Overview
The AD538BD, manufactured by Analog Devices Inc., is a monolithic real-time analog computational unit (ACU) designed for precision analog multiplication, division, and exponentiation. This device offers high accuracy and flexibility, making it suitable for a wide range of analog signal processing applications. The AD538BD features low input and output offset voltages, excellent linearity, and a wide dynamic range, ensuring accurate computations over a broad input range. Laser wafer trimming enhances its performance by reducing errors to as low as 0.25% of reading. The device operates with a 400 kHz bandwidth and supports various power supply ranges from ±4.5 V to ±18 V, making it compatible with standard ±5 V, ±12 V, and ±15 V supplies.
Key Specifications
| Parameter | Specification |
|---|---|
| Package | 18-Lead TO-118 Hermetic Side-Brazed Ceramic DIP |
| Accuracy Grades | A, B (Industrial: -25°C to +85°C), S (Military: -55°C to +125°C) |
| Bandwidth | 400 kHz |
| Input Offset Voltage | < 100 μV |
| Output Offset Voltage | < 100 μV |
| Error (100:1 Range) | ±0.25% of reading |
| Power Supply Range | ±4.5 V to ±18 V |
| On-Chip References | +2 V, +10 V |
Key Features
- Precision analog multiplication, division, and exponentiation
- Low input and output offset voltages (< 100 μV)
- Excellent linearity and wide dynamic range (up to 1000:1)
- No external trims required for one-quadrant operations
- Simultaneous multiplication and division capabilities
- Resistor-programmable powers and roots
- Direct log ratio computation and access to multiple summing junctions
- Wide power supply range compatibility
Applications
- One- or two-quadrant multiply/divide operations
- Log ratio computation
- Squaring/square rooting
- Trigonometric function approximations
- Linearization via curve fitting
- Precision Automatic Gain Control (AGC)
- Power functions
Q & A
- What is the primary function of the AD538BD?
The AD538BD is a real-time analog computational unit that provides precision analog multiplication, division, and exponentiation.
- What is the typical error range for the AD538BD in a 100:1 input range?
The typical error is ±0.25% of reading.
- What is the bandwidth of the AD538BD?
The bandwidth is 400 kHz.
- What are the available accuracy grades for the AD538BD?
The device is available in accuracy grades A and B for industrial temperatures and grade S for military temperatures.
- What is the power supply range for the AD538BD?
The power supply range is from ±4.5 V to ±18 V.
- Does the AD538BD require external components for one-quadrant operations?
No, external components are not required for one-quadrant (positive input) multiplication and division.
- How can the desired scale factor be set for multiplication and division?
The desired scale factor can be set using the on-chip +2 V or +10 V references or controlled externally.
- What types of computations can be performed using the log ratio section alone?
Direct log ratio computation is possible by using only the log ratio and output sections of the chip.
- What are some common applications of the AD538BD?
Common applications include one- or two-quadrant multiply/divide operations, log ratio computation, squaring/square rooting, and precision AGC.
- In what package is the AD538BD available?
The device is packaged in an 18-lead TO-118 hermetic side-brazed ceramic DIP.
