Tech Papers
New Amplifier Designs Improve In-Position Stability
POSTED 12/18/2018
A new drive rack, the XR3, was recently released to work with Aerotech’s industry-leading A3200 software-based machine controller. The XR3 includes completely redesigned amplifiers: the XSP3, a pulse-width modulated (PWM) amplifier, and the XSL3, a linear amplifier.
Figure 1. Aerotech XR3 3U, 19” Drive Rack.
The Performance Test
Both amplifiers were performance tested on an Aerotech ABL1500 air-bearing direct-drive linear stage. The in-position stability was measured using the integral encoder feedback signal when commanding the stage to hold position. New and previous generation PWM and linear amplifiers (4 total devices) were tested.
The ABL1500 stage includes a 1 Vpp amplified sine-wave encoder with a 4 μm encoder scale pitch. The stage is driven by Aerotech’s BLMC series brushless linear motor. The stage was mounted to granite, which sat on a passive air isolation system, supported by a steel weldment.
Figure 2. Aerotech’s ABL1500 Air-Bearing Direct-Drive Linear Stage.
Testing Results
Both the XSP3 and the XSL3 far surpass previous generations of Aerotech drives in amplifier performance. The XSP3 amplifier outperformed the previous generation DP32010e amplifier when measuring in-position noise. The XSP3 measures 1.5 nm of in-position noise while the DP32010e measured 4.8 nm. An interesting note is that the previous generation linear amplifier, the DL4010, measured 2.8 nm of in-position noise in the ABL1500 test. This puts Aerotech’s latest PWM amplifier at nearly 2X superior performance than the previous generation linear amplifier. The final test was Aerotech’s new XSL3 linear amplifier. This new amplifier measured 0.7 nm of in-position noise, outperforming the DL4010 by a factor of 4.
Table 1. In-position noise test results. Lines in bold indicate Aerotech’s new drive technology.
Amplifier |
In-Position Noise |
XSL3 Linear Amplifier |
0.7 nm |
XSP3 PWM Amplifier |
1.5 nm |
DL4010 Linear Amplifier |
2.8 nm |
DP32010e PWM Amplifier |
4.5 nm |
Figure 3. Aerotech’s new amplifiers for the XR3 drive rack – the XSP3 PWM amplifier and the XSL3 linear amplifier.
In addition to the improved in-position reading, the XSL3 is also able to dissipate six times the peak power versus the DL4010.