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THREE PHASE UNIDIRECTIONAL POWER/ENERGY
FEATURES
SA9105A
METERING IC WITH PULSE OUTPUT
n Performs unidirectional one, two or
three phase power and energy
measurement
n Meets the IEC 521/1036 Specification
requirements for Class 1 AC Watt hour
meters
n Operates over a wide temperature
Range
n Uses current transformers for current
sensing
DESCRIPTION
The SAMES SA9105A Three Phase
unidirectional Power/Energy metering
integrated circuit generates a pulse rate
output, the frequency of which is proportional
to the power consumption. The SA9105A
performs the calculations of active power.
The method of calculation takes the power
factor into account.
Energy consumption is determined by the
power measurement being integrated over
time.
The output of this innovative universal three
phase power/energy metering integrated
circuit, is ideally suited for applications such
as residential and industrial energy metering
and control.
The SA9105A integrated circuit is available
in 40 pin dual-in-line plastic (DIP-40), as
well as in 44 pin plastic leaded chip carrier
(PLCC-44) packages types.
n Excellent long term stability
n Easily adaptable to different signal
levels
n Precision voltage reference on-chip
n Three pulse rate outputs available
n Protected against ESD
PIN CONNECTIONS
CIN1
CIP2
CIN2
CIP3
CIN3
IIN1
IIP1
IIN2
IIP2
IIN3
IIP3
COPP
CONP
CIPP
CINP
V
SS
TP17
TP18
OSC1
OSC2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
DR-00838
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
CIP1
COP1
CON1
CON2
COP2
GND
IVP1
IVP2
IVP3
COP3
CON3
VREF
V
DD
TP27
TP26
TP25
TP24
FOUT3
FOUT2
FOUT1
Package: DIP-40
4032 PDS039-SA9105A-001 Rev. C 15-08-1995
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SA9105A
PIN CONNECTIONS
BLOCK DIAGRAM
16 CONNECTIONS
IVP1
IVP2
IVP3
IIP1
IIN1
IIP2
IIN2
IIP3
IIN3
GND
39 37 3536
40
TP26
41
TP27
42
V
DD
43
VREF
44
N.C.
1
CON3
2
COP3
3
IVP3
4
IVP2
5
IVP1
6
GND
DR-00840
Package: PLCC-44
FOR LOOPCAPS
ANALOG
SIGNAL
PRO-
CESSING
FOUT3
FOUT2
TP24
109811
COP1
CON2
CON1
FOUT1
34
12
CIP1
TP25
38
7
COP2
INTEG.
&
AVERAGE
N.C.
N.C.
OSC2
OSC1
CIP2
CIN1
TP18
151413
CIN2
TP17
3033 32 31
16
CIP3
SS
V
29
28
CINP
27
CIPP
26
CONP
25
COPP
24
N.C.
23
IIP3
22
IIN3
21
IIP2
20
IIN2
19
IIP1
18
IIN1
17
CIN3
POWER
TO
PULSE
RATE
V
DD
V
SS
FOUT1
FOUT2
FOUT3
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VREF
DR-00839
REF
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TIMING & CONTROL
OSC
OSC1
OSC2
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SA9105A
ABSOLUTE MAXIMUM RATINGS *
Parameter Symbol Min Max Unit
Supply Voltage VDD-V
Current on any Pin I
Storage Temperature T
Operating Temperature T
PIN
STG
O
SS
-0.3 6.0 V
-150 +150 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 conditions above those indicated in the operation sections of this
specification, is not implied. Exposure to Absolute Maximum Ratings for extended
periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(Over the temperature range -10°C to +70°C#, unless otherwise specified.)
Parameter Symbol Min Typ Max Unit Condition
Supply Voltage VDD-V
Supply Current I
DD
4.5 5.5 V
SS
15 mA
Nonlinearity of
Power Calculation -0.3 +0.3 % 1% - 100% of
rated power
Current Sensor Inputs (Differential)
Input Current Range I
II
-25 +25 µA Peak value
Voltage Sensor Inputs (Asymmetric)
Input Current Range I
IV
-25 +25 µA Peak value
Pins FOUT1,FOUT2,FOUT3
Output Low Voltage V
Output High Voltage V
Pulse Rate: FOUT1 f
OL
OH
p
VDD-1 V IOH = -2mA
10 1160 Hz Specified linearity
VSS+1 V IOL = 5mA
0.5 3000 Hz Min and max limits
FOUT2 f
FOUT3 f
p2
p3
fp/4
fp/290
Oscillator Recommended crystal:
TV colour burst crystal, f = 3.5795 MHz
Pin VREF With R = 24 kΩ
Ref. Current -I
Ref. Voltage V
#
Extended Operating Temperature Range available on request.
R
R
45 50 55 µA connected to V
1.1 1.3 V Referred to V
SS
SS
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SA9105A
PIN DESCRIPTION
Pin Pin
PLCC DIP
6 35 GND Ground
42 28 V
29 16 V
5 34 IVP1 Analog Input for Voltage : Phase 1
4 33 IVP2 Analog Input for Voltage : Phase 2
3 32 IVP3 Analog Input for Voltage : Phase 3
18 6 IIN1 Inputs for current sensor : Phase 1
19 7 IIP1
20 8 IIN2 Inputs for current sensor : Phase 2
21 9 IIP2
22 10 IIN3 Inputs for current sensor : Phase 3
23 11 IIP3
32 19 OSC1 Connections for crystal or ceramic resonator
33 20 OSC2 (OSC1 = Input ; OSC2 = Output)
35 21 FOUT1 Pulse rate outputs
36 22 FOUT2
37 23 FOUT3
9 38 CON1 Connections for outer loop capacitors of A/D
10 39 COP1 converters
8 37 CON2
7 36 COP2
1 30 CON3
2 31 COP3
26 13 CONP
25 12 COPP
13 1 CIN1 Connections for inner loop capacitors of A/D
11 40 CIP1 converters
15 3 CIN2
14 2 CIP2
17 5 CIN3
16 4 CIP3
28 15 CINP
27 14 CIPP
43 29 VREF Connection for current setting resistor
30 17 TP17 Manufacturer's Test Pins (Leave unconnected)
31 18 TP18
38 24 TP24
39 25 TP25
40 26 TP26
41 27 TP27
Designation Description
DD
SS
Positive Supply Voltage
Negative Suply Voltage
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SA9105A
PIN DESCRIPTION (Continued)
Pin Pin
PLCC DIP
12 NC Not connected
24 NC
34 NC
44 NC
Designation Description
FUNCTIONAL DESCRIPTION
The SAMES SA9105A is a CMOS mixed signal Analog/Digital integrated circuit, which
performs three phase power/energy calculations over a range of 1000:1, to an overall
accuracy of better than Class 1.
The integrated circuit includes all the required functions for 3-phase power and energy
measurement such as 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 SA9105A generates pulses, the frequency of which is proportional to the power
consumption. Three frequency outputs (FOUT1, FOUT2 and FOUT3) are available.
1. Power Calculation
In the Application Circuit (Figure 1), the mains voltages from Line 1, Line 2 and Line
3, are converted to currents and applied to the voltage sense inputs IVP1, IVP2 and
IVP3.
The current levels on the voltage sense inputs are derived from the mains voltage
(3 x 230 VAC) being divided down through voltage dividers to 14V. The resulting
input currents into the A/D converters are 14µA through the resistors R15, R16 and
R17.
For the current sense inputs the voltage drop across the current transformers
terminating resistors are converted to currents of 16µA for rated conditions, by
means of resistors R8, R9 (Phase 1); R10, R11 (Phase 2) and R12, R13 (Phase 3).
The signals providing the current information are applied to the current sensor inputs
IIN1, IIP1; IIN2, IIP2 and IIN3, IIP3.
In this configuration, with the mains voltage of 3 x 230 V and rated currents of 80A,
the output frequency of the SA9105A energy metering integrated circuit at FOUT1
is 1.16kHz. In this case 1 pulse will correspond to an energy consumption of 3 x 18.4
kW/1160Hz = 47.6 Ws.
The output frequency at FOUT2 is FOUT1/4. At FOUT3 the output frequency is
FOUT1/290.
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SA9105A
2. Analog Input Configuration
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 processing circuitry
V
DD
IIP
CURRENT
SENSOR
INPUTS
IIN
IVP
VOLTAGE
SENSOR
INPUT
DR-00904
V
SS
V
DD
V
SS
V
DD
V
SS
GND
A
A
I
V
3. Electrostatic Discharge (ESD) Protection
The SA9105A integrated circuit's inputs/outputs are protected against ESD according
to Mil-Std 883 method 3015. The SA9105A integrated circuit's resistance to
transients is also dependant upon the external protection components used.
4. Power Consumption
The overall power consumption rating of the SA9105A integrated circuit is less than
75mW with a 5V supply.
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SA9105A
TYPICAL APPLICATION
In the Application Circuit (Figure 1), the components required for a three phase power
metering application are shown. Terminated current transformers are used for current
sensing.
The most important external components for the SA9105A integrated circuit are:
C7, C9, C10 and C11 are the outer loop capacitors for the integrated oversampling
A/D converters. The typical value of C7 is 2.2nF and the value of C9, C10 and C11 is
560pF.
The actual values determine the signal to noise and stability performance. The tolerances
should be within ± 10%.
C4, C5, C6 and C8 are the inner loop capacitors for the integrated oversampling A/D
converters. The typical value of C4, C5, C6 and C8 is 3.3nF. Values smaller than 0.5nF
and larger than 5nF should be avoided.
Terminated current sensors (current transformers) are connected to the current sensor
inputs of the SA9105A through current setting resistors (R8 ..R13).
The resistor values should be selected for an input current of 16µA into the SA9105A at
the rated line current.
The values of these resistors should be calculated as follows:
Phase 1:
R8 = R9 = (IL1/16µA) * R18/2
Phase 2:
R10 = R11 = (IL2/16µA) * R19/2
Phase 3:
R12 = R13 = (IL3/16µA) * R20/2
Where I
LX
R18, R19 and R
= Secondary CT current at rated conditions.
= Current transformer termination resistors for the three phases.
20
R1 + R1A, R4 and R15 set the current for the phase 1 voltage sense input. R2 + R2A, R5 +
P5 and R16 set the current for phase 2 and R3 + R3A, R6 + P6 and R17 set the current for phase
3. The values should be selected so that the input current into the voltage sense inputs
(virtual ground) are set to 14µA for nominal line voltage. Capacitors C1, C2 and C3 are
for decoupling and phase compensation.
R
+ P14 defines all on-chip bias and reference currents. With R14+ P14 = 24kΩ, optimum
14
conditions are set. R14 may be varied within ± 10% for calibration purposes. Any changes
to R
will affect the output quadratically (i.e: ∆R = +5%, ∆f = +10%).
14
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SA9105A
The formula for calculating the Output Frequency (f) is given below:
f = 11.16
3.58MHz 3 * I
FOUTX
*
FOSC * (II1 IV1) + (II2 IV2) + (II3 IV3)
*
2
R
Where FOUTX = Nominal rated frequency (4Hz, 290Hz or 1160Hz)
FOSC = Oscillator frequency (2MHz ...... 4MHz)
II1, II2, II3= Input currents for current inputs (16µA at rated)
IV1, IV2, IV3= Input currents for voltage inputs (14µA at rated)
I
R
= Reference current (typically 50µA)
XTAL is a colour burst TV crystal (f = 3.5795 MHz) for the oscillator. The oscillator
frequency is divided down to 1.7897 MHz on-chip, to supply the digital circuitry and the
A/D converters.
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SA9105A
Figure 1: Application Circuit for Three Phase Power/Energy Measurement.
MAINS VOLTAGES
LINE 1
LINE 2
LINE 3
N
0V
FROM CTs
2.5V
R18
R19
R20
2.5V
0V
VI1P
VI1N
VI2P
VI2N
VI3P
VI3N
R1
R2
R3
C5
C6
R8
R9
R10
R11
R12
R13
C7
C8
XTAL
DR-00233
R1A
R2A
R3A
1
2
3
4
5
6
7
SA9105A
8
DIP-40
9
10
IC-1
11
12
13
14
15
16
17
18
19
20
C4
C12
40
39
C9
38
37
C10
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
R15
R16
R17
C11
+
+
C13
0V
C1+
C2
C3
5V
FOUT3
FOUT2
FOUT1
R6
R5 R4 R21
P6
P5
0V
5V
R7
2.5V
C14
0V
0V
R14
P14
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0V
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SA9105A
Parts List for Application Circuit: Figure 1
Item Symbol Description Detail
1 IC-1 Integrated SA9105A DIP-40/PLCC-44
2 XTAL Crystal, 3.5795 MHz Colour burst TV
3 R1 Resistor, 200k, 1%, ¼W
4 R1A Resistor, 180k, 1%, ¼W
5 R2 Resistor, 200k, 1%, ¼W
6 R2A Resistor, 200k, 1%, ¼W
7 R3 Resistor, 200k, 1% , ¼W
8 R3A Resistor, 180k, 1%, ¼W
9 R4 Resistor, 24k, 1%, ¼W
10 R5 Resistor, 22k, 1%, ¼W
11 R6 Resistor, 22k, 1%, ¼W
12 R7 Resistor, 820 Ω, 1%, ¼W
13 R8 Resistor Note 1
14 R9 Resistor Note 1
15 R10 Resistor Note 1
16 R11 Resistor Note 1
17 R12 Resistor Note 1
18 R13 Resistor Note 1
19 R14 Resistor, 22k, 1%, ¼W
20 R15 Resistor, 1M, 1%, ¼W
21 R16 Resistor, 1M, 1%, ¼W
22 R17 Resistor, 1M, 1%, ¼W
23 R18 Resistor Note 1
24 R19 Resistor Note 1
25 R20 Resistor Note 1
26 R21 Resistor, 820Ω, 1%, ¼W
27 P5 Potentiometer, 4.7k Multi turn
28 P6 Potentiometer, 4.7k Multi turn
29 P14 Potentiometer, 4.7k Multi turn
30 C1 Capacitor, electrolytic, 1µF, 16V Note 2
31 C2 Capacitor, electrolytic, 1µF, 16V Note 2
32 C3 Capacitor, electrolytic, 1µF, 16V Note 2
33 C4 Capacitor, 3.3nF
34 C5 Capacitor, 3.3nF
35 C6 Capacitor, 3.3nF
36 C7 Capacitor, 2.2nF
37 C8 Capacitor, 3.3nF
38 C9 Capacitor, 560pF
39 C10 Capacitor, 560pF
40 C11 Capacitor, 560pF
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SA9105A
Parts List for Application Circuit: Figure 1 (Continued)
Item Symbol Description Detail
41 C12 Capacitor, 820nF Note 3
42 C13 Capacitor, 100nF
43 C14 Capacitor, 100nF
Note 1: Resistor (R8, R9, R10, R11, R12 and R13) values are dependant upon the selected
values of the current transformer termination resistors R18, R19 and R20.
Note 2: Capacitor values may be selected to compensate for phase errors caused by the
current transformers.
Note 3: Capacitor (C12) to be positioned as close to Supply Pins (VDD & VSS) of IC-1, as
possible.
ORDERING INFORMATION
Part Number Package
SA9105APA DIP-40
SA9105AFA PLCC-44
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SA9105A
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.
Any Sales or technical questions may be posted to our e-mail address below:
energy@sames.co.za
For the latest updates on datasheets, please visit out web site:
http://www.sames.co.za
South African Micro-Electronic Systems (Pty) Ltd
P O Box 15888, 33 Eland Street,
Lynn East, Koedoespoort Industrial Area,
0039 Pretoria,
Republic of South Africa, Republic of South Africa
Tel: 012 333-6021 Tel: Int +27 12 333-6021
Fax: 012 333-8071 Fax: Int +27 12 333-8071
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