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11A34 (view source)

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Option 23 added four [[P6134]] probes.
Option 23 added four [[P6134]] probes.


There is also a later version, the 11A34V introduced in 1991, for video applications.  
There is also a version for video applications, the 11A34V, that was introduced in 1991
Development of the 11A34V was managed by [[Murlan Kaufman]]. (See also [[11T5H]].) ''more Information needed''  
(see also [[11T5H]]). Development of the 11A34V was managed by [[Murlan Kaufman]].
: ''more information about 11A34V needed''


The 11A34 and the [[11A32]] use exactly the same firmware.
{{BeginSpecs}}
Each of the 11A34’s four channels has its own M377 amplifier.  
{{Spec | Bandwidth | DC to 300 MHz, 100 MHz and 20 MHz BWL filters may be selected.}}
The display outputs of the four amplifiers are hard wired in parallel and drive the mainframe’s 50 Ω input impedance.  
{{Spec | Rise time | 1.2 ns in 1 GHz mainframe such as the [[11402]], [[11402|11402A]], [[11403]], [[11403|11403A]], [[DSA600|DSA601A]], or [[DSA600|DSA602A]] }}
The same is true of the trigger outputs of the four amplifiers.  
{{Spec | Deflection | 1 mV to 10 V/div 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}}
 
==Links==
* [[11A-series plug-in NVRAM replacement]]
* [http://www.barrytech.com/tektronix/tek11000/tek11a34.html Tek 11A34 @ barrytech.com]
 
==Internals==
===Analog===
Each channel's attenuator module contains an [[M474]] buffer amplifier.
Each of the attenuator modules drives an [[M377]] amplifier IC, one per input channel.
 
The display outputs of the four amplifiers are hard-wired in parallel and drive the mainframe’s  
50 Ω input impedance. The same is true of the trigger outputs of the four amplifiers.
The version of the M377 used in the 11A34 has 200 Ω output impedance so that four of them in parallel create a source impedance of 50 Ω.
The version of the M377 used in the 11A34 has 200 Ω output impedance so that four 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 the block diagram below.
Each of the four channels has its own AUX output on dedicated pins of the plug-in interface connector:


Each of the four channels has its own AUX output that is sent across the plug-in interface connector.
{| class="wikitable" style="margin:auto"
{| class="wikitable" style="margin:auto"
|+ 11A34 AUX Signals and their pin numbers on the plug-in connector
|-
|-
! signal name !! positive pin number !! negative pin number
! signal name !! positive pin number !! negative pin number
Line 50: Line 67:
| AUX 4 || A32 || A31
| AUX 4 || A32 || A31
|}
|}
The AUX signals emerge from each M377 amplifier as 200 Ω source impedance.
An external 66.5 Ω shunt resistor on each AUX output (on the circuit board)
brings this down to the 50 Ω source impedance specified by the 11k plug-in interface.


{{BeginSpecs}}
See also the block diagram below.
{{Spec | Bandwidth | DC to 300 MHz, 100 MHz and 20 MHz BWL filters may be selected.}}
{{Spec | Rise time | 1.2 ns in 1 GHz mainframe such as the [[11402]], [[11402|11402A]]. [[11403]], [[11403|11403A]], [[DSA600|DSA601A]], or [[DSA600|DSA602A]] }}
{{Spec | Deflection | 1 mV to 10 V/div in 1% calibrated steps}}
{{Spec | Input impedance | 50 Ω or 1 MΩ }}
{{Spec | Features |
* High-Resolution Calibrated DC Offset
* Fast Overdrive Recovery
* 50 Ω mode: 5 V RMS overload protected with manual reset
}}
{{EndSpecs}}
 
==Links==
* [[11A-series plug-in NVRAM replacement]]
* [http://www.barrytech.com/tektronix/tek11000/tek11a34.html Tek 11A34 @ barrytech.com]


==Internals==
===Digital===
Each channel's attenuator module contains an [[M474]] buffer amplifier.
The 11A34 and the [[11A32]] use exactly the same firmware.
Each of the attenuator modules drives an [[M377]] amplifier IC.


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 on-chip  
[[Doug Haines]] found an alternate supplier of 8051-compatible chips (OKI Semiconductor) that offered a 16Kbyte on-chip ROM,  
ROM size. [[Doug Haines]] found an alternate supplier of 8051-compatible chips (OKI Semiconductor)
and that's what the plug-ins wound up with. The finished code size wound up at about 14 KB.
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 11A34 contains two [[ACVS]] sample and hold modules.


The AUX signals emerge from each M377 amplifier as 200 Ω source impedance.
The 11A34 contains two [[ACVS]] modules to generate the analog control voltages needed for gain/offset control etc.
A external (on the board) 66.5 ohm shunt resistor on each AUX output forms the 50 Ω source impedance
specified by the 11k plug-in interface.


==Pictures==
==Pictures==
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