LM7301: Please recommend a voltage reference of 1.5V for LM7301IM5/NOPB

Hi,

a middsupply reference voltage can very easily be generated in this way:

R1 and R2 form a voltage divider to provide middsupply. Togehter with C1 they form a low pass filter to remove noise and glitches. C1 can be increased, if needed. R3 limits the input current into the +input of LM7301, if the 3.3V supply voltage is suddenly shorted to ground. If this can never happen, R3 can also be removed. The LM7301, finally, works as a voltage follower with a gain of 1 and buffers the middsupply reference voltage.

Of course, with the same method another reference voltage can be generated, like 1.5V for instance.

Last point, remove your C341, if the reference voltage is provided by this voltage follower. A high capacitive load directly at the output of LM7301 would erode the phase margin and cause stability issues.

Kai

It is a good way to get 1.5V. But we need a higher accurate voltage reference than 3.3V.Thank you.

We need a higher accurate 1.5V than 3.3V that use in analog input circuit in servo controller. REF1930 was recommended to use by another team. But we only need 1.5V.

Hi.

with the circuit I proposed you can use nearly any voltage reference. Just adapt the voltage divider. Eventually, you might want to choose an OPAmp with a smaller offset voltage, though.

You haven't answered Michael's question: How accurate does the 1.5V need to be?

Kai

REF1930 can be used for 1.5V and the 3V output can be left unconnected.