The SAMES SA9105E Three Phase
unidirectional Power/Energy metering
integrated circuit generates a pulse rate
output, the frequency of which is proportional
to the power consumption. The SA9105E
performs the calculation for 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 SA9105E 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) package types.
nUses current transformers for current
sensing
nExcellent long term stability
nEasily adaptable to different signal
levels
nPrecision voltage reference on-chip
nThree pulse rate options available
nProtected 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
4262PDS039-SA9105E-001 Rev. B 15-09-1995
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SA9105E
PIN CONNECTIONS
BLOCK DIAGRAM
16 CONNECTIONS
IVP1
IVP2
IVP3
IIP1
IIN1
IIP2
IIN2
IIP3
IIN3
GND
TP25
38
39373536
40
TP26
41
TP27
V
42
DD
43
VREF
44
N.C.
1
CON3
2
COP3
3
IVP3
4
IVP2
5
IVP1
6
GND
8
7
CON2
DR-00840
COP2
Package: PLCC-44
FOR LOOPCAPS
ANALOG
SIGNAL
PRO-
CESSING
N.C.
FOUT3
FOUT2
FOUT1
TP24
34
12
10911
COP1
N.C.
CON1
CIP1
INTEG.
&
AVERAGE
OSC2
OSC1
CIN1
CIP2
TP18
151413
CIN2
TP17
3033 32 31
16
CIP3
29
17
SS
V
28
27
26
25
24
23
22
21
20
19
18
CIN3
POWER
TO
PULSE
RATE
CINP
CIPP
CONP
COPP
N.C.
IIP3
IIN3
IIP2
IIN2
IIP1
IIN1
VV
DD
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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SA9105E
ABSOLUTE MAXIMUM RATINGS *
ParameterSymbolMinMaxUnit
Supply VoltageVDD-V
Current on any PinI
Storage TemperatureT
Operating TemperatureT
PIN
STG
O
SS
-0.36.0V
-150+150mA
-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.)
ParameterSymbol Min Typ Max Unit Condition
Supply VoltageVDD-V
Supply CurrentI
DD
4.55.5V
SS
15mA
Nonlinearity of
Power Calculation-0.3+0.3% 1% - 100% of
rated power
Current Sensor Inputs (Differential)
Input Current RangeI
II
-25+25µAPeak value
Voltage Sensor Inputs (Asymmetric)
Input Current RangeI
IV
-25+25µAPeak value
Pins FOUT1,FOUT2,FOUT3
Output Low VoltageV
Output High VoltageV
Pulse Rate: FOUT1f
OL
OH
p
VDD-1VIOH = -2mA
101160HzSpecified linearity
VSS+1VIOL = 5mA
0.53000HzMin and max limits
FOUT2f
FOUT3f
p2
p3
fp/4
fp/290
OscillatorRecommended crystal:
TV colour burst crystal, f = 3.5795 MHz
Pin VREFWith R = 24 kΩ
Ref. Current-I
Ref. VoltageV
#
Extended Operating Temperature Range available on request.
R
R
455055µAconnected to V
1.11.3VReferred to V
SS
SS
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SA9105E
PIN DESCRIPTION
PinPin
PLCCDIP
635GNDGround
4228V
2916V
534IVP1Analog input for Voltage : Phase 1
433IVP2Analog input for Voltage : Phase 2
332IVP3Analog input for Voltage : Phase 3
186IIN1Inputs for current sensor : Phase 1
197IIP1
208IIN2Inputs for current sensor : Phase 2
219IIP2
2210IIN3Inputs for current sensor : Phase 3
2311IIP3
3219OSC1Connections for crystal or ceramic resonator
3320OSC2(OSC1 = Input ; OSC2 = Output)
3521FOUT1Pulse rate outputs
3622FOUT2
3723FOUT3
938CON1Connections for outer loop capacitors of A/D
1039COP1converters
837CON2
736COP2
130CON3
231COP3
2613CONP
2512COPP
131CIN1Connections for inner loop capacitors of A/D
1140CIP1converters
153CIN2
142CIP2
175CIN3
164CIP3
2815CINP
2714CIPP
4329VREFConnection for current setting resistor
3017TP17Manufacturer's test pins (Leave unconnected)
3118TP18
3824TP24
3925TP25
4026TP26
4127TP27
Designation Description
DD
SS
Positive Supply Voltage
Negative Suply Voltage
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SA9105E
PIN DESCRIPTION (Continued)
PinPin
PLCCDIP
12NCNot connected
24NC
34NC
44NC
Designation Description
FUNCTIONAL DESCRIPTION
The SAMES SA9105E 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 SA9105E generates pulses, the frequency of which is proportional to the power
consumption. Three frequency outputs (FOUT1, FOUT2 and FOUT3) are available. The
pulse rate follows the instantaneous power measured.
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 SA9105E 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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SA9105E
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
V
CURRENT
SENSOR
INPUTS
IIN
SS
V
DD
V
SS
V
DD
A
I
IVP
VOLTAGE
SENSOR
INPUT
DR-00524
V
SS
GND
A
V
3.Electrostatic Discharge (ESD) Protection
The SA9105E integrated circuit's inputs/outputs are protected against ESD
according to Mil-Std 883 method 3015. The SA9105E 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 SA9105E integrated circuit is less than
75mW with a 5V supply.
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SA9105E
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 SA9105E 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 SA9105E through current setting resistors (R8 ..R13).
The resistor values should be selected for an input current of 16µA into the SA9105E, 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 currents 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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SA9105E
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.
Figure 1: Application Circuit for Three Phase Power/Energy Measurement.
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 NumberPackage
SA9105EPADIP-40
SA9105EFAPLCC-44
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Notes:
SA9105E
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SA9105E
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,Koedoespoort Industrial Area,
0039Pretoria,
Republic of South Africa,Republic of South Africa