Texas Instruments LM324N

Overview

LM324N from STMicroelectronics is a quad low-power operational amplifier in SO14 package, designed for single-supply operation from 3 V to 30 V or dual supplies ±1.5 V to ±15 V. It delivers 1.3 MHz gain bandwidth, 100 dB large-signal voltage gain, and input common-mode range extending to ground-enabling use in sensor signal conditioning, industrial analog front-ends, and battery-powered instrumentation.

For engineers reviewing the LM324N datasheet, LM324N pinout, LM324N application, or LM324N equivalent, key selection criteria include its rail-to-rail input capability (0 V to V_CC − 1.5 V), 375 µA per amplifier supply current, 20 nA input bias current, and guaranteed 0–70 °C operating temperature range-critical for cost-sensitive industrial control and consumer electronics designs.

Technical Context

The LM324N integrates four independent high-gain op-amps with internal frequency compensation, enabling stable unity-gain operation without external components. Its PNP input stage enables true ground-sensing input voltage range and low input bias current.

It features open-collector compatible output stages capable of sourcing up to 40 mA and sinking ≥10 mA, with output swing within 1.5 V of rails under load. Input offset voltage is specified at ≤7 mV (max) over temperature, and ESD rating is 250 V HBM per IEC 61000-4-2.

Key Specifications

Pinout & Package

LM324N is supplied in a 14-pin plastic small-outline (SO14) package with standard 1.27 mm pitch, JEDEC MS-012AC compliant footprint, and exposed pad not present (unlike QFN variant). Thermal resistance R_thJA is 103 °C/W on single-layer board.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad operational amplifier applications.

Compared with LM324N, LM324DR offers identical functional behavior but slightly higher input bias current and thermal resistance, while TSB572IDT delivers superior precision and robustness at the cost of higher voltage operation and non-drop-in packaging-making it suitable only for redesigns targeting long-term reliability upgrades.

Availability

LM324N is available at Aetrix Electronics and suitable for industrial sensor interfaces, consumer audio preamplifiers, and medical patient monitor front-ends requiring stable component supply across production lifecycles.

Supply support for LM324N 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, delivering silicon solutions for smart driving, power management, and analog/mixed-signal applications since 1987.

The LM324x series belongs to ST's general-purpose analog amplifier portfolio, engineered for cost-effective, reliable signal conditioning in commercial and industrial systems where wide supply range and ground-sensing capability are essential.

FAQ

Is LM324N pin-compatible with LM2902?

Yes-LM324N and LM2902 share identical SO14 pinout and core electrical specifications (gain bandwidth, input range, supply range), but LM2902 is automotive-qualified (−40°C to +125°C) with enhanced ESD (800 V HBM) and tighter V_IO (3 mV max). No PCB change is needed for drop-in replacement in commercial designs.

Can LM324N drive a 10 kΩ load to rail in single-supply mode?

No-LM324N output swing is limited to within 1.5 V of each rail under load. At V_CC = 5 V, maximum high-level output is ~3.5 V and minimum low-level is ~20 mV into 10 kΩ, per Table 3 in DS0985 Rev 8. For rail-to-rail output, consider TSB572 or TSX564.

What is the maximum capacitive load LM324N can drive without oscillation?

LM324N is stable for capacitive loads ≤100 pF with unity-gain configuration, as verified in Figure 10 (open-loop frequency response) and Figure 14 (small-signal pulse response) of DS0985 Rev 8. For larger loads (e.g., cables or ADC inputs), an isolation resistor (≥200 Ω) must be placed in series with the output.

Does LM324N have internal ESD protection on all pins?

Yes-LM324N includes integrated ESD protection diodes on all input and output pins rated at 250 V HBM (human body model), per Table 1 in DS0985 Rev 8. This meets basic IEC 61000-4-2 Level 2 requirements but is insufficient for harsh industrial or automotive environments without external TVS devices.