STMicroelectronics LM358WST

Introduction to the LM358WST

The LM358WST from STMicroelectronics is a general-purpose, low-power dual operational amplifier designed to meet the diverse requirements of analog signal processing in both industrial and consumer electronic systems. Housed in an 8-lead MiniSO package, this IC integrates two independent, high-gain op-amp circuits. The LM358WST is especially suited for single-supply operation over a wide voltage range and is an ideal candidate for engineers seeking reliable signal conditioning and amplification solutions in compact designs.

Main specifications of the LM358WST

The LM358WST distinguishes itself with a host of valuable features for modern circuit design. It offers robust Electrostatic Discharge (ESD) protection rated at 2 kV, ensuring resilience during board assembly or field operations. Internal frequency compensation is implemented, allowing stable operation without requiring external compensation networks.

In terms of performance, the device provides a large DC voltage gain of 100 dB and a unity-gain bandwidth of 1.1 MHz (with temperature compensation). Supply current consumption is minimal and remains effectively independent of the supply voltage, benefiting battery-powered and low-power applications. Additional characteristics include low input bias current (20 nA, temperature compensated), low input offset voltage (2 mV), and low input offset current (2 nA). Input common-mode voltage range includes ground, and the differential input voltage can reach the full supply range, supporting broad input scenarios. The output voltage swing extends from 0 V up to (VCC+) – 1.5 V.

Maximum ratings and optimal operating ranges of the LM358WST

Designers should adhere to the absolute maximum ratings to ensure device integrity during operation. Each op-amp in the LM358WST supports a maximum output current of approximately 40 mA, regardless of supply voltage magnitude. Care should be taken to prevent simultaneous short-circuits on both amplifiers to avoid excessive heating.

The common-mode input voltage should not become more negative than –0.3 V. The upper range is limited to (VCC+) – 1.5 V, but the device is safe with inputs up to +32 V without damage. During comparator operation, at least one input should remain within the operational common-mode voltage range. The device is tolerant to various ESD models, including human body, machine, and charged device model scenarios, ensuring robust handling through the assembly process.

Electrical specs and performance parameters of the LM358WST

Under typical conditions (VCC+ = 5 V, VCC– = ground, VO = 1.4 V, ambient temperature = 25°C), the LM358WST presents a compelling set of electrical characteristics:

Large DC voltage gain: 100 dB

Unity-gain bandwidth: 1.1 MHz

Input bias current: 20 nA (temperature compensated)

Input offset voltage: 2 mV

Input offset current: 2 nA

Output voltage swing: 0 V to (VCC+) – 1.5 V

Supply current per amplifier is low and stable across the supply voltage range

The open-loop frequency response and pulse response diagrams highlight stable amplifier behavior across a wide temperature and supply voltage range. Power supply and common-mode rejection ratios are high, enhancing performance in noisy supply environments. The device's small-signal and large-signal characteristics ensure versatility for various analog signal conditioning tasks.

Common use cases for the LM358WST

The LM358WST is engineered for single-supply analog circuit needs, particularly systems powered by standard +5 V rails common in today's digital logic environments. Key application examples include:

Non-inverting and AC-coupled amplifier configurations for sensor and signal interface

DC summing amplifiers for analog computation and mixing

High input impedance differential amplifiers for measurement and instrumentation

Active filters (such as band-pass filters) for signal pre-processing

Adjustable gain instrumentation amplifiers suiting precise, low-level signal acquisition

For systems that demand operational amplifiers capable of rail-to-rail inputs and outputs or require operation very close to ground, the LM358WST's architecture enables ground-level output swing and input ranges extending to ground, reducing the necessity for negative supply rails.

Available packages and physical dimensions of the LM358WST

To address diverse integration needs, the LM358WST is available in multiple compact package options, including MiniSO8, SO8, and TSSOP8 outlines. This allows for flexibility in PCB layout depending on the application's size and assembly constraints. All package versions are compliant with the latest ECOPACK standards, supporting environmentally sensitive design and manufacturing. The MiniSO8 package is particularly attractive where board space is at a premium, such as in portable or densely populated electronics.

Alternative or compatible models for the LM358WST

When considering alternatives or drop-in replacements for the LM358WST, engineers may look toward other models in the STMicroelectronics LMx58W family, such as the LM158W and LM258W, which provide comparable electrical characteristics and pinouts, with extended temperature ranges or different screening levels. Additionally, other industry-standard dual op-amps that feature single-supply operation, low input bias current, and similar bandwidth specifications may serve as replacements, though careful review of offset voltage, slew rate, and input/output voltage ranges is necessary to confirm suitability.

Conclusion

The STMicroelectronics LM358WST dual operational amplifier stands out as a highly versatile, energy-efficient, and robust component for a wide variety of analog signal processing applications. With internal compensation, extensive input and output voltage ranges, and multiple package choices, it simplifies analog circuit design for engineers prioritizing reliability and footprint efficiency. The LM358WST’s electrical performance, proven application versatility, and readily available equivalents make it a solid choice for both new designs and legacy system upgrades in industrial, instrumentation, and consumer markets.