User Manual

TMCM-1310 V1.2 Hardware Manual (Rev. 1.12 / 2013-JUL-05) 16
www.trinamic.com
3.5.2 Reference Switch Inputs
The reference switch connector provides two reference/limit switch inputs, REF_L and REF_R. Both inputs
offer the same input circuit including voltage resistor dividers, limiting diodes against over- and under-
voltage, and programmable 1k pull-ups to +5V. The programmable pull-ups can be switched on or off in
software (both together).
+3.3V
REF_L
REF_R
10k
22k
1nF
GND
GND GND
1k
+5V
microcontroller
Figure 3.4 Reference switch input circuit (simplified diagram)
3.5.3 General Purpose Inputs
The TMCM-1310 has two I/O connectors with 8 inputs altogether including two dedicated analog inputs.
All inputs offer the same basic input protection circuit, but digital and analog inputs have different input
voltages: the digital inputs have been designed for +5V and +24V signal levels. The analog inputs have
different input voltage dividers in order to support a full scale input voltage range of 0… +10V.
+3.3V
IN_1
IN_2
IN_3
IN_5
IN_6
IN_7
microcontroller
10k
22k
1nF
GND
GND GND
Figure 3.5 General purpose digital input circuit
+3.3V
AIN_0
AIN_4
microcontroller
22k
10k
1nF
GND
GND GND
Figure 3.6 General purpose analog input circuit
The function of the inputs might differ depending on the firmware version.