Texas Instruments CAHC1G126QDCKRQ1

Overview

CAHC1G126QDCKRQ1 from Texas Instruments is an automotive-grade single 3-state bus buffer gate performing Y = A logic with integrated voltage translation, operating from 2 V to 5.5 V, delivering ±8 mA output drive at 5 V, supporting -40°C to +125°C ambient, and qualified per AEC-Q100 Grade 1 for use in vehicle body control modules and infotainment power management.

For engineers reviewing the CAHC1G126QDCKRQ1 datasheet, CAHC1G126QDCKRQ1 pinout, CAHC1G126QDCKRQ1 application, or CAHC1G126QDCKRQ1 equivalent, key selection considerations include its 5-pin SC-70 (DCK) package, 3-state enable control timing (tPLZ/tPHZ ≤ 16 ns at 5 V), low ICC (≤4 µA), and CMOS input compatibility across 1.8–5 V logic domains.

Technical Context

The CAHC1G126QDCKRQ1 implements a single non-inverting buffer with active-high 3-state output enable (OE), where output Y follows input A when OE = HIGH and enters high-impedance when OE = LOW. Its CMOS input structure requires fast edge rates (≤20 ns/V at 5 V) to prevent oscillation and excessive ICC.

It supports voltage translation between mixed-supply systems: inputs accept 0–5.5 V, outputs swing rail-to-rail referenced to VCC (2–5.5 V), enabling interface between 3.3-V controllers and 5-V peripherals. Thermal resistance for the DCK package is RθJA = 293.4°C/W, limiting continuous power dissipation to ~17 mW at TA = 125°C.

Key Specifications

Pinout & Package

CAHC1G126QDCKRQ1 uses the 5-pin SC-70 (DCK) package, measuring 2.0 mm × 2.1 mm overall with a 2.0 mm × 1.25 mm body footprint, optimized for space-constrained automotive PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1G126QDCKRQ1 and MC74VHC1G126DTT1G, CAHC1G126QDCKRQ1 uniquely balances AEC-Q100 compliance, 2–5.5 V operation, and sub-4 µA ICC-making it the only choice for automotive body electronics requiring both low quiescent power and certified reliability.

Availability

CAHC1G126QDCKRQ1 is available at Aetrix Electronics and suitable for automotive body control modules, infotainment display interfaces, and ADAS camera power sequencing requiring stable component supply, long-lifecycle support, and AEC-Q100 traceability.

Supply support for CAHC1G126QDCKRQ1 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 company specializing in analog and embedded processing solutions, with leadership in automotive, industrial, and personal electronics markets.

CAHC1G126QDCKRQ1 belongs to TI's AHC logic family designed specifically for automotive signal integrity and low-power bus interfacing-emphasizing robust ESD tolerance, wide supply range, and guaranteed operation across extreme temperature gradients.

FAQ

What is the maximum capacitive load supported by CAHC1G126QDCKRQ1 while maintaining full timing specifications?

CAHC1G126QDCKRQ1 maintains all switching characteristics (tPHL, tPLH, tPLZ, etc.) up to 50 pF load capacitance at 3.3 V and 5 V supplies. Driving >50 pF increases propagation delay and may violate setup/hold margins in high-speed buses; for loads exceeding 50 pF, add series termination or reduce clock frequency. The device itself does not fail at higher capacitance but loses guaranteed timing compliance.

Can CAHC1G126QDCKRQ1 interface a 1.8-V microcontroller GPIO with a 5-V peripheral enable line?

Yes, CAHC1G126QDCKRQ1 supports this voltage translation: its input accepts 0–5.5 V, so a 1.8-V logic HIGH (≥1.5 V at VCC = 2 V) is recognized correctly, and its output swings rail-to-rail to 5 V when VCC = 5 V. No external level shifter is needed-CAHC1G126QDCKRQ1 performs bidirectional domain bridging in a single device.

Is CAHC1G126QDCKRQ1 pin-compatible with SN74AHC1G125QDCKRQ1?

No-CAHC1G126QDCKRQ1 has active-high OE (Y = A when OE = HIGH), whereas SN74AHC1G125QDCKRQ1 has active-low OE (Y = A when OE = LOW). Both share identical 5-pin SC-70 (DCK) packaging and pinout (OE, A, GND, Y, VCC), but logic inversion at the enable input requires firmware or schematic changes to maintain functional equivalence.

Does CAHC1G126QDCKRQ1 require external pull-up or pull-down resistors on unused pins?

Yes-unused input A must be tied to VCC or GND (not left floating) to prevent undefined logic states and excessive ICC. OE should also be terminated-typically to GND for default Hi-Z or VCC for default enabled state. Outputs Y may float when disabled, but if bus state must be defined during Hi-Z, add a 10-kΩ pull-up/down resistor per TI recommendations.

What is the thermal derating limit for CAHC126QDCKRQ1 at 125°C ambient temperature?

With RθJA = 293.4°C/W, CAHC1G126QDCKRQ1 reaches its 150°C max junction temperature at just 17 mW total power dissipation (P = (TJmax − TA)/RθJA). At 5 V and 8 mA output, worst-case dynamic power is ~40 mW-but actual dissipation remains <1 mW under typical 1-MHz toggle conditions due to low CPD (14 pF) and ICC (≤4 µA), keeping TJ well within limits.