11

Definitions

Gain

Gain is defined as the slope of the best-fit line of differen-

offset error adjusted out.

Nonlinearity

Nonlinearity is defined as half of the peak-to-peak output

deviation from the best-fit gain line, expressed as a per-

centage of the full-scale differential output voltage.

tied together and the signal applied to both inputs with

respect to pin GND1), expressed in dB.

Common Mode Transient Immunity, CMTI, also known as Com-

mon Mode Rejection

CMTI is tested by applying an exponentially rising/falling

voltage step on pin 4 (GND1) with respect to pin 5 (GND2).

The rise time of the test waveform is set to approximately

50 ns. The amplitude of the step is adjusted until the dif-

mV deviation from the average output voltage for more

than 1

µs. The ACPL-C79B/C79A/C790 will continue to

function if more than 10 kV/μs common mode slopes are

applied, as long as the breakdown voltage limitations are

observed.

Power Supply Rejection, PSR

PSR is the ratio of differential amplitude of the ripple

outputs over power supply ripple voltage, referred to the

input, expressed in dB.

0.1 µF

8

7

6

1

3

U2

5

2

4

R1

2.00 K

+15 V

C8

0.1 µF

0.1 µF

-15 V

–

+ TL032A

R3

10.0 K

ACPL-C79B/

ACPL-C79A/

ACPL-C790

C4

R4

10.0 K

C6

47 pF

U3

U1

78L05

IN OUT

C1

C2

47 nF

R5

10

GATE DRIVE

CIRCUIT

POSITIVE

FLOATING

SUPPLY

HV+

* * *

HV-

–

+

MOTOR

C5

47 pF

0.1

µF

0.1

µ F

C3

C7

R2

2.00 K

* * *

* * *

GND1

GND2

GND2

GND2

GND2

Figure 21. Typical application circuit for motor phase current sensing.