Overview
The STMicroelectronics LM158DT is a dual operational amplifier (op-amp) designed for general-purpose applications requiring low power consumption, low input offset voltage, and wide bandwidth. It is particularly suitable for applications such as signal conditioning, active filters, integrators, and voltage followers. The LM158DT offers high gain and is optimized to operate over a wide range of supply voltages, making it versatile for both single-supply and split-supply systems.
Device Architecture and Package
The LM158DT contains two independent, high-gain, internally frequency-compensated operational amplifiers. Each amplifier features input protection circuitry to withstand input voltages beyond the supply rails without damage. The device is housed in a standard SO-8 plastic surface-mount package, ideal for compact PCB layouts and automated assembly.
Key Features
* Dual operational amplifiers in one package
* Wide supply voltage range: 3 V to 32 V (single supply) or ±1.5 V to ±16 V (dual supply)
* Low input offset voltage: typically 2 mV
* Low input bias current: typically 20 nA
* Input offset current: typically 5 nA
* Wide bandwidth: 1 MHz (unity gain)
* Slew rate: 0.3 V/µs typical
* Low quiescent current: 0.7 mA per amplifier
* Output short-circuit protected
* Internally frequency compensated for unity gain stability
* Compatible with standard TTL and CMOS logic levels
Electrical Specifications
* Supply Voltage (VCC): 3 V to 32 V (single supply), or ±1.5 V to ±16 V (dual supply)
* Input Offset Voltage (VOS): Typical 2 mV, maximum 7 mV
* Input Offset Current (IOS): Typical 5 nA
* Input Bias Current (IB): Typical 20 nA
* Input Voltage Range: Extends to ground on the negative side; differential input voltage of ±30 V max
* Gain Bandwidth Product (GBP): 1 MHz
* Slew Rate (SR): 0.3 V/µs
* Output Voltage Swing:
* Typically within 1.5 V of supply rails at no load
* Total Supply Current: 1.4 mA (both amplifiers active)
* Common-Mode Rejection Ratio (CMRR): 70 dB minimum at 1 kHz
* Power Supply Rejection Ratio (PSRR): 86 dB minimum at 60 Hz
* Voltage Gain (Open Loop): 100,000 (100 dB) typical
Thermal and Mechanical Characteristics
* Operating Temperature Range: 0°C to +70°C (commercial grade)
* Storage Temperature Range: -65°C to +150°C
* Junction Temperature: Maximum 150°C
* Thermal Resistance, Junction to Ambient (RθJA): Approximately 150°C/W (in free air)
* Package: SO-8 surface-mount package
* Package Dimensions: Approximate length 4.9 mm, width 3.9 mm, height 1.75 mm
Typical Applications
* Signal conditioning circuits in sensor systems
* Low-frequency active filters
* Voltage followers/buffers in data acquisition systems
* Integrators and summing amplifiers
* Battery-powered instrumentation requiring low power
* General-purpose analog signal processing
* Low-frequency oscillators and waveform generators
Performance Characteristics
The LM158DT’s design focuses on low input offset voltage and low input bias current, which is advantageous for precision DC-coupled applications. Its ability to operate at low supply voltages makes it suitable for battery-powered devices. The moderate slew rate and gain bandwidth product mean it is optimized for low-frequency and low-speed applications rather than high-frequency or high-speed circuits.
The internal frequency compensation ensures stability even at unity gain, simplifying circuit design and reducing the need for external compensation components. The output stage can drive moderate loads, typically up to 2 kΩ, but is not designed for high-current driving applications.
Reliability and Compliance
The LM158DT complies with industry-standard quality and reliability requirements. It is lead-free and RoHS-compliant, ensuring compatibility with environmental regulations. The device undergoes thorough testing to guarantee stable operation across the specified temperature and voltage ranges.
Conclusion
The STMicroelectronics LM158DT is a reliable, low-power, dual operational amplifier suitable for a broad spectrum of general-purpose analog applications. Its combination of low offset voltage, low bias current, wide supply range, and unity gain stability makes it a versatile component in precision analog signal processing tasks, particularly where low-frequency and low-speed operation are required. Its compact SO-8 package allows for efficient PCB space utilization in modern electronic designs.
