HA13605A Datasheet, PDF (9/18 Pages) Hitachi Semiconductor – Three-Phase Brushless Motor Driver

HA13605A
V_R1: Charge pump reference voltage
5.6 (V: See the electrical characteristics table.)
2. The voltage gain (Gfg) of the FG amplifier is determined by the following formula. Here Rfgf is
the internal feedback resistance. See the electrical characteristics table.
However, note that R103 must be equal to R104.
Gfg = ^Rfgf
R103
3. The output current limit is given by the following formula.
Iomax = ^{(VX1 — 25 mV)} (A)
Rnf
4. The PWM carrier frequency is determined by the following formula. Here VR1 and K are the
charge pump voltage and the oscillator amplitude (see the electrical characteristics table),
respectively.
f_P =..
VR1
KCt R1 V_OSC
(Hz)
5. The FG amplifier bandwidth BW is determined by the following formula. Here Rfgo is the pin 15
output resistance. See the electrical characteristics table.
However, when C105 is 0, BW is limited to 8 kHz by the internal capacitance.
BW =
1
(Hz)
2π C105 Rfgo
6. Determine C106 using the following formula as a rough estimate.
C106 ≥
1
(F)
π(R103 + R104) f_FG
Consult with the oscillator element manufacturer.
7. Relationship of between the CLK frequency fc and the FG frequency f_FG. Are determined by the
under table.
D
fc (Hz)
1/3
2048.5 • ^fFG But rotation response is 80 ppm down
D
1/6
1/12
2048.5 • ^fFG
D
8. If an input of 1.25/G_FG (Vp-p) or higher is applied, irregular rotation may occur due to FG amplifier
saturation.
9. The absolute value of the whole amplifier input voltage must be within the in-phase input voltage
range.
10. This should be decided after consultation with the oscillator manufacturer.
11. Determine C109 using the following formula as a rough estimate.
3 kΩ ≤ R107 ≤ 6 kΩ
300pF < C109 ≤
20
Fc (R108 + 200 Ω)
(F)
9