TB6559FG

2013-04-10

9

(3)

Changing the predefined current (during acceleration)

Even when the reference voltage is increased, the regulator remains in Discharge mode for four CK

cycles and then it enters Charge mode.

The average current value becomes lower than the set current value because of the peak current detection

method. It should be noted that the average current value changes, depending on the motor characteristics.

Calculation of the Internal Oscillation Frequency

The OSC oscillation frequency can be approximated by the following equation:

Reference Voltage Generator

Vref/6

Discharge

Internal clock

OSC

Discharge

Charge

GND

Coil current

M

OUT1

1/6

RSA

Control circuit

Vref

OUT2