sames
SA9108F
TWO PHASE BIDIRECTIONAL POWER/ENERGY
METERING IC WITH INSTANTANEOUS PULSE OUTPUT
FEATURES
n
Performs bidirectional one or two phase
power and energy measurement
n
Meets the IEC 521/1036 Specification
requirements for Class 1 AC Watt hour
meters
n
n
Operates over a wide temperature
range
n
Excellent long term stability
n
Easily adaptable to different signal
levels
n
Precision voltage reference on-chip
n
Two pulse rate output formats available
n
Protected against ESD
Adaptable to different types of current
sensors
DESCRIPTION
The SAMES SA9108F Two Phase bidirectional Power/Energy metering integrated
circuit generates pulse rate outputs for
positive and negative energy directions,
the frequency of which is proportional to the
power consumption. The SA9108F
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 two
phase power/energy metering integrated
circuit is ideally suited for applications such
as residential and industrial energy metering
and control.
The SA9108F integrated circuit is available
in 40 pin dual-in-line plastic (DIP-40), as
well as 44 pin plastic leaded chip carrier
(PLCC-44) package types.
PIN CONNECTIONS
CIP1
CIN1
CIP2
CIN2
1
40
2
39
3
38
TP4
TP5
IIN1
IIP1
4
COP1
CON1
37 CON2
5
36
6
35
COP2
GND
34 IVP1
7
8
IIN2
9
IIP2
TP10 10
TP11 11
33
32
31
30
COPP 12
CONP 13
CIPP 14
29
CINP 15
V SS 16
TP17 17
26
28
27
IVP2
TP32
TP31
TP30
VREF
V DD
TP27
TP26
25
DIR
TP24
23 FOUT2
22 TP22
24
TP18 18
OSC1 19
OSC2 20
21
FOUT1
DR-00940
Package: DIP-40
1/12
4364
PDS039-SA9108F-001
Rev. B
09-01-97
SA9108F
DIR
TP24
FOUT2
TP22
FOUT1
N.C.
OSC2
OSC1
TP18
TP17
V SS
PIN CONNECTIONS
39 38
35 34
33
32
31 30
29
40
28
41
27
42
26
43
25
44
24
1
23
2
22
3
21
4
20
5
19
6
18
8
9
10
11 12
COP2
CON2
CON1
COP1
CIP1
N.C.
7
13 14
15 16
CINP
CIPP
CONP
COPP
N.C.
TP11
TP10
IIP2
IIN2
IIP1
IIN1
17
CIN1
CIP2
CIN2
TP4
TP5
TP26
TP27
V DD
VREF
N.C.
TP30
TP31
TP32
IVP2
IVP1
GND
37 36
DR-00941
Package: PLCC-44
BLOCK DIAGRAM
12 CONNECTIONS
FOR LOOPCAPS
V D D VSS
IVP1
IVP2
ANALOG
INTEG.
POWER
FOUT1
&
TO
FOUT2
AVERAGE
PULSERATE
SIGNAL
IIP1
IIN1
PRO-
IIP2
IIN2
DIR
CESSING
GND
REF
VREF
DR-00942
2/12
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TIMING & CONTROL
OSC
OSC1
OSC2
SA9108F
ABSOLUTE MAXIMUM RATINGS *
Parameter
Symbol
Supply Voltage
VDD-VSS
Current on any Pin
IPIN
Storage Temperature
TSTG
Operating Temperature
TO
Min
-0.3
Max
6.0
Unit
V
-150
-40
-40
+150
+125
+85
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 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
(VDD = 5V over the temperature range -10°C to +70°C#, unless otherwise specified.)
Parameter
Supply Voltage
Supply Current
Nonlinearity of
Power Calculation
Symbol
VDD-VSS
IDD
Min Typ
4.5
Max Unit Condition
5.5
V
10 mA
-0.3
+0.3
%
-25
+25
µA
Peak value
-25
+25
µA
Peak value
1% -100% of rated
power
Current Sensor Inputs (Differential)
Input Current Range
III
Voltage Sensor Inputs (Asymmetric)
Input Current Range
IIV
Digital Outputs:
Output Low Voltage
VOL
Output High Voltage
VOH
Pulse Rate: FOUT1, FOUT2 fp
Oscillator
Pin VREF
Ref. Current
Ref. Voltage
#
VSS+1 V IOL = 5mA
VDD-1
V IOH = -2mA
0
64
Hz Specified linearity
0
180 Hz Min and max limits
Recommended crystal:
TV colour burst crystal, f = 3.5795 MHz
With R = 24 kΩ
-IR
45
50
55
µA connected to VSS
VR
1.1
1.3
V Referred to V SS
Extended Operating Temperature Range available on request.
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3/12
SA9108F
PIN DESCRIPTION
Pin
Pin
PLCC-44 DIP-40
6
35
42
28
29
16
5
34
4
33
18
6
19
7
20
8
21
9
32
19
33
20
35
21
37
23
39
25
9
38
10
39
8
37
7
36
26
13
25
12
13
1
11
40
15
3
14
2
28
15
27
14
43
29
41
27
16
4
17
5
22
10
23
11
30
17
31
18
36
22
38
24
40
26
1
30
2
31
3
32
4/12
Designation
GND
VDD
VSS
IVP1
IVP2
IIN1
IIP1
IIN2
IIP2
OSC1
OSC2
FOUT1
FOUT2
DIR
CON1
COP1
CON2
COP2
CONP
COPP
CIN1
CIP1
CIN2
CIP2
CINP
CIPP
VREF
TP27
TP4
TP5
TP10
TP11
TP17
TP18
TP22
TP24
TP26
TP30
TP31
TP32
sames
Description
Ground
Positive Supply Voltage
Negative Suply Voltage
Analog input for Voltage : Phase 1
Analog input for Voltage : Phase 2
Inputs for current sensor : Phase 1
Inputs for current sensor : Phase 2
Connections for crystal or ceramic resonator
(OSC1 = Input; OSC2 = Output)
Pulse rate outputs
Direction indication
Connections for outer loop capacitors of A/D
converters
Connections for inner loop capacitors of A/D
converters
Connection for current setting resistor
Test Pin. Connect to VSS
Manufacturer's test pins (Leave unconnected)
SA9108F
PIN DESCRIPTION (Continued)
Pin
Pin
Designation
PLCC-44 DIP-40
12
NC
24
NC
34
NC
44
NC
Description
Not connected
FUNCTIONAL DESCRIPTION
The SAMES SA9108F is a CMOS mixed signal Analog/Digital integrated circuit, which
performs two phase power/energy calculations over a dynamic range of greater than
1000:1, to an overall accuracy of better than Class 1.
The integrated circuit includes all the required functions for 2-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 SA9108F generates pulses, the frequency of which is proportional to the power
consumption. The pulse rate follows the instantenous power measured. Direction
information is also provided.
1.
Power Calculation
In the Application Circuit (Figure 1), the mains voltages from Line 1 and Line 2, are
converted to currents and applied to the voltage sense inputs IVP1 and IVP2. The
mains voltage (2 x 115 V) is divided down through voltage dividers to 14V. The
resulting input currents into the A/D converters are 14µARMS through the resistors R9
and R10.
For the current sense inputs the voltage drop across the current transformers'
terminating resistors are converted to currents of 16µARMS for rated conditions, by
means of resistors R5, R6, (Phase 1) and R7, R8 (Phase 2).
The signals providing the current information are applied to the current sensor inputs
IIN1, IIP1 and IIN2, IIP2.
In this configuration, with the mains voltage of 2 x 115 VAC and rated currents of
80A, the output frequency of the SA9108F energy metering integrated circuit at
FOUT1 is 64Hz. In this case 1 pulse will correspond to an energy consumption of
2 x 9.2 kW/64Hz = 287.5 Ws.
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5/12
SA9108F
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
II P
CURRE NT
S ENSOR
INPUTS
V SS
A
I
V DD
II N
V SS
V DD
IV P
V OL TAGE
S ENSOR
INPUT
V SS
AV
GND
D R -0 0 9 4 3
3.
Electrostatic Discharge (ESD) Protection
The SA9108F integrated circuit's inputs/outputs are protected against ESD .
4.
Power Consumption
The overall power consumption rating of the SA9108F integrated circuit is less than
40mW having a 5V supply.
6/12
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SA9108F
5.
Pulse Output Signals
The calculated power is divided down to a pulse rate 64Hz, for rated conditions on
FOUT1 and FOUT2.
Two formats of pulse output signals are available which provide both power/energy
and direction information.
The direction of the energy flow is defined by the mark/space ratio on FOUT1 while
the pulse width defines the direction on FOUT2.
Positive Energy Flow
Negative Energy Flow
Wave form on FOUT1
Wave form on FOUT2
t pp
t pp
mm
mm
t pp = 1.1ms
t pn
mm
t pn
mm
t pn = 3.4ms
Wave form on DIR
DR-00944
An integrated anticreep function ensures no metering at zero line currents.
The formula for calculating the Output Frequency (f) is given below:
FOSC
(II1 IV1) + (I I2 I V2)
f = 11.16 * FOUTX *
3.58MHz *
2 * IR2
Where FOUTX
= Nominal rated frequency (64Hz)
FOSC
= Oscillator frequency (2MHz ...... 4MHz)
II1, II2
= Input currents for current sensor inputs (16µA at rated line current)
IV1, IV2
= Input currents for voltage sensor inputs (14µA at rated line voltage)
IR
= Reference current (typically 50µA)
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7/12
SA9108F
TYPICAL APPLICATION
In the Application Circuit (Figure 1), the components required for a two phase power
metering application, are shown. Terminated current transformers are used for current
sensing.
The most important external components for the SA9108F integrated circuit are:
C2, C 6 and C7 are the outer loop capacitors for the integrated oversampling A/D
converters. The typical value of C2 is 2.2nF and the value of C6 and C7 is 560µF.
The actual values determine the signal to noise and stability performance. The
tolerances should be within ± 10%.
C1, C 3 and C4 are the inner loop capacitors for the integrated oversampling A/D
converters. The typical value of C 1, C3 and C4 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 SA9108F through current setting resistors (R5, R6 and R7, R8).
The resistor values should be selected for an input current of 16µARMS into the SA9108F,
at the rated line current.
The values of these resistors should be calculated as follows:
Phase 1:
R5 = R 6 = (IL1/16µARMS) * R 3/2
Phase 2:
R7 = R 8 = (IL2/16µARMS) * R 4/2
Where ILX
= Secondary CT current at rated conditions.
R3 and R 4
= Current transformer termination resistors for the two phases.
R1 + R 1A, R13 and R9 set the current for the phase 1 voltage sense input. R2 + R2A , R12 +
P2 and R10 set the currents for phase 2. The values should be selected so that the input
currents into the voltage sense inputs (virtual ground) are set to 14µA RMS for nominal line
voltage. Capacitors C8 and C9 are for decoupling and phase compensation.
R11 and P1 defines all on-chip bias and reference currents. With a total resistance of
24kΩ, optimum conditions are set. R11 + P1 may be varied within ± 10% for calibration
purposes. Any change in resistance will affect the output quadratically (i.e: ∆R = +5%,
∆f = +10%).
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.
8/12
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SA9108F
Figure 1: Application Circuit for Two Phase Power/Energy Measurement.
M AINS VOL TAGES
L IN E 1
L IN E 2
R1
R1A
R2
R2A
C4
N
0 V
C1
F ROM CT s
R3
R5
V I1 P
V I1 N
R6
R4
R7
V I2 P
R8
V I2 N
1
40
2
39
3
38
4
37
5
36
6
35
7
34
C2
C3
0 V
C7
33
S A 9108F
R9
+ C8
R10
+ C9
32
R12
31
10
11
C6
R14
8
9
5 V
IC - 1
R15
C11
30
12
29
13
28
14
27
15
26
16
25
17
24
18
23
P2
+ C10
0 V
D IR
19
22
20
21
0 V
0 V
F OU T 2
F OU T 1
XT A L
D R -0 0 9 4 5
R13
0 V
C5
R1 1
P1
0 V
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9/12
SA9108F
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
29
30
31
32
Symbol
IC-1
XTAL
R1
R1A
R2
R2A
R13
R12
R14
R5
R6
R7
R8
R11
R9
R10
R3
R4
R15
P2
P1
C8
C9
C4
C1
C2
C3
C6
C7
C5
C10
C11
Description
SA9108FPA
Crystal, 3.5795 MHz
Resistor, 120k, 1%, 1/4W
Resistor, 82k, 1%, 1/4W
Resistor, 120k, 1%, 1/4W
Resistor, 82k, 1%, 1/4W
Resistor, 24k, 1%, 1/4W
Resistor, 22k, 1%, 1/4W
Resistor, 820Ω, 1%, 1/4W
Resistor
Resistor
Resistor
Resistor
Resistor, 22k, 1%, 1/4W
Resistor, 1M, 1%, 1/4W
Resistor, 1M, 1%, 1/4W
Resistor
Resistor
Resistor, 820Ω, 1%, 1/4W
Potentiometer, 4.7k
Potentiometer, 4.7k
Capacitor, electrolytic, 1µF, 16V
Capacitor, electrolytic, 1µF, 16V
Capacitor, 3.3nF
Capacitor, 3.3nF
Capacitor, 2.2nF
Capacitor, 3.3nF
Capacitor, 560pF
Capacitor, 560pF
Capacitor, 820nF
Capacitor, 100nF
Capacitor, 100nF
Detail
DIP-40
Colour burst TV
Note 1
Note 1
Note 1
Note 1
Note 1
Note 1
Multi turn
Multi turn
Note 2
Note 2
Note 3
Note 1: Resistor (R5, R 6, R7 and R8) values are dependant upon the selected values of
the current transformer termination resistors R3 and R4.
Note 2: Capacitor values may be selected for DC blocking and to compensate for phase
errors caused by the current transformers.
Note 3: Capacitor (C5) to be positioned as close to Supply Pins (VDD & VSS ) of IC-1, as
possible.
10/12
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SA9108F
ORDERING INFORMATION
Part Number
Package
SA9108FPA
DIP-40
SA9108FFA
PLCC-44
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11/12
SA9108F
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.
Any Sales or technical questions may be posted to our e-mail address below:
[email protected]
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:
Fax:
12/12
012 333-6021
012 333-8071
sames
Tel:
Fax:
Int +27 12 333-6021
Int +27 12 333-8071