Pump Rate Control Via Microcontroller - Bartels Mikrotechnik mp6 Operating Manual

Table 6.2 : Typical capacitor values for different pump frequency values

6.4.3 Pump rate control via microcontroller

To control the mp6-OEM with a microcontroller, an external clock with four times the desired frequency
connected to the CLOCK pin can directly set the output frequency. In this case the pump frequency can be
decreased down to the single Hz range. Working at pump frequencies below 25 Hz, the duty cycle of the
frequency signal needs to be high (95% on time) to result in an appropriate output signal.
The amplitude can either be adjusted by an analog voltage according to table 6.2, or by an equivalent PWM
signal with a frequency between 0.2 and1 MHz connected to the AMPLITUDE pin (see table 6.2 for details).
The PWM signal should be higher than 1.3 V to make the output solely dependent on the duty cycle of the
PWM signal.
For a minimum of power consumption the electronics can be switched off by applying zero volts to the
AMPLITUDE input and the SHUTDOWN port, but the most efficient way is to cut the power supply.
Schematic 3: External control via microcontroller
Bartels Mikrotechnik GmbH, Otto-Hahn-Str. 15, 44227 Dortmund, Germany
www.micro-components.com, microComponents@bartels-mikrotechnik.de
Tel: +49-231-9742-500, Fax: +49-231-9742-501
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