LM224N - Quad Operational Amplifier

Overview

The LM224N is a quad operational amplifier (op-amp) belonging to the LM124 series. It consists of four independent, high-gain, internally frequency-compensated operational amplifiers designed specifically for single-supply operation over a wide voltage range. The device can also operate from split power supplies while maintaining low power consumption that remains independent of the supply voltage magnitude.

This component is particularly suitable for applications requiring multiple op-amps in a single package, offering space savings and improved system reliability through reduced component count. The LM224N is characterized for operation from 0°C to 70°C, making it suitable for commercial temperature range applications.

Key Features

• Four internally compensated op-amps in single package
• Wide power supply range:
  • Single supply: 3V to 32V
  • Dual supplies: ±1.5V to ±16V
• Low supply current drain (700µA typical) - independent of supply voltage
• Internally frequency compensated for unity gain
• Large DC voltage gain: 100dB typical
• Wide bandwidth (unity gain): 1MHz typical
• Wide common-mode range (includes ground)
• Low input offset voltage: 2mV typical
• Input offset current: 2nA typical
• Output short-circuit protection
• Differential input voltage range equal to power supply voltage

Applications

The LM224N is versatile and finds use in numerous analog circuit applications, including:

• Transducer amplifiers
• DC gain blocks
• Active filters
• Voltage followers
• Integrators
• Summing amplifiers
• Oscillators
• Signal conditioning circuits
• Power supply control circuits
• Portable and battery-powered systems
• Industrial control systems
• Automotive electronics

Electrical Characteristics

All specifications are typical at 25°C unless otherwise noted.

DC Characteristics

• Input Offset Voltage: 2mV (max 7mV)
• Input Offset Current: 2nA (max 30nA)
• Input Bias Current: 45nA (max 250nA)
• Large Signal Voltage Gain: 100V/mV (min 25V/mV) at V_CC=15V, R_L≥2kΩ
• Supply Current (all four amplifiers): 2.8mA (max 4.3mA) at V_CC=15V
• Common Mode Input Voltage Range: -0.3V to V_CC-1.5V
• Output Voltage Swing: 0V to V_CC-1.5V (R_L≥2kΩ)

AC Characteristics

• Gain Bandwidth Product: 1MHz (typ)
• Slew Rate: 0.5V/µs (typ)
• Input Noise Voltage: 35nV/√Hz (typ) at 1kHz
• Input Noise Current: 0.01pA/√Hz (typ) at 1kHz

Package Information

The LM224N is available in a standard 14-pin PDIP (Plastic Dual In-line Package):

• Package Type: PDIP-14
• Dimensions: 19.3mm x 6.35mm x 4.57mm (L x W x H)
• Pin Spacing: 2.54mm (100 mil)
• Lead Material: Copper Alloy
• Lead Finish: Matte Tin
• RoHS Compliant: Yes
• Moisture Sensitivity Level (MSL): 1 (Unlimited Floor Life)

Pin Configuration

The pinout for the 14-pin DIP package is as follows:

• Pin 1: Output 1
• Pin 2: Inverting Input 1
• Pin 3: Non-Inverting Input 1
• Pin 4: V_CC+ (Positive Power Supply)
• Pin 5: Non-Inverting Input 2
• Pin 6: Inverting Input 2
• Pin 7: Output 2
• Pin 8: Output 3
• Pin 9: Inverting Input 3
• Pin 10: Non-Inverting Input 3
• Pin 11: V_EE- (Negative Power Supply or Ground)
• Pin 12: Non-Inverting Input 4
• Pin 13: Inverting Input 4
• Pin 14: Output 4

Design Considerations

Power Supply

The LM224N can operate from a single power supply (3V to 32V) or dual power supplies (±1.5V to ±16V). When using a single supply, the negative supply pin (Pin 11) should be connected to ground. Decoupling capacitors (0.1µF ceramic) should be placed close to the power supply pins to minimize noise and oscillations.

Input Protection

While the device has built-in ESD protection, inputs should not be driven beyond the supply rails. For applications where this might occur, external clamping diodes or series resistors should be used.

Output Considerations

The output can typically source or sink 20mA. For heavier loads, an external buffer should be used. The output swing is limited to approximately 1.5V from either supply rail under loaded conditions.

Reliability and Quality

• Operating Temperature Range: 0°C to +70°C
• Storage Temperature Range: -65°C to +150°C
• Maximum Junction Temperature: 150°C
• ESD Protection: ≥1000V (Human Body Model)
• Manufacturing Process: Standard bipolar

Alternative Parts

For different package options or temperature ranges, consider:

• LM124: Military temperature range (-55°C to +125°C)
• LM224: Industrial temperature range (-25°C to +85°C)
• LM324: Similar quad op-amp with lower power consumption
• TL074: JFET-input quad op-amp for higher impedance applications