Overview
The AD640BPZ, produced by Analog Devices Inc., is a complete monolithic logarithmic amplifier designed for high precision and stability over a wide range of supply voltages and temperatures. This device is particularly suited for applications requiring dynamic range and accurate signal compression. The AD640BPZ uses a successive detection scheme to provide an output current proportional to the logarithm of the input voltage, ensuring high accuracy and stability across the full military temperature range.
Key Specifications
| Parameter | Conditions | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| SIGNAL INPUTS (Pins 1, 20) | Input Capacitance Either Pin to COM | 2 | 2 | 2 | pF |
| Noise Spectral Density | 1 kHz to 10 MHz | 2 | 2 | 2 | nV/√Hz |
| Tangential Sensitivity | BW = 100 MHz | -72 | -72 | -72 | dBm |
| 3 dB BANDWIDTH Each Stage | 350 | 350 | 350 | MHz | |
| LOGARITHMIC OUTPUTS Slope Current, IY f < 1 MHz | 0.96 | 1.0 | 1.04 | mA | |
| LOGARITHMIC OUTPUTS Slope Current, IY f = 30 MHz | 0.88 | 0.94 | 1.00 | mA | |
| LOGARITHMIC OUTPUTS Slope Current, IY f = 60 MHz | 0.82 | 0.90 | 0.98 | mA | |
| LOGARITHMIC OUTPUTS Slope Current, IY f = 90 MHz | 0.85 | 0.85 | 0.85 | mA | |
| LOGARITHMIC OUTPUTS Slope Current, IY f = 120 MHz | 0.85 | 0.85 | 0.85 | mA | |
| Supply Voltage | ±4.5 V | ±7.5 V | V | ||
| Temperature Range | Commercial | 0°C | 70°C | °C | |
| Temperature Range | Industrial | -40°C | 85°C | °C | |
| Temperature Range | Military | -55°C | 125°C | °C |
Key Features
- Complete, fully calibrated monolithic system with five cascaded dc-coupled amplifier/limiter stages, each having a small signal voltage gain of 10 dB and a –3 dB bandwidth of 350 MHz.
- Direct coupled fully differential signal path with logarithmic slope, intercept, and AC response stable over the full military temperature range.
- Dual polarity current outputs scaled at 1 mA per decade (50 µA per dB).
- Low power operation, typically 220 mW at ±5 V.
- Available in various packages including 20-lead side-brazed ceramic DIPs, leadless chip carriers (LCC), and plastic DIP and PLCC packages.
- Integral X10 attenuator providing an alternative input range of ±7.5 mV to ±2 V dc.
Applications
- Radar, sonar, ultrasonic, and audio systems.
- Precision instrumentation from DC to 120 MHz.
- Power measurement with absolute calibration.
- Wide range high accuracy signal compression.
- Alternative to discrete and hybrid IF strips, replacing several discrete log amp ICs.
Q & A
- What is the AD640BPZ?
The AD640BPZ is a complete monolithic logarithmic amplifier produced by Analog Devices Inc.
- What is the dynamic range of the AD640BPZ?
The AD640BPZ provides up to 50 dB of dynamic range for frequencies from DC to 120 MHz. Two AD640s in cascade can provide up to 95 dB of dynamic range at reduced bandwidth.
- What is the bandwidth of each stage in the AD640BPZ?
Each stage has a –3 dB bandwidth of 350 MHz.
- What are the supply voltage requirements for the AD640BPZ?
The AD640BPZ operates with supply voltages from ±4.5 V to ±7.5 V.
- What are the temperature ranges for the AD640BPZ?
The AD640BPZ is available in commercial (0°C to 70°C), industrial (–40°C to 85°C), and military (–55°C to 125°C) temperature ranges.
- What types of packages are available for the AD640BPZ?
The AD640BPZ is available in 20-lead side-brazed ceramic DIPs, leadless chip carriers (LCC), and plastic DIP and PLCC packages.
- How does the AD640BPZ handle input signals?
The AD640BPZ uses a successive detection scheme to provide an output current proportional to the logarithm of the input voltage, with an integral X10 attenuator for alternative input ranges.
- What are some common applications of the AD640BPZ?
Common applications include radar, sonar, ultrasonic and audio systems, precision instrumentation, power measurement, and signal compression.
- How does the AD640BPZ compare to discrete log amp ICs?
The AD640BPZ replaces several discrete log amp ICs, offering a more integrated and efficient solution.
- What is the power consumption of the AD640BPZ?
The AD640BPZ typically operates at 220 mW at ±5 V.
