ADS774JU/1K datasheet by Texas Instruments

ADS774JU/1K Frequently Asked Questions (FAQs)

• What is the recommended layout and routing for the ADS774JU/1K to minimize noise and ensure accurate conversions?
  The ADS774JU/1K requires careful PCB layout and routing to minimize noise and ensure accurate conversions. TI recommends using a 4-layer PCB with a dedicated analog ground plane, keeping analog and digital signals separate, and using short, direct traces for the analog inputs. Additionally, decoupling capacitors should be placed close to the device.
• How do I handle the internal reference voltage and what are the implications of using an external reference?
  The ADS774JU/1K has an internal 2.5V reference voltage, but it can also be overridden with an external reference. When using an external reference, ensure it is stable and has a low output impedance. The internal reference can be disabled by connecting the REFOUT pin to AVDD. Using an external reference may affect the device's accuracy and linearity.
• What is the recommended clock frequency and what are the implications of using a different clock frequency?
  The ADS774JU/1K can operate with a clock frequency between 1 MHz and 20 MHz. The recommended clock frequency is 10 MHz, which provides the best balance between conversion speed and noise performance. Using a different clock frequency may affect the device's conversion speed, noise performance, and power consumption.
• How do I handle the device's power-on reset and what are the implications of not using a power-on reset circuit?
  The ADS774JU/1K requires a power-on reset (POR) circuit to ensure proper device initialization. A POR circuit ensures that the device is properly reset after power-up. Without a POR circuit, the device may not function correctly, and conversions may be inaccurate or unreliable.
• What is the recommended approach for driving the analog inputs and what are the implications of not using a proper input driver?
  The ADS774JU/1K requires a proper input driver to ensure accurate conversions. A recommended approach is to use a low-impedance driver, such as an op-amp, to drive the analog inputs. Without a proper input driver, the device may not be able to accurately convert the input signal, leading to errors and inaccuracies.