Lesson 1 – Analog Modules
92
3GHz Sampler
The 3GHz Sampler (software identifier: SPB) can be used to
capture single-ended or differential repetitive waveforms up to
3 GHz with 12-bit resolution.
The 3GHz Sampler module has two identical samplers (called
sampler cores) that share the trigger/timing system and sequencer.
As shown in the following figure, the SYNC CLK pin (which is the
trigger input pin), the timing generator, and sequencer are shared
between its two sampler cores. The two sampler cores can capture
two single-ended or two differential waveforms simultaneously
with the common sampling rate, common sampling-timing, and
common sequencer program.
The one specified sampler core only can also be triggered.
3GHz Sampler (SPB) (Single-ended input routes shown with bold lines)
The two sampler cores in the module can capture two waveforms
with a very tight timing skew: around ±100 ps when the same
input range and the same normal/high-precision mode are used in
both sampler cores. To do this, on the DUT board, connect
between the sampler input pogo pads and the DUT output pins by
using coaxial cables (or printed circuit patterns) that have 50 ohm
characteristic-impedance and the same electrical length.
The 3GHz Sampler (SPB) is a single-slot analog module installed in
the testhead.
In the 3GHz Sampler, the single-ended signal or differential signal
can be captured from the pins shown in the following table.
Max. Input Frequency Resolution Sampling Rate Waveform Memory
3 GHz 12 bits 100 ksps to 10 Msps 1 M samples (per sampler core)
Input Multiplexer
CCLK Stop Seq Start
Conversion Clock (CCLK)
Core 1
Waveform
Memory
Sequencer
50
1k
ADC
S/H
Amp
50 S/H
Amp
Pogo Pin
A+ (16/Mode1)
B+ (14/Mode2)
DGND
SYNC CLK (04)
SYNC DATA (03)
C+ (12/Mode3)
D+ (10/Mode4)
AGND
(GND for SYNC CLK)
1k
AGND
Input
Amp
Master Clock
Timing
Generator
CCLK
CCLK
Input Multiplexer
Offset DAC
Offset DAC
Core 2
Waveform
Memory
50
1k
ADC
S/H
Amp
50 S/H
Amp
1k
Input
Amp
CCLK
CCLK
Offset DAC
Offset DAC
(C–)
(A–)