Can someone recommend a rail to rail op amp please? i have found a couple online but they are a little expensive.

 

Can someone recommend a rail to rail op amp please? i have found a couple online but they are a little expensive.

For that we need to know, at a minimum, your voltage, max frequency, and input offset requirements?

 

For that we need to know, at a minimum, your voltage, max frequency, and input offset requirements?

The voltage of my circuit is 5V, max frequency is 1 Hz and i don't know about input offset requirement

 

Oh and it has to be a dual device.

 

ok i am going for the TLV2462

All good!

 

MCP6476 If you do SMD watch out for the pinout. There are options.
MCP6002

 

I was going to recommend MCP6002, so I guess I will second it.

$0.44 at DigiKey

 

OPA2340UA
$ 0.95/lot (Lot 10 pcs)

• Rail-to-Rail Input
• Rail-to-Rail Output (Within 1 mV)
• MicroSize Packages
• Wide Bandwidth: 5.5 MHz
• High Slew Rate: 6 V/µs
• Low THD + Noise: 0.0007% (f = 1 kHz)
• Low Quiescent Current: 750 µA/Channel
• Single, Dual, and Quad Versions

 

I was going to recommend MCP6002, so I guess I will second it.

$0.44 at DigiKey

Just ordered 5 from Digikey

thank you

 

MCP6476 If you do SMD watch out for the pinout. There are options.
MCP6002

Thanks Ron, just ordered 5 from Digikey (MCP6002)

 

MCP6476 If you do SMD watch out for the pinout. There are options.
MCP6002

My order from Digikey of MCP6002's came today Ron...my circuit works superb with them

thanks for the recommendation.

 

So, "rail-to-rail" may refer to either input or output range. I'm surprised how people most often are not clear on that.
I recently acquired (but have not yet tested) T.I. TLV9062IDR and Microchip MCP6002T-E/SN (mentioned above.) They both look good on the datasheet. I'm operating at 5.0 volts single-sided supply.

 

So, "rail-to-rail" may refer to either input or output range. I'm surprised how people most often are not clear on that.
I recently acquired (but have not yet tested) T.I. TLV9062IDR and Microchip MCP6002T-E/SN (mentioned above.) They both look good on the datasheet. I'm operating at 5.0 volts single-sided supply.

The term "rail to rail" almost always refers to the output voltage swing.

When talking about the input, the usual terminology is something like, "common-mode input includes the rails". Even this is misleading if interpreted strictly. If the positive rail were 10 V and one input was 7 V and the other input was 12 V, then the common-mode input is 9.5 V, but this would almost certainly not function as intended. But saying that the common-mode input includes the rails gets the point across, especially for opamps since if there is much difference at all between the two inputs the device is going to saturate anyway.

 

"rail-to-rail" may refer to either input or output range

Or both.

 

an LTspice test log from years ago
Pass TEST
► TLV314 -- struggles near rails but passes (1.8÷5.5V) ◄
?? ~ TLV2371 -- inp max 2.58V ~ ??
► TLV9102 -- struggles near the low rail but passes (2.7÷16V) ◄
?? ~ TL3472 -- inp min max 1.0 to 3.4 V ~ ??
?? ~ OPA2990 -- inp max 2.49V ~ ??
► OP284 struggles near rails but passes better the TLV314 (3÷36V) ◄ ← this has performed superior to the rest at many cases ? at simulations
?? ~ LMV824 -- inp MAX ? 3.1 to 3.8 V (exact value indeterminable) ~ ??
► LM7321 -- struggles near the rails but passes smoother than OP284 (2.5÷32V) ◄
► LM6142 -- same as LM7321 but faster (1.8÷24V) ◄
► AD8628 -- struggles near rails but passes somewhat worse the rest R2R passers (2.7÷5V) ◄

 

max frequency is 1 Hz and i don't know about input offset requirement...

If you require extreme DC accuracy (Vos < 10 uV), look into "precision", "zero-drift", or "chopper-stabilized" op amps.