Texas Instruments SN74LV138APWRG4

Overview

SN74LV138APWRG4 from Texas Instruments is a 3-line to 8-line decoder/demultiplexer IC operating from 2 V to 5.5 V, delivering 9.5 ns maximum propagation delay at 5 V, supporting mixed-mode voltage operation across all ports, and featuring Ioff for partial-power-down mode. It is used in LED matrix control and 7-segment display systems where precise address decoding and low-voltage compatibility are required.

For engineers reviewing the SN74LV138APWRG4 datasheet, SN74LV138APWRG4 pinout, SN74LV138APWRG4 application, or SN74LV138APWRG4 equivalent, key selection criteria include VCC range (2–5.5 V), tpd ≤ 9.5 ns at 5 V, active-low G0/G1 + active-high G2 enables, Ioff support, and TSSOP-16 package compatibility with space-constrained PCB layouts.

Technical Context

The SN74LV138APWRG4 implements positive-logic 3-to-8 decoding using binary-select inputs A0–A2 and three enable inputs (G2 high-active, G0/G1 low-active) to activate exactly one of eight active-low outputs (Y0–Y7). Its CMOS architecture ensures rail-to-rail output swing and high noise immunity across its full 2–5.5 V supply range.

It integrates standard CMOS inputs with ≤2.1 pF input capacitance and balanced push-pull outputs capable of sourcing/sinking up to ±12 mA at 5 V, while Ioff circuitry disables outputs and limits leakage to ≤5 μA when VCC = 0 V-enabling safe back-drive protection during power sequencing.

Key Specifications

Pinout & Package

PW package: 16-pin TSSOP, body size 5.00 mm × 4.40 mm, 0.65 mm pitch, exposed thermal pad (not electrically connected).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 3-to-8 decoder applications.

Compared with SN74HC138N and 74LVC138PW, the SN74LV138APWRG4 uniquely bridges 2–5.5 V operation, delivers sub-10 ns speed at 5 V, and provides Ioff for robust power sequencing - making it the only choice for industrial designs requiring wide-VCC flexibility and hot-swap safety.

Availability

SN74LV138APWRG4 is available at Aetrix Electronics and suitable for LED matrix control, 7-segment display systems, and memory address expansion requiring stable component supply, long-term industrial lifecycle support, and consistent TSSOP-16 packaging.

Supply support for SN74LV138APWRG4 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 decades of expertise in high-reliability logic families and industrial-grade qualification.

The SN74LV138APWRG4 belongs to TI's LV (Low-Voltage) logic series, designed specifically for mixed-supply systems requiring interoperability across 2.5 V, 3.3 V, and 5 V domains while maintaining speed, noise immunity, and power-down safety.

FAQ

What is the maximum propagation delay of the SN74LV138APWRG4 at 3.3 V supply?

The SN74LV138APWRG4 has a maximum propagation delay of 13.5 ns at VCC = 3.3 V with 15 pF load, as specified in Section 6.7 of the official datasheet. This value reflects worst-case timing across temperature and process variation, ensuring reliable setup/hold margins in real-world 3.3 V systems.

Does the SN74LV138APWRG4 support partial-power-down mode?

Yes, the SN74LV138APWRG4 supports partial-power-down mode via its Ioff feature. When VCC = 0 V, all outputs enter high-impedance state with ≤5 μA leakage current, preventing back-current flow from powered sections - a critical capability for hot-plug and power-gated architectures.

Can the SN74LV138APWRG4 drive LEDs directly?

Yes, the SN74LV138APWRG4 can drive LEDs directly: each active-low output (Y0–Y7) sinks up to 12 mA at VCC = 5 V, sufficient for standard indicator LEDs or low-current segments of 7-segment displays without external transistors - provided total device current stays within ±50 mA limits.

What is the function of the G2, G0, and G1 pins on the SN74LV138APWRG4?

G2 is an active-high enable input; G0 and G1 are active-low enable inputs. All three must be asserted (G2 = HIGH, G0 = LOW, G1 = LOW) for decoding to occur. This triple-enable structure reduces external logic count when expanding to larger decoder configurations like 24-line systems.

Is the SN74LV138APWRG4 pin-compatible with the SN74HC138?

No, the SN74LV138APWRG4 is not pin-compatible with the SN74HC138. While both are 3-to-8 decoders, the SN74HC138 uses different enable polarity (all three enables active-low) and is offered in DIP-16 or SOIC-16 packages - whereas SN74LV138APWRG4 uses G2 (active-high) + G0/G1 (active-low) and is exclusively in TSSOP-16 (PW) packaging.