36,756
edits
No edit summary |
(Removed some redundancies) |
||
Line 17: | Line 17: | ||
}} | }} | ||
The '''Tektronix 11A32''' is a 400 MHz dual-channel amplifier plug-in for [[11000-series scopes]]. | The '''Tektronix 11A32''' is a 400 MHz dual-channel amplifier plug-in for [[11000-series scopes]]. | ||
{{BeginSpecs}} | |||
{{Spec | Bandwidth | DC to 400 MHz; 100 MHz and 20 MHz BWL filters }} | |||
{{Spec | Rise time | 875 ps in 1 GHz mainframes such as the [[11402]], [[11402|11402A]], [[11403]], [[11403|11403A]], [[DSA600|DSA601A]], or [[DSA600|DSA602A]]}} | |||
{{Spec | Deflection | 1 mV to 10 V per division in 1% calibrated steps}} | |||
{{Spec | Input impedance | 50 Ω or 1 MΩ }} | |||
{{Spec | Features | | |||
* High-resolution calibrated DC offset | |||
* Fast overdrive recovery | |||
* 5 V<sub>RMS</sub> overload protection in 50 Ω mode, with manual reset | |||
}} | |||
{{EndSpecs}} | |||
==Internals== | |||
===Analog=== | |||
Each input channel has a separate attenuator modules containing an [[M474]] buffer amplifier, | |||
feeding an [[M377]] amplifier IC, one per input channel. | |||
The display outputs of the two M377s are hard-wired in parallel and drive the mainframe’s | |||
The display outputs of the two | 50 Ω input impedance. The same is true of the trigger outputs of the two amplifiers. | ||
The same is true of the trigger outputs of the two amplifiers. | |||
The version of the M377 used in the 11A32 has 100 Ω output impedance so that two of them in parallel create a source impedance of 50 Ω. | The version of the M377 used in the 11A32 has 100 Ω output impedance so that two of them in parallel create a source impedance of 50 Ω. | ||
Each M377 amplifier's nominal common-mode output voltage is zero whether enabled or not. | Each M377 amplifier's nominal common-mode output voltage is zero whether enabled or not. | ||
When not enabled each M377 differential output is exactly zero by design. | When not enabled, each M377 differential output is exactly zero by design. | ||
This fact is used during calibration by the plugin’s firmware to determine the mainframe’s imbalance and compensate for it during normal operation. | This fact is used during calibration by the plugin’s firmware to determine the mainframe’s imbalance and compensate for it during normal operation. | ||
See also the block diagram below. | |||
===Digital=== | |||
The 11A32 and the [[11A34]] use exactly the same firmware. | |||
The 11A32 and [[11A34]] were originally intended to use [[Intel 8052]] microcontrollers. | The 11A32 and [[11A34]] were originally intended to use [[Intel 8052]] microcontrollers. | ||
However, during development, the firmware swelled beyond that chip's 8192-byte maximum on-chip ROM size. | However, during development, the firmware swelled beyond that chip's 8192-byte maximum | ||
[[Doug Haines]] found an alternate supplier of 8051-compatible chips (OKI Semiconductor) that offered a 16Kbyte on-chip ROM, | on-chip ROM size. [[Doug Haines]] found an alternate supplier of 8051-compatible chips | ||
and that's what the plug-ins wound up with. The finished code size wound up at about 14 KB. | (OKI Semiconductor) that offered a 16Kbyte on-chip ROM, and that's what the plug-ins | ||
wound up with. The finished code size wound up at about 14 KB. | |||
The 11A32 also contains a DS1120 NVRAM and an [[ACVS]] | The 11A32 also contains a DS1120 NVRAM and an [[ACVS]] module that generates the analog control voltages needed for gain/offset control etc. | ||
==Links== | ==Links== |