Print version of this Book (PDF file)
Pulse Generators
This section describes the HP 8130 and the HP 8131 pulse generators.
HP 8130 Pulse Generator
The HP 8130 is a programmable pulse generator controllable by IC-CAP. It provides excellent features for time-domain characterization using pulse stimuli. The following pulse characteristics are programmable:
| • | Period, Width, and Delay |
| • | Risetime and Falltime |
| • | Initial and Pulsed Voltage Levels |
IC-CAP assigns the following name to the channel 1 output unit:
| • | PULSE1 |
The HP 8130 offers a fixed source impedance of 50 ohms. Pulse period can be varied from 3 nsec to 99.9 msec. Rise and falltimes can be varied from 670 psec to 100 
sec. The output voltage range is from -5.2 to +5.2V, but the maximum voltage swing must be less than or equal to 5.2V. A complementary output signal is available (refer to the following table).
A Setup configured for measurements using the HP 8130, along with HP 54120 Series digitizing oscilloscopes is in the model file 54120.demo.mdl. Additional information about this demonstration file is available in Appendix G, "54120 Demo." These files also include examples using an HP 54120 Series oscilloscope with no pulse generator, or with a manually controlled pulse generator. The "54120 Demo" also provides hints for obtaining good alignment between measured and simulated waveforms.
The following table describes the HP 8131 options and their default values, where applicable.
Width at Top
Flag provided to aid simulator compatibility. The HP 8130 defines pulse width to include the top section of the pulse plus one-half of the rising and falling edges. SPICE defines pulse width to include the top of the pulse only. For compatibility with SPICE, set this option to Yes (the 8130 pulse will become wider). Default = No
Enable Comp Out
If Yes, complementary data can be obtained by cabling to the complementary output connector on the HP 8130. Default = No
Pulse Delay Offset
The HP 8130 has a delay between its trigger output and signal output (SPICE has nothing like this). The value is added to the TDR or PULSE sweep Delay value. Positive values will shift the waveform to the right; negative values will shift the waveform to the left. This option permits one to align the simulated and measured waveforms. The option may need adjustment if the period is changed. Additional hints about the use of this option are provided in Appendix G, "54120 Demo," in the section Aligning Data. Default = 0
Init Command
Command field to set the instrument to a mode not supported by the option table. This command is sent at the end of instrument initialization for each measurement. Normal C escape characters such as \n (new line) are available. Default = none
HP 8131 Pulse Generator
The HP 8131 is a programmable pulse generator controllable by IC-CAP. It provides excellent features for time-domain characterization using pulse stimuli. The following pulse characteristics are programmable:
| • | Period, Width, and Delay |
| • | Initial and Pulsed Voltage Levels |
IC-CAP assigns the following name to the channel 1 output unit:
The HP 8131 offers a fixed source impedance of 50 ohms. Pulse period can be varied from 2 nsec to 99.9 msec. Rise and fall times are fixed <200 psec; if >200 psec, IC-CAP will issue a warning PULSE1 Rise/Fall time fixed at less than 200ps.
The output voltage range is from -5.0 to +5.0V; the maximum voltage swing must be less than or equal to 5.0V. The offset voltage is from -4.95V to +4.95V. A complementary output signal is available (refer to the following table).
A Setup configured for measurements using the HP 8131, along with HP 54120 Series digitizing oscilloscopes is in the model file 54120.demo.mdl. Additional information about this demonstration file is available Appendix G, "54120 Demo." These files also include examples using a HP 54120 Series oscilloscope without a pulse generator, or with a manually controlled pulse generator. The "54120 Demo" also provides hints for obtaining good alignment between measured and simulated waveforms.
The following table describes the HP 8131 options and their default values, where applicable.
Width at Top
Flag provided to aid compatibility with SPICE and other simulators. The HP 8131 defines pulse width to include the top section of the pulse plus one-half of the rising and falling edges. SPICE defines pulse width to include only the top of the pulse; as a result, SPICE pulses are wider. For SPICE compatibility, set this option to Yes. Default = No
Enable Comp Out
If Yes, complementary data can be obtained by cabling to the complementary output connector on the HP 8131. Default = No
Pulse Delay Offset
The HP 8131 has a delay between its trigger output and signal output (SPICE does not). The value is added to the TDR or PULSE sweep Delay value. Positive values will shift the waveform to the right; negative values will shift the waveform to the left. This option permits alignment of simulated and measured waveforms. The option may need adjustment if the period is changed. Additional hints about the use of this option are provided in Appendix G, "54120 Demo," in the section Aligning Data. Default = 0
Init Command
Command field to set the instrument to a mode not supported by the option table. This command is sent at the end of instrument initialization for each measurement. Normal C escape characters such as \n (new line) are available. Default = none