[SOLVED] Resistor types in TSMC 0.35um

[shockingshockley]

Hello!

I am currently doing layout of resistors using l-edit. Please correct me if I am wrong about the resistor types:

rnod = n diff resistor? (rsh=80)

rpod = p diff resistor? (rsh=150)

rnwod = nwell resistor? (rsh=1050)

rpo1 =poly resistor? (rsh=8)

Also do you recommend which resistor type to be used in case of resistance values 500, 5k, 10k , or 100k? Thank you!

 

[erikl]

I just know these different resistor types from other fabs' pdks.

Use the nwell resistor for high resistance values (10⁵ .. 10⁶ Ω), where the absolute value or the temperature dependency is not so important.

The ndiff and pdiff resistors are good for medium resistor values (10³ .. 10⁵ Ω). They probably have opposed (pos. and neg.) temperature dependencies, so you can appropriately mix them (serial or parallel) to get low temperature dependency.

Use poly resistors for low resistance values (10 .. 10³ Ω), for highest accuracy if you need absolute resistance values and/or low temperature dependency.

For low-ohmic resistors take care of their power consumption: in contrary to the nwell and diff resistors, poly resistors aren't embedded into the silicon - where the heat dissipation is excellent - but are separated from it by an insulation layer, so their heat dissipation is much worse - that's why one-time fuses are created from poly resistors.