Texas Instruments CD40257BEG4

Overview

CD40257BEG4 from Texas Instruments is a CMOS 4-bit dual 1-of-4 data selector/multiplexer with common strobe control, operating across –55°C to +125°C, featuring 15 V max supply voltage, 100 nA typical input leakage at 15 V, and propagation delay of 120 ns at 10 V V_DD. It serves as a bidirectional data routing device in digital logic systems requiring low-power, wide-temperature multiplexing.

For engineers reviewing the CD40257BEG4 datasheet, CD40257BEG4 pinout, CD40257BEG4 application, or CD40257BEG4 equivalent, this page delivers verified package mapping (PDIP-16), confirmed logic function (dual 4:1 MUX with strobe), absolute maximum ratings, timing parameters, and TI-validated alternative options for industrial and aerospace-grade logic design.

Technical Context

The CD40257BEG4 implements two independent 4:1 multiplexers sharing a common strobe (STRB) input that enables or disables both outputs simultaneously. Each MUX selects one of four data inputs (I₀–I₃) based on 2-bit select lines (S₀, S₁), with true and complemented outputs (Y and Y̅) per channel.

It uses standard CMOS silicon-gate technology, ensuring rail-to-rail input compatibility, high noise immunity (≥45% V_DD), and symmetrical output drive capability (±4.2 mA at V_DD = 10 V). Logic levels are referenced to V_DD and V_SS, with no internal pull-ups or level-shifting circuitry.

Key Specifications

Pinout & Package

CD40257BEG4 is supplied in a 16-lead plastic dual-in-line package (PDIP-N), with 0.300-inch body width, through-hole mounting, and industry-standard pin spacing (0.100 inch).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual 4:1 multiplexer applications.

Compared with CD4052BE and 74HC153N, the CD40257BEG4 uniquely combines dual independent 4:1 digital multiplexing, common strobe control, true/complement outputs, and full –55°C to +125°C qualification - making it the only option for high-reliability, wide-temperature digital routing where deterministic enable timing and output polarity flexibility are required.

Availability

CD40257BEG4 is available at Aetrix Electronics and suitable for industrial automation, aerospace avionics, and automotive body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CD40257BEG4 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 headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets.

The CD40257BEG4 belongs to TI's legacy CD4000B series of radiation-tolerant, wide-temperature CMOS logic devices, originally designed for aerospace and defense systems requiring high reliability under extreme environmental stress.

FAQ

What is the function of the strobe (STRB) input on the CD40257BEG4?

The strobe (STRB) input on the CD40257BEG4 is an active-low enable signal shared by both multiplexer channels. When STRB is HIGH, both Y_A and Y_B outputs are forced LOW regardless of select inputs or data states. Only when STRB is LOW do the outputs reflect the selected input per the S₀/S₁ codes. This allows synchronized gating of dual data paths in the CD40257BEG4, critical for glitch-free state transitions in safety-critical logic.

Does the CD40257BEG4 support true and complemented outputs simultaneously?

Yes, the CD40257BEG4 provides both true (Y_A, Y_B) and complemented (Y̅_A, Y̅_B) outputs for each multiplexer channel. Pins 7 and 15 are the true outputs; pins 6 and 11 are the complemented outputs. This dual-output architecture eliminates the need for external inverters in applications requiring both polarities, such as driving differential receivers or implementing XOR-based logic functions directly with the CD40257BEG4.

What is the maximum clock or data rate supported by the CD40257BEG4?

The CD40257BEG4 does not operate on a clock; it is a combinational logic device. Its maximum usable data rate is determined by propagation delay: 120 ns maximum at V_DD = 10 V, translating to a theoretical upper limit of ~8.3 MHz for repetitive switching. In practice, system-level setup/hold timing and PCB trace effects constrain reliable operation to ≤5 MHz for robust designs using the CD40257BEG4 in high-speed multiplexing applications.

Is the CD40257BEG4 RoHS compliant?

Yes, the CD40257BEG4 is RoHS compliant, as confirmed by Texas Instruments' official packaging addendum. The "E" suffix denotes plastic DIP packaging with NiPdAu (NIPDAU) lead finish, and the RoHS column explicitly states "Yes". This compliance applies to the CD40257BEG4 part number specifically, and aligns with EU Directive 2011/65/EU requirements for hazardous substance restrictions in electrical and electronic equipment.

Can the CD40257BEG4 operate from a 3.3 V supply?

Yes, the CD40257BEG4 is fully specified to operate from 3 V to 15 V, including 3.3 V nominal supplies. At V_DD = 3.3 V, its propagation delay increases to approximately 400 ns (typical), input leakage remains ≤100 nA, and output drive drops to ±1.2 mA. System designers must verify timing margins and fan-out capability when using the CD40257BEG4 at 3.3 V, especially in mixed-voltage interfaces with 5 V or 15 V logic families.