SN74AHCT3G99-Q1 - Triple Configurable Gate | TI | Automotive
MPN: SN74AHCT3G99-Q1 β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.75 | $0.75 |
| 10 | $0.68 | $6.80 |
| 100 | $0.52 | $52.00 |
| 500 | $0.44 | $220.00 |
| 1,000 | $0.38 | $380.00 |
Drop-in alternatives for SN74AHCT3G99-Q1 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:
SN74AHCT3G99PWR
β Drop-Inπ Reference alternative (not in catalog)
SN74AHC3G99QPWRQ1
β Drop-Inπ Reference alternative (not in catalog)
SN74LVC3G99QPWRQ1
β Drop-Inπ Reference alternative (not in catalog)
SN74AHCT3G99-Q1 Maximum Ratings & Electrical Characteristics
| Logic Function | Configurable: Y = (A β’ /C + B β’ C) β D per gate |
| Number of Gates | 3 |
| Inputs per Gate | 4 |
| Supply Voltage Range | 4.5 V to 5.5 V |
| Input Type | Schmitt-Trigger, TTL-compatible |
| Output Type | 3-State |
| Configurable Functions | MUX, AND, OR, NAND, NOR, XOR, XNOR and more |
| Max Load Capacitance | 50 pF (for full datasheet compliance) |
| Operating Temperature | -40C to +125C |
| Qualification | AEC-Q100 (Automotive) |
| Package | 20-TSSOP (PW) |
| Mounting Type | Surface Mount |
| Propagation Delay | [DATA_NEEDED: propagation delay] |
| Output Drive Current | [DATA_NEEDED: output drive current] |
| Input Hysteresis | [DATA_NEEDED: hysteresis voltage] |
| Family | AHCT |
| RoHS Status | [DATA_NEEDED: RoHS status] |
SN74AHCT3G99-Q1 Pin Configuration
| Pin 1 | 1A β Gate 1 input A |
| Pin 2 | 1B β Gate 1 input B |
| Pin 3 | 1C β Gate 1 select input C |
| Pin 4 | 1D β Gate 1 input D |
| Pin 5 | 1OE β Gate 1 output enable (3-state control) |
| Pin 6 | 1Y β Gate 1 3-state output, Y = (A β’ /C + B β’ C) β D |
| Pin 8 | 2A β Gate 2 input A |
| Pin 9 | 2B β Gate 2 input B |
| Pin 10 | 2C β Gate 2 select input C |
| Pin 11 | 2D β Gate 2 input D |
| Pin 12 | 2OE β Gate 2 output enable |
| Pin 13 | 2Y β Gate 2 3-state output |
| Pin 15 | 3A β Gate 3 input A |
| Pin 16 | 3B β Gate 3 input B |
| Pin 17 | 3C β Gate 3 select input C |
| Pin 18 | 3D β Gate 3 input D |
| Pin 19 | 3OE β Gate 3 output enable |
| Pin 20 | 3Y β Gate 3 3-state output |
| Pin 14 | GND β Ground |
| Pin 7 | VCC β Power supply, 4.5V to 5.5V |
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
SN74AHCT3G99-Q1 is suitable for 6 applications: Automotive Body Control Modules, Automotive Infotainment and Cluster Logic, Industrial PLC and Control I/O, Networking and Telecom Line-Card Glue Logic, Test and Measurement Instrumentation, Sensor Interface Signal Conditioning.
Automotive Body Control Modules
Body control modules combine switch inputs from door, seat, and lighting circuits that arrive slowly and noisily after wiring-harness filtering. The SN74AHCT3G99-Q1's Schmitt-trigger inputs remove chatter-induced false triggering on these edges, while its configurable gates implement custom combine/invert logic (MUX, AND, NAND, XOR) that would otherwise require several fixed-function ICs. Its 4.5V-5.5V TTL-compatible operation matches legacy 5V BCM supply rails, and the AEC-Q100 qualification with -40C to +125C range covers underhood and interior locations. Keeping per-gate output load at 50pF or below preserves timing margins across the module.
Recommended
Automotive Infotainment and Cluster Logic
Infotainment head units and instrument clusters need glue logic to gate display reset lines, mux between backup-camera and main video wake signals, and qualify power-good flags. The SN74AHCT3G99-Q1 implements the XOR/XNOR comparison and MUX selection functions on demand from one 20-TSSOP package, reducing logic IC count on crowded boards. Schmitt-trigger inputs tolerate slow enable edges from power-management ICs, and 3-state outputs let multiple sources share status lines without contention when OE pins are managed. At -40C to +125C and AEC-Q100, it survives cabin and dashboard thermal cycling. Place 100nF decoupling per supply pin near the device.
Recommended
Industrial PLC and Control I/O
Industrial controllers frequently combine discrete sensor signals with enable gating before feeding MCU inputs. The SN74AHCT3G99-Q1 provides three independently configurable four-input gates, so one device handles OR-ing of fault flags, AND-ing of interlocks, and XOR of redundant encoder signals simultaneously. The 5V TTL-compatible AHCT inputs interface directly with optocoupler and comparator outputs common in PLC front ends, while Schmitt-trigger hysteresis suppresses relay-contact bounce artifacts on slow edges. Although not AEC-Q100-marked for this use, its -40C to +125C rating suits industrial cabinets; keep total load capacitance per output at or under 50pF for guaranteed timing.
Recommended
Networking and Telecom Line-Card Glue Logic
Line cards and switch management planes use the SN74AHCT3G99-Q1 to gate module-present and interrupt signals and to mux between redundant power-good indications. The 3-state outputs are key here: multiple cards can drive a shared backplane status bus, with each card tri-stating via its OE pin when not addressed, preventing bus contention. Configurability means one footprint covers several netlist variants during board spins, shortening redesign cycles. The device's Schmitt-trigger inputs clean up slow status edges from hot-swap controllers, and 5V AHCT drive levels remain compatible with legacy telecom 5V logic on many platforms.
Recommended
Test and Measurement Instrumentation
Bench instruments and automated test equipment use configurable gates for trigger qualification - AND-ing arming, hold-off, and channel-condition signals before they reach timer circuits. The SN74AHCT3G99-Q1 lets designers remap gate functions via input strapping rather than redesign, useful across instrument variants. Its Schmitt-trigger inputs accept slow analog-comparator edges without double-clocking, and the XOR/XNOR modes support phase-comparison and coincidence-detection circuits. Operating at 5V with TTL thresholds interfaces cleanly with legacy instrument logic families. Verify propagation delay against your trigger-path budget since datasheet timing is only guaranteed at loads up to 50pF per output.
Recommended
Sensor Interface Signal Conditioning
Automotive and industrial sensor front ends produce slow, noisy edges from Hall switches, level switches, and comparator outputs that benefit from Schmitt-trigger re-clocking before further logic. The SN74AHCT3G99-Q1 conditions these inputs and simultaneously performs the direction-decode XOR of quadrature signals or the majority-vote AND of redundant sensors, all in one package. Its 5V supply and TTL thresholds match common sensor output standards, and AEC-Q100 qualification supports in-vehicle placement near the sensor harness. Use short traces to the gate inputs, add RC filtering ahead of the Schmitt stage, and respect the 50pF load guideline on outputs driving MCU GPIOs.
Recommended
Recommended Products Summary
Engineering reference data for SN74AHCT3G99-Q1 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | SN74AHCT3G99PWR | SN74AHC3G99QPWRQ1 | SN74LVC3G99QPWRQ1 |
|---|---|---|---|---|
| Package | 20-TSSOP (PW) | 20-TSSOP (PW) - same | 20-TSSOP (PW) - same | 20-TSSOP (PW) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Logic Family | AHCT (TTL-compatible inputs) | AHCT | AHC (CMOS thresholds) | LVC |
| Supply Voltage | 4.5V to 5.5V | 4.5V to 5.5V | [DATA_NEEDED] | 1.65V to 5.5V |
| Gates x Inputs | 3 x 4-input configurable | 3 x 4-input configurable | 3 x 4-input configurable | 3 x 4-input configurable |
| Output Type | 3-State | 3-State | 3-State | 3-State |
| AEC-Q100 Qualified | Yes | No (standard grade) | Yes | Yes |
| Max Load Capacitance | 50 pF | 50 pF | [DATA_NEEDED] | [DATA_NEEDED] |
Key Differentiators
- AEC-Q100 automotive qualification (vs SN74AHCT3G99PWR)
- TTL-compatible input thresholds (vs SN74AHC3G99QPWRQ1)
- Three independent configurable gates vs fixed-function (vs SN74HC21-Q1)
Design Notes
Place a 100nF ceramic decoupling capacitor within 5mm of the VCC pin (pin 7) with a low-inductance via to ground, plus one bulk 1uF per device. CMOS outputs cause supply transients on simultaneous switching of the three gates; inadequate decoupling can couple glitches into adjacent Schmitt inputs, defeating their noise immunity. For automotive 5V rails with load-dump transients, add a local TVS or series ferrite ahead of the decoupling network.
Two pitfalls dominate field failures with this device. First, floating OE pins: the 3-state outputs are undefined if OE floats, causing bus contention or high-Idq leakage - always tie OE to a rail or driven signal. Second, exceeding the 50pF load guideline: TI states the device meets all datasheet specs only up to 50pF total load; larger loads work but propagation delay and transition times are unguaranteed, breaking timing budgets on trigger or bus paths. Also do not leave unused gate inputs floating - strap them via the configuration truth table.
The Schmitt-trigger inputs tolerate slow edges, but hysteresis thresholds vary with VCC, so noise margin shrinks near the 4.5V minimum supply. Route gate inputs away from switching-regulator nodes and clock lines; although Schmitt inputs resist slow-edge false triggering, directly coupled fast glitches can still exceed hysteresis. Use the configuration truth table to strap C and D so unused inputs are at defined levels, and keep output traces short to respect the 50pF capacitance budget including trace capacitance (~1pF per cm).
Compliance Information
AEC-Q100 automotive qualification confirmed from TI product data. RoHS/REACH/lead-free status not stated in provided verified data.
