Datasheet

Product Data Sheet RER175-42/14/2TDMLP
02/01/2019 page 7 of 14
3.3 Electrical Interface - Output
Tacho type /2 (open collector)
Please note:
At zero speed the tacho signal is at a static HIGH. It will be also HIGH when the fan is still spinning, but the speed
control signal is set to zero speed already.
The tacho signal is only activated after the start-up is completed.
Features Note Values
Tacho operating voltage U
BS
<= 60,0 V
Tacho signal Low U
S low
I sink: 2 mA <=0,4 V
Tacho signal High U
S high
I source: 0 mA <=60,0 V
Maximum sink current I
sink
<= 20 mA
External resistor
External resistor Ra from UBS to US required. All voltages measured
to GND.
Tacho frequency (6 x n) / 60 340 Hz
Tacho isolated from motor No
Slew rate => 0,5 V/us
n = revolutions per minute (1/min)
Note to the tacho-frequency: (6 Pulse per revolution!)
3.4 Electrical Features
Electronic function Speed-Controlled
Reversed polarity protection Rectifying diode