Broadcom

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ACNT-H79A, ACNT-H790

Data Sheet

Definitions

Definitions

Gain

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

adjusted out.

Nonlinearity

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

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

of the full-scale differential output voltage.

the input side common-mode gain (input pins 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 Common Mode Rejection

CMTI is tested by applying an exponentially rising/falling

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

amplitude of the step is adjusted until the differential output

average output voltage for more than 1μs. The

ACNT-H79A/H790 will continue to function if more than

15 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.

Application Information

Application Circuit

The typical application circuit is shown in Figure 21. A floating

power supply (which in many applications could be the same

supply that is used to drive the high-side power transistor) is

regulated to 5 V using a simple three-terminal voltage

regulator (U1). The voltage from the current sensing resistor, or

through an RC anti-aliasing filter (R5 and C3). And finally, the

differential output of the isolation amplifier is converted to a

ground-referenced single-ended output voltage with a simple

differential amplifier circuit (U3 and associated components).

Although the application circuit is relatively simple, a few

recommendations should be followed to ensure optimal

performance.