155-0032-00: Difference between revisions
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{{Monolithic IC | {{Monolithic IC | ||
|Manufacturer=Tektronix | |Manufacturer=Tektronix | ||
|Model= | |Model=M55 | ||
|Part_nos=155-0032-00,155-0032-01 | |Part_nos=155-0032-00,155-0032-01 | ||
|Description= | |Description=variable-gain transconductance amplifier | ||
|Used_in=335;464;465;465B;466;475;475A;475M;634;650;651;652;653;655;656;670;671;7A12;475;FG504;1440;1460;1480;1481;1482;1485 | |Used_in=335;464;465;465B;466;475;475A;475M;634;650;651;652;653;655;656;670;671;7A12;475;FG504;1440;1460;1480;1481;1482;1485 | ||
|Designers=Roy Hayes | |Designers=Roy Hayes;Einar Traa | ||
}} in a 16-pin DIP, designed by [[Roy Hayes]]. | }} in a 16-pin DIP, designed by [[Roy Hayes]]. The [[155-0216-00]] and [[155-0217-00]] (M55D aka M055D) appear to be improved successor versions. | ||
Regarding the 155-0032-xx, [[John Addis]] says, | Regarding the 155-0032-xx, [[John Addis]] says, | ||
<blockquote> | <blockquote> | ||
The 155-0032-00’s IC process had an FT of 1.0 or 1.2 GHz (don’t remember), rather inadequate for the job. | |||
The on-chip resistors were diffused and thus had too poor a TC and tolerance for use as gain-setting resistors. | The on-chip resistors were diffused and thus had too poor a TC and tolerance for use as gain-setting resistors. | ||
As you can see, there are two separate gain selections determined by which set of emitters is chosen, pins 1 and 16 or 2 and 15. | As you can see, there are two separate gain selections determined by which set of emitters is chosen, pins 1 and 16 or 2 and 15. | ||
This selection is made off chip by choosing Q205 or Q215 to carry the current through R212. | This selection is made off chip by choosing Q205 or Q215 to carry the current through R212. | ||
Pot R217 allows dc balance at 5 mV/div to match that at all other sensitivities, controlled elsewhere. | Pot R217 allows dc balance at 5 mV/div to match that at all other sensitivities, controlled elsewhere. | ||
Pin 12 ultimately selects which pair of the four output cross-connected transistors passes | Pin 12 ultimately selects which pair of the four output cross-connected transistors passes | ||
the signal current from the two transistors whose bases are connected to pin 4. | the signal current from the two transistors whose bases are connected to pin 4. | ||
Which pair of output transistors is chosen determines the polarity of the output signal. | Which pair of output transistors is chosen determines the polarity of the output signal. | ||
This same pair of transistors also enables variable gain by allowing | This same pair of transistors also enables variable gain by allowing a controlled amount of cross-coupling of the signal. | ||
a controlled amount of cross-coupling of the signal. | |||
This is an undesirable way of doing variable gain control, but neither Roy nor I knew that at the time. | This is an undesirable way of doing variable gain control, but neither Roy nor I knew that at the time. | ||
It is a noisy configuration. At the 0% signal gain there is lots of noise gain. | It is a noisy configuration. At the 0% signal gain there is lots of noise gain. | ||
It has poor thermal balance at anything other than 100% and the not very useful 0% signal gain. | It has poor thermal balance at anything other than 100% and the not very useful 0% signal gain. | ||
In between 0% and 100% gain, the circuit is poor in noise and thermal balance. | In between 0% and 100% gain, the circuit is poor in noise and thermal balance. | ||
I went on to use the same (Gilbert Multiplier) circuit in the [[155-0078-00|155-0078-xx (M84)]] and | |||
made the same bad choice again in the [[7A29]]. | I went on to use the same (Gilbert Multiplier) circuit in the [[155-0078-00|155-0078-xx (M84)]] and made the same bad choice again in the [[7A29]]. | ||
In our defense, with just two stages and the need to do both invert and variable gain control somewhere, there was not a lot of choice. | In our defense, with just two stages and the need to do both invert and variable gain control somewhere, there was not a lot of choice. | ||
It was not until I designed the [[M377]] for the 11000 series of plugins ([[11A32]], [[11A33]], [[11A34]], [[11A52]]) that I finally got it right. | It was not until I designed the [[M377]] for the 11000 series of plugins ([[11A32]], [[11A33]], [[11A34]], [[11A52]]) that I finally got it right. | ||
(See the British magazine Electronic Engineering, September, 1988, pp 40-41.) | (See the British magazine Electronic Engineering, September, 1988, pp 40-41.) | ||
The M377 was a single channel plugin on a chip with 0 V common mode input and output voltages, | The M377 was a single channel plugin on a chip with 0 V common mode input and output voltages, | ||
excellent variable gain control, two four pole bandwidth limits, | excellent variable gain control, two four pole bandwidth limits, three outputs which could be separately inverted and turned on or off. | ||
three outputs which could be separately inverted and turned on or off. | |||
It was the first wideband analog IC with level shift on chip (allowing 0 V common mode input and output and without PNP transistors), | It was the first wideband analog IC with level shift on chip (allowing 0 V common mode input and output and without PNP transistors), | ||
first wideband amplifier with any on-chip bandwidth limit selection, first to have more than two fixed gain settings (it has six), | first wideband amplifier with any on-chip bandwidth limit selection, first to have more than two fixed gain settings (it has six), | ||
and first to require only one transient response adjustment (no thermals), | and first to require only one transient response adjustment (no thermals), and the first to have a highly linear relationship | ||
and the first to have a highly linear relationship between a control voltage and gain. | between a control voltage and gain. It also had excellent overdrive recovery. Live and learn. | ||
It also had excellent overdrive recovery. Live and learn. | |||
</blockquote> | </blockquote> | ||
| Line 61: | Line 51: | ||
* pin 3: input balance | * pin 3: input balance | ||
* pin 4: bias | * pin 4: bias | ||
* pin 5: | * pin 5: −8 V | ||
* pin 6: position current source | * pin 6: position current source | ||
* pin 7: ground | * pin 7: ground | ||
| Line 67: | Line 57: | ||
* pin 9: signal out + | * pin 9: signal out + | ||
* pin 10: position | * pin 10: position | ||
* pin 11: + | * pin 11: +8 V | ||
* pin 12: norm / -inv | * pin 12: norm / -inv | ||
* pin 13: + | * pin 13: +5 V | ||
* pin 14: signal in − | * pin 14: signal in − | ||
* pin 15: gain switching | * pin 15: gain switching | ||
| Line 84: | Line 74: | ||
* [[464]], [[465]], [[465B]], [[466]], [[475]], [[475A]], [[475M]] | * [[464]], [[465]], [[465B]], [[466]], [[475]], [[475A]], [[475M]] | ||
* [[634]], [[650]], [[651]], [[652]], [[653]], [[655]], [[656]], [[670]], [[671]] | * [[634]], [[650]], [[651]], [[652]], [[653]], [[655]], [[656]], [[670]], [[671]] | ||
* See also [[155-0217-00]] | |||
==Datasheet== | ==Datasheet== | ||
| Line 90: | Line 81: | ||
==Diagrams== | ==Diagrams== | ||
<gallery> | <gallery> | ||
Tek 155-0032-01 1.jpg|155-0032-01 | Tek 155-0032-01 1.jpg | 155-0032-01 | ||
Tek 155-0032-01 2.jpg|155-0032-01 | Tek 155-0032-01 2.jpg | 155-0032-01 | ||
Tek 155-0032-01 3.jpg|155-0032-01 | Tek 155-0032-01 3.jpg | 155-0032-01 | ||
155-0032-00.png|Block diagram | 155-0032-00.png | Block diagram | ||
155-0032-XX in 7A12.jpg|155-0032-00 schematic shown in the 7A12 schematic | 155-0032-XX in 7A12.jpg | 155-0032-00 schematic shown in the 7A12 schematic | ||
Comparison of 155-0032-00 155-0216-00 155-0217-00 diagrams.png | Comparison of 155-0032-00, 155-0216-00, and 155-0217-00 diagrams | |||
</gallery> | </gallery> | ||
[[Category:Tektronix-made monolithic integrated circuits]] | [[Category:Tektronix-made monolithic integrated circuits]] | ||