Datasheet

Product Data Sheet RER175-42/18/2TDMP

02/01/2019 page 7 of 13

3.3 Electrical Interface - Output

Tacho type /2 (open collector)

Features Note Values

Tacho operating voltage U

<= 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) / 60 480 Hz @ 4.800 1/min

Tacho isolated from motor No

Slew rate => 0,5 V/us

n = revolutions per minute (1/min)

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.

3.4 Electrical Features

Electronic function Speed-Controlled

Reversed polarity protection P-CH FET

Max. residual current at U

<= 5 mA