Add circuit implementation label to AFE documentation

Added a section on circuit implementation to the AFE documentation.

Author: MarcoVogt

docs/source/afe.rst

@@ -21,6 +21,8 @@ A typical analog read-out chain - also called analog front-end - for a semicondu
 
     Generic read-out chain for a semiconductor detector: charge sensitive amplifier (CSA), pulse shaping amplifier (SHA), and comparator (COMP). Shown are typical signal waveforms between the blocks and the parameters that can be controlled for each block.
 
+.. _circuit-implementation:
+
 Circuit Implementation
 ======================
 The simplified schematic in the figure below shows the implementation of the signal processing chain on the AFE board.
@@ -214,4 +216,4 @@ The in-lab exercises (Exercises 1-3) are grouped into three section. In the firs
 
   #. Acquire s-curves for different shaping time constants. What is the effect of the shaping time on the noise? (Do not connect a sensor diode to the CSA during this step, as we just want characterize the AFE circuit in isolation.)
   #. Now connect a sensor diode to the CSA and apply 20 V bias voltage. Repeat the s-curves measurements. What happens if you lower the bias voltage? What is the effect of the detector capacitance on the noise performance?
-  #. Connect various test capacitors instead of the sensor diode and plot the noise vs. input capacitance. Repeat the measurements for different shaping time constants.
+  #. Connect various test capacitors instead of the sensor diode and plot the noise vs. input capacitance. Repeat the measurements for different shaping time constants.