RZ/T2M Group RZ/T2M Motor Solution Board Hardware Manual
R01AN5986EJ0100 Rev.1.00 Page 28 of 30
Jul.31.21
5.2 Current detection circuit 1(Current Transducer)
Figure 5.2 Current Transducer circuit
■Current calculation formula by Current Transducer circuit
CT sensitivity = 0.05 [V / A]
V(AD_Ix) = (0.05[V/A] x i0[A] x 3.5 + 1.65[V]) x 0.5
= 0.0875[V/A] x i0[A] +0.825[V]
RZ/T2M A/D converter Resolution:12bit (VCC18_ADC0/1=1.8[V])
1LSB (A/D converter value) =1.8[V] / 0.00875[V/A] /4095 = 5.024[mA]
Current detection range:
i0[A] = (V(AD_Ix) – 0.825[V]) / 0.0875[V/A]
i0[A] = -0.825[V] / 0.0875[V/A] = -9.429[A] (V(AD_Ix) = 0V)
i0[A] = (1.8[V] – 0.825[V]) / 0.0875[V/A] = 11.143[A] (V(AD_Ix) = 1.8V)
Figure 5.3 Current detection circuit 1 characteristics
) [V]