AD848 and AD849 High-Speed, Low-Power Operational Amplifiers

Overview

The AD848 and AD849 are high-speed, low-power monolithic operational amplifiers designed for precision applications requiring fast signal processing. These amplifiers leverage Analog Devices' proprietary junction-isolated complementary bipolar (CB) process to deliver exceptional AC and DC performance while maintaining low power consumption. The AD848 is internally compensated for stability at closed-loop gains of 5 or greater, while the AD849 is decompensated and stable at gains exceeding 24. Both devices are part of Analog Devices' high-speed op-amp family, which includes variants like the AD847 (unity-gain stable) and the higher-precision AD840 series.

Features

The AD848 and AD849 offer a robust set of features tailored for high-speed signal conditioning:

• High Gain Bandwidth: 175 MHz (AD848) and 725 MHz (AD849)
• Low Power Consumption: 4.8 mA supply current
• Fast Slew Rate: 300 V/µs
• Rapid Settling Time: 80 ns to 0.1% for a 10 V step (AD849)
• Excellent Differential Performance:
  • Differential Gain: 0.07% (AD848), 0.08% (AD849)
  • Differential Phase: 0.08° (AD848), 0.04° (AD849)
• Capacitive Load Drive Capability: Stable with challenging loads
• Low Noise: 3 nV/√Hz input voltage noise (AD849)
• High Open-Loop Gain: 85 V/mV into a 1 kΩ load (AD849)
• Low Offset Voltage: 1 mV max
• Wide Supply Range: Specified for ±5 V and ±15 V operation
• Packaging Options: Plastic, hermetic CERDIP, and small-outline packages
• Military-Grade Availability: MIL-STD-883B compliant versions
• Tape and Reel Packaging: Compliant with EIA-481A standards

Applications

The AD848 and AD849 are versatile amplifiers suitable for a wide range of high-speed and precision applications, including:

• Cable Drivers: High slew rate and bandwidth make them ideal for driving long transmission lines.
• Data Acquisition Systems: Suitable for 8- and 10-bit systems requiring fast settling times.
• Video and RF Amplification: Excellent differential gain and phase performance ensure minimal signal distortion.
• Signal Generators: Low noise and high speed enable clean signal synthesis.
• Active Filters: High gain bandwidth supports wideband filter designs.
• Medical Imaging Equipment: Precision and speed are critical for signal processing in imaging systems.

Electrical Characteristics

DC Performance

• Input Offset Voltage: 1 mV (max)
• Input Bias Current: Typically 2 µA
• Open-Loop Gain: 85 V/mV (AD849, into 1 kΩ)
• Power Supply Rejection Ratio (PSRR): 80 dB (min)

AC Performance

• Gain Bandwidth Product: 175 MHz (AD848), 725 MHz (AD849)
• Slew Rate: 300 V/µs
• Settling Time: 80 ns to 0.1% (AD849, 10 V step)
• Input Voltage Noise: 3 nV/√Hz (AD849)
• Differential Gain/Phase: 0.07%/0.08° (AD848), 0.08%/0.04° (AD849)

Power Requirements

• Supply Voltage Range: ±5 V to ±15 V
• Quiescent Current: 4.8 mA (typical)
• Power Dissipation: 72 mW (typical at ±15 V)

Package Information

The AD848 and AD849 are available in multiple package options to suit various application requirements:

• Plastic DIP (N): 8-lead, 0.3" wide
• Hermetic CERDIP (D): 8-lead, MIL-STD-883B compliant
• Small Outline (SOIC): 8-lead, surface-mount
• Chip Form: Die available for custom assemblies

Ordering Information

• AD848JN: Plastic DIP, commercial temperature range (0°C to +70°C)
• AD848JD: CERDIP, commercial temperature range
• AD848JR: SOIC, commercial temperature range (tape and reel)
• AD849KN: Plastic DIP, industrial temperature range (-40°C to +85°C)
• AD849SQ/883B: MIL-STD-883B compliant, extended temperature range (-55°C to +125°C)

Conclusion

The AD848 and AD849 operational amplifiers combine high-speed performance with low power consumption, making them ideal for demanding applications in data acquisition, video processing, and RF amplification. Their robust electrical characteristics, including high gain bandwidth, fast slew rate, and excellent differential performance, ensure reliable operation in precision circuits. With multiple packaging options and military-grade availability, these amplifiers offer flexibility for both commercial and high-reliability applications.