Texas Instruments SN74LVC1G79DBVT

Overview

SN74LVC1G79DBVT from Texas Instruments is a single positive-edge-triggered D-type flip-flop designed for 1.65V to 5.5V V_CC operation, delivering 6ns maximum propagation delay at 3.3V/50pF, ±24mA output drive, and I_off-enabled partial-power-down protection. It functions as a synchronous data latch in low-voltage digital control paths, such as GPIO-expansion interfaces in portable electronics.

For engineers reviewing the SN74LVC1G79DBVT datasheet, SN74LVC1G79DBVT pinout, SN74LVC1G79DBVT application, or SN74LVC1G79DBVT equivalent, key selection criteria include its 5-pin SOT-23 (DBV) package, guaranteed data retention down to 1.5V V_CC, 160MHz maximum clock frequency, and over-voltage tolerant inputs supporting 5.5V signals on 1.8V–3.3V supplies.

Technical Context

This device implements a standard positive-edge-triggered D flip-flop logic function with no asynchronous reset or set. Clock triggering occurs at a defined voltage threshold-not dependent on edge slew rate-enabling robust timing behavior across supply voltages from 1.65V to 5.5V.

Its I_off circuitry actively disables outputs during power-down, preventing back-drive current and enabling safe hot-insertion in multi-rail systems. Input tolerance up to 5.5V allows interfacing with higher-voltage logic without level shifters, while balanced CMOS push-pull outputs support ±24mA drive at 3.3V.

Key Specifications

Pinout & Package

SN74LVC1G79DBVT uses the 5-pin SOT-23 (DBV) package measuring 2.90mm × 2.80mm, optimized for space-constrained PCB layouts and automated assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1G79DBVT, SN74LVC1G74DBVT provides dual functionality in identical packaging but lacks flexibility for single-latch designs, while 74LVC1G80GV,568 matches electrical performance in a smaller SC70 package-requiring layout revision but offering higher component density.

Availability

SN74LVC1G79DBVT is available at Aetrix Electronics and suitable for test and measurement instrumentation, enterprise switching infrastructure, and white goods control systems requiring stable component supply across extended temperature ranges (–40°C to +125°C).

Supply support for SN74LVC1G79DBVT 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, low-power digital ICs.

SN74LVC1G79DBVT belongs to TI's LVC logic family, engineered for voltage-flexible, low-power data synchronization in portable, industrial, and consumer electronics where space, power, and mixed-voltage interoperability are critical.

FAQ

What is the minimum V_CC required for functional operation of SN74LVC1G79DBVT?

The SN74LVC1G79DBVT operates functionally across 1.65V to 5.5V V_CC. Below 1.65V, timing parameters and output drive are not guaranteed. However, data retention is maintained down to 1.5V V_CC, allowing the Q output to hold its last state during brief brown-outs - a feature confirmed in TI's application curve Figure 8-2. This behavior is specific to SN74LVC1G79DBVT and applies only when inputs are static during the undervoltage event.

Does SN74LVC1G79DBVT support 5V input signals when powered at 1.8V?

Yes, SN74LVC1G79DBVT supports input voltages up to 5.5V on both D and CLK pins regardless of V_CC, as verified in Section 5.1 Absolute Maximum Ratings and Section 5.3 Recommended Operating Conditions. This over-voltage tolerance eliminates external level shifters in mixed-voltage interfaces - for example, connecting a 5V sensor output directly to the D input while SN74LVC1G79DBVT runs at 1.8V. No series resistor is required for protection.

What is the purpose of the I_off feature in SN74LVC1G79DBVT?

The I_off feature in SN74LVC1G79DBVT disables all outputs when V_CC = 0V, limiting leakage current to ±10µA maximum. This prevents back-drive current from other powered sections of the system into the unpowered SN74LVC1G79DBVT, protecting it from latch-up or damage. It is essential for partial-power-down architectures - such as USB-C port controllers or hot-pluggable modules - where subsystems power up/down independently.

Can SN74LVC1G79DBVT replace SN74LVC1G74DBVT in a design?

No, SN74LVC1G79DBVT cannot directly replace SN74LVC1G74DBVT because they differ in logic function: SN74LVC1G79DBVT is a single D-type flip-flop, while SN74LVC1G74DBVT contains two independent D-type flip-flops in the same DBV package. Pin compatibility does not imply functional equivalence - replacing one with the other would require redesigning signal routing and firmware logic. Always verify functional mapping before substitution.

What is the maximum clock frequency supported by SN74LVC1G79DBVT across temperature?

SN74LVC1G79DBVT supports a maximum clock frequency of 160MHz across its full operating temperature range (–40°C to +125°C), as specified in Sections 5.6 and 5.7 Timing Requirements. This value holds for all V_CC levels (1.8V, 2.5V, 3.3V, 5V) and load conditions (CL = 15pF, 30pF, or 50pF). The 160MHz limit is derived from worst-case setup/hold and propagation delay margins - not a typical or derated value - and applies to production-grade SN74LVC1G79DBVT units.