Texas Instruments CD74AC32M

Overview

CD74AC32M from Texas Instruments is a quadruple 2-input positive-OR gate IC in SOIC-14 package, operating from 1.5 V to 5.5 V, delivering ±24 mA output drive at 5 V, with propagation delays as low as 2.4 ns (tPLH/tPHL, VCC = 5 V), and ESD protection exceeding 2 kV per MIL-STD-883. It performs Boolean Y = A + B logic in positive logic and is used in digital signal routing, bus arbitration, and discrete logic consolidation in industrial control systems.

For engineers reviewing the CD74AC32M datasheet, CD74AC32M pinout, CD74AC32M application, or CD74AC32M equivalent, key selection criteria include its 14-pin SOIC package, rail-to-rail input compatibility across 1.5–5.5 V, balanced propagation delays, SCR-latchup-resistant CMOS process, and guaranteed operation from –55°C to +125°C.

Technical Context

The CD74AC32M implements four independent OR gates in a single monolithic CMOS die using an SCR-latchup-resistant process. Each gate accepts two inputs and produces one output with fully buffered inputs, ensuring consistent noise immunity and stable switching behavior across voltage rails.

Its architecture supports mixed-voltage system interfacing via 30% supply noise margin and operates reliably under transient load conditions due to ±24 mA drive capability and low power dissipation capacitance (47 pF at 5 V), enabling direct fanout to 15 F-series logic devices without buffering.

Key Specifications

Pinout & Package

CD74AC32M is housed in a 14-pin Small Outline Integrated Circuit (SOIC) package with 8.65 mm × 6 mm footprint and 1.75 mm maximum height, compatible with standard surface-mount assembly processes and IPC-7351 land patterns.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar OR gate applications.

Compared with SN74AC32DR and CD74HC32M, CD74AC32M uniquely delivers military-grade temperature range (–55°C to +125°C) alongside bipolar-F-class speed and full 15-F fanout capability - making it the only choice for high-reliability, high-speed OR logic in harsh environments.

Availability

CD74AC32M is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, automotive body control modules, test equipment signal routing, and avionics power sequencing requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CD74AC32M 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 headquartered in Dallas, Texas, specializing in analog and embedded processing solutions with over 90 years of innovation in high-reliability logic, power management, and signal chain technologies.

The CD74AC32M belongs to TI's AC-series advanced CMOS logic family, designed specifically for applications demanding high speed, low power, and robust operation across extreme temperatures and noisy electrical environments.

FAQ

What is the maximum operating temperature range for CD74AC32M?

The CD74AC32M is specified for operation from –55°C to +125°C, meeting extended-temperature requirements for military, aerospace, and under-hood automotive applications. This rating is confirmed in Section 4.3 of the official TI datasheet SCHS343A and applies to the SOIC (D) package variant including CD74AC32M and CD74AC32M96G4.A. The device maintains full functionality and parameter compliance across this entire range.

Does CD74AC32M support 1.8 V logic interface?

Yes, CD74AC32M supports 1.8 V logic interface. Its recommended operating supply range is 1.5 V to 5.5 V (Section 4.3), and input thresholds scale proportionally: VIH = 0.7 × VCC and VIL = 0.3 × VCC. At VCC = 1.8 V, VIH = 1.26 V and VIL = 0.54 V - fully compatible with standard 1.8 V CMOS outputs. The device also provides 30% noise margin, ensuring reliable operation in noisy 1.8 V systems.

Is CD74AC32M pin-compatible with CD74HC32M?

Yes, CD74AC32M is pin-compatible with CD74HC32M. Both devices use the same SOIC-14 (D) package with identical pin configuration (Table 3-1), including shared assignments for all inputs (1A–4B), outputs (1Y–4Y), VCC (Pin 14), GND (Pin 7), and NC (Pin 11). However, they differ in speed, drive strength, and temperature range - CD74AC32M offers faster propagation (2.4 ns vs. 17 ns), higher drive (±24 mA vs. ±5.2 mA), and extended temperature rating (–55°C to +125°C vs. –55°C to +125°C for HC, though HC datasheet specifies –40°C to +85°C for most variants).

What is the recommended bypass capacitor value for CD74AC32M?

Texas Instruments recommends a 0.1 µF ceramic bypass capacitor placed as close as possible to the VCC pin (Pin 14) of CD74AC32M, with short, low-inductance traces to GND (Pin 7). This value is specified in Section 7.1 of the datasheet for single-supply logic devices. For multi-VCC systems or high-noise environments, paralleling a 1 µF capacitor is acceptable to suppress lower-frequency ripple while maintaining high-frequency decoupling.

Can unused inputs on CD74AC32M be left floating?

No, unused inputs on CD74AC32M must not be left floating. As stated in Section 7.2.1 and Figure 7-1 of the datasheet, all unused inputs must be tied to either VCC or GND to prevent undefined operational states, increased power consumption, and potential oscillation. The choice between VCC or GND depends on the desired logic state for that gate - tying to VCC forces output high (since OR with high = high), while tying to GND leaves output dependent only on the other input.