sames
SA9102 / SA9602 APPLICATION NOTE
PM9102AP
SINGLE PHASE POWER/ENERGY METERING MODULE
PULSE OUTPUT
FEATURES
n
Performs both power and energy
measurement
n
Total power consumption rating below
500mW (excluding current sensing)
n
Meets the accuracy requirements for
Class 1 AC Watt hour meters
n
Uses a shunt resistor for current sensing
n
Operates over a wide temperature range
n
Protected against ESD
DESCRIPTION
The SAMES single phase power/energy metering module, the PM9102AP, provides two
pulse rate output options, the frequency of which are proportional to the active power
consumption.
Energy consumption is determined by the power measurement being integrated over
time.
The method of calculation takes the power factor into account.
The output of this innovative universal power/energy metering circuit is ideally suited for
energy calculations in applications using a µ-controller or mechanical counter.
The application utilises the SAMES SA9102CP, SA9102FP, SA9102HP, SA9602EP
(DIP-20), SA9602HP (DIP-20) or SA9602MP power metering integrated circuits for
power measurement.
As a safety measure, this application shows the current sensor connected to the neutral
line. In practice, the live line may be used for current sensing, provided that the supply
connections (MAINS) are reversed on the module.
BLOCK DIAGRAM
NEUTRAL
NEUTRAL
NEUTRAL
LIVE
IN
OUT
SHUNT
POWER
SUPPLY
SA9102
SA9602
OCTO
COUPLER POWER OUTPUT
POWER
METER
VOLTAGE SENSE
DR-01447
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4308
PDS038-SA9102-001
REV.C
06-08-98
PM9102AP
ABSOLUTE MAXIMUM RATINGS*
Parameter
Supply Voltage (Note 1)
Current Sense Input (Note 1)
Storage Temperature
Operating Temperature (Note2)
Max Current
through Sensor
Note 1:
Note 2:
Symbol
VAC
VIV
TSTG
TO
IMAX
IMAX
Min
-2.5
-25
-10
Max
540
+2.5
+125
+70
800 (Note 3)
Unit
V
V
°C
°C
A
2000 (Note 4)
A
Voltages are specified with reference to Live.
The SA9102 and SA9602 integrated circuits are specified to operate over the
temperature range -10°C to +70°C. The module functionality will however
depend upon the external components used.
t = 500ms
t = 1ms
Note 3:
Note 4:
*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 operational 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. Power
consumption figures are applicable to the PM9102APE only.)
Parameter
Symbol Min
Typ Max
Unit Condition
Supply voltage
VAC
180
230
265
V
PM9102APE
(Continuous)
90
115
135
V
PM9102APA
Frequency output
FOUTX Refer to applicable IC data sheet
1
Power consumption
800
mW
VAC = 230V
Supply direct
from mains
200
mW
5VAC supply
2
Isolation voltage
VIS
2500
V
Continuous
Output transistor
collector current
IO
10
mA
VOL =1V
Note 1: Power consumption specifications exclude power consumed by the current
sensor.
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PM9102AP
Note 2: Isolation voltage may be specified, depending on customer requirements.
CONNECTION DESCRIPTION
Designation
MAINS
Description
Voltage supply connection to Neutral line
Voltage supply connection to Live line
Neutral In
Connection to positive side of current sensor
Neutral Out
Connection to negative side of current sensor
JP1
SA9102/SA9602 output pin selector (Jumper)
SK1
Power measurement output
FUNCTIONAL DESCRIPTION
1. Power Calculation
In the Application Circuit (Figure 2), the output current from the current sensor will
be between 0 and 16µA (0 to 80A through a shunt resistor of 625µS). The current
input stage saturates at input currents greater than18µA RMS. The mains voltage
(230V + 15% -20%) is used to supply the circuitry with power and for the power
calculation, together with the current information from the current sensor (shunt
resistor).
The SA9102CP, SA9602EP (DIP-20), SA9602HP (DIP-20) and SA9602MP
integrated circuits may be adjusted to accommodate any voltage or current values.
The method of calculating external component values is described in paragraph 5
(Circuit Description).
SAMES offers evaluation module options, namely 230V/80A and 115V/80A.
The calculated power is integrated over time and converted into a corresponding
frequency. The frequency is transmitted as a pulse rate through an opto-coupler.
2.
Electrostatic Discharge (ESD) Protection
The device's inputs/outputs are protected against ESD according to Mil-Std 883C,
method 3015. The modules resistance to transients will be dependant upon the
protection components used.
3.
Power Consumption
The overall power consumption rating for this power metering application (Figure
2), is under 500mW, excluding the current sensor, if a supply is taken directly from
the mains.
4.
Isolation
The pulse output is isolated from the module, which is at mains potential, via an
opto-coupler. (In the event of the use of a current transformer for current sensing,
an opto-coupler would not be required.)
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PM9102AP
5.
Circuit Description
The Application Circuit (Figure 2) details the components required for the power
metering module, using a shunt resistor for current sensing.
In this application the device requires +2,5V, 0V, -2,5V DC supply.
The most important external components 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
signal to noise and stability performance. The tolerance 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 16µARMS into the SA9102
/ SA9602 at maximum line current.
Values for RSH of less than 200µS should be avoided.
R1 = R2 = (IL/16µARMS) * RSH/2
Where
IL
=
RSH =
Line current
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 14µARMS.
R7 and P7 defines all on-chip bias and reference currents. With R7 + P7 = 24kS,
optimum conditions are set. R7 + P7 may be varied by ±10% for calibration
purposes. Any change to R7 + P7 will affect the output quadratically.
XTAL is a colour burst TV crystal (f = 3.5795MHz) for the oscillator. The oscillator
frequency is divided down to 1.7897MHz on-chip and supplies the A/D converters
and the digital circuitry.
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Figure 1: Connection Diagram
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Figure 2: Application using a Shunt Resistor for Current Sensing.
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Parts List for Application Circuit: Figure 2
Item
Symbol
Description
1
IC-1
SA9102CP/EP/FP/HP / SA9602EP/HP/MP
2
IC-2
Optocoupler, 4N35
3
D1
Diode, Silicon, 1N4148
4
D2
Diode, Silicon, 1N4148
5
ZD1
Diode, Zener, 2.4V, 200mW
6
ZD2
Diode, Zener, 2.4V, 200mW
7
XTAL
Crystal, 3.5795MHz
8
R1
Resistor, 1.6kS, 1%, metal
9
R2
Resistor, 1.6kS, 1%, metal
10
R3A
Resistor, 1%, metal
11
R3B
Resistor, 1%, metal
12
R4
Resistor, 1MS, ¼W, 1%, metal
13
R5
Resistor, 470S, 2W, 5%, carbon
14
R6
Resistor, 24k, ¼W, 1%, metal
15
R7
Resistor, 22k, ¼W, 1%, metal
16
P7
Trimpot, 5kS
17
R8
Resistor, 680S, ¼W, 5%
18
R9
Resistor, 680S, ¼W, 5%
19
R10
Resistor, 680S, ¼W, 5%
20
C1
Capacitor, 560pF
21
C2
Capacitor, 560pF
22
C3
Capacitor, 3.3nF
23
C4
Capacitor, 3.3nF
24
C9
Capacitor, 100nF
25
C10
Capacitor, 100nF
26
C11
Capacitor, polyester
27
C13
Capacitor, 100µF, 16V
28
C14
Capacitor, 100µF, 16V
29
C15
Capacitor, 820nF
30
JP1
Jumper
31
RSH
Shunt Resistor, 80A, 50mV (625µS)
Detail
DIP-20
DIP-6
Colour burst TV
Note 1
Note 1
Note 2
Note 2
Multi turn
Note 2
Note 3
Note 1
Note 1 : Resistor (R1 and R2) values are dependant upon the selected value of RSH.
See paragraph 5 (Circuit Description) when selecting the value for RSH.
Note 2 : See the table below, detailing the component values for the selected voltage
standard.
Note 3 : Capacitor (C15) to be positioned as close as possible to Supply Pins
(VDD & VSS) of IC-1.
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Item
Symbol
10
11
26
R3A
R3B
C11
Description
PM9102APA
PM9102APE
115V
230V
120kS
200kS
82kS
180kS
1µF
0.47µF
ORDERING INFORMATION
Part Number
PM9102APA
PM9102APE
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Description
115V, 80A Module
230V, 80A Module
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Detail
PM9102AP
Notes:
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PM9102AP
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:
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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