Texas Instruments CAHCT1G126DBVRQ1

Overview

CAHCT1G126DBVRQ1 from Texas Instruments is an automotive-qualified single 3-state bus buffer gate with TTL-compatible inputs, operating from 3 V to 5.5 V, delivering ±8-mA output drive at 5 V, 6 ns max propagation delay (tpd), and 10 µA max ICC - used for signal enable/disable in vehicle body control modules and communication interface isolation.

For engineers reviewing the CAHCT1G126DBVRQ1 datasheet, CAHCT1G126DBVRQ1 pinout, CAHCT1G126DBVRQ1 application, or CAHCT1G126DBVRQ1 equivalent, key selection criteria include automotive AEC-Q100 qualification, SOT-23 (DBV) package thermal resistance (RθJA = 278.0 °C/W), 3-state output timing behavior, and input voltage compatibility across 3–5.5 V supply rails.

Technical Context

The CAHCT1G126DBVRQ1 implements a positive-logic single-channel buffer with active-high output enable (OE), where Y follows A when OE = HIGH and enters high-impedance state when OE = LOW. Its CMOS output stage supports bidirectional current sourcing/sinking up to ±8 mA at 5 V, with TTL-voltage compatible input thresholds (VIH = 2 V min at VCC ≥ 4.5 V).

It operates across –40°C to +125°C ambient temperature, meets AEC-Q100 Grade 1 requirements, and features ESD protection per HBM (±2000 V) and CDM (±1000 V). Switching performance is characterized at both 3 V ±0.3 V and 5 V ±0.5 V, with load capacitance up to 50 pF specified for full timing compliance.

Key Specifications

Pinout & Package

SOT-23 (DBV) 5-pin package: 2.9 mm × 2.8 mm footprint, 1.45 mm max height, JEDEC MO-178 compliant, with exposed pad not present. Thermal resistance RθJA = 278.0 °C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AHCT1G125DBVRQ1 and SN74LVC1G126DBVR, the CAHCT1G126DBVRQ1 uniquely provides non-inverting 3-state buffering with full automotive qualification, making it the sole option for production-grade AEC-Q100-compliant signal gating where polarity integrity and environmental robustness are mandatory.

Availability

CAHCT1G126DBVRQ1 is available at Aetrix Electronics and suitable for automotive body control units, instrument cluster interfaces, sensor multiplexing circuits, and infotainment subsystems requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for CAHCT1G126DBVRQ1 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 technologies, with leadership in automotive, industrial, and communications markets.

The SN74AHCT1Gxx-Q1 series delivers AEC-Q100-qualified single-gate logic devices optimized for space-constrained automotive subsystems requiring low power, high reliability, and interoperability with legacy TTL and modern CMOS interfaces.

FAQ

What is the maximum capacitive load supported by the CAHCT1G126DBVRQ1 while maintaining full timing specifications?

The CAHCT1G126DBVRQ1 is fully characterized for load capacitances up to 50 pF at both 3 V and 5 V supply voltages. While larger loads may function, timing parameters such as tPLH, tPHL, and tPZH exceed datasheet limits beyond this value. For designs targeting guaranteed 6 ns max tpd at 5 V, keep total output node capacitance ≤50 pF including trace, probe, and receiver input capacitance. The CAHCT1G126DBVRQ1 datasheet specifies CL = 15 pF and CL = 50 pF test conditions explicitly in Sections 6.6 and 6.7.

Does the CAHCT1G126DBVRQ1 require external pull-up or pull-down resistors on its OE pin?

Yes - to ensure a known high-impedance state during power-up and power-down, the OE pin of the CAHCT1G126DBVRQ1 must be pulled to GND via an external resistor. TI recommends a pulldown resistor to prevent bus contention before firmware initializes the pin. The minimum value depends on the driving source's current-sourcing capability; typical values range from 4.7 kΩ to 10 kΩ. This requirement is documented in Section 8.1 of the CAHCT1G126DBVRQ1 datasheet.

Can the CAHCT1G126DBVRQ1 operate reliably at 3.3 V supply voltage?

Yes - the CAHCT1G126DBVRQ1 is fully specified for operation from 3.0 V to 5.5 V, including 3.3 V nominal systems. At 3.3 V, it delivers 2.58 V min VOH (IOH = –4 mA) and 0.36 V max VOL (IOL = 4 mA), with 8 ns max propagation delay (CL = 15 pF). All recommended operating conditions, electrical characteristics, and switching parameters in the CAHCT1G126DBVRQ1 datasheet apply across this entire voltage range.

Is the CAHCT1G126DBVRQ1 pin-compatible with other SOT-23 5-pin logic buffers from Texas Instruments?

Yes - the CAHCT1G126DBVRQ1 uses the standard SOT-23 (DBV) 5-pin pinout defined in TI's logic family: Pin 1 = OE, Pin 2 = A, Pin 3 = GND, Pin 4 = Y, Pin 5 = VCC. This matches SN74AHCT1G125DBVRQ1, SN74LVC1G126DBVR, and SN74LVC1G125DBVR. However, functional differences (e.g., inverting vs. non-inverting) mean PCB layout reuse is possible but firmware and signal routing must be verified per device function.

What is the thermal resistance (RθJA) of the CAHCT1G126DBVRQ1 in its SOT-23 package?

For the CAHCT1G126DBVRQ1 in the DBV (SOT-23) package, the junction-to-ambient thermal resistance RθJA is 278.0 °C/W, as measured per JEDEC JESD51 standards on a 1-inch² copper pad. This value assumes standard 2-layer board construction with no internal ground/power planes. The CAHCT1G126DBVRQ1 datasheet lists this in Section 6.4 and confirms it applies specifically to the DBV variant used in this part number.