Texas Instruments SN74LVCH244APWRG4

Overview

SN74LVCH244APWRG4 from Texas Instruments is an octal buffer/line driver with 3-state outputs, designed for 1.65-V to 3.6-V VCC operation. It features two independent 4-bit channels, bus-hold circuitry on all inputs, Ioff partial-power-down support, and mixed-mode 5-V input tolerance with 3.3-V VCC - enabling use as a level translator in heterogeneous voltage systems such as industrial I/O expansion and FPGA interface buffering.

For engineers reviewing the SN74LVCH244APWRG4 datasheet, SN74LVCH244APWRG4 pinout, SN74LVCH244APWRG4 application, or SN74LVCH244APWRG4 equivalent, key selection criteria include its 20-pin TSSOP package, guaranteed 5.9 ns propagation delay at 3.3 V, ±24 mA output drive capability, bus-hold functionality eliminating external resistors, and Ioff protection for hot-swap and power sequencing scenarios.

Technical Context

This device implements dual 4-bit noninverting buffers with independent 3-state control (1OE and 2OE), supporting bidirectional signal isolation in data buses. Each channel passes A-inputs to Y-outputs when its OE is low; outputs enter high-impedance state when OE is high.

Its bus-hold circuitry actively maintains valid logic states on undriven inputs without external pullup/pulldown resistors, and Ioff limits current flow during partial power-down - critical for system-level power management in embedded controllers and programmable logic interfaces.

Key Specifications

Pinout & Package

TSSOP-20 (PW) package: 6.95 mm × 4.4 mm × 1.2 mm body, 0.65 mm pitch, exposed thermal pad optional, RoHS-compliant NiPdAu lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal buffer applications.

Compared with SN74LVC244APWR and SN74AHC244PW, the SN74LVCH244APWRG4 uniquely combines 5-V-tolerant inputs, integrated bus-hold, and Ioff - making it the sole option among these three for reliable mixed-voltage buffering with zero external bias components and safe hot-swap operation.

Availability

SN74LVCH244APWRG4 is available at Aetrix Electronics and suitable for industrial automation, FPGA interface design, and embedded test equipment requiring stable component supply and long-term lifecycle support.

Supply support for SN74LVCH244APWRG4 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 delivering analog and embedded processing solutions, with over 90 years of innovation in precision analog, power management, and logic ICs.

The SN74LVCH244A belongs to TI's LVC/LVCH logic family, engineered specifically for low-voltage, mixed-signal interfacing in space-constrained industrial and communications systems where voltage translation, power sequencing resilience, and input robustness are critical.

FAQ

What is the maximum propagation delay of SN74LVCH244APWRG4 at 3.3 V?

The maximum propagation delay (tpd) of SN74LVCH244APWRG4 is 5.9 ns when VCC = 3.3 V, TA = 25°C, and loaded with CL = 50 pF. This value is specified under recommended operating conditions and reflects worst-case performance across process, voltage, and temperature corners - critical for timing closure in high-speed digital interfaces using the SN74LVCH244APWRG4.

Does SN74LVCH244APWRG4 support 5-V input signals while powered from a 3.3-V supply?

Yes, SN74LVCH244APWRG4 supports input voltages up to 5.5 V regardless of VCC level (1.65–3.6 V). This 5-V-tolerant input capability is explicitly documented in the Absolute Maximum Ratings and Recommended Operating Conditions tables, enabling its use as a level translator in mixed-voltage systems without external circuitry - a core feature of the SN74LVCH244APWRG4.

How does the bus-hold feature of SN74LVCH244APWRG4 eliminate external resistors?

The bus-hold circuitry in SN74LVCH244APWRG4 actively maintains the last-valid logic state on each input pin using internal feedback transistors. With ±75 µA hold current at VCC = 3.0 V, it prevents floating inputs from drifting into undefined regions - removing the need for external pullup or pulldown resistors and simplifying layout. This behavior is intrinsic to the SN74LVCH244APWRG4 and requires no configuration.

What is the purpose of Ioff in SN74LVCH244APWRG4, and when is it active?

Ioff in SN74LVCH244APWRG4 disables output drivers and limits leakage current to ±10 µA when VCC = 0 V but input or output pins remain biased (e.g., during hot-swap or partial power-down). It activates automatically whenever VCC is below functional threshold - protecting downstream circuitry from back-current damage. This function is inherent to the SN74LVCH244APWRG4 silicon design and requires no external control.

Is SN74LVCH244APWRG4 pin-compatible with other TSSOP-20 octal buffers like SN74LVC244APWR?

Yes, SN74LVCH244APWRG4 shares identical pinout, footprint, and terminal assignment with SN74LVC244APWR and SN74AHC244PW in the TSSOP-20 (PW) package. All three devices use the same 20-pin layout with matching 1OE, 1A1–1A4, 1Y1–1Y4, 2OE, 2A1–2A4, 2Y1–2Y4, VCC, and GND positions - enabling drop-in replacement where electrical compatibility permits, though SN74LVCH244APWRG4 adds bus-hold and Ioff not present in the others.