Renesas 74LS151P-E

Overview

74LS151P-E from Renesas Electronics is a 1-of-8 TTL data selector/multiplexer with active-low strobe enable, 16-pin PDIP package, propagation delays as low as 12 ns (D→W), and guaranteed operation from –20°C to +75°C at 4.75–5.25 V supply. It routes one of eight digital inputs (D0–D7) to complementary outputs Y and W based on 3-bit binary select lines A/B/C, used in address decoding, data routing, and logic function generation.

For engineers reviewing the 74LS151P-E datasheet, 74LS151P-E pinout, 74LS151P-E application, or 74LS151P-E equivalent, key selection criteria include its dual active-high/active-low outputs (Y/W), strict 5 V ±5% supply requirement, -20°C to +75°C industrial temperature range, 8 mA output sink capability, and compatibility with legacy LS-TTL logic families in retro-computing, test equipment, and industrial control backplanes.

Technical Context

The 74LS151P-E implements full on-chip binary decoding for 3-bit select inputs (A, B, C), enabling direct mapping of input codes to one of eight data channels without external logic. Its strobe (S) input operates as an active-low enable: only when S = L are outputs Y and W responsive to data and select inputs; S = H forces Y = L and W = H regardless of other inputs.

It features complementary outputs - Y provides true logic level of selected input, while W provides inverted level - supporting both inverting and non-inverting signal paths in combinational logic design. All inputs meet standard LS-TTL voltage thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V), and outputs drive standard LS loads with IOL = 8 mA and IOH = –400 µA under specified conditions.

Key Specifications

Pinout & Package

74LS151P-E is housed in a 16-pin plastic dual in-line package (PDIP), JEDEC MS-001, Renesas code PRDP0016AE-B, package abbreviation P, dimensions 19.2 mm × 6.3 mm × 3.3 mm (L×W×H), with 2.54 mm lead pitch and Ni/Pd/Au plating.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar data selector/multiplexer applications.

Compared with SN74LS151N and MC74LS151N, the 74LS151P-E offers identical multiplexing functionality and pin compatibility but is characterized specifically over –20°C to +75°C and carries Renesas' quality assurance for industrial computing and instrumentation applications.

Availability

74LS151P-E is available at Aetrix Electronics and suitable for industrial control backplanes, retro-computing restoration projects, and test equipment design requiring stable component supply and verified legacy TTL interoperability.

Supply support for 74LS151P-E 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

Renesas Electronics Corporation is a Japanese semiconductor manufacturer formed in 2010 through the merger of NEC Electronics and Renesas Technology, specializing in microcontrollers, analog, and legacy logic solutions.

The 74LS151P-E belongs to Renesas' legacy TTL logic product line, designed to support long-life industrial, instrumentation, and maintenance-critical systems requiring drop-in replacements for discontinued 74-series components.

FAQ

What is the function of the strobe (S) pin on the 74LS151P-E?

The strobe (S) pin on the 74LS151P-E is an active-low enable input. When S is high, the 74LS151P-E disables multiplexing: output Y is forced low and W is forced high, regardless of select or data inputs. Only when S is low does the 74LS151P-E respond to A/B/C and D0–D7 to route the selected input to Y and W. This allows hierarchical control in multi-device configurations.

Does the 74LS151P-E support mixed-voltage interfacing, such as 3.3 V logic inputs?

No, the 74LS151P-E does not reliably support 3.3 V logic inputs. Its input high threshold (VIH) is specified at ≥2.0 V minimum, but 3.3 V CMOS outputs may not guarantee sufficient noise margin or consistent switching across temperature and process variation. For robust operation, the 74LS151P-E should be driven by 5 V TTL or LS-compatible sources; level-shifting is required for 3.3 V systems.

Can the 74LS151P-E be used as a 3-to-8 line decoder?

Yes, the 74LS151P-E can function as a 3-to-8 line decoder by tying all eight data inputs (D0–D7) to fixed logic levels (e.g., VCC or GND) and using Y or W as active-high or active-low decoded outputs. With strobe (S) held low, each unique A/B/C combination asserts exactly one output line - making it a compact, pin-compatible alternative to dedicated decoders like the 74LS138 when combined logic and decoding are needed.

What is the maximum capacitive load the 74LS151P-E can drive while maintaining specified timing?

The 74LS151P-E's switching characteristics are specified with CL = 15 pF and RL = 2 kΩ. Exceeding 15 pF increases propagation delay nonlinearly and may cause marginal timing - especially for critical paths like address decoding. For loads >15 pF, buffer stages or reduced fanout are recommended. The 74LS151P-E itself does not specify drive capability beyond standard LS loads (10 units), so external drivers are needed for heavy capacitive or transmission-line loads.

Is the 74LS151P-E suitable for new designs, or is it intended only for legacy repair?

The 74LS151P-E is actively supported by Renesas for legacy system maintenance and industrial retrofit applications. While not recommended for high-density, low-power, or high-speed new designs, it remains suitable for new builds where TTL compatibility, deterministic timing, long-term supply assurance, and mechanical fit in existing PDIP footprints are priorities - such as in test jigs, educational platforms, and ruggedized control panels.