SPEC-3116 (REV. 9)

5/11

29-09-2017

SA2002H

FUNCTIONAL DESCRIPTION

The SA2002H is a CMOS mixed signal analog/digital

integrated circuit, which performs power/energy calculations

across a power range of 500:1, to an overall accuracy of

better than Class 1.

The integrated circuit includes all the required functions for

single phase power and energy measurement such as two

oversampling A/D converters for the voltage and current

sense inputs, power calculation and energy integration.

Internal offsets are eliminated through the use of cancellation

procedures. The SA2002H generates pulses, the frequency

of which is proportional to the measured power consumption.

One frequency output (FOUT) is available. The pulse rate

follows the instantaneous power consumption measured.

POWER CALCULATION

In the application circuit (see Figure 5), the voltage drop

80A through a shunt

resistor of 200μ

). This voltage is

converted to a current of between 0 and 16

of resistors R1 and R2. The current sense inputs saturate at

an input current of ±25μA peak.

Figure 5: Application Circuit

For the voltage sensor input, the mains voltage (220VAC) is

divided down through a divider (R3, R4 and P1) to 14V. The

nominal mains voltage, via resistor R5 (1M

). P1 may be

varied for calibration purposes.

In this configuration, with a mains voltage of 220V and a

current of 80A, the output frequency measured on the FOUT

pin is 1160Hz. In this case, one pulse on FOUT will

correspond to an energy consumption of 17.6kW/1160Hz =

15.17Ws.

ANALOG INPUT CONFIGURATION

The input circuitry of the current and voltage sensor inputs is

illustrated in Figure 6. These inputs are protected against

electrostatic

discharge

through

clamping

diodes.

The

generate

virtual

shorts

on

the

signal

inputs.

Exact

duplications of the input currents are generated for the analog

signal processing circuitry.

Figure 6: Internal analog input configuration

Power

Supply

N

GND

VSS

RSH

R1

R2

R3

R5

R4

U1

P1

R6

SA2002H

VDD

L

VDD

VSS

GND

GND

L

N

VDD

FOUT

DIR

FMO

VSS

IIN

IIP

IVP

AGND

VREF

Fwd/Rev. Energy

Pulse Output

Zero Crossing

A

I

IIN

IIP

VDD

VSS

VDD

VSS

A

V

IVP

VDD

VSS

AGND

VOLTAGE

SENSOR

INPUT

CURRENT

SENSOR

INPUT

CURRENT

CHANNEL

ADC

VOLTAGE

CHANNEL

ADC