TL081CP JFET-Input Operational Amplifier

Overview

The TL081CP is a high-performance, low-cost JFET-input operational amplifier that combines the benefits of BI-FET II™ technology with excellent speed and precision characteristics. This device features an internally trimmed input offset voltage, making it suitable for applications requiring high accuracy without external trimming. The TL081CP maintains a strong balance between power consumption and performance, offering a wide gain bandwidth product of 4 MHz and a fast slew rate of 13 V/µs while consuming only 1.8 mA of supply current.

Designed as a pin-compatible upgrade to the industry-standard LM741, the TL081CP allows for easy replacement in existing designs while providing superior JFET-input characteristics including extremely high input impedance (10¹²Ω) and low input bias currents. The device is particularly well-suited for audio applications due to its low distortion characteristics and excellent noise performance.

Key Features

• Internally trimmed offset voltage: 15 mV maximum
• Exceptionally low input bias current: 50 pA typical
• Low noise performance: 25 nV/√Hz input noise voltage
• Wide gain bandwidth product: 4 MHz typical
• High slew rate: 13 V/µs typical
• Low power consumption: 1.8 mA supply current
• Very high input impedance: 10¹²Ω typical
• Low total harmonic distortion: 0.02% (AV = 10, RL = 10kΩ)
• Fast settling time: 2 µs to 0.01%
• Low 1/f noise corner: 50 Hz typical

Applications

The TL081CP's combination of features makes it ideal for a wide range of analog applications:

Audio Applications

• Preamplifiers and microphone amplifiers
• Active filters and equalizers
• Mixers and summing amplifiers
• Headphone amplifiers

Instrumentation and Measurement

• Precision integrators
• Sample-and-hold circuits
• Data acquisition systems
• Medical instrumentation

General Purpose Analog

• Voltage followers
• Comparators with hysteresis
• Signal conditioning circuits
• Oscillators and waveform generators

Electrical Characteristics

All specifications at VCC± = ±15V, TA = 25°C unless otherwise noted.

Input Characteristics

• Input Offset Voltage: 3 mV typical, 15 mV maximum
• Input Bias Current: 50 pA typical, 200 pA maximum
• Input Offset Current: 25 pA typical, 100 pA maximum
• Input Resistance: 10¹²Ω typical
• Input Capacitance: 4 pF typical
• Input Voltage Range: ±12 V minimum

Output Characteristics

• Output Voltage Swing: ±10 V minimum into 10 kΩ
• Output Current: 10 mA typical
• Short-Circuit Current: 60 mA typical

Dynamic Characteristics

• Gain Bandwidth Product: 4 MHz typical
• Slew Rate: 13 V/µs typical
• Settling Time to 0.01%: 2 µs typical
• Total Harmonic Distortion: 0.02% typical (AV = 10, RL = 10kΩ)

Power Supply Characteristics

• Supply Voltage Range: ±5 V to ±18 V
• Supply Current: 1.8 mA typical, 2.8 mA maximum
• Power Supply Rejection Ratio: 86 dB typical

Package Information

The TL081CP is available in a standard 8-pin PDIP (Plastic Dual-In-Line Package):

N08E Package Details

• Package Type: PDIP-8
• Lead Count: 8
• Body Dimensions: 9.81mm x 6.35mm
• Lead Pitch: 2.54mm
• Lead Length: 3.3mm typical
• Operating Temperature Range: 0°C to +70°C
• Storage Temperature Range: -65°C to +150°C
• Moisture Sensitivity Level (MSL): MSL 1

Pin Configuration

• Pin 1: Offset Null
• Pin 2: Inverting Input (-)
• Pin 3: Non-Inverting Input (+)
• Pin 4: V- (Negative Supply)
• Pin 5: Offset Null
• Pin 6: Output
• Pin 7: V+ (Positive Supply)
• Pin 8: NC (No Connection)

Design Considerations

When implementing the TL081CP in circuit designs, several factors should be considered:

Power Supply Decoupling

Proper power supply decoupling is essential for optimal performance. A 0.1 µF ceramic capacitor should be placed as close as possible to each power supply pin, with larger bulk capacitors (10 µF) used for each supply rail.

Offset Voltage Adjustment

While the TL081CP features internally trimmed offset voltage, applications requiring the lowest possible offset can utilize the offset null pins (1 and 5) with a 10 kΩ potentiometer connected between these pins, with the wiper connected to the negative supply.

Thermal Considerations

Although the TL081CP has relatively low power consumption, in high-temperature environments or when driving heavy loads, thermal effects on parameters such as input offset voltage should be considered. The device exhibits a typical offset voltage drift of 18 µV/°C.

Stability Considerations

The TL081CP is unity-gain stable, but proper attention should be paid to board layout and feedback network design to maintain stability, particularly in high-gain applications. Keeping feedback and input traces short and minimizing stray capacitance at the inputs will help prevent oscillations.