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Tutorial
Pulse Waveform Generation
To eliminate distortion due to aliasing at higher frequencies, the Keysight 33210A
also uses a different waveform generation technique to create pulse waveforms.
For pulse waveform generation, clock cycles are counted to derive both the period
and the pulse width. To achieve fine period resolution, the clock frequency is
varied from 95 to 100 MHz by a phase lock loop (PLL) circuit (which also multiplies
the incoming frequency from the DDS by five). The rising and falling edge times
are controlled by a circuit that varies the charging currents in a capacitor. Period,
pulse width, and edge time are controlled independently, within certain limits. The
pulse waveform generation circuitry is represented in the following block diagram.
From DDS
Phase
Lock
Loop
(x5)
Pulse Waveform Generation Circuitry
350
Period
Counter
95 - 100 MHz
Load
Width
Counter
Load
Leading Edge
Set
Clear
Flip/Flop
Trailing Edge
Edge Time
Circuit
Keysight 33210A User's Guide
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