Has anybody looked at these as an alternative to relays or the Analog Devices muxes?
MPC507: 8-channel differential (or stereo)
MPC509: 4-channel differential
Pricing seems reasonable, about $8 CDN apiece.
http://www-s.ti.com/sc/ds/mpc507.pdf
MPC507: 8-channel differential (or stereo)
MPC509: 4-channel differential
Pricing seems reasonable, about $8 CDN apiece.
http://www-s.ti.com/sc/ds/mpc507.pdf
> MPC507: 8-channel differential
These are second-source for a very old Harris Gates part.
The series has been available for about 20 years, so it is probably not going to vanish soon.
These used to cost a heck of a lot more than $8, though I do recall them falling past $25 quite a few years ago.
Voltage handling is very good.
ON-resistance is very high. You need to consider this in all phases of design. The last time I considered them, the ON-resistance promised more noise than I could accept in a microphone preamp. It is not a big issue in line-level work. However the resistance variation with voltage, while small, is not clearly specified. You typicially need a LARGE swamping impedance to mask Ron variations and get low THD numbers.
In fact Ron for this heavily-protected part looks higher than I remember on the Harris parts.
Note this TI tip:
"Keep loading impedance as high as possible. This minimizes the resistive loading effects of the source resistance and multiplexer ON resistance. As a guideline, load impedance of 10^8Ω or greater will keep resistive loading errors to 0.002% or less for 1000Ω source impedances. A 10^6Ω load impedance will increase source loading error to 0.2% or more."
They want you to use 100MegΩ load! The error they are discussing isn't what we call distortion: THD will be lower than static DC error. But clearly you want at least 1 Meg.
Ah, TI has good Ron curves. Not very precise: drawn flat/level from -10V to +4.6V, but you can eyeball significant error above +5V. This may not be too important at line-level, and you may not need a super-high load impedance.
These are second-source for a very old Harris Gates part.
The series has been available for about 20 years, so it is probably not going to vanish soon.
These used to cost a heck of a lot more than $8, though I do recall them falling past $25 quite a few years ago.
Voltage handling is very good.
ON-resistance is very high. You need to consider this in all phases of design. The last time I considered them, the ON-resistance promised more noise than I could accept in a microphone preamp. It is not a big issue in line-level work. However the resistance variation with voltage, while small, is not clearly specified. You typicially need a LARGE swamping impedance to mask Ron variations and get low THD numbers.
In fact Ron for this heavily-protected part looks higher than I remember on the Harris parts.
Note this TI tip:
"Keep loading impedance as high as possible. This minimizes the resistive loading effects of the source resistance and multiplexer ON resistance. As a guideline, load impedance of 10^8Ω or greater will keep resistive loading errors to 0.002% or less for 1000Ω source impedances. A 10^6Ω load impedance will increase source loading error to 0.2% or more."
They want you to use 100MegΩ load! The error they are discussing isn't what we call distortion: THD will be lower than static DC error. But clearly you want at least 1 Meg.
Ah, TI has good Ron curves. Not very precise: drawn flat/level from -10V to +4.6V, but you can eyeball significant error above +5V. This may not be too important at line-level, and you may not need a super-high load impedance.
> quick google didn't pin it on Harris.
I don't know that Harris, or Gates, makes them any more.
I think Intersil got the government contract and the tooling.
The original part numbers start DG or ADG.
Google "509 multiplexer" got me these hits:
http://www.intersil.com/products/deviceinfo.asp?pn=DG409
http://www.intersil.com/products/deviceinfo.asp?pn=HI-509
http://www.intersil.com/data/fn/fn3142.pdf
http://www.xs4all.nl/~ganswijk/chipdir/f/mux.htm
I don't know that Harris, or Gates, makes them any more.
I think Intersil got the government contract and the tooling.
The original part numbers start DG or ADG.
Google "509 multiplexer" got me these hits:
http://www.intersil.com/products/deviceinfo.asp?pn=DG409
http://www.intersil.com/products/deviceinfo.asp?pn=HI-509
http://www.intersil.com/data/fn/fn3142.pdf
http://www.xs4all.nl/~ganswijk/chipdir/f/mux.htm
PRR said:ON-resistance is very high. You need to consider this in all phases of design. The last time I considered them, the ON-resistance promised more noise than I could accept in a microphone preamp. It is not a big issue in line-level work. However the resistance variation with voltage, while small, is not clearly specified. You typicially need a LARGE swamping impedance to mask Ron variations and get low THD numbers.
Does this mean that you can't use them to source a power amp ?
Power amps have input impedance more or less around 50k
Having a 1k input source is still a problem ?
I got some sample of the mpc507 and was wondering if someone could answer the last question posted
Thanx
Thanx
Johnix said:
Does this mean that you can't use them to source a power amp ?
Power amps have input impedance more or less around 50k
Having a 1k input source is still a problem ?
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