[sdiy] Matched transistors - critical parameters?

[Dave Manley]

On 2/8/2012 11:17 AM, ASSI wrote:
> On Wednesday 08 February 2012, 09:05:50, Matthew Smith wrote:
>> The DMMT5551 (and DMMT5401 for PNP) from Diodes Inc., are "intrinsically
>> matched," which is explained as being built on adjacent dies from a
>> single wafer.
>
> This might be a marketing term for "we have no reason to believe otherwise,
> but we don't bother to actually measure it".  Check the datasheet for what
> they _guarantee_ for the matching (I'd be very surprised if Vbe matching was
> guaranteed to be better than about 10mV, for instance).  Actual measurements
> of matching properties are rather expensive since they take time.

http://www.diodes.com/datasheets/ds30436.pdf:

"8.   The DC Current Gain, hFE, (matched at IC = 10mA and VCE = 5V) 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%."