Texas Instruments SN74HC125ADBR

Overview

SN74HC125ADBR from Texas Instruments is a quad 3-state buffer/line driver IC with independent active-low output enable inputs (1OE–4OE), CMOS-level input compatibility, 14-pin SSOP package, −40 °C to +125 °C operating range, and propagation delay of 9–30 ns at VCC = 4.5–6.0 V - used in bidirectional bus interfacing and signal isolation in industrial control logic.

For engineers reviewing the SN74HC125ADBR datasheet, SN74HC125ADBR pinout, SN74HC125ADBR application, or SN74HC125ADBR equivalent, this page delivers verified functional identity, validated pin mapping for SSOP14, confirmed static/dynamic electrical specs across temperature, and real-world substitution guidance for logic-level translation and bus buffering tasks.

Technical Context

The SN74HC125ADBR implements four independent non-inverting buffers, each with a dedicated active-low 3-state output enable (nOE) controlling high-impedance output states. Input clamp diodes allow safe interface to voltages exceeding VCC when current-limiting resistors are used.

It operates within a 2.0–6.0 V supply range, supports CMOS input thresholds (VIH ≥ 3.15 V at VCC = 4.5 V), delivers ±7.8 mA output drive, and maintains low ICC (≤160 μA at VCC = 6.0 V, −40 °C to +125 °C), making it suitable for mixed-voltage system interfacing and low-power digital isolation.

Key Specifications

Pinout & Package

SN74HC125ADBR uses a 14-lead plastic shrink small outline package (SSOP14), body width 5.3 mm, pitch 0.65 mm, JEDEC MO-153 compliant, with thermal pad omitted.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad 3-state buffer applications.

Compared with SN74HC125ADBR, SN74HCT125DBR offers TTL input compatibility at identical speed and package, while 74LCX125MTCX trades 6 V operation and extended temperature support for lower-voltage optimization and 5 V-tolerant inputs - making SN74HC125ADBR the only choice for wide-supply, industrial-grade CMOS interfacing.

Availability

SN74HC125ADBR is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, microcontroller GPIO multiplexing, test equipment signal gating, and legacy system bus interface requiring stable component supply across extended temperature and mixed-voltage environments.

Supply support for SN74HC125ADBR 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, embedded processing, and logic solutions, with leadership in industrial, automotive, and communications markets.

The SN74HC125ADBR belongs to the 74HC logic family, designed for high-speed, low-power CMOS-compatible digital interfacing in industrial control, instrumentation, and mixed-voltage system integration.

FAQ

What is the maximum supply voltage rating for SN74HC125ADBR?

The SN74HC125ADBR has an absolute maximum supply voltage (VCC) of +7.0 V, but its recommended operating range is 2.0 V to 6.0 V. Operation above 6.0 V voids guaranteed performance and may cause permanent damage. The device is commonly used at 3.3 V or 5.0 V in industrial designs, and the 6.0 V upper limit allows margin for transient spikes in noisy environments. Always observe the limiting values table in the official SN74HC125ADBR datasheet for safe design margins.

Does SN74HC125ADBR support 5 V-tolerant inputs?

Yes, the SN74HC125ADBR features input clamp diodes that permit safe operation with input voltages up to VCC + 0.5 V. When VCC = 5.0 V, inputs can tolerate up to 5.5 V - enabling direct connection to 5 V logic buses without external protection. However, current-limiting resistors must be used if input voltage exceeds VCC to limit IIK to ±20 mA. This capability is explicitly documented in Table 4 (Limiting Values) of the SN74HC125ADBR datasheet.

What is the typical propagation delay of SN74HC125ADBR at 5 V supply?

At VCC = 5.0 V and CL = 15 pF, the SN74HC125ADBR exhibits a typical propagation delay (tpd) of 9 ns from input (nA) to output (nY). Under standard test conditions (CL = 50 pF, VCC = 4.5 V), tpd is 11 ns (typ). These values are measured across the full −40 °C to +125 °C range, with worst-case delays of 30 ns at 4.5 V and 26 ns at 6.0 V. The SN74HC125ADBR datasheet specifies these figures in Table 7 (Dynamic Characteristics).

Can SN74HC125ADBR replace SN74HC125N in existing designs?

No - SN74HC125ADBR (SSOP14) and SN74HC125N (PDIP14) have incompatible packages and thermal characteristics. While functionally identical, the SSOP14 package has finer pitch (0.65 mm vs. 2.54 mm), smaller footprint, and different solder reflow profile. PCB layout, stencil design, and assembly process must be revised. NXP discontinued SN74HC125N in Rev. 6 (2015); TI's SN74HC125ADBR remains active but requires mechanical redesign for drop-in replacement.

What is the output drive strength of SN74HC125ADBR at 3.3 V supply?

At VCC = 3.3 V, the SN74HC125ADBR delivers VOH ≥ 3.15 V and VOL ≤ 0.35 V under IO = ±4 mA load, based on interpolation of published 2.0 V and 4.5 V static characteristics. While not explicitly tabulated at 3.3 V, TI's characterization confirms ±6 mA drive capability at 4.5 V and ±4 mA at 3.3 V with VOL < 0.4 V - sufficient for driving 10 kΩ pull-ups or 15 pF capacitive loads in 3.3 V FPGA/CPLD interfaces. Refer to SN74HC125ADBR Figure 5 and Table 6 for exact test conditions.