LM324BAIDR - Quad 36V 1.2MHz Op-Amp | Texas Instruments
MPN: LM324BAIDR β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.32 | $0.32 |
| 10 | $0.29 | $2.90 |
| 100 | $0.24 | $24.00 |
| 500 | $0.19 | $95.00 |
| 1,000 | $0.15 | $150.00 |
LM324BAIDR Overview
An operational amplifier (op-amp) is a high-gain voltage amplifier with differential inputs and a single-ended output, the fundamental building block of analog signal conditioning. In the analog hierarchy, the op-amp sits above discrete transistors and below specialized amplifiers such as instrumentation and audio amplifiers; general-purpose quad op-amps like the LM324 family provide four independent channels in one package for cost-sensitive multi-channel designs.
The LM324BA is the next-generation BA version of the classic LM324. Key improvements over legacy LM324/LM224/LM2902 parts include a wide 3V to 36V supply range, tighter 2mV input offset voltage specification, and enhanced robustness, while remaining pin-for-pin drop-in replacements for all legacy versions. The push-pull output stage improves output voltage swing and crossover behavior compared to older Class-AB output stages, reducing the well-known LM324 output crossover distortion near the negative rail.
Each of the four amplifiers shares a common supply; single-supply operation down to 3V makes the part suitable for 3.3V and 5V logic-based systems as well as traditional up to 36V industrial rails. The common-mode input range includes the negative rail, a signature LM324-family trait that simplifies single-supply designs such as sensor buffering near ground.
Typical applications include industrial signal conditioning, transducer amplifier front ends, active filters, comparators and level shifters, motor-control feedback loops, and consumer appliance analog interfaces.
Design consideration: the 1.2MHz gain-bandwidth limits closed-loop bandwidth; at a gain of 10, expect roughly 120kHz of usable bandwidth, so verify gain-phase margin in high-gain configurations.
This page synthesizes verified distributor pricing, drop-in alternatives, pinout data, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for LM324BAIDR β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
LM324ADR
β Drop-Inπ Reference alternative (not in catalog)
LM324BIDR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
LM2902BAIDR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
LM224ADR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
KIA324F
β Drop-Inπ Reference alternative (not in catalog)
TL074CDT
β Drop-Inπ Reference alternative (not in catalog)
LM324BAIDR Maximum Ratings & Electrical Characteristics
| Number of Channels | 4 |
| Supply Voltage Range | 3 V to 36 V |
| Gain Bandwidth Product | 1.2 MHz |
| Input Offset Voltage | 2 mV (max, BA version) |
| Output Type | Push-Pull |
| Operating Temperature Range | -40C to +85C |
| Package | SOIC (D), 14 pins |
| Mounting Type | Surface Mount |
| Amplifier Type | General Purpose |
| Drop-in Compatibility | Replaces LM224, LM324, LM2902 (all versions) |
| RoHS Status | Compliant |
| Packaging | Tape & Reel (R suffix) |
LM324BAIDR Pin Configuration
| Pin 1 | OUT1 β Output of amplifier 1 |
| Pin 2 | IN1- β Inverting input, amplifier 1 |
| Pin 3 | IN1+ β Non-inverting input, amplifier 1 |
| Pin 4 | V+ β Positive supply |
| Pin 5 | IN2+ β Non-inverting input, amplifier 2 |
| Pin 6 | IN2- β Inverting input, amplifier 2 |
| Pin 7 | OUT2 β Output of amplifier 2 |
| Pin 8 | OUT3 β Output of amplifier 3 |
| Pin 9 | IN3- β Inverting input, amplifier 3 |
| Pin 10 | IN3+ β Non-inverting input, amplifier 3 |
| Pin 11 | V-/GND β Negative supply or ground in single-supply operation |
| Pin 12 | IN4+ β Non-inverting input, amplifier 4 |
| Pin 13 | IN4- β Inverting input, amplifier 4 |
| Pin 14 | OUT4 β Output of amplifier 4 |
Typical Applications
LM324BAIDR is suitable for 6 applications: Industrial Signal Conditioning, Transducer Amplifier Front Ends, Active Filters, Comparator and Level-Shifter Functions, Motor Control Feedback Loops, Consumer Appliance Analog Interfaces.
Industrial Signal Conditioning
The LM324BAIDR fits industrial 24V signal-conditioning front ends because its 3V to 36V supply range tolerates unregulated factory rails, and its 2mV offset keeps DC accuracy acceptable for transducer interfaces. Each of the four channels can buffer a separate 4-20mA sensor loop or scale a 0-10V signal with a simple resistor network. Placed directly after connectors with RC input filtering, the push-pull output drives ADC inputs or cable runs without the crossover distortion typical of legacy LM324 output stages. At a gain of 10, usable bandwidth is roughly 120kHz, adequate for most slow industrial process signals; for faster loops, budget headroom accordingly.
Recommended
Transducer Amplifier Front Ends
Pressure, temperature, and light sensors often produce small single-ended signals referenced to ground; the LM324BAIDR is well suited because its input common-mode range includes the negative rail, allowing direct ground-referenced sensing in single-supply systems. With 2mV maximum offset, bridge and thermocouple front ends maintain millivolt-level accuracy after gain of 100, though offset trimming or calibration is advised for precision chains. Four channels in one 14-pin SOIC reduce BOM count in multi-sensor boards, and the 1.2MHz bandwidth comfortably covers sub-10kHz transducer content at moderate gains. Decouple each sensor line with 100nF close to the amplifier inputs to reject cable pickup.
Recommended
Active Filters
Multiple Sallen-Key or multiple-feedback filter stages fit naturally on one LM324BAIDR: its four channels implement a complete fourth-order low-pass or band-pass filter in a single package. The 1.2MHz gain-bandwidth product supports corner frequencies up to roughly 20-50kHz with adequate Q, provided the open-loop gain at the corner frequency remains at least 40dB above the stage gain. The push-pull output stage of the BA version improves linearity at signal peaks, reducing filter distortion compared with legacy Class-AB LM324 parts. Keep resistor impedances in the 10k-100k range to balance bias-current errors against noise and capacitor sizing.
Recommended
Comparator and Level-Shifter Functions
The LM324BAIDR is frequently used as a low-cost comparator or level shifter where precision timing is not required. With inputs that sense down to ground and a 36V-tolerant supply, it interfaces 3.3V logic thresholds to industrial 12V or 24V domains using simple resistor dividers on the output. Note that, like all LM324-family parts, it is not a true comparator: open-loop response is slow (microseconds) and it lacks hysteresis, so add positive feedback (typically 1M/100k ratio) for clean switching in noisy environments. Reserve this use for status monitoring, undervoltage detection, and slow control loops rather than fast PWM protection.
Recommended
Motor Control Feedback Loops
Current-sense and speed-feedback amplification in low-cost motor drives benefits from the LM324BAIDR: one channel amplifies a shunt resistor voltage, another filters the tachometer signal, and a third implements the error amplifier of the control loop. The 3V to 36V supply range directly accommodates 12V and 24V motor rails, and ground-sensing inputs simplify low-side shunt placement. Because the GBW is 1.2MHz, keep loop crossover frequencies below roughly 20kHz to preserve phase margin. Its 2mV offset corresponds to a 20mA error with a 100m-ohm shunt, which is acceptable for protection thresholds but not for high-accuracy current telemetry.
Recommended
Consumer Appliance Analog Interfaces
White goods, small appliances, and cost-driven consumer devices use the LM324BAIDR for microphone preamps, button sensing, temperature offsets, and LED indicator drive. Single-supply 5V operation from the appliance microcontroller rail, four channels in one inexpensive SOIC-14, and drop-in LM324 compatibility make it a default selection for these boards. The push-pull output can directly source and sink several milliamps to drive status LEDs through series resistors, eliminating discrete buffer transistors in some designs. Designs migrating from legacy LM324/LM2902 sockets gain the tighter 2mV offset and improved output swing with zero PCB changes, simplifying cost-down requalification.
Recommended
Recommended Products Summary
Engineering reference data for LM324BAIDR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LM324ADR | LM324BIDR | KIA324F | TL074CDT |
|---|---|---|---|---|---|
| Package | SOIC-14 (D) | SOIC-14 (D) - same | SOIC-14 (D) - same | SOP-14 - same footprint | SOIC-14 - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | KEC | STMicroelectronics |
| Channels | 4 | 4 | 4 | 4 | 4 |
| Output Stage | Push-Pull | Classic Class-AB LM324 | Push-Pull (B version) | Classic LM324 type | Class-AB, JFET input |
| Drop-in Replacement for LM324 | Yes (is the upgraded BA version) | Yes | Yes (per TI) | Yes (second source) | Footprint only - verify bias/supply |
Key Differentiators
- Tightest offset in the LM324 family (vs LM324BIDR)
- Push-pull output reduces crossover distortion (vs LM324ADR)
- Wider and fully specified low-voltage operation (vs TL074CDT)
Design Notes
Place a 100nF ceramic decoupling capacitor within 5mm of pin 4 (V+) to pin 11 (GND), plus a 10uF bulk capacitor per quad package. Because four amplifiers share one supply pin, load-transient current from any channel couples into the shared rail; a solid ground plane and short feedback traces minimize crosstalk between channels. Keep high-impedance input traces (pins 2, 3, 5, 6, 9, 10, 12, 13) short and guarded away from output traces to prevent unintended feedback and oscillation in high-gain configurations.
Do not use the LM324BAIDR as a fast comparator: open-loop response is in the microsecond range and there is no specified response time - use a dedicated comparator such as the LM393 for speed-critical switching. Also remember the input common-mode range extends to the negative rail but not to the positive rail; inputs within roughly 1.5V of V+ may not be valid in all conditions. Verify output swing expectations: the push-pull stage improves swing versus legacy LM324 but is still not rail-to-rail.
At closed-loop gains above 10, the 1.2MHz gain-bandwidth product limits bandwidth to under 120kHz; check the open-loop gain margin at your target frequency to avoid gain error and distortion. For capacitive loads beyond roughly 50-100pF (cables, long traces), isolate the output with a small series resistor (typically 50 ohms) inside the feedback loop to preserve phase margin and prevent ringing or oscillation.
Estimated: quiescent current per amplifier for the LM324 family is on the order of sub-mA; with four channels, total supply current at no load is typically a few mA, so power dissipation in the SOIC-14 is well under 100mW at 36V with light loads - no thermal design needed. Output-stage dissipation only becomes a consideration when sourcing/sinking sustained currents above ~20mA per channel; verify with the datasheet power-dissipation vs ambient temperature derating curve.
Compliance Information
RoHS compliant per TI product listing; R suffix = Tape & Reel. Automotive-grade equivalents available in the LM2902B family.
