User guide

E-M-HC2 Probes-V1_26
Rotronic AG
Bassersdorf, Switzerland
Document code Unit
HygroClip 2 (HC2) Humidity Temperature
Probes: User Guide
Instruction Manual
Document Type
Page
21 of 31
Document title
© 2009-2013; Rotronic AG E-M-HC2 Probes-V1_26
7.2.1 Minimum load requirements for the probe voltage outputs
The following requirements apply to any external device or circuit connected to the probe voltage outputs:
In the situation where the external device uses an internal pull-up resistor the value of this resistor should
meet the requirements shown below. It is also necessary to add a pull-down resistor RL connected to ground
in order to be able to read 100% of the range of the probe voltage output.
HFC2 output signal Input resistance RL
0…1V >=1kOhm
HC2 signal
V
CC R pull-up RL
0…1V 3.3V ≥ 250 kOhm 1 kOhm
HC2 signal
V
CC R pull-up RL
0…1V 5.0V ≥ 400 kOhm 1 kOhm
HC2 signal
V
CC R pull-up RL
0…1V 10.0V ≥ 1 MOhm 1 kOhm
RL
GND
HC2
Voltage Output
R Pull-up
RL
GND
VCC
HC2
Voltage Output