HA13563/V

8

5. Determine the component value using the following formula as a guideline:

C108 (

µF) =

220

ffg (Hz)

Digital filter time T

1

CLK

× D2

2

CLK

× D2

∼

where, CLK : The reference frequency.

D2

: CLK frequency dividing ratio.

FG signal

wave shaping output

After digital filter

6. The PWM carrier frequency is determined roughly by the following formula:

1180

Rt (k

Ω) Ct1 (pF)

7. The formula shown below roughly determines the time, Tprot (s), until the stuck rotor protection

circuit operates. Figure 2 shows the operating waveforms. The latched state can be cleared by

either

CE or V

Note that a capacitor with a leakage current sufficiently smaller than the

charging current Ict+ must be used.

Tprot = 0.24 Ct2 (

µF)

CE

H

Vth+0.7V

Vth

0

0

L

Vref1

R

NF

Tprot

Tset = 0.004

⋅ Ct2 (µF) [sec]

LVI

Figure 2

Stuck Rotor Protection Operating Waveforms

8. The reference frequency CLK (Hz) and the FG frequency ffg (Hz) are related by the following

formula:

CLK =

1024 ffg

D2