xe88lc05 ETC-unknow, xe88lc05 Datasheet - Page 28

• Manufacturer Part Number: xe88lc05
• Description: 16 10 Bit Data Acquisition Ultra Low-power Microcontroller
• Manufacturer: ETC-unknow

Data Acquisition Microcontroller
XE88LC05
Typical output noise of ZoomingADC preamplifiers
8.11 Gain Error and Offset Error
28
Figure 8.17:
Where V
As one can see on the figures above, increase the gain of the first amplifier lowers the output
noise for constant global gain. It also lowers sensitivity to temperature drift as offset is better
compensated on first amplifier.
Gain error is defined as the amount of deviation between the ideal transfer function and the
measured transfer function (with the offset error removed). The left figure shows gain error vs.
temperature for different PGA gains. The curves are expressed in% of Full-Scale Range (FSR)
normalized to 25°C .
Offset error is defined as the output code error for a zero volt input (ideally, output code = 0).
The measured offset errors vs. temperature curves for different PGA gains are depicted in the
right figure below. The output offset error, expressed in (LSB), is normalized to 25°C .
Noise measured at the output of the ZoomingADC
Amplifier
PGA1
PGA2
PGA3
n,outx
ADC only
PGA1: 10
PGA2: 10
PGA3: off
PGA1: 1
PGA2: 10
PGA3: off
is the rms output noise of amplifier x.
Symbol
V
V
V
n,out1
n,out2
n,out3
Typical output noise
per over-sample
205
340
365
uVrms
uVrms
uVrms
Unit
PGA1: 1
PGA2: 10
PGA3: 10
PGA1: off
PGA2: 1
PGA3: 10
D0109-40