MC34071 equivalent?

I'm using the MC34071 op-amp in my design as it needs just a single supply and tolerates an input voltage of 40vdc, though I'm using about 24vdc.

I'm finding the MC34071 a little difficult to find at decent prices here in Australia... does anyone here know of an equivalent I can use?

Thanks in advance,
Paul

Hi aussiepoof,

You could try to substitute it with a TL084.

https://pdf1.alldatasheet.com/datasheet-pdf/view/28781/TI/TL084.html

on1aag.

Thanks on1aag... but the TL084 is a dual-supply part with a +/-18v input max, isn't it?

Here are the specs on the MC34071:
• Wide Bandwidth: 4.5 MHz
• High Slew Rate: 13 V/ms
• Fast Settling Time: 1.1 ms to 0.1%
• Wide Single Supply Operation: 3.0 V to 44 V
• Wide Input Common Mode Voltage Range: Includes Ground (VEE)
• Low Input Offset Voltage: 3.0 mV Maximum (A Suffix)
• Large Output Voltage Swing: −14.7 V to +14 V (with ±15 V
• Large Capacitance Drive Capability: 0 pF to 10,000 pF
• Low Total Harmonic Distortion: 0.02%
• Excellent Phase Margin: 60°
• Excellent Gain Margin: 12 dB
• Output Short Circuit Protection
• ESD Diodes/Clamps Provide Input Protection for Dual and Quad

Like all opamps, the TL081 works with a single supply if it is biased correctly.

The max input voltage of the MC34071 is not 40V, it is the power supply voltage like nearly all opamps including the TL081.

The inputs of the MC34071 work down to ground in a single supply system. The inputs of a TL081 work down to only 3V or 4V in a single supply system. If an input voltage becomes lower then its output suddenly inverts.

The MC34071 ia a single opamp and so is a TL081. A TL084 is a quad opamp and so is an MC34074.

Thanks $scrooge... my op-amp theory really isn't up to scratch. So how does one go about biasing the inputs in a single-supply situation?

Thanks in advance,
P.

Attach the schematic and parts list of your circuit for us to see if the opamp is biased or not.