dsPIC33CK256MP508

DS50002756A-page 8

 2018 Microchip Technology Inc.

Table 4 classifies the passive components according to

their functionality and also quotes the design equations

applicable in each case.

Op Amp 1, as seen in Figure 3, is not used by default. If

the filter, bias and feedback circuit section are popu-

lated, and configured by software, it can be used to

amplify the IBUS current. Prior to using Op Amp 1, the

resistor jumpers, R23, R24, R25, R26, should be

removed to enable IBUS current to use the Op Amp 1

inputs. As a result, this limits the Power Factor Correc-

tion (PFC) functionality in the case of MCHV-2 or Field

Oriented Control (FOC) on Inverter B of the Low-Voltage

Motor Control Development Bundle.

TABLE 4:

ANALOG FUNCTIONALITY LISTING

Op Amp #

Analog Function

Passive Components

Design Equations

1

Low-Pass Filter

R15, R16, R17, R18, C14,

C15, C16

R15 = R16 = R17 = R18 = R

C14 = C16 = C

R10 = R11

Reference Voltage Bias

R19, R20, R21, R22

Voltage Divider

R20, R21

Differential Amplifier

Input

R15, R16, R17, R18

Differential Amplifier

Feedback

R22

2

Low-Pass Filter

R1, R2, R3, R4, C8, C9, C10 R1 = R2 = R3 = R4 = R

C8 = C110 = C

R5 = R6

Reference Voltage Bias

R5, R6

Differential Amplifier

Input

R1, R2, R3, R4

Differential Amplifier

Feedback

R6

3

Low-Pass Filter

R8, R9, R10, R11, C11,

C12, C13

R8 = R9 = R10 = R11 = R

C11 = C13 = C

R12 = R13

Reference Voltage Bias

R12, R13

Differential Amplifier

Input

R8, R9, R10, R11

Differential Amplifier

Feedback

R13

Common-mode

f – 3 dB 

1

2

RC

Differential-mode

f – 3 dB 

1

2

R)

Differential Amplifier Gain =

R22

2R

C

2

+ C15

()

Common-mode

f – 3 dB 

1

2

RC

Differential-mode

f – 3 dB 

1

2

R)

Differential Amplifier Gain =

R6

2R

C

2

+ C9

()

Common-mode

f – 3 dB 

1

2

RC

Differential-mode

f – 3 dB 

1

2

R)

Differential Amplifier Gain =

R13

2R

C

2

+ C12

()