SPEC-3116 (REV. 9)

6/11

29-09-2017

SA2002H

ELECTROSTATIC DISCHARGE (ESD)

PROTECTION

The SA2002H integrated circuits inputs and outputs are

protected against ESD.

POWER CONSUMPTION

The power consumption rating of the SA2002H integrated

circuit is less than 25mW.

INPUT SIGNALS

VREF

A bias resistor of 24k

 sets optimum bias conditions on chip.

Calibration of the SA2002H should be done on the voltage

input as described in Typical Applications.

Current Sense Inputs (IIP and IIN)

Figure 5 shows the typical connections for the current sensor

input. The resistors R1 and R2 define the current level into

the current sense inputs of the SA2002H. At maximum rated

current the resistor values should be selected for input

currents

Values for resistors R1 and R2 can be calculated as follows:

����1 = ����2 =

16��������

×

������������

2

where

RSH is the shunt resistor or termination resistor if a CT

(current transformer) is used as the current sensor.

The value of RSH, if used as a CT termination resistor, should

be less than the DC resistance of the secondary winding of

the CT. The voltage drop across RSH should not be less than

Voltage Sense Input (IVP)

The current into the A/D converter should

at nominal mains voltage. The voltage sense input saturates

at

an input current of ±25μA peak. Referring to Figure 5, the

typical connections for the voltage sense input is illustrated.

Resistors R3, R4 and R5 set the current for the voltage sense

current into the

resistor R5.

OUTPUT SIGNALS

Pulse Output (FOUT)

The output on FOUT is a pulse density signal representing

the instantaneous power/energy measurement as shown in

Figure 7. The pulse width on FOUT changes with the direction

71,5μs for positive energy and doubles if negative energy is

measured. The output frequency may be calculated using the

following formula:

���� = 11.16 × ���������������� ×

2

where

FOUT is the typical rated output frequency (1160Hz),

(16μA at rated conditions),

(14

μA at rated conditions) and

typically 50μA.

An integrated anti-creep function does not allow output

pulses on FOUT if no power is measured by the device.

Figure 7: Instantaneous pulse output

Direction Indication (DIRO)

The direction output DIR can be used to determine the

direction of energy flow. The pin is high for positive energy

and low when negative energy is measured. Figure 8 shows

the behavior of the direction output DIR, when energy

reversal takes place. The time period for the DIR signal to

to count (down) from its present value to zero. Thus the

energy consumption rate determines the speed of change on

t

V

MAINS

t

P

t

Power

V x I

FOUT