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11A34: Difference between revisions
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===Analog=== | ===Analog=== | ||
Each input channel has a separate [[119-2000-0x]] attenuator module containing passive 1 megohm attenuators, an AC coupling capacitor, a switch selecting the calibrator or signal input and an [[M474]] buffer amplifier. The calibrator signal is turned off inside the plugin when not in use. | Each input channel has a separate [[119-2000-0x]] attenuator module containing passive 1 megohm attenuators, an AC coupling capacitor, a switch selecting the calibrator or signal input and an [[M474]] buffer amplifier. The calibrator signal is turned off inside the plugin when not in use. | ||
The attenuator module output feeds the + input of the [[M377]] amplifier IC through a (blue) 50 ohm transmission line, one per input channel. The cable lengths set a standard delay per plugin. | The attenuator module output feeds the + input of the [[M377]] amplifier IC through a (blue) 50 ohm transmission line, one per input channel. The cable lengths set a standard delay per plugin. | ||
The M377's - input is connected to the [[ACVS]] (Analog Control Voltage System) output. | The M377's - input is connected to the [[ACVS]] (Analog Control Voltage System) output. | ||
The (differential) display outputs of the four amplifiers are hard-wired in parallel and drive the mainframe’s | The (differential) display outputs of the four amplifiers are hard-wired in parallel and drive the mainframe’s 50 Ω per side input impedance. The same is true of the trigger outputs of the four amplifiers. | ||
50 Ω per side input impedance. The same is true of the trigger outputs of the four amplifiers. | |||
The version of the M377 used in the 11A34 has a 200 Ω output impedance per side so that four of them in parallel | The version of the M377 used in the 11A34 has a 200 Ω output impedance per side so that four of them in parallel create a source impedance of 50 Ω. | ||
create a source impedance of 50 Ω. | |||
Each M377 amplifier's nominal common-mode output voltage is zero whether enabled or not. When not enabled, each M377 | 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. | ||
differential output is exactly zero by design. This fact is used during calibration by the plugin’s firmware to | This fact is used during calibration by the plugin’s firmware to determine the mainframe’s imbalance and compensate for it during normal operation. | ||
determine the mainframe’s imbalance and compensate for it during normal operation. | |||
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 on dedicated pins of the plug-in interface connector: | ||
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The DS1220Y contains a battery with a typical life time of 20-30 years. | The DS1220Y contains a battery with a typical life time of 20-30 years. | ||
There are also two [[ACVS]] (Analog Control Voltage System) sample and hold modules on two daughter boards that generate the analog voltages needed for gain and offset, including error correction | There are also two [[ACVS]] (Analog Control Voltage System) sample and hold modules on two daughter boards that generate the analog voltages needed for gain and offset, including error correction under microcontroller firmware control. | ||
under microcontroller firmware control. | |||
The microcontroller also provides the digital signals sent to the M377 amplifier, setting one of its six fixed gains, one of its three bandwidths, turning on or off its selected output, and each output's + up or invert state. | The microcontroller also provides the digital signals sent to the M377 amplifier, setting one of its six fixed gains, one of its three bandwidths, turning on or off its selected output, and each output's + up or invert state. | ||
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* [[11A-series plug-in NVRAM replacement]] | * [[11A-series plug-in NVRAM replacement]] | ||
* [http://www.barrytech.com/tektronix/tek11000/tek11a34.html Tek 11A34 @ barrytech.com] | * [http://www.barrytech.com/tektronix/tek11000/tek11a34.html Tek 11A34 @ barrytech.com] | ||
{{Documents|Link=11A34}} | |||
==Pictures== | ==Pictures== | ||