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SA9102C

FEATURES

Performs unidirectional power and
energy measurement

Meets the IEC 521/1036 Specification
requirements for Class 1 AC Watt hour
meters

Protected against ESD

Total power consumption rating typically
25mW

Adaptable to different types of current
sensors

Operates over a wide temperature
range

Precision voltage reference on-chip

Different pulse rate options available

SINGLE PHASE UNIDIRECTIONAL POWER/ENERGY

METERING IC PULSE OUTPUT

2047

PDS039-SA9102C-001

REV. D

05-09-1995

Package: DIP-20

SOIC-20

DESCRIPTION

The SAMES SA9102C Single Phase
unidirectional Power/Energy metering
integrated circuit generates a pulse rate
output, the frequency of which is
proportional to the power consumption.
The SA9102C performs the calculation for
active power.

This method of calculation takes the power
factor into account.

Energy consumption is determined by the
power measurement being integrated over
time.

This innovative universal single phase
power/energy metering integrated circuit
is ideally suited for energy calculations in
applications such as electricity dispensing
systems (ED's), residential municipal
metering and factory energy metering and
control.

The SA9102C integrated circuit is available
in both 20 pin dual-in-line plastic (DIP-20),
as well as 20 pin small outline (SOIC-20)
package types.

PIN CONNECTIONS

VREF

CVIN

CVIP

V DD
NC

OSC2

CVOP

CVON

IIN

IIP

DR-00020

OSC1

FOUT1

FOUT2

V SS

CIIP

CIIN

CIOP

CION

IVP

GND

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ABSOLUTE MAXIMUM RATINGS*

Parameter

Symbol

Min

Max

Unit

Supply Voltage

-V

-0.3

6.0

Current on any pin

-200

+200

Storage Temperature

STG

-40

+125

癈

Operating Temperature

-40

+85

癈

* Stresses above those listed under "Absolute Maximum Ratings" may cause permanent

damage to the device. This is a stress rating only. Functional operation of the device
at these or any other condition above those indicated in the operational sections of this
specification, is not implied. Exposure to Absolute Maximum Ratings for extended
periods may affect device reliability.

BLOCK DIAGRAM

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ELECTRICAL CHARACTERISTICS
(V

= 2.5V, V

= -2.5V, over the temperature range -10癈 to +70癈

, unless otherwise

specified.)

Parameter

Symbol

Min

Typ

Max

Unit

Condition

Supply Voltage: Positive

2.25

2.75

Supply Voltage: Negative

-2.75

-2.25

Supply Current: Positive

Supply Current: Negative

Current Sensor Inputs (Differential)

Input Current Range

-25

+25

礎

Peak value

Voltage Sensor Input (Asymetrical)

Input Current Range

-25

+25

礎

Peak value

Pins FOUT1, FOUT2

Output Low Voltage

-1

= 5mA

Output High Voltage

-1

= -2mA

Pulse Rate FOUT1

1160

Specified linearity

0.5

1600

Min and max limits

FOUT2

/290

Oscillator

Recommended crystal:
TV colour burst crystal f = 3.5795 MHz

Pin VREF

With R = 24k

Ref. Current

礎

connected to V

Ref. Voltage

1.1

1.3

Referred to V

Note 1: An option of FOUT2 = f

/4 is available on request.

Extended Operating Temperature Range available on request.

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PIN DESCRIPTION

Pin

Designation

Description

GND

Ground

Positive Supply Voltage

Negative Supply Voltage

IVP

Analog input for Voltage

IIN

Inputs for current sensor

IIP

OSC1

Connections for crystal or ceramic resonator

OSC2

(OSC1 = Input : OSC2 = Output)

FOUT1

First pulse rate output

FOUT2

Second pulse rate output

CVON

Connections for outer loop capacitor of

CVOP

A/D converter (Voltage)

CVIN

Connections for inner loop capacitor of

CVIP

A/D converter (Voltage)

CIIP

Connections for inner loop capacitor of

CIIN

A/D converter (Current)

CIOP

Connections for outer loop capacitor of

CION

A/D converter (Current)

VREF

Connection for current setting resistor

Not connected

FUNCTIONAL DESCRIPTION
The SA9102C is a CMOS mixed signal Analog/Digital integrated circuit, which performs
power/energy calculations across a power range of 1000:1, to an overall accurancy of
better than Class 1.

The integrated circuit includes all the required functions for 1-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 SA9102C generates pulses, the
frequency of which is proportional to the power consumption. Two frequency outputs'
(FOUT1 and FOUT2) are available, with a third frequency option available on request.

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Power calculation
In the Application Circuit (Figure 1), the voltage drop across the shunt will be
between 0 and 16mV (0 to 80A through a shunt resistor of 200�

). This voltage is

converted to a current of between 0 and 16礎, by means of resistors R

and R

The current sense input saturates at an input current of �25礎 peak.

For the voltage sensor input, the mains voltage (230VAC) is divided down through
a divider to 14V. The current into the A/D converter input is set at 14礎 for a nominal
mains voltage, via the resistor R4 (1M

In this configuration, with a mains voltage of 230V and a current of 80A, the output
frequency of the SA9102C power meter chip at FOUT1 (Pin 12) is 1.16kHz. In this
case 1 pulse will correspond to an energy consumption of 18.4kVA/1160Hz =
15.9Ws.

The output frequency at FOUT2 is FOUT1

/290 (i.e. The frequency ouput at pin 12

is divided by 290).

Analog Input configuration
The input circuitry of the current and voltage sensor inputs are illustrated below.

These inputs are protected against electrostatic discharge through clamping
diodes, in conjunction with the amplifiers input configuration.

The feedback loops from the outputs of the amplifiers A

and A

generate virtual

shorts on the signal inputs. Exact duplications of the input currents are generated
for the analog signal processing circuitry.

V O L T A G E
SENSOR
INPUT

IVP

DR-00502

CURRENT
SENSOR
INPUTS

IIP

IIN

GND

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Electrostatic Discharge (ESD) Protection
The SA9102C integrated circuit's inputs/outputs are protected against ESD according
to Mil-Std 883C, method 3015.

Power Consumption
The power consumption rating of the SA9102C integrated circuit is less than 50mW.

TYPICAL APPLICATIONS
In the Application Circuits (Figures 1 and 2) the components required for power metering
applications, are shown.

In Figure 1 a shunt resistor is used for current sensing. In this application, the circuit
requires a +2.5V, 0V, -2.5V DC supply.

In the case of Figure 2, when using a current transformer for current sensing, a +5V, 0V
DC supply is sufficient.

The most important external components for the SA9102C integrated circuit are:

and C

are the outer loop capacitors for the two integrated oversampling A/D

converters. The value of these capacitors is 560pF.

The actual values determine the signal to noise and stability performance. The tolerances
should be within �10%.

and C

are the inner loop capacitors of the A/D converters. The optimum value is

3.3nF. The actual values are uncritical. Values smaller than 0.5nF and larger than 5nF
should be avoided.

, R

and RSH are the resistors defining the current level into the current sense input.

The values should be selected for an input current of 16礎 into the SA9102C at maximum
line current.

Values for RSH of less than 200�

should be avoided.

= R

= (I

/16礎) * R

Where

Line current

RSH

Shunt resistor/termination resistor

, R

and R

set the current for the voltage sense input. The values should be selected

so that the input current into the voltage sense input (virtual ground) is set to 14礎.

defines all on-chip bias and reference currents. With R

= 24k

, optimum conditions

are set. R

may be varied within �10% for calibration purposes. Any change to R

will

affect the output quadratically (i.e.: R

= +5%, f

= +10%).

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The formula for calculating the output frequency (f) is given below:

11.16

* FOUTX *

FOSC

. I

3.58MHz I

Where FOUTX

= Nominall rated frequency (4Hz or 1160Hz)

FOSC

= Oscillator frequency (2MHz ...... 4MHz)

= Input currents for current input (16礎 at rated)

= Input current for voltage input (14礎 at rated)

= Reference current (typically 50礎)

XTAL is a colour burst TV crystal (f = 3.5795MHz) for the oscillator. The oscillator
frequency is divided down to 1.7897MHz on-chip to supply the digital circuitry and the
A/D converters.

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Parts List for Application Circuit: Figure 1

Item

Symbol

Description

Detail

IC-1

SA9102C

DIP-20/SOIC-20

IC-2

Optocoupler 4N35

DIP-6

Diode, Silicon, 1N4148

ZD1

Diode, Zener, 2,4V, 200mW

ZD2

Diode, Zener 2,4V, 200mW

XTAL

Crystal, 3.5795MHz

Resistor, 1% metal

Note 1

Resistor, 1% metal

Note 1

Resistor, 390k, (230VAC), 1% metal

Resistor, 1M, 1/8W, 1%, metal

Resistor, 470

, 1W, 5%, carbon

Resistor, 24k, 1/4W, 1%, metal

Resistor, 680

, 1/4W, 1%

Resistor, 680

, 1/4W, 1%

R10

Resistor, 680

, 1/4W, 1%

Capacitor, 560pF

Capacitor, 3.3nF

Capacitor, 100nF

C10

Capacitor, 100nF

C11

Capacitor, 0.47礔, 250VAC, polyester

C13

Capacitor, 100礔

C14

Capacitor, 100礔

C15

Capacitor, 820nF

Note 2

RSH

Shunt Resistor

Note 3

Note 1: Resistor (R1 and R2) values are dependant upon the selected value of RSH.

Note 2: Capacitor (C15) to be positioned as close to Supply Pins (V

& V

) of IC-1 as

possible.

Note 3: See TYPICAL APPLICATIONS when selecting the value of RSH.

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Parts List for Application Circuit: Figure 2

Item

Symbol

Description

Detail

IC-1

SA9102C

DIP-20/SOIC-20

XTAL

Crystal, 3.5795MHz

Colour burst TV

RSH

Resistor

Note 1

Resistor, 1% metal

Note 2

Resistor, 1% metal

Note 2

Resistor, 390k, (230VAC), 1% metal

Resistor, 1M, 1/4W, 1%, metal

Resistor, 24k, 1/4W, metal

Resistor, 24k, 1/4W, 1%, metal

Resistor, 2.2k, 1/4W, 5%

Capacitor, 560pF

Capacitor, 3.3nF

Capacitor, 820nF

Note 3

C10

Capacitor, 100nF

C11

Capacitor

Current transformer

Note 1:

See TYPICAL APPLICATIONS when selecting the value of RSH.

Note 2:

Resistor (R1and R2) values are dependant upon the selected value of RSH.

Note 3:

Capacitor (C9) to be positioned as close to Supply Pins (V

& V

) of IC-1,

as possible.

Note 4:

Capacitor (C11) selected to minimize phase error introduced by current
transformer (typically 1.5礔)

ORDERING INFORMATION

Part Number

Package

SA9102CPA

DIP-20

SA9102CSA

SOIC-20

SA9102C

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South African Micro-Electronic Systems (Pty) Ltd
P O Box 15888,

33 Eland Street,

Lynn East, 0039

Koedoespoort Industrial Area,

Republic of South Africa,

Pretoria,
Republic of South Africa

Tel:

012 333-6021

Tel:

Int +27 12 333-6021

Fax:

012 333-8071

Fax:

Int +27 12 333-8071

Disclaimer:

The information contained in this document is confidential and proprietary to South African Micro-

Electronic Systems (Pty) Ltd ("SAMES) and may not be copied or disclosed to a third party, in whole or in part,
without the express written consent of SAMES. The information contained herein is current as of the date of
publication; however, delivery of this document shall not under any circumstances create any implication that the
information contained herein is correct as of any time subsequent to such date. SAMES does not undertake to
inform any recipient of this document of any changes in the information contained herein, and SAMES expressly
reserves the right to make changes in such information, without notification,even if such changes would render
information contained herein inaccurate or incomplete. SAMES makes no representation or warranty that any
circuit designed by reference to the information contained herein, will function without errors and as intended by
the designer.

协谢械泻褌褉芯薪薪褘泄 泻芯屑锌芯薪械薪褌: SA9102CSA

协谢械泻褌褉芯薪薪褘泄泻芯屑锌芯薪械薪褌: SA9102CSA