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Topic: Need suggestion on single supply rail to rail op-amp to use with arduino uno? (Read 2 times) previous topic - next topic

yaantey

Can someone tell me a rail to rail op-amp that can be used with single supply 5V to 9V. Something easy and similar to LM358, also inexpensive.

I want a rail to rail op-amp that use single supply so that I can bais it somewhere at 2.5V and still get 0 to 5V using a battery. I have found a couple of op-amps, which are: TLC272, LT1466, LM324N, TLV2771, LM6144. What could be the best choice, or is there anything else that you suggest?

Thanks

RuggedCircuits

"Best choice" depends on your other criteria: cost? DIP or SMT? 1/2/4 op-amps per package? low noise? low input current? low offset voltage?

I usually start with the TLV2371 and look for other options only if that workhorse won't do the job for me. It's rail-to-rail input and output, works between 2.7V and 16V, has 3 MHz bandwidth, comes in 1/2/4 packages (TLV2371, TLV2372, TLV2374), comes in DIP and SMT versions, and has worst-case 6mV input offset voltage. It's also pretty cheap.

Usually it's the offset voltage that sends me looking for other op-amps, if necessary.

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The Ruggeduino: compatible with Arduino UNO, 24V operation, all I/O's fused and protected

yaantey

1) Rail to rail mean, +ve to -ve voltage right?
2) If I want Gnd to +Vcc, can it be rail to rail?
3) I want to use gnd and +Vcc using a single supply battery, so whats the best option?
4) I want a single supply so that I can use gnd and +ve and bias in the positive region. So that the minimum would be 0V and maximum would be +Vcc.
5) I want an op-amp that can give me closest to +Vcc in this configuration.

RuggedCircuits

All your questions seem to be asking the same thing :)  And the answer to all of them is "yes". A rail-to-rail input op-amp allows input voltages anywhere from V- (negative voltage supply of the op-amp) to V+ (positive voltage supply of the op-amp). A rail-to-rail output op-amp allows the output voltages to go all the way down to V-, and all the way up to V+ (well, within a few millivolts). A rail-to-rail input/output (RRIO) op-amp does both. The TLV2371 is RRIO.

This is why RRIO op-amps are often referred to as "single supply" since they can operate from just positive voltages and GND and don't need a negative supply rail to work with 0V at the inputs.

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The Gadget Shield: accelerometer, RGB LED, IR transmit/receive, speaker, microphone, light sensor, potentiometer, pushbuttons

yaantey

1) By using TLV2371, I can bias at 2.5V and use from Gnd to +5V, right?
2) Whats the  maximum gain of TLV2371? I need maximum gain of 200 either with single op-amp (like lm386) or dual op amp (like lm 358)?

Thanks

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