT is deployed.

Is the thermal pad on the SN74LVC157APWT package electrically connected?

No, the thermal pad on the SN74LVC157APWT's TSSOP-16 (PW) package is not internally connected to any die node. Per TI's mechanical documentation, it may be left floating or connected to GND for improved thermal dissipation - but must never be tied to VCC or signal nets. This design choice avoids unintended electrical coupling while allowing board-level thermal management flexibility for the SN74LVC157APWT in thermally demanding applications.