Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

Home > Products > Integrated Circuits (ICs) > Logic > Latches

STMicroelectronics 74V1T77STR

Name: 74V1T77STR
Brand: STMicroelectronics
SKU: 74V1T77STR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: 74V1T77STR

Manufacturer:: STMicroelectronics

Category:: Latches

Package:: SC-74A, SOT-753

Datasheet:: 74V1T77STR.pdf

Description:: IC LATCH SGL D-TYPE SOT23-5

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:3,188

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

74V1T77STR from STMicroelectronics is a single D-type transparent latch in SOT23-5L package, operating at 4.5–5.5 V with 4.7 ns typical propagation delay (D→Q, CL=15 pF), ±8 mA symmetrical output drive, and 1 µA max quiescent current at 25°C. It enables level-sensitive data capture in 5V logic systems with power-down input protection and 5V-to-3V interface capability.

For engineers reviewing the 74V1T77STR datasheet, 74V1T77STR pinout, 74V1T77STR application, or 74V1T77STR equivalent, key selection criteria include latch enable timing (3 ns min LE pulse width), input voltage tolerance (0–7 V independent of VCC), balanced tPLH/tPHL propagation, and ESD-protected I/O for industrial control and portable logic interfacing.

Technical Context

The 74V1T77STR implements a single-edge-transparent D-latch using sub-micron C2MOS technology, where Q follows D only while LE is high; latching occurs synchronously on LE falling edge. Its input structure accepts 0–7 V regardless of VCC, enabling robust level translation between 5V and 3V domains without external biasing.

It features symmetrical output impedance (|IOH| = IOL ≥ 8 mA at VCC = 4.5 V), balanced propagation delays (tPLH ≅ tPHL), and built-in power-down protection that prevents back-driving during VCC-off conditions. The device meets commercial and extended temperature ranges (–55°C to +125°C) with latch enable setup/hold times of 2.0 ns / 1.0 ns respectively.

Key Specifications

Parameter	Value and Actual Design Meaning
VCC Operating Range	4.5 V to 5.5 V - Ensures compatibility with standard 5V TTL/CMOS rails and margin for supply variation.
tPD (D→Q, typ)	4.7 ns at VCC = 5 V, CL = 15 pF - Enables high-speed data sampling in real-time control loops.
IOL / IOH (min)	8 mA at VCC = 4.5 V - Drives multiple standard TTL loads or one 50 Ω transmission line.
ICC (max)	1 µA at TA = 25°C - Supports ultra-low-power operation in battery-backed or standby logic stages.
Input Voltage Range	–0.5 V to +7.0 V - Allows safe interfacing across mixed-voltage systems without clamping diodes.
LE Pulse Width (min)	3.0 ns - Permits fast enable/disable cycling in high-throughput data gating applications.
ESD Protection	Human Body Model ≥ 2 kV - Provides inherent static immunity for handling and board-level integration.

Pinout & Package

SOT23-5L package: 5-pin surface-mount, 1.3 mm height, 2.8 × 2.6 mm body, 0.95 mm lead pitch, moisture sensitivity level 1.

Pin/Terminal	Circuit Role	Design Meaning
1	D	Data input - Directly drives internal latch node; tolerant to 0–7 V regardless of VCC.
2	LE	Latch Enable - High enables transparency; falling edge triggers latching; 0.8 V/2.0 V TTL-compatible thresholds.
3	GND	Ground reference - Shared return path for all I/O and internal circuitry; must be low-impedance.
4	Q	True output - Latched or transparent data; symmetrical sourcing/sinking capability up to 8 mA.
5	VCC	Positive supply - Powers internal logic and output stage; supports 4.5–5.5 V operation with 1 µA quiescent draw.

Key Features

Feature	Design Value
Single D-type transparent latch	Enables precise, level-sensitive data capture without clock edge dependency-ideal for asynchronous handshaking.
Input overvoltage tolerance	Accepts 0–7 V on D and LE inputs irrespective of VCC, eliminating need for external level shifters in 5V↔3V interfaces.
Symmetrical output drive	Guarantees matched rise/fall times and load driving capability (≥8 mA sink/source), reducing signal skew in bus applications.
Power-down input protection	Prevents reverse current flow when VCC = 0 V, protecting upstream drivers and enabling hot-swap compatibility.
High ESD immunity	Integrated protection circuits meet ≥2 kV HBM, simplifying PCB layout and reducing need for external TVS devices.

Applications

Industrial PLC I/O Expansion

Portable Instrument Data Capture

Use Scenario: Capturing sensor status signals in modular I/O modules where microcontroller read timing is non-deterministic.

IC Role / Device Role / Timing Role: D-latch holds stable digital state during CPU polling cycles; LE driven by address decode to isolate valid data windows.

Use Value: Eliminates metastability risk from asynchronous reads and reduces firmware overhead versus interrupt-driven sampling.

Use Scenario: Buffering ADC output bits in handheld multimeters before serial transfer to display controller.

IC Role / Device Role / Timing Role: Transparent latch captures parallel ADC result on LE assertion; Q outputs feed low-power SPI shift register.

Use Value: Enables 5V ADC interfacing with 3.3V display subsystem while maintaining <5 ns timing margin for 1 MSPS sampling.

Legacy Bus Interface Adapter

Test Equipment Signal Gating

Use Scenario: Adapting 5V TTL control lines to modern 3.3V FPGA I/O banks in retro-compatibility test fixtures.

IC Role / Device Role / Timing Role: Level-translating latch isolates voltage domains; D driven by 5V bus, Q feeds 3.3V FPGA input with no external bias.

Use Value: Avoids discrete resistor-divider networks and ensures rail-to-rail logic levels with <1 µA static current draw.

Use Scenario: Enabling precise time-gated acquisition of transient waveforms in automated test equipment.

IC Role / Device Role / Timing Role: LE synchronized to trigger event; D connected to comparator output; Q provides clean strobed enable to ADC sample clock.

Use Value: Achieves sub-10 ns jitter-free gating window with guaranteed 3 ns minimum LE pulse width and 2 ns setup time.

Equivalent & Alternatives

The following parts are listed as comparable options for similar single D-type latch applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
SN74LVC1G74DCKR	Dual-edge-triggered D flip-flop (not transparent latch); requires clock edge, not level enable.	Requires synchronous clock domain; unsuitable for asynchronous data capture or level-sensitive gating.	Select only if system uses edge-triggered control and needs dual flip-flop functionality in same package.
74AUP1G79GW,125	Lower VCC range (0.8–3.6 V); 3.7 ns tPD at 3.3 V; no 5V-tolerant inputs.	Not compatible with 5V buses; requires external level shifting for legacy interface use cases.	Prefer for ultra-low-power 3.3V-only designs where 5V tolerance is unnecessary and propagation delay is critical.

Compared with SN74LVC1G74DCKR and 74AUP1G79GW,125, the 74V1T77STR uniquely combines 5V-tolerant inputs, level-sensitive transparency, and 5V operation-making it irreplaceable for asynchronous 5V system interfacing where edge-triggered alternatives introduce timing constraints or voltage translation complexity.

Availability

74V1T77STR is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, portable instrument data capture, legacy bus interface adapters, and test equipment signal gating requiring stable component supply and long-term lifecycle support.

Supply support for 74V1T77STR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.

The 74V1T77STR belongs to ST's high-speed CMOS logic family, engineered specifically for low-power, high-reliability level translation and data latching in mixed-voltage industrial and portable systems.

FAQ

Can the 74V1T77STR operate with VCC = 3.3 V?

No. The 74V1T77STR is specified only for 4.5–5.5 V operation per its Recommended Operating Conditions. At 3.3 V, VIH/VIL thresholds and output drive fall outside guaranteed specifications, and internal logic may fail to function reliably. Use 74AUP1G79 or similar for 3.3 V–only systems.

What is the maximum capacitive load the 74V1T77STR can drive while maintaining 4.7 ns tPD?

The 4.7 ns typical propagation delay is measured with CL = 15 pF. At CL = 50 pF, tPD increases to 5.3 ns (D→Q). For designs requiring ≤5 ns delay, keep total load (including trace and input capacitance) below 25 pF to maintain timing margin across temperature and voltage extremes.

Does the 74V1T77STR support hot insertion when VCC = 0 V?

Yes. Its power-down protection allows D and LE inputs to accept 0–7 V even with VCC = 0 V, preventing reverse current flow into the supply rail. This enables safe hot-plug operation in modular backplane systems, provided GND is established before signal connections.

How does the 74V1T77STR differ from a D flip-flop like the 74HC74?

Unlike edge-triggered D flip-flops, the 74V1T77STR is level-sensitive: Q follows D continuously while LE is high and freezes on LE falling edge. This eliminates setup/hold timing constraints relative to a clock edge, making it ideal for asynchronous data capture where clock synchronization is impractical or undesirable.

74V1T77STR Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: 74V

Package/Case:: SC-74A, SOT-753

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Logic Type:: D-Type Transparent Latch

Circuit:: 1:1

Output Type:: Standard

Voltage - Supply:: 4.5V ~ 5.5V

Independent Circuits:: 1

Delay Time - Propagation:: 5.3ns

Current - Output High, Low:: 8mA, 8mA

Operating Temperature:: -55°C ~ 125°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-5

74V1T77STR FAQ

1.How can I place an order for 74V1T77STR through Aetrix?

Please submit a Request for Quotation (RFQ) for 74V1T77STR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for 74V1T77STR reliable?

The price and inventory of 74V1T77STR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74V1T77STR is usually 5 days.

3.What payment methods are accepted for 74V1T77STR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74V1T77STR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 74V1T77STR?

74V1T77STR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 74V1T77STR order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for 74V1T77STR?

For technical support, including 74V1T77STR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74V1T77STR requirements.

6.How does Aetrix verify that 74V1T77STR is sourced from the original manufacturer or authorized distributors?

All 74V1T77STR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 74V1T77STR meets industry standards.

7.What is the process for return or replacement of 74V1T77STR?

All 74V1T77STR units undergo pre-shipment inspection (PSI). If there is an issue with 74V1T77STR, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The 74V1T77STR part is unused and in its original packaging.

Return procedure for 74V1T77STR:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

Tech Hub

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…