ZHCSIG8A July 2018 – November 2018 DAC61408 , DAC71408 , DAC81408
PRODUCTION DATA.
There is no off-the-shelf solution for generating a 300-mV offset, unfortunately. Figure 67 depicts a method to generate it using discrete components. It uses LM4041 adjustable shunt regulator on high-side from the 2.5-V reference. It has a reference input pin that sets the voltage across this device. Given that VRef is 1.233 V, choosing R1 = 16 kΩ and R2 = 12 kΩ the voltage Vo can be calculated by superposition as 2.16 V. This will provide an offset of (2.5 V – 2.16 V) = 340 mV that will provide a safe margin from DAC ground.