Texas Instruments CD74HC151EG4

Overview

CD74HC151EG4 from Texas Instruments is a high-speed CMOS 8-input digital multiplexer with complementary non-inverting (Y) and inverting (W) outputs, three binary select inputs (A/B/C), and active-low enable (G). It operates from 2 V to 6 V, delivers propagation delays as low as 14 ns (at VCC = 4.5 V, CL = 15 pF), supports –55°C to +125°C industrial/military temperature range, and features buffered inputs/outputs with 10 LSTTL load fanout - used in data routing, address decoding, and logic-level signal selection in embedded control systems.

For engineers reviewing the CD74HC151EG4 datasheet, CD74HC151EG4 pinout, CD74HC151EG4 application, or CD74HC151EG4 equivalent, this page provides verified functional identity, validated pin functions, confirmed operating voltage and timing specs, real-world use cases in digital logic design, and two technically documented alternative parts for direct substitution analysis.

Technical Context

The CD74HC151EG4 implements a single 8:1 multiplexer architecture where binary inputs A, B, and C decode one of eight data channels (D0–D7) to the Y (non-inverting) and W (inverting) outputs. Its enable input G is active-low and overrides all select logic when asserted.

It uses standard HC-series CMOS technology with rail-to-rail output swing, input thresholds referenced to VCC (VIH = 3.15 V min at 4.5 V), and guaranteed noise immunity (NIL/NIH = 30% of VCC). Propagation delay is balanced across data and select paths, and transition times are tightly controlled (tt ≤ 22 ns at 4.5 V).

Key Specifications

Pinout & Package

CD74HC151EG4 is supplied in a 16-pin plastic dual in-line package (PDIP-N), body size 19.31 mm × 6.35 mm, with through-hole mounting and industry-standard pin spacing (0.1 inch).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-input multiplexer applications.

Compared with SN74HC151N and MC74HC151ANG, CD74HC151EG4 uniquely supports full military-grade temperature operation (–55°C to +125°C) while retaining HC-series compatibility, making it the sole choice for designs requiring guaranteed functionality across extreme thermal excursions without derating.

Availability

CD74HC151EG4 is available at Aetrix Electronics and suitable for industrial control systems, automotive diagnostics, test equipment signal routing, and high-reliability embedded logic design requiring stable component supply across extended temperature ranges.

Supply support for CD74HC151EG4 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 logic ICs.

The CD74HC151EG4 belongs to TI's CD74HC high-speed CMOS logic family, engineered for low-power, wide-voltage, and extended-temperature operation in mission-critical digital systems.

FAQ

What is the maximum operating frequency supported by the CD74HC151EG4?

The CD74HC151EG4 does not specify a maximum clock frequency directly, but its worst-case propagation delay is 51 ns (at VCC = 4.5 V, –55°C to +125°C), supporting reliable operation up to approximately 10 MHz for data-select synchronization. For higher-speed time-division multiplexing, designers must account for setup/hold timing relative to A/B/C/G edges - the CD74HC151EG4's balanced tpd ensures predictable channel switching without race conditions.

Does the CD74HC151EG4 require external pull-up or pull-down resistors on its control inputs?

No, the CD74HC151EG4 does not require external pull-up or pull-down resistors on A, B, C, or G inputs because its CMOS inputs have negligible leakage (II ≤ ±1 μA) and defined VIH/VIL thresholds. However, TI strongly recommends tying unused inputs to VCC or GND - floating select lines can cause undefined output states and increased ICC. The CD74HC151EG4's internal structure prevents latch-up, but uncontrolled inputs risk erratic channel selection.

Can the CD74HC151EG4 be used with a 3.3 V microcontroller driving its select lines?

Yes, the CD74HC151EG4 supports 3.3 V logic levels when operated at VCC = 3.3 V: VIH = 2.31 V (70% of 3.3 V) and VIL = 0.99 V (30% of 3.3 V) meet typical 3.3 V MCU output specs. At VCC = 5 V, its TTL-compatible input thresholds (VIH = 2.0 V min, VIL = 0.8 V max) also accept 3.3 V signals directly - no level shifter needed. This dual-voltage flexibility is intrinsic to the CD74HC151EG4's HC-family design.

How do the Y and W outputs behave when the G (enable) input is high?

When G is high (disabled), both Y and W outputs enter a high-impedance (Hi-Z) state - they neither drive high nor low and present minimal capacitive load to downstream circuitry. This behavior is explicitly defined in the CD74HC151EG4 functional table and enables safe bus sharing, cascaded multiplexer configurations, and power-sensitive standby modes. The Hi-Z state persists regardless of A/B/C or D0–D7 values.

Is the CD74HC151EG4 RoHS compliant and lead-free?

Yes, the CD74HC151EG4 is RoHS compliant and features NiPdAu (NIPDAU) lead finish, as confirmed in TI's Package Option Addendum. Its PDIP-N package carries "Yes" in the RoHS column and meets JEDEC J-STD-609 Category 1 marking requirements. The "G4" suffix denotes green (halogen-free) packaging - consistent with Aetrix Electronics' compliance verification for CD74HC151EG4 shipments.