Overview
The AD7538KN is a 14-bit monolithic CMOS digital-to-analog converter (DAC) produced by Analog Devices Inc. This device utilizes laser-trimmed thin-film resistors to achieve excellent linearity and is designed for compatibility with most microprocessors. It operates using standard chip select and memory write logic, and features double buffering, which allows for simultaneous updates in systems with multiple AD7538s. The AD7538KN is manufactured using the linear-compatible CMOS (LC2MOS) process, ensuring speed compatibility with TTL or CMOS logic level inputs.
Key Specifications
| Parameter | Rating/Value | Units | Comments |
|---|---|---|---|
| VDD (Pin 23) to DGND | −0.3 V, +17 V | V | Absolute Maximum Rating |
| VSS (Pin 24) to AGND | −15 V, +0.3 V | V | Absolute Maximum Rating |
| VREF (Pin 1) to AGND | ±25 V | V | Absolute Maximum Rating |
| VRFB (Pin 2) to AGND | ±25 V | V | Absolute Maximum Rating |
| Digital Input Voltage (Pins 6 to 22) to DGND | −0.3 V, VDD +0.3 V | V | Absolute Maximum Rating |
| Operating Temperature Range (Commercial) | 0°C to +70°C | °C | J, K Versions |
| Operating Temperature Range (Industrial) | −25°C to +85°C | °C | A, B Versions |
| Power Dissipation (Any Package) | 1000 mW (to 75°C), 10 mW/°C (above 75°C) | mW | |
| Resolution | 14 bits | ||
| Package Type | 24-Pin PDIP, 24-Pin SOIC |
Key Features
- Guaranteed Monotonicity: The AD7538 is guaranteed monotonic to 14 bits over the full temperature range for all grades.
- Low Cost: Offers a low-cost solution for 12-bit system upgrades with its 14-bit dynamic range.
- Small Package Size: Available in a small 24-pin, 0.3" DIP and a 24-pin SOIC package.
- Low Output Leakage: Achieves low output leakage current at high temperatures by tying VSS to a negative voltage.
- Wide Power Supply Tolerance: Operates on a +12 V to +15 V VDD with a ±5% tolerance.
- Double Buffering: Allows simultaneous updates in systems with multiple AD7538s using the LDAC feature.
- Microprocessor Compatibility: Designed for easy interfacing to 16-bit microprocessors and accepts TTL or CMOS logic level inputs.
Applications
- Digital Audio: Suitable for precision audio applications requiring high linearity and accuracy.
- Precision Servo Control: Used in servo control systems where precise analog output is necessary.
- Control and Measurement in High Temperature Environments: Ideal for applications in high-temperature environments due to its excellent temperature stability.
- Microprocessor Interfacing: Easily interfaces with 16-bit microprocessors, reducing the need for external logic.
Q & A
- What is the resolution of the AD7538KN?
The AD7538KN has a resolution of 14 bits.
- What are the operating temperature ranges for the AD7538KN?
The operating temperature ranges are 0°C to +70°C for commercial versions and −25°C to +85°C for industrial versions.
- What is the power supply voltage range for the AD7538KN?
The device operates on a +12 V to +15 V VDD with a ±5% tolerance.
- What package types are available for the AD7538KN?
The AD7538KN is available in 24-pin PDIP and 24-pin SOIC packages.
- How does the AD7538KN achieve low output leakage current?
By tying VSS to a negative voltage, the AD7538KN can achieve low output leakage current at high temperatures.
- Is the AD7538KN compatible with microprocessors?
Yes, the AD7538KN is designed for easy interfacing to 16-bit microprocessors and accepts TTL or CMOS logic level inputs.
- What is the significance of the LDAC feature in the AD7538KN?
The LDAC feature allows for double buffering, enabling simultaneous updates in systems with multiple AD7538s.
- How does the AD7538KN ensure monotonicity?
The AD7538KN is guaranteed monotonic to 14 bits over the full temperature range for all grades.
- What are some common applications of the AD7538KN?
Common applications include digital audio, precision servo control, and control and measurement in high temperature environments.
- How important is proper grounding for the AD7538KN?
Proper grounding is crucial to prevent noise injection into the analog output. It is recommended to tie AGND and DGND together or use diodes in inverse parallel between them.
