Hi all:
I have the experience on using LTC2666-12/LTC2666-16 evaluation board, and have designed my own layout DAC by using LTC2666 chips.
All LTC2666s follow the set up below:
MSP0/MSP1/MSP2/V+/Vcc/IOVcc are connected to +5V
GND is connected to ground
V- is not connected and bypassed to GND by two 0.1uF capacitors
REF/REFCOMP are bypassed to GND by a 0.1uF capacitor
TGP/CLR/LDAC/OVRTMP are connected to IOVcc by a 4.99k Ohm resistor
and LTC2666 is controled by STM32 by SPI commands.
Vout0~Vout7 are able to output 0V~+5V, however on both the evaluation board and my own PCB design have an issue that the exact output voltage is slightly higher than the designated value send from the STM32.
It seems like the output voltage is always 0.05V~0.06V higher than the value send by the command unless the output voltage hits the limit of +5V from the supply voltage.
Is there anyway to elimate this positive DC bias from the output to match the output voltage and the voltage send by the command?
Sincerely
