I am unable to get any output voltages from an EVAL-AD5360 evaluation board. The software indicates correct operation, but all physical DAC outputs measure 0V.
SYMPTOMS:
- All 16 DAC output pins (VOUT0-VOUT15) measure 0V at both chip pins and test points
- Tested multiple channels (DAC0, DAC1) with various input codes (0000, 8000, FFFF) - all show 0V
- Software "Output Voltages" tab calculates expected values correctly (e.g., 9.9999V for input code FFFF)
- Output Data Word updates correctly when codes are entered, confirming USB communication works
CONFIGURATION VERIFIED:
Power Supply (measured at AD5360 chip pins):
- VDD = +15.0V
- VSS = -15.0V
- DVCC = +5.0V
- AGND/DGND connected correctly
Reference Voltages:
- VREF0 = 4.99V (measured at test point T25)
- VREF1 = 4.99V (measured at test point T26)
- LK4 set to Position B (5V internal reference)
Links Configuration:
- LK1: Inserted (USB interface enabled)
- LK2: Position A (Binary format for PC software)
- LK3: Inserted (USB controls RESET)
- LK4: Position B (5V internal reference selected)
- LK8: Inserted (USB controls CLR)
SOFTWARE OPERATION:
- Evaluation software connects successfully via USB
- Can write to DAC registers - Output Data Word changes correctly
- Pulse LDAC button pressed after loading values
- Pulse RESET attempted
- Tested on Windows PC with latest evaluation software
MEASUREMENTS TAKEN:
- Direct measurement at AD5360 chip VOUT0 pin: 0V
- Measurement at test point T2 (VOUT0): 0V
- All power rails at chip: correct voltages
- VREF at chip: correct voltages
QUESTION:
Is there a control register setting, initialization sequence, hardware jumper, or unpopulated component that would prevent all DAC outputs from functioning, even though the chip is powered correctly and communicating with the software?
I have reviewed the datasheet and user guide but cannot identify what is preventing the outputs from working. All software indicators suggest normal operation, but zero voltage appears at all physical outputs.
