33,118
edits
155-0078-00: Difference between revisions
Jump to navigation
Jump to search
no edit summary
mNo edit summary |
No edit summary |
||
| Line 41: | Line 41: | ||
The M84 also comes in 14-pin DIP, as 155-0273-00 and 155-0274-00 (slower grade). | The M84 also comes in 14-pin DIP, as 155-0273-00 and 155-0274-00 (slower grade). | ||
Regarding the various grades of M84, John Addis says: | |||
<blockquote> | |||
There are several DC specs which differ with part suffix. | |||
Suffixes -10, -11, -12 and -13 were used with the redesigned M84, known as the M705. | |||
The M705 was necessary because the original SH2 (2-2.5GHz?) process was being discontinued. | |||
The M705 was designed by Hal Lilliwhite using the faster SH3 process (6-7GHz). | |||
Additionally, the M705 apparently had the gain setting resistor laser trimmed at the wafer level. | |||
The M705 was designed in late 1989 and tested in early 1990. | |||
There are two test fixtures and every M84 was subjected to all tests on each test fixture, and all tests were done manually. | |||
I designed both test fixtures and the 25ps PPPG. | |||
Transient Response (schematic not shown) uses 25ps Push Pull Pulse Generator (PPPG) and a sampling scope. | |||
Sampler load supplies dc current (through X2 pads and sampler input resistance. | |||
The sampling scope chassis is floating at (probably) +5V through 8.2 ohms. | |||
25ps PPPG has transformer coupled trigger output to sampling scope trigger input. | |||
DC test fixture: | |||
I have attached a schematic of a dc test fixture for manufacturing. | |||
It looks like this fixture only tests for V_hump. | |||
There may have been another test fixture for the other dc tests. | |||
Those tests may have been done on a system. | |||
The V_hump test may have been so difficult to perform on an automated system that it needed this extra fixture. | |||
V_hump is the amount of maximum dc imbalance, probably referred to the input, which occurs when the variable gain function is swept from full invert to full normal. | |||
I think that the two ends of the curve are set to the same dc output level. | |||
Ideally, there is no change in dc level under these conditions, but various imbalances in the M84 output devices result in a hump for inverted gain and a hump for the normal gain. | |||
Only the -00, -04 and -10 suffixed parts were required to pass this stringent V_hump test. | |||
The fixture was in a rubber footed metal chassis about 4” high 5” deep, and 7” wide. | |||
</blockquote> | |||
* [[Media:Tek m84.pdf|Tektronix M84 155-0078-00 Description (PDF)]] | * [[Media:Tek m84.pdf|Tektronix M84 155-0078-00 Description (PDF)]] | ||