Texas Instruments CD40257BM96

Overview

CD40257BM96 from Texas Instruments is a CMOS quad 2-line-to-1-line data selector/multiplexer with common strobe control, operating over –55°C to +125°C, featuring 100% tested DC parameters, TTL-compatible inputs, and symmetrical output drive capability of ±4.2 mA at V_DD = 10 V. It enables signal routing in digital logic systems such as address/data bus switching and serial-to-parallel conversion.

For engineers reviewing the CD40257BM96 datasheet, CD40257BM96 pinout, CD40257BM96 application, or CD40257BM96 equivalent, key selection considerations include its 16-pin SOIC package, wide temperature range, dual-supply tolerance (3–18 V), strobe-enabled channel selection, and compatibility with legacy CD4000B-series logic families.

Technical Context

The CD40257BM96 implements four independent 2:1 multiplexers sharing a single active-low strobe (STR) input that disables all outputs when high. Each multiplexer selects between two data inputs (A_n, B_n) based on a binary select line (S), producing inverted outputs (Y_n). All logic thresholds are referenced to V_DD/2, enabling stable operation across supply voltages.

It uses standard CMOS silicon-gate technology with buffered inputs and outputs, delivering propagation delays of 80 ns typical at V_DD = 10 V and 25°C. Input leakage current remains below ±100 nA over full temperature range, supporting low-power system design without external pull-ups or level shifters.

Key Specifications

Pinout & Package

CD40257BM96 is housed in a 16-pin SOIC (Small-Outline Integrated Circuit) package, 3.9 mm wide, with 1.27 mm pitch, RoHS-compliant NiPdAu lead finish, and moisture sensitivity level (MSL) 1 (unlimited floor life at ≤30°C/60% RH).

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD4053BE and 74HC157D, CD40257BM96 uniquely combines strobe control, 3–18 V operation, and –55°C to +125°C qualification-making it the sole choice for ruggedized, multi-supply, synchronously gated digital routing where reliability trumps raw speed.

Availability

CD40257BM96 is available at Aetrix Electronics and suitable for industrial control systems, aerospace avionics interfaces, and automotive engine management units requiring stable component supply across extended temperature and voltage ranges.

Supply support for CD40257BM96 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 company founded in 1930, specializing in analog, embedded processing, and logic ICs with leadership in high-reliability and industrial-grade products.

CD40257BM96 belongs to the CD4000B-series CMOS logic family, designed for robust digital signal routing in harsh-environment applications where wide supply range, temperature resilience, and long-term obsolescence resistance are critical.

FAQ

What is the function of the STR pin on the CD40257BM96?

The STR (strobe) pin on the CD40257BM96 is an active-low control input that disables all four multiplexer outputs (Y0–Y3) when driven high, forcing them into a high-impedance state. When STR is low, the outputs reflect the selected inputs (A_n or B_n) based on the S select line. This enables synchronized channel gating in time-critical applications like data acquisition sequencing. The CD40257BM96's STR functionality is not present in non-strobe logic multiplexers such as the 74HC157.

Does the CD40257BM96 support 3.3 V logic levels?

Yes, the CD40257BM96 supports 3.3 V operation: its specified supply range is 3 V to 18 V, and input thresholds scale with V_DD (V_IL ≈ 0.3×V_DD, V_IH ≈ 0.7×V_DD). At V_DD = 3.3 V, it reliably accepts 0.99 V (low) and 2.31 V (high) logic levels. However, output drive strength drops to ±1.5 mA, so verify load compatibility. The CD40257BM96 maintains full –55°C to +125°C performance at 3.3 V, unlike many 74HC variants.

Is the CD40257BM96 pin-compatible with the CD40257BE (PDIP version)?

Yes, the CD40257BM96 is pin-compatible with the CD40257BE: both use identical 16-pin functional assignments across SOIC (M96) and PDIP (E) packages. The pinout matches per TI datasheet SCHS108C, including V_DD (pin 16), V_SS (pin 7), STR (pin 11), S (pin 15), and all data/output terminals. No PCB redesign is needed when migrating from CD40257BE to CD40257BM96-only footprint and reflow profile adjustments for SOIC.

What is the maximum clock frequency supported by the CD40257BM96?

The CD40257BM96 does not operate on a clock signal-it is a combinational logic device with propagation delay as its primary timing parameter. Its maximum usable data rate depends on system setup/hold timing and load capacitance. With 50 pF load and V_DD = 10 V, t_PD is 80 ns typical, supporting reliable operation up to ~5 MHz in cascaded logic paths. For higher-speed digital routing, the CD40257BM96 is typically used in static or low-frequency multiplexing-not high-speed serial data switching.

Can the CD40257BM96 be used as a level shifter between 5 V and 12 V logic domains?

Yes, the CD40257BM96 can perform bidirectional level translation: inputs tolerate 0–V_DD voltage swings, and outputs swing rail-to-rail. Driving S and STR from a 5 V controller while powering V_DD at 12 V allows 5 V logic to control 12 V signal routing. However, input thresholds scale with V_DD, so 5 V inputs remain valid at V_DD = 12 V (V_IH ≈ 8.4 V). The CD40257BM96 avoids external resistors or translators required by non-CMOS solutions.