Datasheet SA9102CPA, SA9102CSA Datasheet (SAMES)

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SINGLE PHASE UNIDIRECTIONAL POWER/ENERGY

FEATURES

SA9102C

METERING IC PULSE OUTPUT

■ 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

DESCRIPTION

■ Adaptable to different types of current

sensors

■ Operates over a wide temperature

range

■ Precision voltage reference on-chip

■ Different pulse rate options available

PIN CONNECTIONS

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

IN

IIP
VREF

VON

1
2
3
4

20
19
18
17

GND
IVP

CION
CIOP

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

VOP
CVIN
CVIP

V

DD

NC

5
6
7
8
9

16
15
14
13
12

CIIN
CIIP

V

SS
FOUT2
FOUT1

applications such as electricity dispensing
systems (ED's), residential municipal

SC2

10

11

OSC1

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)

DR-00020

Package: DIP-20

SOIC-20

package types.

2047 PDS039-SA9102C-001 REV. D 05-09-1995

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SA9102C

BLOCK DIAGRAM

ABSOLUTE MAXIMUM RATINGS*

Parameter Symbol Min Max Unit

Supply Voltage VDD -V
Current on any pin I
Storage Temperature T
Operating Temperature T

PIN

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SS

-0.3 6.0 V

-200 +200 mA

-40 +125 °C

-40 +85 °C

* 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.

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SA9102C

ELECTRICAL CHARACTERISTICS

(VDD = 2.5V, VSS = -2.5V, over the temperature range -10°C to +70°C#, unless otherwise
specified.)

Parameter Symbol Min Typ Max Unit Condition

Supply Voltage: Positive V
Supply Voltage: Negative V
Supply Current: Positive I
Supply Current: Negative I

2.25 2.75 V

DD

-2.75 -2.25 V

SS

DD

SS

510mA

510mA
Current Sensor Inputs (Differential)
Input Current Range I

II

-25 +25 µA Peak value
Voltage Sensor Input (Asymetrical)
Input Current Range I

IV

-25 +25 µA Peak value
Pins FOUT1, FOUT2

Output Low Voltage V
Output High Voltage V

Pulse Rate FOUT1 f

OL

VDD-1 V IOH = -2mA

OH

P

10 1160 Hz Specified linearity

0.5 1600 Hz Min and max limits

FOUT2

1

f

P2

fP/290

Oscillator Recommended crystal:

TV colour burst crystal f = 3.5795 MHz

VSS-1 V IOL = 5mA

Pin VREF With R = 24kΩ

Ref. Current I
Ref. Voltage V

R

45 50 55 µA connected to V

1.1 1.3 V Referred to V

R

Note 1: An option of FOUT2 = fp/4 is available on request.

#

Extended Operating Temperature Range available on request.

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SA9102C

PIN DESCRIPTION

Pin Designation Description

20 GND Ground
8 V

14 V

DD

SS

Positive Supply Voltage

Negative Supply Voltage
19 IVP Analog input for Voltage
1 IIN Inputs for current sensor
2 IIP
11 OSC1 Connections for crystal or ceramic resonator
10 OSC2 (OSC1 = Input : OSC2 = Output)
12 FOUT1 First pulse rate output
13 FOUT2 Second pulse rate output
4 CVON Connections for outer loop capacitor of
5 CVOP A/D converter (Voltage)
6 CVIN Connections for inner loop capacitor of
7 CVIP A/D converter (Voltage)
15 CIIP Connections for inner loop capacitor of
16 CIIN A/D converter (Current)
17 CIOP Connections for outer loop capacitor of
18 CION A/D converter (Current)
3 VREF Connection for current setting resistor
9 NC 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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1. Power calculation

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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 200µΩ). This voltage is
converted to a current of between 0 and 16µA, by means of resistors R1 and R2.

The current sense input saturates at an input current of ±25µA 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 14µA for a nominal
mains voltage, via the resistor R4 (1MΩ).

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).

2. 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 AI and AV generate virtual

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

SA9102C

V

DD

IIP

IIN

IVP

V

SS

DDV

SSV

DD

V

V

SS

GND

A

I

A

V

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URRENT
ENSOR

NPUTS

VOLTAGE

ENSOR

NPUT

R-00502

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SA9102C

3. Electrostatic Discharge (ESD) Protection

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

4. 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:
C1 and C2 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%.
C3 and C4 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.

R2, R1 and RSH are the resistors defining the current level into the current sense input.
The values should be selected for an input current of 16µA into the SA9102C at maximum
line current.

Values for RSH of less than 200µΩ should be avoided.
R1 = R2 = (IL/16µA) * RSH/2
Where I

L

= Line current

RSH = Shunt resistor/termination resistor

R3, R6 and R4 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 14µA.

R7 defines all on-chip bias and reference currents. With R7 = 24kΩ, optimum conditions
are set. R7 may be varied within ±10% for calibration purposes. Any change to R7 will
affect the output quadratically (i.e.: R7 = +5%, fp = +10%).

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

3.58MHz I

11.16

FOUTX

*

FOSC * II . I

*

V

2

R

Where FOUTX = Nominall rated frequency (4Hz or 1160Hz)

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

SA9102C

I

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= Input currents for current input (16µA at rated)
= Input current for voltage input (14µA at rated)
= Reference current (typically 50µA)

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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SA9102C

Figure 1: Application Circuit using a Shunt Resistor for Current Sensing.

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Parts List for Application Circuit: Figure 1

Item Symbol Description Detail

1 IC-1 SA9102C DIP-20/SOIC-20
2 IC-2 Optocoupler 4N35 DIP-6
3 D1 Diode, Silicon, 1N4148
4 D2 Diode, Silicon, 1N4148
5 ZD1 Diode, Zener, 2,4V, 200mW
6 ZD2 Diode, Zener 2,4V, 200mW
7 XTAL Crystal, 3.5795MHz
8 R1 Resistor, 1% metal Note 1

9 R2 Resistor, 1% metal Note 1
10 R3 Resistor, 390k, (230VAC), 1% metal
11 R4 Resistor, 1M, 1/8W, 1%, metal
12 R5 Resistor, 470Ω, 1W, 5%, carbon
13 R6 Resistor, 24k, 1/4W, 1%, metal
14 R7 Resistor, 24k, 1/4W, 1%, metal
15 R8 Resistor, 680Ω, 1/4W, 1%
16 R9 Resistor, 680Ω, 1/4W, 1%
17 R10 Resistor, 680Ω, 1/4W, 1%
18 C1 Capacitor, 560pF
19 C2 Capacitor, 560pF
20 C3 Capacitor, 3.3nF
21 C4 Capacitor, 3.3nF
22 C9 Capacitor, 100nF
23 C10 Capacitor, 100nF
24 C11 Capacitor, 0.47µF, 250VAC, polyester
25 C13 Capacitor, 100µF
26 C14 Capacitor, 100µF
27 C15 Capacitor, 820nF Note 2
28 RSH Shunt Resistor Note 3

SA9102C

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 (VDD & VSS) of IC-1 as

possible.

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

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SA9102C

Figure 2: Application Circuit using a Current Transformer for Current Sensing.

Note: Capacitor C11 may be selected for phase compensation and DC blocking.

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Parts List for Application Circuit: Figure 2

Item Symbol Description Detail

1 IC-1 SA9102C DIP-20/SOIC-20

2 XTAL Crystal, 3.5795MHz Colour burst TV

3 RSH Resistor Note 1

4 R1 Resistor, 1% metal Note 2

5 R2 Resistor, 1% metal Note 2

6 R3 Resistor, 390k, (230VAC), 1% metal

7 R4 Resistor, 1M, 1/4W, 1%, metal

8 R6 Resistor, 24k, 1/4W, metal

9 R7 Resistor, 24k, 1/4W, 1%, metal
10 R8 Resistor, 2.2k, 1/4W, 5%
11 R9 Resistor, 2.2k, 1/4W, 5%
12 C1 Capacitor, 560pF
13 C2 Capacitor, 560pF
14 C3 Capacitor, 3.3nF
15 C4 Capacitor, 3.3nF
16 C9 Capacitor, 820nF Note 3
17 C10 Capacitor, 100nF
18 C11 Capacitor
19 CT Current transformer

SA9102C

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 (VDD & VSS) of IC-1,

as possible.

Note 4: Capacitor (C11) selected to minimize phase error introduced by current

transformer (typically 1.5µF)

ORDERING INFORMATION

Part Number Package

SA9102CPA DIP-20
SA9102CSA SOIC-20

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SA9102C

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.

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: [phone] Tel: Int [phone]
Fax: [phone] Fax: Int [phone]

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