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SA9102C
SINGLE PHASE UNIDIRECTIONAL POWER/ENERGY
METERING IC PULSE OUTPUT
FEATURES
■
Performs unidirectional power and
energy measurement
■
Adaptable to different types of current
sensors
■
Meets the IEC 521/1036 Specification
requirements for Class 1 AC Watt hour
meters
■
Operates over a wide temperature
range
■
Protected against ESD
■
Precision voltage reference on-chip
■
Total power consumption rating typically
25mW
■
Different pulse rate options available
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
IIN
1
20
GND
IIP
2
19
IVP
VREF
3
18
CION
CVON
4
17
CIOP
CVOP
5
16
CIIN
CVIN
6
15
CIIP
CVIP
7
14
V SS
V DD
8
13
FOUT2
NC
9
12
FOUT1
OSC2
10
11
OSC1
DR-00020
Package: DIP-20
SOIC-20
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2047
PDS039-SA9102C-001
REV. D
05-09-1995
SA9102C
BLOCK DIAGRAM
ABSOLUTE MAXIMUM RATINGS*
Parameter
Symbol
Supply Voltage
V DD -VSS
Current on any pin
IPIN
Storage Temperature
TSTG
Operating Temperature
TO
Min
-0.3
-200
-40
-40
Max
6.0
+200
+125
+85
Unit
V
mA
°C
°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
Supply Voltage: Positive
VDD
Supply Voltage: Negative
VSS
Supply Current: Positive
IDD
Supply Current: Negative
ISS
Typ
Max
Unit
Condition
2.25
2.75
V
-2.75
-2.25
V
5
10
mA
5
10
mA
-25
+25
µA
Peak value
+25
µA
Peak value
VSS -1
V
V
IOL = 5mA
IOH = -2mA
1160
1600
Hz
Hz
Specified linearity
Min and max limits
Current Sensor Inputs (Differential)
Input Current Range
III
Voltage Sensor Input (Asymetrical)
Input Current Range
IIV
-25
Pins FOUT1, FOUT2
Output Low Voltage
Output High Voltage
VOL
VOH
V DD-1
Pulse Rate FOUT1
FOUT21
Oscillator
fP
10
0.5
fP2
fP/290
Recommended crystal:
TV colour burst crystal f = 3.5795 MHz
Pin VREF
Ref. Current
Ref. Voltage
IR
VR
45
1.1
50
55
1.3
µA
V
With R = 24kΩ
connected to VSS
Referred to VSS
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
8
GND
VDD
Ground
Positive Supply Voltage
14
VSS
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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SA9102C
1.
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 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.
V DD
IIP
CURRENT
SENSOR
INPUTS
V SS
AI
V DD
IIN
V SS
V DD
IVP
VOLTAGE
SENSOR
INPUT
DR-00502
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V SS
A
V
GND
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SA9102C
3.
4.
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:
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 IL
= 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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SA9102C
The formula for calculating the output frequency (f) is given below:
f = 11.16 * FOUTX *
Where FOUTX
FOSC
3.58MHz
*
I I . IV
IR 2
= Nominall rated frequency (4Hz or 1160Hz)
FOSC
= Oscillator frequency (2MHz ...... 4MHz)
II
= Input currents for current input (16µA at rated)
IV
= Input current for voltage input (14µA at rated)
IR
= 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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SA9102C
Parts List for Application Circuit: Figure 1
Item
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Symbol
IC-1
IC-2
D1
D2
ZD1
ZD2
XTAL
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10
C1
C2
C3
C4
C9
C10
C11
C13
C14
C15
RSH
Description
SA9102C
Optocoupler 4N35
Diode, Silicon, 1N4148
Diode, Silicon, 1N4148
Diode, Zener, 2,4V, 200mW
Diode, Zener 2,4V, 200mW
Crystal, 3.5795MHz
Resistor, 1% metal
Resistor, 1% metal
Resistor, 390k, (230VAC), 1% metal
Resistor, 1M, 1/8W, 1%, metal
Resistor, 470Ω, 1W, 5%, carbon
Resistor, 24k, 1/4W, 1%, metal
Resistor, 24k, 1/4W, 1%, metal
Resistor, 680Ω, 1/4W, 1%
Resistor, 680Ω, 1/4W, 1%
Resistor, 680Ω, 1/4W, 1%
Capacitor, 560pF
Capacitor, 560pF
Capacitor, 3.3nF
Capacitor, 3.3nF
Capacitor, 100nF
Capacitor, 100nF
Capacitor, 0.47µF, 250VAC, polyester
Capacitor, 100µF
Capacitor, 100µF
Capacitor, 820nF
Shunt Resistor
Detail
DIP-20/SOIC-20
DIP-6
Note 1
Note 1
Note 2
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 (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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SA9102C
Parts List for Application Circuit: Figure 2
Item
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Symbol
IC-1
XTAL
RSH
R1
R2
R3
R4
R6
R7
R8
R9
C1
C2
C3
C4
C9
C10
C11
CT
Description
SA9102C
Crystal, 3.5795MHz
Resistor
Resistor, 1% metal
Resistor, 1% metal
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%
Resistor, 2.2k, 1/4W, 5%
Capacitor, 560pF
Capacitor, 560pF
Capacitor, 3.3nF
Capacitor, 3.3nF
Capacitor, 820nF
Capacitor, 100nF
Capacitor
Current transformer
Detail
DIP-20/SOIC-20
Colour burst TV
Note 1
Note 2
Note 2
Note 3
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 MicroElectronic 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:
Fax:
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012 333-6021
012 333-8071
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Tel:
Fax:
Int +27 12 333-6021
Int +27 12 333-8071