Texas Instruments SN74LVC821ANSRE4

Overview

SN74LVC821ANSRE4 from Texas Instruments is a 10-bit bus-interface D-type flip-flop with 3-state outputs, designed for 1.65-V to 3.6-V V_CC operation. It features edge-triggered clocking (CLK), buffered output-enable (OE), and true-Q outputs. Used in bidirectional bus drivers with parity and I/O port expansion in mixed-voltage systems.

For engineers reviewing the SN74LVC821ANSRE4 datasheet, SN74LVC821ANSRE4 pinout, SN74LVC821ANSRE4 application, or SN74LVC821ANSRE4 equivalent, key selection considerations include 3.3-V/5-V mixed-mode signal compatibility, I_off partial-power-down support, 7.3-ns max propagation delay at 3.3 V, and 24-pin SSOP (DB) package footprint.

Technical Context

This device implements ten independent positive-edge-triggered D-type flip-flops with synchronous 3-state output control via OE. Each channel latches data on CLK's rising edge and drives true logic levels to Q outputs when enabled.

It supports mixed-mode operation: inputs tolerate up to 5.5 V while V_CC operates from 1.65 V to 3.6 V, enabling level translation between 3.3-V logic and legacy 5-V peripherals. I_off circuitry disables outputs during power-down to prevent backflow current.

Key Specifications

Pinout & Package

SN74LVC821ANSRE4 is packaged in a 24-pin SSOP (Shrink Small-Outline Package), designated DB, with 0.65-mm lead pitch and 7.5-mm body width. The package is RoHS-compliant, moisture-sensitive level 1, and rated for reflow up to 260°C.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit bus-interface flip-flop applications.

Compared with SN74LVC821ADBR, SN74LVC821ANSRE4 offers identical functionality and performance but is specifically marked and tested to TI's current production release (SCAS304J revision FEBRUARY 2005). Unlike obsolete 74LVC821ADB, it guarantees I_off operation and 5.5-V input tolerance-critical for robust mixed-voltage system integration.

Availability

SN74LVC821ANSRE4 is available at Aetrix Electronics and suitable for industrial I/O expansion, memory interface buffering, and automotive body control modules requiring stable component supply, long-term lifecycle support, and guaranteed RoHS compliance.

Supply support for SN74LVC821ANSRE4 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 ICs, with decades of expertise in high-reliability digital interface solutions.

The SN74LVC821A product line delivers robust, low-voltage bus-interface flip-flops optimized for mixed-signal systems requiring voltage translation, bus isolation, and deterministic timing in industrial and automotive applications.

FAQ

What is the maximum clock frequency supported by SN74LVC821ANSRE4?

The SN74LVC821ANSRE4 supports a maximum clock frequency of 150 MHz under recommended operating conditions (V_CC = 3.3 V, T_A = 25°C), as confirmed by timing parameter f_max in the official TI datasheet SCAS304J. This rating assumes proper signal integrity, load capacitance ≤50 pF, and monotonic CLK edges meeting the 10 ns/V slew-rate requirement.

Does SN74LVC821ANSRE4 support partial-power-down operation?

Yes, SN74LVC821ANSRE4 fully supports partial-power-down operation via its I_off circuitry. When V_CC = 0 V, I_off limits current to <±10 µA even with inputs or outputs biased to 5.5 V-preventing damaging backflow and enabling safe hot-swap or subsystem sleep modes without affecting other powered rails.

What package type is used for SN74LVC821ANSRE4?

SN74LVC821ANSRE4 uses the SSOP-24 (Shrink Small-Outline Package) with JEDEC MO-150 registration, designated DB package. It has a 7.5-mm body width, 0.65-mm lead pitch, and 1.2-mm maximum height. Pin 1 is located in quadrant Q1 per TI tape-and-reel specifications.

Can SN74LVC821ANSRE4 interface directly with 5-V logic devices?

Yes, SN74LVC821ANSRE4 accepts input voltages up to 5.5 V while operating from a 1.65–3.6-V V_CC, enabling direct connection to 5-V TTL or CMOS outputs without external level shifters. Its outputs swing rail-to-rail (0 V to V_CC) but remain compatible with 5-V inputs due to input tolerance-not output voltage level.

What is the propagation delay (t_pd) of SN74LVC821ANSRE4 at 3.3 V?

The maximum propagation delay (t_pd) of SN74LVC821ANSRE4 is 7.3 ns at V_CC = 3.3 V and T_A = 25°C, measured from CLK to Q under specified load conditions (CL = 50 pF). Typical t_pd is 2.2 ns, and the value remains stable across the full industrial temperature range (–40°C to +85°C) per TI's switching characteristics table.