BA6901F

Motor driver ICs

7/10

•CR, TOUT terminal

By connecting the external capacitor and resistor to the CR terminal, the saw tooth wave is produced by the charge-

discharge of the capacitor which are corresponding to the cycle of the hall signal.

The saw tooth wave of CR terminal varies with the external capacitor and resistor.

The waveform of the CR terminal passes through the buffer amplifier and is outputted to TOUT terminal.

The input voltage range of the CR terminal for the buffer amplifier of TOUT is 0.26V

In case that the signal of the CR terminal is out of the range, outputted TOUT signal is not the same as the CR signal.

And, the voltage range of the TOUT terminal waveform is different from the CR terminal.

CR : VCRCP (0.35V ; Typ.)

TOUT : VTOUTL (1.0V ; Typ.)

Hall input

CR

TOUT

VCRCP

VTOUTL

In case that the CR waveform exceeds

Hall input

CR

TOUT

VCRCP

VTOUTL

In case that the CR waveform dose not

Timing chart for CR terminal, TOUT terminal

•PWM terminal

If the signal inputted to the PWM terminal is L (less than 0.8V), output (A1, A2) is forced to be turned off. For the normal

operation of output (A1, A2), PWM signal is needed to be H (more than 2.0V).

In case that PWM terminal is open, outputs are in the normal operation mode, because the PWM terminal is pulled up

with resistor (30k

Ω : Typ. ) in the IC.

The application circuit example that changes the rotation speed of fan motor dependent on ambient temperature by

using charge-discharge pulse circuit, PWM input and the thermistor is shown below.

+

−

Thermistor

H

Current

limit