Hello,
I'm using the AD9117BCPZ in pin mode with AVDD = 1.8 V, and I'm trying to achieve precise control of the DAC output current.
I've configured the DAC with:
-
RSET = 8.04 kΩ
-
Internal reference (1.0 V nominal)
-
100 Ω resistors from IOUTP and IOUTN to ground (All other circuits are disconnected for now)
- CMLx are tied to GND.
-
Expecting IOUTFS = 3.98 mA, but measuring 3.75 mA, a consistent ~6% shortfall
The load voltage is ~375 mV, close to the expected compliance range maximum (0.4 V @ 1.8 V AVDD). To validate this, I decreased the current by half (Rset=16k1, targeting IFS=1.99mA) but I measured 1.87mA instead, still -6% below the targeted current.
All external resistors are 0.1% tolerance, the internal reference should be 2%. I can not explain why I have such important difference between theoretical and measured value. At this point I dont have SPI to access internal registers but they should be at the default values.
Any idea how to explain this behaviour?
Thanks in advance for your support!
