Texas Instruments SN74LVTH273NSR

Overview

SN74LVTH273NSR from Texas Instruments is an octal positive-edge-triggered D-type flip-flop with direct-clear input, designed for 3.3-V V_CC operation while supporting 5-V TTL-level inputs and outputs. It features bus-hold circuitry on all data inputs, I_off partial-power-down protection, and operates down to 2.7 V. It is used in level-shifting register interfaces in mixed-voltage digital systems such as industrial control backplanes and legacy bus adapters.

For engineers reviewing the SN74LVTH273NSR datasheet, SN74LVTH273NSR pinout, SN74LVTH273NSR application, or SN74LVTH273NSR equivalent, key selection criteria include its 20-pin SOP (NS) package, 150-MHz maximum clock frequency, ±100 µA I_off current, bus-hold input retention, and compatibility with both 3.3-V logic domains and 5-V signal environments.

Technical Context

This device implements eight independent D-type latches synchronized to the rising edge of CLK, with asynchronous active-low CLR controlling all outputs simultaneously. Each flip-flop has dedicated D and Q terminals, and no internal feedback or scan logic - it functions strictly as a parallel register stage.

The bus-hold circuitry actively maintains valid logic states on undriven D inputs without external resistors, while the I_off feature disables outputs during power-down to prevent backflow current. Input voltage tolerance extends to 5.5 V regardless of V_CC, enabling robust interfacing with higher-voltage peripherals.

Key Specifications

Pinout & Package

SN74LVTH273NSR is housed in a 20-pin SOP (Small Outline Package) with 0.65-mm lead pitch, 7.4-mm body width, and 2.0-mm maximum height per JEDEC MO-150. The package is RoHS-compliant, tape-and-reel packaged (2000 units/reel), and rated MSL-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal D-type flip-flop applications.

Compared with SN74LVTH273NSR, SN74LVC273PWR offers lower static power but sacrifices 5-V input tolerance and bus-hold, while 74ALVCH273MTCX improves propagation delay at the expense of robustness in uncontrolled signal environments.

Availability

SN74LVTH273NSR is available at Aetrix Electronics and suitable for industrial backplane interfaces, legacy bus adapters, low-power sensor hubs, and test equipment digital I/O modules requiring stable component supply across extended temperature ranges (−40°C to +85°C).

Supply support for SN74LVTH273NSR 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 experience in industrial-grade interface ICs.

The SN74LVTH273NSR belongs to TI's LVTH logic family, engineered specifically for mixed-voltage system integration where 3.3-V core logic must interoperate reliably with legacy 5-V TTL signaling infrastructure.

FAQ

What is the operating voltage range for SN74LVTH273NSR?

The SN74LVTH273NSR operates from 2.7 V to 3.6 V on V_CC. Its inputs tolerate up to 5.5 V, allowing direct connection to 5-V TTL sources without level shifting. This dual-voltage capability makes SN74LVTH273NSR ideal for bridging 3.3-V logic domains with legacy 5-V systems while maintaining low power consumption and noise immunity.

Does SN74LVTH273NSR support partial power-down operation?

Yes, SN74LVTH273NSR includes I_off circuitry that disables outputs when V_CC is at 0 V, limiting current flow to ±100 µA. This prevents backflow current from live inputs into a powered-down section of the system - a critical feature for hot-swap, power-gated, or modular subsystem designs where SN74LVTH273NSR may reside on a removable board or isolated power domain.

How does the bus-hold function work on SN74LVTH273NSR?

SN74LVTH273NSR integrates active bus-hold circuitry on all eight D inputs, which detects and maintains the last-valid logic state (high or low) when inputs float or become undriven. This eliminates the need for external pull-up or pull-down resistors, reducing component count and PCB space. The bus-hold current is specified up to ±750 µA, ensuring reliable state retention even under moderate noise or leakage conditions.

What is the maximum clock frequency supported by SN74LVTH273NSR?

SN74LVTH273NSR supports a maximum clock frequency of 150 MHz under recommended operating conditions (V_CC = 3.3 V ± 0.3 V, T_A = −40°C to +85°C). This is validated by timing parameters including t_w (3.3 ns minimum pulse width) and f_max (150 MHz), making SN74LVTH273NSR suitable for high-speed register applications such as data capture in communication interfaces and real-time control loops.

Is SN74LVTH273NSR pin-compatible with other packages in the LVTH273 family?

Yes, SN74LVTH273NSR shares identical pinout and functionality with other LVTH273 variants in SOIC (DW), SSOP (DB), and TSSOP (PW) packages. All versions use the same 20-pin arrangement with identical signal assignments (e.g., Pin 1 = CLR, Pins 2–9/11–18 = D/Q pairs, Pin 10 = GND, Pin 19 = V_CC, Pin 20 = CLK). This allows drop-in replacement across packages based on board space, thermal, or assembly requirements - SN74LVTH273NSR itself uses the SOP-20 (NS) footprint.