MCP6001 Spice Model Posted

The MCP600x parts have an interesting (for an opamp) input protection circuit - it has clamps to the negative rail but no clamps to the positive rail, much like the input protection used in many digital logic families.

Despite that, the datasheet abs max ratings say the input voltage cannot go above the positive rail. I never established whether that was because of some fundamental limitation of the device, or just an overly conservative datasheet. I asked about it in s.e.d. earlier this year, but no-one knew:

BTW, the input protection doesn't seem to be modelled in MCP6001_JT.zip (Either that, or I've lost my ability to read netlists.)

Regards, Allan

"They (ESD diodes to Vss) also clamp any voltages that go too far above VDD; their breakdown voltage is high enough to allow normal operation, and low enough to bypass quick ESD events within the specified limits."

Those input limits are to prevent phase reversal. Like most spec sheets they define an envelope inside of which maloperation is guaranteed not to occur.

They do insist on input currents being limited to 2mA...

No. That model was a quicky for John Woodgate (remember him from back when SED was about electronics ?:-) So only fundamental function was modeled.

In the wings I am modeling a universal output stage that properly routes rail current and has current limiting.

My "commercial-grade" models include protection devices and quiescent current ramp up versus rails... and various shutdown modes... you name it, I model it >:-} ...Jim Thompson