Octal, Low power, 16-bit, +/-16.5V Output Serial Input Digital-to-Analog Converter 48-VQFN -40 to 105# Technical Documentation: DAC8718SRGZT Digital-to-Analog Converter
Manufacturer : Texas Instruments (TI)
Component : DAC8718SRGZT (16-Bit, 8-Channel, High-Voltage Output DAC)
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## 1. Application Scenarios
### Typical Use Cases
The DAC8718SRGZT is a precision 8-channel, 16-bit digital-to-analog converter designed for applications requiring high-voltage analog outputs with excellent DC accuracy and low noise. Each channel incorporates an output amplifier capable of driving up to ±20 V, making it suitable for directly interfacing with high-voltage systems without additional amplification stages.
Primary use cases include:
- Industrial Control Systems : Providing control voltages for PLC analog output modules, valve positioning, and actuator drives
- Automated Test Equipment (ATE) : Generating programmable voltage stimuli for device testing and calibration
- Medical Instrumentation : Controlling high-voltage circuits in imaging systems and therapeutic devices
- Scientific Instrumentation : Precision voltage sources for laboratory equipment and measurement systems
- Communications Infrastructure : Bias voltage control in RF power amplifiers and optical network components
### Industry Applications
Process Control & Factory Automation
In industrial environments, the DAC8718SRGZT serves as the interface between digital control systems and analog field devices. Its 8-channel architecture allows simultaneous control of multiple process variables (temperature, pressure, flow rate) through 4-20 mA current loops or 0-10 V voltage signals. The integrated ±20 V output capability eliminates the need for external high-voltage amplifiers, reducing component count and board space.
Advantages in this context:
- High channel density (8 channels in a single package)
- Excellent DC precision (16-bit resolution, ±2 LSB INL max)
- Robust operation in industrial temperature ranges (-40°C to +125°C)
- Integrated reference buffers simplify system design
Limitations:
- Maximum update rate of 1 MSPS shared across all channels
- Higher power consumption compared to low-voltage DACs (typically 15 mW per channel at 5 V)
- Requires careful thermal management in high-channel-utilization scenarios
Medical Imaging Systems
In computed tomography (CT) and magnetic resonance imaging (MRI) systems, the DAC8718SRGZT controls gradient amplifiers and detector bias voltages. The device's low glitch energy (0.1 nV-s typical) minimizes artifacts in sensitive measurements.
Advantages:
- Excellent DC accuracy ensures precise voltage settings
- Low noise performance (0.3 μVrms typical at 10 Hz to 100 kHz)
- Flexible power supply options (single +12 V to ±15 V operation)
Limitations:
- Not optimized for high-speed waveform generation (>100 kHz)
- Requires external protection circuits for fault conditions in medical safety applications
### Practical Advantages and Limitations
Advantages:
1. High Integration : Combines 8 DAC channels, output amplifiers, and reference buffers in a single 48-pin VQFN package
2. Flexible Interface : Supports SPI, QSPI, MICROWIRE, and DSP-compatible serial interfaces
3. Power-On Reset : Ensures predictable startup conditions with outputs at zero scale or midscale
4. Simultaneous Update : All channels can be updated simultaneously via LDAC pin
5. Diagnostic Features : Includes open-circuit detection and thermal shutdown protection
Limitations:
1. Channel Crosstalk : -110 dB typical, which may require isolation in ultra-precision applications
2. Settling Time : 10 μs to ±0.003% for a 20 V step change, limiting high-speed applications
3. Cost Considerations : Higher per-channel cost compared to discrete solutions for non-critical applications
4. Package Constraints : VQFN package requires careful PCB design for
