SN74HC21QPWRQ1 - Dual 4-Input AND Gate, 2-6V | Texas Instruments
MPN: SN74HC21QPWRQ1 β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.62 | $0.62 |
| 10 | $0.56 | $5.60 |
| 100 | $0.41 | $41.00 |
| 500 | $0.33 | $165.00 |
| 1,000 | $0.27 | $270.00 |
Drop-in alternatives for SN74HC21QPWRQ1 β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
SN74HC21QPWRG4Q1
β Drop-Inβ In Stock
$0.38 / Unit
View Datasheet βSN74HC21PWR
β Drop-Inβ In Stock
$0.15 / Unit
View Datasheet βSN74HC21PWT
β Drop-Inπ Reference alternative (not in catalog)
SN74HC21PWG4
β Drop-Inπ Reference alternative (not in catalog)
74HC21PW,118
β Drop-Inπ Reference alternative (not in catalog)
SN74HC21QPWRQ1 Maximum Ratings & Electrical Characteristics
| Logic Type | AND Gate |
| Number of Circuits | 2 |
| Number of Inputs per Gate | 4 |
| Supply Voltage Range | 2 V to 6 V |
| Output Drive Strength | 5.2 mA at 6 V |
| Supply Current (Max ICC) | 20 uA |
| LSTTL Loads per Output | 10 |
| Operating Temperature Range | -40C to +125C |
| Qualification | AEC-Q100 (Automotive) |
| Package | TSSOP-14 (PW), 4.40 mm width |
| Mounting Type | Surface Mount |
| Logic Family | HC (High-Speed CMOS) |
| Boolean Function | Y = A - B - C - D (positive logic) |
| Output Type | Push-Pull CMOS |
| Packaging | Tape and Reel (Digi-Reel available) |
| RoHS Status | Compliant |
SN74HC21QPWRQ1 Pin Configuration
| Pin 1 | A1 β Gate 1 input A |
| Pin 2 | B1 β Gate 1 input B |
| Pin 3 | NC β Not connected (per datasheet) |
| Pin 4 | C1 β Gate 1 input C |
| Pin 5 | D1 β Gate 1 input D |
| Pin 6 | Y1 β Gate 1 output Y = A1-B1-C1-D1 |
| Pin 7 | GND β Ground |
| Pin 8 | A2 β Gate 2 input A |
| Pin 9 | B2 β Gate 2 input B |
| Pin 10 | NC β Not connected (per datasheet) |
| Pin 11 | C2 β Gate 2 input C |
| Pin 12 | D2 β Gate 2 input D |
| Pin 13 | Y2 β Gate 2 output Y = A2-B2-C2-D2 |
| Pin 14 | VCC β Power supply, 2 V to 6 V |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this digital IC. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
SN74HC21QPWRQ1 is suitable for 6 applications: Automotive Body Control Modules, Motor Drive Enable and Fault Logic, Power Supply Sequencing and Good-Signal Logic, Safety Interlock and E-Stop Logic, General Combinational Logic in Industrial PLCs, Test and Measurement Instrumentation.
Automotive Body Control Modules
Body control modules combine dozens of switch, sensor, and diagnostic signals before actuating loads such as lamps, locks, and relays. The SN74HC21QPWRQ1 fits this environment directly: its AEC-Q100 qualification and -40C to +125C rating survive under-hood-adjacent temperatures, and its 2 V to 6 V supply range tolerates automotive rail variation during cranking transients. Each 4-input gate can AND four condition signals - for example, ignition-on, door-closed, seatbelt-latched, and brake-pressed - into a single enable line feeding a microcontroller GPIO. The 5.2 mA drive at 6 V is ample for MCU inputs and LED indicators, while the 20 uA maximum ICC keeps quiescent drain negligible in always-on BCM circuits. Unlike open-drain solutions, the push-pull CMOS output needs no pull-up resistor, reducing component count on high-channel-count boards.
Recommended
Motor Drive Enable and Fault Logic
In motor-control systems, multiple interlocks - over-temperature, over-current, gate-driver ready, and system enable - must all be true before PWM signals reach the power stage. The SN74HC21QPWRQ1 consolidates four such flags into one hardware enable line, providing a fail-safe gate that removes firmware latency from the safety path. Its 2 V to 6 V operation interfaces cleanly with 3.3 V or 5 V microcontroller I/O banks, and the -40C to +125C AEC-Q100 rating suits industrial drives and traction inverters alike. Placing the AND gate between fault-monitor comparators and the gate-driver EN pin ensures that any single fault de-energizes the stage in nanoseconds, independent of software. The HC-family CMOS input thresholds provide noise margin against inverter switching transients, and the dual-gate package lets one device handle both enable and brake-interlock logic.
Recommended
Power Supply Sequencing and Good-Signal Logic
Multi-rail systems often require that several power-good signals be true before releasing the main enable or releasing the processor from reset. The SN74HC21QPWRQ1 ANDs up to four power-good outputs into one master-enable signal. Its 2 V to 6 V range matches the logic levels of both 5 V and 3.3 V supervisor outputs, and the CMOS push-pull output drives reset controllers or enable pins directly at 5.2 mA without pull-ups. The 20 uA maximum ICC matters in standby and battery-backup domains where sequencing logic stays powered continuously. In automotive ECUs, the AEC-Q100 qualification and +125C rating allow placement near hot voltage-regulator zones. A typical circuit feeds four regulator power-good pins into gate 1, with gate 2 combining a manual reset line and watchdog output for a two-level release hierarchy on one 14-pin TSSOP footprint.
Recommended
Safety Interlock and E-Stop Logic
Safety interlock chains require that all guards be closed and all E-stop channels reset before machinery can energize. The SN74HC21QPWRQ1 provides redundant-condition gating in hardware: four guard-switch inputs per gate yield a single permissive output, and the second gate can build a separate two-channel monitoring function. Hardware AND logic is preferred over firmware for the first line of interlock because it operates with sub-microsecond propagation delay and cannot be bypassed by software faults. The -40C to +125C automotive-grade rating extends applicability from factory floor cells to mobile equipment. HC-family inputs feature high noise immunity, important near contactors and VFDs. Designers should still perform a full ISO 13849-style risk assessment; this gate handles signal-conditioning logic, not the certified safety controller itself.
Recommended
General Combinational Logic in Industrial PLCs
Programmable logic controllers and I/O modules use discrete gates for address decoding, chip-select qualification, and combining module-present and backplane-enable signals. The SN74HC21QPWRQ1 suits these roles with its wide 2 V to 6 V operation, which bridges legacy 5 V backplanes and newer 3.3 V logic; its 10-LSTTL-load drive capability, which handles multi-fanout address lines; and its low 20 uA supply current, which reduces I/O-card power budgets. The industrial -40C to +125C rating (via the Q1 automotive grade) covers cabinet environments that exceed commercial limits. Two gates per package allow one TSSOP-14 device to qualify both a chip-select and a data-direction signal. The small 4.4 mm body fits high-density I/O cards where DIP logic would be impractical, and surface-mount assembly keeps automated production straightforward.
Recommended
Test and Measurement Instrumentation
Bench instruments and automated test equipment use AND gates to qualify triggers - for example, requiring arm signal, threshold crossing, and software enable to be simultaneously true before a capture event. The SN74HC21QPWRQ1 provides deterministic sub-microsecond gating with clean CMOS edges, avoiding the jitter a firmware path would add. Its 2 V to 6 V supply matches common 5 V trigger buses, and the 5.2 mA output drives trigger distribution lines or timer inputs directly. The wide -40C to +125C range permits use in thermally stressed rack enclosures. Designers should keep traces carrying the qualified output short and route them away from clock lines to preserve edge integrity; a 0.1 uF decoupling capacitor at pin 14 suppresses supply-borne glitches from nearby switching circuitry. The dual-gate format supports two independent trigger-conditioning channels in one footprint.
Recommended
Recommended Products Summary
Engineering reference data for SN74HC21QPWRQ1 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | SN74HC21QPWRG4Q1 | SN74HC21PWR | SN74HC21PWT | SN74HC21PWG4 | 74HC21PW,118 |
|---|---|---|---|---|---|---|
| Package | TSSOP-14 (PW) | TSSOP-14 (PW) - same | TSSOP-14 (PW) - same | TSSOP-14 (PW) - same | TSSOP-14 (PW) - same | TSSOP-14 (PW) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Nexperia |
| Logic Function | Dual 4-input AND | Dual 4-input AND | Dual 4-input AND | Dual 4-input AND | Dual 4-input AND | Dual 4-input AND |
| Supply Voltage Range | 2 V to 6 V | 2 V to 6 V | 2 V to 6 V | 2 V to 6 V | 2 V to 6 V | 2 V to 6 V |
| Temperature Range | -40C to +125C | -40C to +125C | -40C to +85C | -40C to +85C | -40C to +85C | [DATA_NEEDED] |
| AEC-Q100 Automotive Qualification | Yes (Q1) | Yes (Q1) | No | No | No | [DATA_NEEDED] |
| Output Drive | 5.2 mA at 6 V | 5.2 mA at 6 V | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] |
| Approx. Unit Price (qty 1) | $0.62 | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] |
Key Differentiators
- AEC-Q100 automotive qualification to +125C (vs SN74HC21PWR)
- Identical-die TI substitute available (vs SN74HC21QPWRG4Q1)
- Second-source cross-brand option on same footprint (vs 74HC21PW,118)
Design Notes
Place a 0.1 uF ceramic decoupling capacitor between VCC (pin 14) and GND (pin 7), as close to the pins as possible. HC-family CMOS draws dynamic shoot-through current during output transitions; without local decoupling, these transients couple supply glitches into adjacent logic. For boards with multiple HC devices sharing a rail, add one bulk 1 uF to 10 uF capacitor per power domain. Keep the NC pins 3 and 10 unconnected - do not use them as jumpers.
Never leave HC-family CMOS inputs floating. An unterminated input drifts to an undefined level, causing both gates to oscillate or draw excess shoot-through current and increasing susceptibility to EMI. Tie unused inputs of unused gates to GND (or VCC) and the corresponding other inputs likewise so the output settles to a defined state. This is the single most common field failure mode for HC logic in prototype builds.
At 6 V, HC outputs transition fast enough that long unterminated lines (>10 cm) can ring. For interlock or enable lines running across backplanes or cable harnesses, add a series 33 ohm resistor at the gate output to damp reflections, or route the signal differentially for harsh automotive environments. Input protection diodes clamp only to about 20 mA injection - never apply inputs above VCC+0.5 V during power-up sequencing of mixed-rail systems.
Estimated: at 5 V VCC with a light logic load, total supply current is dominated by the 20 uA maximum ICC plus dynamic dissipation (P = Cpd * V^2 * f * N). For a typical HC gate with Cpd around 25 pF switching at 1 MHz and 5 V, dynamic power is roughly 0.3 mW per output - negligible for most designs, but worth totaling across hundreds of gates in dense logic boards.
Compliance Information
AEC-Q100 automotive qualification per TI SN74HC21-Q1 product page. RoHS/lead-free status per DigiKey and TI listings as of 2026-09-04.
