Three Phase Bidirectional Power/Energy
Metering IC with Instantaneous Pulse Output
sames
SA2005F
FEATURES
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Functionally compatible with the SA9105F with reduced
external components
Performs bidirectional one, two or three phase power and
energy measurement
Meets the IEC 521/1036 Specification requirements for
Class 1 AC Watt hour meters
Operates over a wide temperature range
Uses current transformers for current sensing
Easily adaptable to different signal levels
Precision voltage reference on chip
Precision oscillator on chip.
Protected against ESD
DESCRIPTION
Energy consumption is determined by integrating the power
measurement over time.
The SAMES SA2005F is an enhancement of the SA9105F. A
precision oscillator and the loop capacitors are integrated on
chip.
This innovate universal three phase power/energy metering
integrated circuit is ideally suited for applications such as
residential and industrial energy metering and control.
The SAMES SA2005F three phase bidirectional power/energy
metering integrated circuit generates pulse rate outputs for
positive and negative energy directions. The frequency of the
pulses is proportional to the measured power consumption.
The SA2005F performs active power calculation.
The SA2005F integrated circuit is available in 20 pin dual-inline plastic (DIP-20), and 20 pin small outline (SOIC-20)
package types.
The method of calculation takes the power factor into account.
VDD VSS
IIN1
IIP1
I1
IVN1
V1
IIN2
IIP2
I2
IVN2
V2
PGM0 PGM1
X
INTEGRATE
AND
X
IIN3
IIP3
I3
IVN3
V3
AVERAGE
POWER
TO
PULSE
RATE
FOUT
DIR
X
GND
Dr-01570
REF
TIMING & CONTROL
OSC
VREF
TEST
TCLK
Figure 1: Block Diagram
SPEC-0042 (REV. 1)
1/10
03-07-00
sames
SA2005F
ELECTRICAL CHARACTERISTICS
(VDD = 2.5V, VSS = -2.5V, over the temperature range -10°C to +70°C#, unless otherwise specified.)
Symbol
Min
TO
Supply Voltage
VDD - VSS
Supply Current
IDD
Typ
Max
Unit
-25
+85
°C
4.5
5.5
V
10
mA
Output unloaded
-0.3
+0.3
%
1% - 100% of rated
power
III
-25
+25
µA
Peak value
IIV
-25
+25
µA
Peak value
VOL
VOH
VDD-1
VSS+1
V
V
fP
0
0
64
200
Hz
Hz
MODES 0, 1, 2
Specified linearity
Min and Max limits
fP
0
0
1160
3500
Hz
Hz
MODE 3
Specified linearity
Min and Max Limits
Pin PGM0, PGM1, TEST, TCLK
High Voltage
Low Voltage
VIH
VIL
VDD-1
VSS+1
V
V
Pin VREF
Ref. Current
Ref. Voltage
-IR
VR
45
1.1
Parameter
Operating temp. Range
Nonlinearity of Power
Calculation
Condition
Current Sensor Inputs (Diffferential)
Input Current Range
Voltage Sensor Input (Asymmetrical)
Input Current Range
Pins FOUT, DIR
Output Low Voltage
Output High Voltage
Pulse Rate: FOUT
50
55
1.3
IOL = 5mA
IOH = -2mA
With R = 24kW
connected to VSS
Referred to VSS
µA
V
ABSOLUTE MAXIMUM RATINGS*
Parameter
Symbol
Min
Max
Unit
Supply Voltage
VDD -VSS
-0.3
6.0
V
Current on any pin
IPIN
-150
+150
mA
Storage Temperature
TSTG
-40
+125
°C
Operating Temperature
TO
-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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SA2005F
PIN DESCRIPTION
PIN
Designation
Description
16
GND
6
VDD
Positive Supply voltage.
14
VSS
Negative Supply voltage.
17, 20, 3
IVN1, IVN2, IVN3
Analog Ground. The voltage to this pin should be mid-way between VDD and VSS.
The current into the A/D converter should be set at 14µARMS at nominal mains
voltage. The voltage sense input saturates at an input current of ±25µA peak.
Inputs from current sensors. The shunt resistor voltage from each channel is
IIN1, IIP1, IIN2, IIP2,
converted to a current of 16µARMS at rated conditions. The current sense input
IIN3, IIP3
saturates at an input current of ±25µA peak.
19, 18, 2, 1,
5, 4
This pin provides the connection for the reference current setting resistor.
A 24kW resistor connected to VSS sets the optimum operating condition.
15
VREF
7, 10
TCLK, TEST
8
FOUT
9
DIR
12, 13
PGM0, PGM1
Test inputs. For normal operation these pins must be connected to VSS.
Pulse rate output. The pulse frequency is proportional to the sum of the power
measured on all three phases. The pulse format also indicates the direction of
energy flow.
Direction output. This output indicates the direction of energy flow.
FOUT Pulse format Select. These inputs define the FOUT pulse width
and format.
ORDERING INFORMATION
IIP2
20
1
IVN2
Part Number
Package
SA2005FPA
DIP-20
SA2005FSA
SOIC-20
IIN2
2
19
IIN1
IVN3
3
18
IIP1
IIP3
4
17
IVN1
IIN3
5
16
GND
VDD
6
15
VREF
TEST
7
14 VSS
FOUT
8
13
PGM1
DIR
9
12
PGM0
TCLK
10
11
NC
DR-01571
Figure 2: Pin connections: Package: DIP-20, SOIC-20
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SA2005F
FUNCTIONAL DESCRIPTION
The SAMES SA2005F is a CMOS mixed signal integrated
circuit, which performs three phase power/energy calculations
over a range of 1000:1, to an overall accuracy of better than
Class 1.
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.
The SA2005F is functionally similar to the SA9105F. No
external loop capacitors are required and an precision
oscillator is integrated on chip.
Voltage Reference Connection (VREF)
A bias resistor of 24k provides an optimum bias conditions on
chip. Calibration of the SA2005F should be done on the
voltage inputs of the device as described in Typical
Applications.
The integrated circuit includes all the required functions for 3phase 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.
Current Sense Inputs (IIN1, IIP1, IIN2, IIP2, IIN3, IIP3)
At rated current the resistor values should be selected for input
currents of 16µARMS. Referring to figure 5, the resistors R1 and
R2 on current channel 1, resistors R3 and R4 on current
channel 2 and resistors R5 and R6 on current channel 3, define
the current level into the current sense inputs of the SA2005F.
The current sense inputs saturates at an input current of ±25µA
peak. Resistors R25, R26 and R27 are the current transformer
termination resistors. The voltage drop across the termination
resistors should be at least 20mV at rated conditions. Values
for the current sense inputs are calculated as follows:
The SA2005F generates pulses with a frequency proportional
to the power measured. The pulse rate follows the
instantaneous power measured. The pulse frequency is
proportional to the total sum of the three phases.
POWER CALCULATION
In the application circuit (figure 5), the mains voltages from V1,
V2 and V3, are converted to currents and applied to the voltage
sense inputs IVP1, IVP2 and IVP3.
R1 = R2 = (IL / 16µARMS) x R25 / 2
R3 = R4 = (IL / 16µARMS) x R26 / 2
R5 = R6 = (IL / 16µARMS) x R27 / 2
The current levels on the voltage sense inputs are derived from
the mains voltages (3 x 230VAC) being divided down to 14V
through voltage dividers. The resulting input currents into the
A/D converters are 14µARMS through the resistors R8, R9 and
R10.
Where:
IL = Line current/CT-ratio
For the current sense inputs the voltage drop across the
current transformers terminating resistors are converted to
currents of 16µARMS at rated conditions, by means of resistors
R1, R2 (Phase 1); R3, R4 (Phase 2) and R5, R6 (Phase 3). The
signals providing the current information are applied to the
current sensor inputs IIN1, IIP1, IIN2, IIP2 and IIN3, IIP3.
V DD
IIP
CURRENT
SENSOR
INPUTS
VSS
AI
VDD
IIN
The output frequency of the SA2005F energy metering
integrated circuit at rated conditions is 64Hz on FOUT
(PGM0=0, PGM1=1).
VSS
VDD
IVP
One pulse (measured in Watt second) correspond to an energy
measured of 3 x IRATED x VRATED / 64Hz.
VOLTAGE
SENSOR
INPUT
V SS
AV
For a more detailed description see the Input Signals section.
INPUT SIGNALS
GND
Analog Input Configuration
The current and voltage sensor inputs are illustrated in figure 3.
These inputs are protected against electrostatic discharge
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DR-01288
Figure 3: Analog Input Internal Configuration
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SA2005F
Voltage Sense Inputs (IVN1, IVN2, IVN3)
The current into the voltage sense inputs (virtual ground)
should be set to 14µARMS at rated voltage conditions. The
individual mains voltages are divided down to 14VRMS per
phase. The resistors R8, R9 and R10 set the current for the
voltage sense inputs. The voltage sense inputs saturate at an
input current of ±25µA peak.
DIR as a logic 1. The DIR pin may be used to drive a LED in
order to indicate reverse energy flow.
Frequency Output (FOUT)
The sum of the measured power, from the three phases
produce a pulse rate of 64Hz or 1160Hz (mode 3), at rated
conditions on FOUT. The format of the pulse output signal,
which provides power/energy and direction information is
shown in figure 4. Refer to Pulse Programming Inputs for pulse
widths.
Pulse Programming Inputs (PGM0, PGM1)
The pulse programming inputs PGM1 and PGM0 define the
representation of energy measured by the device on FOUT.
The table below shows the difference between the various
modes.
Reverse
Pulse
Width
3.4ms
0
0
0
64Hz
Forward
Pulse
Width
1.14ms
1
0
1
64Hz
1.14ms
1.14ms
2
1
0
64Hz
1.14ms
1.14ms
3
1
1
1160Hz
71µs
71µs
Mode PGM1 PGM0
Frequency
at rated
conditions
The following equation may be used for calculating the output
frequency:
f = 11.16 x FOUTX x ((II1 x IV1)+(II2 x IV2)+(II3 x IV3)) / 3 x IR
Where:
FOUTX = Nominal rated frequency (64Hz/1160Hz)
II1, II2, II3 = Input currents for current sensor inputs (16µA at rated
line current)
IV1, IV2, IV3 = Input currents for voltage sensor inputs (14µA at
rated line voltage)
IR = Reference current (typically 50µA)
Test Inputs (TCLK, TEST)
The TEST and TCLK inputs are manufacturers test pins and
must be connected to VSS in a metering application.
An integrated anti-creep function ensures that no pulses are
generated at zero line currents.
ELECTROSTATIC DISCHARGE (ESD) PROTECTION
OUTPUT SIGNALS
The SA2005F integrated circuit's inputs/outputs are protected
against ESD.
Direction Indication (DIRO)
The SA2005F indicates the measured energy flow direction on
pin DIR. A logic 0 on pin DIR indicates reverse energy flow.
Reverse energy flow is defined as the condition where the
voltage sense input and current sense input are out of phase
(greater than 90 degrees). Positive energy flow, when voltage
sense and current sense input are in phase, is indicated on pin
POWER CONSUMPTION
The overall power consumption rating of the SA2005F
integrated circuit is less than 50 mW with a 5V supply.
MODE 0
FOUT
MODE1
FOUT
MODE2
FOUT
MODE3
FOUT
DIR
DR-01582
Note: Frequency of pulse rate in MODE 3 is 18 times higher than other modes
Figure 4: FOUT options
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SA2005F
TYPICAL APPLICATION
VOLTAGE DIVIDER
In figure 5, the components required for the three phase
power/energy metering section of a meter, is shown. The
application uses current transformers for current sensing. The
4-wire meter section is capable of measuring 3x230V/80A with
precision better than Class 1.
The voltage divider is calculated for a voltage drop of 14V.
Equations for the voltage divider in figure 5 are:
RA = R16 + R19 + R22
RB = R8 || (R13+P1)
Combining the two equations gives:
The most important external components for the SA2005F
integrated circuit are the current sense resistors, the voltage
sense resistors as well as the bias setting resistor.
( RA + RB ) / 230V = RB / 14V
A 5k trimpot is used in each of voltage channel for meter
calibration. The center position of the pot is used in the
calculations. P1 = 2.5k and values for resistors R13 = 22k and
R8 =1M is chosen.
BIAS RESISTOR
R7 defines all on-chip and reference currents. With R7=24kW,
optimum conditions are set. Device calibration is done on the
voltage inputs of the device.
Substituting the values result in:
RB = 23.9k
RA = RB x (230V / 14V - 1)
RA = 368.9k.
CT TERMINATION RESISTOR
The voltage drop across the CT termination resistor at rated
current should be at least 20mV. The CT’s used have low
phase shift and a ratio of 1:2500.The CT is terminated with a
2.7W resistor giving a voltage drop across the termination
resistor 864mV at rated conditions (Imax for the meter).
Resistor values of R16, R19 and R22 is chosen to be 120k,
120k and 130k.
CURRENT SENSE RESISTORS
The three voltage channels are identical so R14= R15= R16 =
R17 = R18 = R19 and R20 = R21= R22.
The resistors R1 and R2 define the current level into the
current sense inputs of phase one of the device. The resistor
values are selected for an input current of 16µA on the current
inputs at rated conditions.
According to equation described in the Current Sense inputs
section:
R1 = R2
= (IL / 16µA ) x RSH / 2
= 80A /2500 / 16µA x 2.7W / 2
= 2.7kW
IL = Line current / CT Ratio
The three current channels are identical so R1 = R2 = R3 = R4
= R5 = R6.
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SA2005F
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NEUTRAL
V3 In
R20
R17
R14
GND
R12
R15
V2 In
R18
P3
R21
R11
R19
R16
V1In
P2
R22
R13
R1
CT1
U1
19
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Figure 5: Application Circuit
IIN1
GND
16
P1
GND
R25
IVN1
R2
18
IIP1
IVN2
GND
R3
CT2
2
IIN2
IVN3
17
R8
C5
20
R9
C4
3
R10
C3
R26
R4
1
DIR
9
D1
R28
8
D2
R29
VDD
IIP2
GND
R5
CT3
5
IIN3
FOUT
VSS
VDD
R27
VDD
R6
4
PGM1
IIP3
PGM0
GND
R7
V3 Out
TCLK
VREF
TEST
V2 Out
14
VSS
VSS
SA2002F
VDD
12
R23
C2
R24
C1
10
GND
7
6
Dr-01572
VSS
VSS
C6
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V1 Out
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SA2005F
Parts List for Application Circuit: Figure 5
Symbol
Description
U1
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10
R11
R12
R13
SA2005F
Resistor, 2.7k, 1/4W, 1% metal
Resistor, 2.7k, 1/4W, 1% metal
Resistor, 2.7k, 1/4W, 1% metal
Resistor, 2.7k, 1/4W, 1% metal
Resistor, 2.7k, 1/4W, 1% metal
Resistor, 2.7k, 1/4W, 1% metal
Resistor, 24k, 1/4W, 1%, metal
Resistor, 1M, 1/4W, 1%, metal
Resistor, 1M, 1/4W, 1%, metal
Resistor, 1M, 1/4W, 1%, metal
Resistor, 22k, 1/4W, 1%, metal
Resistor, 22k, 1/4W, 1%, metal
Resistor, 22k, 1/4W, 1%, metal
R14
R15
R16
R17
R18
R19
R20
Resistor, 120k, 1/4W, 1%, metal
Resistor, 120k, 1/4W, 1%, metal
Resistor, 120k, 1/4W, 1%, metal
R21
R22
R23
R24
R25
R26
R27
P1
P2
P2
C1
C2
C3
C4
C5
C6
LED1
LED2
CT1
CT2
CT3
Detail
DIP-20/SOIC-20
Note 1
Note 1
Note 1
Note 1
Note 1
Note 1
Resistor, 120k, 1/4W, 1%, metal
Resistor, 120k, 1/4W, 1%, metal
Resistor, 120k, 1/4W, 1%, metal
Resistor, 130k, 1/4W, 1%, metal
Resistor, 130k, 1/4W, 1%, metal
Resistor, 130k, 1/4W, 1%, metal
Resistor, 1k, 1/4W, 1%, metal
Resistor, 1k, 1/4W, 1%, metal
Resistor, 2.7R, 1/4W, 1%, metal
Resistor, 2.7R, 1/4W, 1%, metal
Resistor, 2.7R, 1/4W, 1%, metal
Trim pot, 5k, Multi turn
Trim pot, 5k, Multi turn
Trim pot, 5k, Multi turn
Capacitor, 220nF
Capacitor, 220nF
Capacitor, 820nF
Note 1
Note 1
Note 1
Note 1
Note 2
Note 2
Note 2
Note 3
Capacitor, 820nF
Capacitor, 820nF
Capacitor, 820nF
3mm Light emitting diode
3mm Light emitting diode
Current Transformer, TZ76
Current Transformer, TZ76
Current Transformer, TZ76
Note 1: Resistor (R1 to R6) values are dependant on the selection of the termination resistors (R25 to R27) and CT combination.
Note 2: Capacitor values may be selected to compensate for phase errors caused by the current transformers.
Note 3: Capacitor C6 to be positioned as close as possible to supply pins VDD and VSS of U1 as possible.
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SA2005F
NOTES:
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PM9607AP
SA2005F
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:
[email protected]
For the latest updates on datasheets, please visit our web site:
http://www.sames.co.za.
SOUTH AFRICAN MICRO-ELECTRONIC SYSTEMS
DIVISION OF LABAT TECHNOLOGIES (PTY) LTD
Tel: (012) 333-6021
Tel: Int +27 12 333-6021
Fax: (012) 333-8071
Fax: Int +27 12 333-8071
33 ELAND STREET
KOEDOESPOORT INDUSTRIAL AREA
PRETORIA
REPUBLIC OF SOUTH AFRICA
P O BOX 15888
33 ELAND STREET
LYNN EAST 0039
REPUBLIC OF SOUTH AFRICA
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