LM324MX - Low Power Quad Op Amp, 3V-32V, 14-SOIC | Texas Instruments
MPN: LM324MX ✓ פעילLM324MX סקירה
An operational amplifier (op amp) is an analog building block that amplifies the difference between two input voltages. The LM324 belongs to the hierarchy of single-supply general-purpose amplifier -> quad operational amplifier -> analog signal conditioning IC -> semiconductor. Internally frequency compensated for unity gain, it needs no external compensation network, which is why it remains the default amplifier for cost-sensitive DC and low-frequency signal conditioning designs.
Key characteristics include four amplifiers sharing one supply pin, a wide 3 V to 32 V rail range, single-supply operation from 2 V output swing above ground, and low quiescent current typical of the low-power family. Because all four channels are in one package, a complete amplifier subsystem costs one PCB footprint instead of four, and channels share a common ground reference, which simplifies layout and reduces ground-bounce risk in multi-channel analog circuits.
The device is internally trimmed and thermally stable, with input stages protected against differential overvoltage through internal clamp diodes. Because the amplifier is a bipolar-input design rather than a CMOS-input design, input bias current is in the nanoamp range and common mode rejection is good over the full supply range, at the cost of higher supply current than CMOS-input amplifiers.
Typical applications include sensor signal conditioning, low-frequency active filters, transducer amplifiers, audio preamplifier stages, current-to-voltage conversion in instrumentation, and general DC gain stages in industrial control and consumer equipment. Because the LM324 family is available from several manufacturers, the same 14-SOIC footprint and pinout are widely supported for second sourcing.
When designing around the LM324MX, keep input and output signals inside the common mode range and account for input offset and bias current when working with high-impedance sources. Place the bypass capacitor close to the supply pin and keep feedback loops short so that the modest gain-bandwidth product does not limit stability.
חלופות תחליף ישיר עבור LM324MX — אותו מארז, תואם פין-לפין. חלקים במארז שונה הדורשים עיבוד מחדש של ה-PCB אינם נכללים.
וריאנטים בסדרה זו
דגמים מאותה סדרה התואמים Drop-in עם LM324MX (אותו גורם צורה וטביעת רגל) — שונים ב Amplifier Type, Input Offset Voltage, Number of Amplifiers, Package, Supply Voltage Range.
LM324D
✅ Drop-In ⚠️ מפרטים לא מאומתיםצור קשר לקבלת מחיר
הצג גיליון נתונים ←LM324KADR
✅ Drop-In ⚠️ מפרטים לא מאומתים📋 חלופה להתייחסות (לא בקטלוג)
LM324ADR2G
✅ Drop-In ⚠️ מפרטים לא מאומתיםצור קשר לקבלת מחיר
הצג גיליון נתונים ←LM324KADRG4
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←LM324DR
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←LM324MX
✅ Drop-Inצור קשר לקבלת מחיר
הצג גיליון נתונים ←LM324MX דירוגים מרביים ומאפיינים חשמליים
| Number of Channels | 4 |
| Number of Amplifiers | 4 (quad) |
| Amplifier Type | Single-supply general-purpose operational amplifier, internally frequency compensated for unity gain |
| Supply Voltage Range | 3 V to 32 V (or plus or minus 16 V dual supply) |
| Large DC Voltage Gain | 100 dB |
| Input Offset Voltage | 7 mV |
| Common Mode Rejection Ratio (Min) | 65 dB |
| טווח טמפרטורת פעולה | 0 C to +70 C |
| מארז | 14-pin SOIC (surface mount) |
| סגנון הרכבה | Surface Mount |
| סטטוס RoHS | unknown |
| REACH Status | unknown |
| AEC-Q100 Qualification | not_applicable |
תצורת פינים של LM324MX
| פין 1 | OUT1 — Output of amplifier 1 |
| פין 2 | IN1- — Inverting input of amplifier 1 |
| פין 3 | IN1+ — Non-inverting input of amplifier 1 |
| פין 4 | V- — Negative supply (ground on single supply) |
| פין 5 | IN2+ — Non-inverting input of amplifier 2 |
| פין 6 | IN2- — Inverting input of amplifier 2 |
| פין 7 | OUT2 — Output of amplifier 2 |
| פין 8 | OUT3 — Output of amplifier 3 |
| פין 9 | IN3- — Inverting input of amplifier 3 |
| פין 10 | IN3+ — Non-inverting input of amplifier 3 |
| פין 11 | V+ — Positive supply |
| פין 12 | IN4+ — Non-inverting input of amplifier 4 |
| פין 13 | IN4- — Inverting input of amplifier 4 |
| פין 14 | OUT4 — Output of amplifier 4 |
יישומים טיפוסיים
LM324MX מתאים עבור 6 יישוםs: Sensor Signal Conditioning, Active Filters and Audio Preamplification, Industrial Control and Data Acquisition, Power Supply Control and Feedback Loops, Consumer and Household Appliance Control, Test and Measurement Buffering.
Sensor Signal Conditioning
The LM324MX is a natural fit for amplifying the millivolt-level outputs of resistive and thermoelectric sensors because its bipolar input stage draws nanoamp-class bias current, so high-impedance sensor sources are not loaded. With 100 dB of large DC voltage gain and 7 mV input offset voltage, a single channel in a non-inverting configuration handles typical gain stages of 10 to 1000 while the remaining three channels provide filtering and buffering. The 3 V to 32 V supply range allows direct connection to 5 V or 24 V industrial rails. Because output swing stays roughly 1 V above ground on a 5 V supply, bias the signal path around mid-supply when using lower rail voltages.
מומלץ
Active Filters and Audio Preamplification
Because each LM324MX channel is internally compensated for unity gain and stable with resistive feedback networks, the quad device builds complete low-pass, high-pass and band-pass active filter stages. A single 14-SOIC package can implement a second-order Sallen-Key low-pass filter plus a microphone preamplifier and output driver, replacing three separate amplifiers and cutting board area. The 100 dB DC gain supports high-Q filter stages, while the moderate gain-bandwidth product suits audio-band signals rather than wideband waveform work. For audio paths where noise floor matters, keep feedback resistors in the low kilo-ohm range and bypass the supply pin locally.
מומלץ
Industrial Control and Data Acquisition
The LM324MX supports 24 V industrial control boards because it accepts supplies up to 32 V, so it can sit directly behind a regulated 24 V rail without a level-shifting stage. Four channels in one package cover instrumentation loops: a current-to-voltage converter for a 4-20 mA sensor, a low-pass filter on the ADC input, an active differential driver, and a comparator-style alarm stage. Its 65 dB minimum common mode rejection ratio helps reject the noise riding on factory wiring, and the single V+ / V- pin arrangement simplifies grounding around a single package. Keep the analog ground return separate from switching-node returns to avoid injecting converter ripple into the signal path.
מומלץ
Power Supply Control and Feedback Loops
The LM324MX is widely used as the error amplifier in linear regulator and DC-DC feedback loops, where it compares a divided feedback voltage against a reference and drives the pass device. Its high DC loop gain supports regulation with modest external compensation components, and the wide 3 V to 32 V input range lets the amplifier sit directly on a 12 V or 24 V intermediate bus. Because the device is not rail-to-rail at the output, the feedback divider must keep the reference inside the common mode range and the output drive should be referenced to a mid-supply point. Place the compensation components close to the pins to avoid added phase lag.
מומלץ
Consumer and Household Appliance Control
Household appliances and consumer products favour simple, low-cost analog blocks, and the LM324MX delivers four general-purpose channels in a single 14-SOIC at a low unit cost. Typical blocks include a thermistor bridge amplifier, a mains-synchronous zero-cross detection stage, a triac or MOSFET gate driver buffer, and a battery-monitor amplifier. The 3 V to 32 V operating range covers both 5 V logic rails and rectified mains-derived supplies after regulation. Its 0 to 70 C commercial rating suits indoor appliance environments, while the internal input clamp diodes provide some protection against accidental differential overvoltage on sensor lines.
מומלץ
Test and Measurement Buffering
Instrumentation buffers often need high input impedance and modest bandwidth, which is exactly where a bipolar-input quad amplifier helps. The LM324MX can buffer a high-impedance probe, scale a 0-1 V reference to a 0-10 V range, form a unity-gain isolation stage between a divider network and the measurement front end, and drive an ADC input with the fourth channel. Its low input bias current prevents probe loading errors on megohm dividers, and the 32 V maximum supply covers high-voltage test ranges after scaling. Because offset and bias current dominate accuracy here, the enhanced-grade LM324KADR or LM324ADR variants reduce error when the measurement budget is tight.
מומלץ
סיכום מוצרים מומלצים
נתוני עזר הנדסיים עבור LM324MX — השוואה, הנחיות תכנון ומידע על תאימות.
מדריך בחירה
השוואה עם חלופות
| פרמטר | מוצר זה | LM324KADR | LM324ADR | LM324DR | LM324MX |
|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Fairchild Semiconductor | ROHM Semiconductor |
| Package | 14-pin SOIC | 14-pin SOIC - same | 14-pin SOIC - same | 14-pin SOIC - same | 14-pin SOIC - same |
| Number of Channels | 4 | 4 | 4 | 4 | 4 |
| Supply Voltage Range | 3 V to 32 V (plus or minus 16 V dual) | 3 V to 32 V (plus or minus 16 V dual) | 3 V to 32 V (plus or minus 16 V dual) | 3 V to 32 V (plus or minus 16 V dual) | Plus or minus 16 V / 32 V |
| Large DC Voltage Gain | 100 dB | 100 dB class | 100 dB class | 100 dB | 100 dB class |
| Gain Stability | Internally frequency compensated for unity gain | Internally compensated, unity-gain stable | Internally compensated, unity-gain stable | Internally frequency compensated for unity gain | Internally compensated, unity-gain stable |
| Operating Temperature Range | 0 C to +70 C | 0 C to +70 C | 0 C to +70 C | 0 C to +70 C | 0 C to +70 C |
| Mounting Style | Surface Mount | Surface Mount | Surface Mount | Surface Mount | Surface Mount |
מבדילים עיקריים
- Four general-purpose amplifiers in a single 14-SOIC package (לעומתLMC660 (single amplifier, 8-pin SOIC))
- Wide supply range for direct industrial rail connection (לעומתLM324ADR (same range, higher cost))
- Bipolar input stage with low input bias current (לעומתTLV2464ID (CMOS-input quad amplifier))
הערות תכנון
Estimated: with four channels running at a typical 0.7 mA per channel from a 5 V rail, total supply current is roughly 2.8 mA, so dissipation is about 14 mW and thermal design is trivial. The real constraint is headroom, not heat: on a 5 V supply the output cannot swing closer than roughly 1 V to the negative rail, so bias single-supply signals around mid-supply (about 2.5 V) when driving a following stage that expects a full-range swing.
Place the supply bypass capacitor between the V+ pin (pin 11) and the V- pin (pin 4) as close to the package as possible, with a short, low-inductance return path. Because all four amplifiers share the same supply pins, a single local 100 nF ceramic plus a 1 uF to 10 uF bulk capacitor near the IC covers all channels. Keep analog ground returns on a separate, low-impedance path from switching and digital returns to avoid injecting converter ripple into the input stage.
Do not assume rail-to-rail behaviour: inputs must stay inside the common mode range and outputs cannot reach either rail, so a 3.3 V design can lose usable output range. Keep feedback resistors low enough to keep the noise contribution of the bipolar input stage small, and remember that the 7 mV input offset and input bias current set the accuracy floor for DC-coupled gain stages. If offset error is unacceptable, specify the enhanced-grade LM324KADR or LM324ADR rather than the standard LM324MX.
מידע על תאימות
RoHS and REACH status depend on the specific manufacturer and ordering code of the LM324MX; lead-free ordering codes such as the G4 suffix are published separately from the standard MPN. Confirm the RoHS declaration on the manufacturer product page for the exact part number and packaging configuration you are sourcing.
