HA13609ANT Datasheet, PDF (17/31 Pages) Hitachi Semiconductor – Three-Phase Brushless Motor Driver

HA13609ANT
5. The PWM carrier frequency f_PWM is determined by the following formula:
1
f_PWM = 0.0489 _{C106 · R1} [Hz]
6. The relationships between the crystal oscillator frequency f_OSC and the speed command clock
f_CLK, the speed detection signal f_MR, and the discriminator resolution (number of counts) C are
shown below.
f_CLK = f_MR·D1
f_OSC = f_CLK·1 / D2·C [Hz]
However, C must be in the range 1024 ≤ C ≤ 4095
Here, D1 : The MR signal divisor determined by D1 select
D2 : The crystal oscillator frequency divisor determined by D2 select.
Configuration of the speed control and phase control blocks when @MD9 = 0
Buffer amplifier
Speed signal
D1
f_MR
SPEED CLK
f_CLK
X’tal
D2
f_OSC
f_MR’
CLK counter
Discriminator
counter setting
Discriminator
(1024 to 4095)
Charge
pump
16
C3
R3
–+
15
R7
19
R1
4Icp
PLL
PLL SEL
Discrimi-
nator
Vp
Discriminator
output
4% pulse
14
R4 R6
PLL output
C4
13
R5
Note: If possible, Tr and Tf for the SPEED CLK signal should be under 20 ns when using this circuit.
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