LM324PT Quad Op Amp in TSSOP-14 for Low Power Analog Circuits

ElecSuppliers Part Number GuideAug 28, 2026

When an electronic design needs several basic analog amplification functions without using a separate operational amplifier for every channel, the LM324PT is a practical option to consider. This STMicroelectronics device contains four independent operational amplifiers in one TSSOP-14 package, allowing several analog functions to share a single IC.

The part is particularly interesting for circuits powered from a single supply because its input common-mode range includes ground and its specified supply range extends from 3 V to 30 V.

What LM324PT Is Designed to Do

LM324PT belongs to the LM324 family of general-purpose, low-power operational amplifiers.

Instead of performing one fixed function, an op amp can be configured by external resistors and other components to perform different analog tasks. With four amplifiers inside the LM324PT, one device can handle several signal paths on the same PCB.

This makes it useful when a design contains multiple sensor signals, voltage-monitoring points or analog control loops.

Four Amplifiers in One TSSOP-14 Package

The most distinctive feature of LM324PT is the combination of four op-amp channels and a TSSOP-14 package.

STMicroelectronics lists LM324PT as an active industrial-grade product with a TSSOP-14 package.

For a new PCB, this package can be attractive when board space matters. For an existing PCB, however, the package is critical because LM324PT is not simply interchangeable with every LM324 variant.

For example, ST also offers LM324DT in SO-14 and LM324QT in QFN-16L.

The electrical family may be similar, but the physical package and PCB footprint are different.

Why the 3V Minimum Supply Matters

LM324PT can operate from a single supply between 3 V and 30 V. It can also operate from split supplies.

The 3 V lower limit is particularly useful for designs that do not have a traditional ±15 V analog supply.

A circuit running from a low-voltage single supply can therefore use the LM324 architecture without creating a separate negative supply solely for the op amp.

This makes the part relevant to many embedded analog circuits where the available power rail is positive-only.

Its Input Range Includes Ground

One reason the LM324 family remains useful in simple single-supply circuits is that its input common-mode voltage range includes ground.

Consider a sensor whose output starts close to 0 V.

An op amp that cannot accept input signals close to its negative supply rail may require additional circuitry or a different power arrangement.

The LM324 architecture was designed with this type of single-supply use in mind.

That does not mean its output can reach every supply rail under every load condition, so designers should still check the relevant input and output limitations in the datasheet.

1.3 MHz Gain Bandwidth Is Enough for Many Basic Analog Tasks

ST specifies a 1.3 MHz gain bandwidth for the LM324 family.

This is not a high-speed amplifier intended for high-frequency signal processing.

Instead, it fits applications where signals change relatively slowly compared with RF or high-speed data interfaces.

That makes LM324PT more appropriate for functions such as sensor conditioning, threshold detection, low-frequency amplification and control loops than for demanding high-speed analog designs.

Low Supply Current Helps Multi-Channel Designs

ST specifies approximately 375 µA supply current per amplifier.

When all four channels are used, the total consumption becomes an important design consideration, but the relatively low per-channel current is still useful for systems where power consumption matters.

This is especially relevant when several analog channels are required but the application does not justify using four separate high-performance op-amp ICs.

Where LM324PT Makes Sense

LM324PT is a general-purpose analog component, so its application is determined largely by the external circuit around each amplifier.

Common uses include:

Sensor signal conditioning

Voltage amplification

Threshold and level detection

Voltage buffering

Analog control circuits

Low-frequency filtering

Battery and power monitoring

Transistor and actuator control

The same four channels can also perform different functions within one product.

For example, one amplifier might monitor a supply voltage while another conditions a sensor output.

LM324PT Is Not a Precision Amplifier

A common mistake when selecting an LM324 variant is to focus on its four-channel configuration without considering the accuracy requirements of the circuit.

LM324PT is designed as a general-purpose operational amplifier, not as a precision instrumentation amplifier.

ST specifies a typical LM324 architecture with low input bias current and low input voltage characteristics, but applications requiring extremely low offset, very low drift or high-speed operation may need a different amplifier family.

The right question is therefore not simply whether LM324PT can amplify the signal.

It is whether its offset, bias current, bandwidth, common-mode behavior and output capability are suitable for the required accuracy.

TSSOP-14 Can Be the Reason to Choose LM324PT

For many replacement projects, the PT suffix matters as much as the LM324 designation.

ST identifies LM324PT specifically as the TSSOP-14 version, while LM324DT uses SO-14 and LM324QT uses QFN-16L.

If an existing PCB was designed for TSSOP-14, replacing LM324PT with an SO-14 device is not a drop-in solution even if both belong to the LM324 family.

This is why buyers should search the complete part number rather than purchasing simply "LM324."

LM324PT and LM324APT Are Not the Same Ordering Code

Another detail worth checking is the difference between LM324PT and LM324APT.

Both are TSSOP-14 devices in the STMicroelectronics LM324 family, but they are different ordering variants. ST's ordering information lists LM324PT and LM324APT separately.

The A version has different electrical specifications, including a lower maximum input offset voltage in the datasheet ordering information.

Therefore, when an original BOM specifically calls for LM324PT, it should not automatically be replaced with LM324APT just because the package looks the same.

Operating Temperature Fits Commercial and General Industrial Designs

LM324PT is specified for 0°C to 70°C operation and is listed by STMicroelectronics as an industrial-grade product.

This temperature range is suitable for many indoor electronics and controlled equipment environments.

For products expected to operate below 0°C or above 70°C, designers should look at the appropriate LM124 or LM224 family variants rather than assuming that every LM324 ordering code has the same temperature range.

What to Check When Replacing LM324PT

For an existing circuit, the replacement check should start with the complete part number.

Confirm:

The four-channel configuration

TSSOP-14 package

Pin assignment

Supply voltage requirements

Input common-mode range

Input offset characteristics

Gain bandwidth

Output requirements

Operating temperature

A part that merely says "quad op amp" is not automatically equivalent to LM324PT.

Why LM324PT Remains Relevant in New Designs

The LM324 architecture is not intended to compete with modern high-speed or precision amplifiers.

Its strength is different.

It offers four analog amplifiers, low power consumption, single-supply operation and a wide supply-voltage range in one inexpensive general-purpose device.

For a control board with several slow analog signals, those characteristics can be more valuable than extremely high bandwidth or ultra-low offset.

That is where LM324PT continues to make practical sense.

Finding the Correct LM324PT

When searching for this exact component, use LM324PT rather than only "LM324 quad op amp."

The complete part number identifies the specific STMicroelectronics TSSOP-14 ordering variant. ST currently lists LM324PT as an active product in volume production.

For purchasing teams, confirming the manufacturer, package and exact suffix before ordering can prevent confusion with the many LM324 variants available from different manufacturers.

ElecSuppliers can also serve as a supplier discovery channel for buyers searching specifically for LM324PT.

The simplest way to understand this part is: LM324PT is a four-channel general-purpose op amp chosen when a design needs several low-power analog functions, single-supply operation and a compact TSSOP-14 package.