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LM4140: connecting multiple reference voltages to the same ADC

Expert 1105 points
Part Number: LM4140


For my application I want to change the reference voltage going to an ADC. I thought of using multiple LM4140s

One for 1024mV and the other 4096mV.

My question is if I use EN pin for this (only 1 LM4140 is enabled) task, would this be okey?

Reading the datasheet I came across below paragrah. it seems that the output is not high-Z so my idea won't work. Can you please comment?

The LM4140 is designed to quickly reduce both VREF and IQ to zero when turned off. VREF is restored
in less than 200 μs when turned on. During the turnoff, the charge across the output capacitor is discharged
to ground through internal circuitry



  • Hi rifo,

    The LM4140 is a very precise device and I it should be able to source both ADCs but they are not too demanding. but it depends heavily on the ADCs.
    Can you give me more information on what type of ADC resolution/architecture/sampling rate you want to use?