[sdiy] LM394 vs MAT-02

[Ian Fritz]

At 08:49 PM 11/17/05, ryan williams wrote:
>Ian Fritz wrote:
>  > Um, what exactly is matched to 2?  Thanks.
>
>"The DC current gain, hFE, (matched at IC = 10mA and VCE = 1.0V) Collector 
>Emitter Saturation Voltage, VCE(SAT), and Base
>Emitter Saturation Voltage, VBE(SAT) are matched with typical matched 
>tolerances of 1% and maximum of 2%."
  Very interesting, thanks.  I don't understand why they use these 
saturated parameters, or how they correlate with parameters we usually 
match for (e.g., Vbe @ .1 mA).  But I have found that good hFE matching 
tends to correlate well with Vbe matching (not guaranteed, though).  Using 
these devices is probably more convenient than hand picking matched 
discrete devices, and the thermal coupling is also probably significantly 
better than glueing discrete devices together.  That being said, monolithic 
pairs are preferable.  Inexpensive PNP pairs are getting pretty hard to 
find, but Japanese NPN's are still available.  The MAT's are still the best 
where close matching is crucial, since you would need to deselect many 
inexpensive pairs to get to the same level of matching.

   Ian