Texas Instruments CAHCT1G125QDCKRQ1

Overview

CAHCT1G125QDCKRQ1 from Texas Instruments is an automotive-qualified single 3-state bus buffer gate used for digital signal enable/disable control in power-sensitive, space-constrained systems. It operates from 3 V to 5.5 V, delivers ±8 mA output drive at 5 V, achieves 5.5 ns typical propagation delay (tPLH/tPHL) at 5 V/15 pF, and consumes ≤10 µA ICC in quiescent state - enabling reliable signal routing in motor control reset logic and LED driver interfaces.

For engineers reviewing the CAHCT1G125QDCKRQ1 datasheet, CAHCT1G125QDCKRQ1 pinout, CAHCT1G125QDCKRQ1 application, or CAHCT1G125QDCKRQ1 equivalent, key selection criteria include its AEC-Q100 Grade 1 qualification (–40°C to +125°C), SC70-5 package footprint (2.0 mm × 2.1 mm), TTL-compatible inputs, and precise 3-state timing behavior under automotive supply and load conditions.

Technical Context

The CAHCT1G125QDCKRQ1 implements a single non-inverting buffer with active-low 3-state output control: when OE is low, A passes transparently to Y; when OE is high, Y enters high-impedance state. Its CMOS input stage accepts TTL-voltage levels (VIH = 2 V min at VCC = 4.5–5.5 V), while the output stage provides rail-to-rail swing and symmetric ±8 mA drive capability at 5 V.

Designed for automotive signal isolation and level translation, it supports dynamic switching at up to 100 MHz (based on tPLH/tPHL ≤ 8.5 ns at 5 V/15 pF), maintains stable operation across 3 V–5.5 V supply range, and features ESD robustness per AEC Q100-002 (±2000 V HBM).

Key Specifications

Pinout & Package

CAHCT1G125QDCKRQ1 is packaged in a 5-pin SC70 (DCK) outline measuring 2.0 mm × 2.1 mm with 0.65 mm pitch, optimized for high-density automotive PCB layouts. The package includes exposed thermal pad for enhanced thermal dissipation and mechanical stability.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bus buffer applications.

Compared with SN74AHCT1G125DRYR and SN74LVC1G125DBVR, CAHCT1G125QDCKRQ1 uniquely balances AEC-Q100 compliance, SC70 manufacturability, and TTL-input compatibility - making it the optimal choice for cost-sensitive, thermally constrained automotive signal routing where legacy interface support is required.

Availability

CAHCT1G125QDCKRQ1 is available at Aetrix Electronics and suitable for automotive motor control, LED driver interfaces, communication module translation, and body control unit isolation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CAHCT1G125QDCKRQ1 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 automotive-grade silicon solutions with over 90 years of innovation in high-reliability electronics.

The SN74AHCT1G125-Q1 product line delivers AEC-Q100-qualified, space-efficient logic buffers designed specifically for automotive signal conditioning, reset management, and bus isolation in harsh-environment electronic control units.

FAQ

What is the operating temperature range for CAHCT1G125QDCKRQ1?

CAHCT1G125QDCKRQ1 is rated for –40°C to +125°C ambient operation and is AEC-Q100 Grade 1 qualified. This specification ensures reliable functionality in under-hood and body-control applications where thermal stress is significant. All electrical parameters in the datasheet - including propagation delay, output drive, and supply current - are guaranteed across this full range, not just at room temperature. CAHCT1G125QDCKRQ1 must be operated within these limits to maintain automotive qualification compliance.

Does CAHCT1G125QDCKRQ1 require external pull-up resistors on the OE pin?

Yes - TI recommends tying OE to VCC through a pull-up resistor during power-up and power-down to ensure a defined high-impedance state before internal logic stabilizes. The minimum resistor value depends on the current-sinking capability of the driving source; typical values range from 10 kΩ to 100 kΩ. Leaving OE floating risks undefined output behavior and potential bus contention. CAHCT1G125QDCKRQ1 does not integrate internal pull-up circuitry on OE.

Can CAHCT1G125QDCKRQ1 interface directly with 3.3 V microcontrollers?

Yes - CAHCT1G125QDCKRQ1 accepts TTL-compatible input voltages, meaning VIH ≥ 2.0 V at VCC = 4.5–5.5 V and VIH ≥ 1.4 V at VCC = 3.0 V. When powered at 3.3 V, its VIH threshold is ~1.4 V, fully compatible with standard 3.3 V CMOS logic outputs. Input thresholds are guaranteed across temperature and supply, so CAHCT1G125QDCKRQ1 reliably interprets 3.3 V controller signals without level translation.

What is the maximum capacitive load CAHCT1G125QDCKRQ1 can drive while maintaining specified timing?

CAHCT1G125QDCKRQ1 is characterized for CL = 15 pF and CL = 50 pF loads. At 5 V supply, tPLH/tPHL is 8.5 ns max at 15 pF and 10.5 ns max at 50 pF. Driving >50 pF increases propagation delay nonlinearly and may cause signal integrity issues. For loads exceeding 50 pF, TI recommends adding series termination or using a higher-drive buffer. CAHCT1G125QDCKRQ1's output structure is optimized for point-to-point or lightly loaded bus segments.

Is CAHCT1G125QDCKRQ1 pin-compatible with other variants in the SN74AHCT1G125-Q1 family?

Yes - CAHCT1G125QDCKRQ1 shares identical pinout (OE-A-GND-Y-VCC) and logic function with SN74AHCT1G125QDBVRQ1 (SOT-23) and SN74AHCT1G125WDTXRQ1 (X2SON). All three use the same 5-pin arrangement and terminal assignments. However, package dimensions, thermal characteristics, and soldering profiles differ significantly - direct substitution requires PCB layout revision. CAHCT1G125QDCKRQ1 is not a drop-in replacement without board redesign.