SA2007H SAMES | Alldatasheet
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Technical content
FEATURES
+ Two current sensor inputs + Dual pulse and energy direction outputs + No external crystal or resonator required + Performs bi-directional power and energy measurement + Meets the IEC 521/1036 Specification for Class 1 AC Watt hour meters samessames Single Phase Bidirectional Dual Element Power/Energy Metering IC with Pulse Output SA2007H 1/10SPEC-0116 (REV. 1) 15-01-01 + Protected against ESD + Total power consumption rating below 25mW + Adaptable to different types of sensors + Operates over a wide temperature range + Precision voltage reference on-chip
DESCRIPTION
The SAMES SA2007H is a single phase bidirectional dual element energy metering integrated circuit. It provides a simple analog interface to a micro-controller and is specifically designed for meter manufacturers to have full control over the meter functionality. The SA2007H has two current sensor inputs. The power consumption on both inputs are continuously measured. A typical application would be to monitor Live and Neutral lines for tamper detection. For each current sensor input the SA2007H integrated circuit has a corresponding pulse output, each generating a pulse rate with a frequency proportional to the power consumption measured on the specific channel. The SA2007H performs active power measurement and takes the power factor into account. Energy consumption can be determined by the power measurement being integrated over time. The energy flow direction information is also available for each channel. Figure 1: Block diagram OUTPUT CONTROL POWER TO PULSE RATE POWER TO PULSE RATE CURRENT CHANNEL 1 VOLTAGE CURRENT CHANNEL 2 VOLTAGE REF. OSC TIMING IIP1 IIN1 IVP AGND IIP2 IIN2 RP OMODE INT TESTTCLKVREFVDD VSS X X FMO POWER 2 POWER 1 dr-01623 PRELIMINARY
2/10http://www.sames.co.za ELECTRICAL CHARACTERISTICS # (V = 2.5V, V = -2.5V, over the temperature range -10°C to +70°C, unless otherwise specified.)DD SS ABSOLUTE MAXIMUM RATINGS* Supply Voltage V -V -0.3 6.0 VDD SS Current on any pin I -150 +150 mAPIN Storage Temperature T -40 +125 °CSTG Operating Temperature T -25 +85 °CO *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. Parameter Symbol Min Max Unit #Extended Operating Temperature Range available on request. V µA µA TO VDD III IIV -25 -25 -25 2.25 +25 +25 +85 2.75 Peak value Peak value At rated input conditions Specified linearity Min and Max frequency ConditionUnitMaxTypMinSymbolParameter VVSS -2.75 -2.25 IDD 65 mA ISS 65 mA Pins TCLK, TEST, OMODE, RP Input High Voltage Input Low Voltage V V V- 1DD V+ 1SS Pins P1, P2, D1, D2, FMO, INT Output High Voltage Output Low Voltage V V VOH VOL V- 1DD V+ 1SS Pulse Width P1, P2 µs µs With R = 24kW connected to VSS Reference to VSS Pin VREF Ref. Current Ref. Voltage µA V 1.1 1.3 -IR VR Hz Hz Hz Pulse Rate P1, P2 I = -2mAOH I = 5mAOL Digital I/O Operating temp. Range Supply Voltage: Positive Supply Voltage: Negative Supply Current: Negative Supply Current: Positive Current Sensor Inputs (Differential) Voltage Sensor Input (Asymmetrical) Input Current Range Input Current Range fp Positive energy flow Negative energy VIH VIL 1600 3000 1360 tpp tpn 71.55 143.1 PRELIMINARY Pins TCLK, TEST, RP, OMODE Pull down current µA VV1 = DDIIL 48 110
http://www.sames.co.za Figure 2: Pin connections: Package: DIP-20, SOIC-20 Part Number SA2007HPA SA2007HSA Package DIP-20 SOIC-20
ORDERING INFORMATION
Analog Ground. The voltage to this pin should be mid-way between V and V .DD SS Positive supply voltage. The voltage to this pin is typically +2.5V if a shunt resistor is used for current sensing or in the case of a current transformer a +5V supply can be applied. DescriptionPIN Negative supply voltage. The voltage to this pin is typically -2.5V if a shunt resistor is used for current sensing or in the case of a current transformer a 0V supply can be applied. Analog Input for Voltage. The current into the A/D converter should be set at 14µA at RMS nominal mains voltage. The voltage sense input saturates at an input current of ±25µA peak. Inputs for current sensor - Channel 1 and Channel 2. The shunt resistor voltage from each channel is converted to a current of 16µA at rated conditions. The current sense input RMS saturates at an input current of ±25µA peak. 1, 2, 3, 4 This pin provides the connection for the reference current setting resistor. A 24kW resistor connected to V sets the optimum operating condition.SS This logic input is used to select between latched or unlatched condition for the pulse and direction outputs. A logic input is used to reset the latched outputs which is required after an interrupt has occurred. The zero crossover of the voltage sense input is signaled on this pin.9 Configure / Test inputs. For normal operations these pins must be connected to V .SS10, 15 This logic output will indicate a change in status of the pulse or direction outputs.12 Pulse outputs. The P1 and P2 outputs give instantaneous pulse outputs of channel 1 and channel 2 respectively. The pulse is active low with a pulse width of 71.5µs for positive energy and doubles for reverse energy. 17, 13 Direction output. These outputs indicate the energy flow direction of each channel.18, 16 No Connection.11 DR-01620 1IIN1 AGND IIP1 IVP TEST IIN2 D1 VSS IIP2 VREF OMODE RP VDD INT NCTCLK FMO 6 15 1110 AGND VDD Designation VSS IVP IIN1, IIP1 IIN2, IIP2 VREF OMODE RP FMO TCLK, TEST INT P1, P2 D1, D2 NC PRELIMINARY
Figure 3: Analog input internal configuration http://www.sames.co.za FUNCTIONAL DESCRIPTION The SA2007H is a CMOS mixed signal analog/digital integrated circuit, which performs power/energy calculations across a power range of 1000:1, to an overall accuracy of better than Class 1. The integrated circuit includes all the required functions for 1- 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. Referring to the block diagram (figure 1) the SA2007H has two current sense channels and a voltage sense channel. The voltage measured is multiplied with the current measured on the two channels. The multiplied signals from each current channel is fed to separate power to pulse rate blocks. The power to pulse rate blocks generate pulses at a frequency proportional to the instantaneous active power measured. Pulses on output P1 represent energy measured on current channel 1. The pulses on output P2 represent energy measured on current channel 2. Counting the pulses generated represents the energy measured. A typical application would be to simultaneous measure energy/power consumption in both Live and Neutral lines. A meter tamper condition could be detected when an imbalance exists between the live and neutral energy/power measured. Two modes of operation is available on the SA2007H, in one mode the device is functionally the same as two SA2002H devices sharing a common voltage channel. Alternatively the pulse output is latched and an interrupt is generated on any change of the pulse outputs. POWER CALCULATION In Figure 8, the voltage drops across the current transformers terminating r esistors are converted to currents for each current sense input, by means of resistors R and R (channel 10 11 1) as well as R and R (channel 2). The current sense input 12 13. saturates at an input current of ±25µA peak. The mains voltage (230VAC) is divided down through a divider to 14V . The current into the A/D converter input is set at RMS 14µA at nominal mains voltage, via resistor R(1MW).RMS 7 In this configuration, with a mains voltage of 230V and a current of 80A, the output frequency measured on P1 or P2 pin is 1360Hz. In this case the energy associated with a single pulse is 18.4kW/1360Hz = 13.5Ws per pulse. ANALOG INPUT CONFIGURATION The input circuitry of the current and voltage sensor inputs are illustrated in figure 3. These inputs are protected against electrostatic discharge through clamping diodes. The feedback loops from the outputs of the amplifiers A and A IV generate virtual shorts on the signal inputs. Exact duplications of the input currents are generated for the analog signal processing circuitry. ELECTROSTATIC DISCHARGE (ESD) PROTECTION The SA2007H integrated circuit's input's/outputs are protected against ESD. POWER CONSUMPTION The power consumption rating of the SA2007H integrated circuit is less than 30mW. VOLTAGE SENSOR INPUT IVP DR-01288 SSV CURRENT SENSOR INPUTS IIP IIN SSV VDD SSV VDD DDV GND A V AI PRELIMINARY
7/10http://www.sames.co.za TYPICAL APPLICATION The analog (metering) interface shown in figure 8, is designed for measuring 230V/60A with precision better than Class 1. The most important external components for the SA2007H integrated circuit are the current sense resistors, the voltage sense resistors and the bias setting resistor. The resistors used in the metering section should be of the same type so temperature effects are minimized. Current Input IIN1, IIP1, IIN2, IIP2 Two current transformers are used to measure the current in the live and neutral phases. The output of the current transformer is terminated with a low impedance resistor. The voltage drop across the termination resistor is converted to a current that is fed to the differential current inputs of the SA2007H. CT Termination Resistor The voltage drop across the CT termination resistor at rated current should be at least 20mV. The CT’s have low phase shift and a ratio of 1:2500. The CT’s are terminated with a 3.6 W resistor giving a voltage drop of 86.4mV across each termination resistor at rated conditions (I for the meter).max Current Sensor Input Resistors The resistors R10, R11 and R12, R13 define the current level into the current sense inputs of the SA2007H. The resistor values are selected for an input current of 16µA at rated conditions. For a 60A meter and a CT Ratio of 2500:1 the resistor values are calculated as follows: R10 = R11 = ( I/ 16µA ) x R / 2 SH = 60A / 2500 / 16µA x 3.6W / 2 = 2.7kW I =Line current L R = CT Termination resistorSH 2500 = CT ratio The two current channels are identical so R10 = R11 = R12 = R13. Voltage Input IVP The voltage input of the SA2007H (IVP) is driven with a current of 14µA at nominal mains voltage. This voltage input saturates at approximately 17µA. At a nominal voltage current of 14µA allows for 20% overdriving. The mains voltage is divided with a voltage divider to 14V that is fed to the voltage input pins via a 1MW resistor. Voltage Divider The voltage divider is calculated for a voltage drop of 14V. Equations for the voltage divider are: RA = R1 + R2 + R3 RA = R7 || (R5 + P1) Combining the two equations gives: (RA + RB) / 230V = RB / 14V Values for resistors R4 = 10W, R5 - 22kW and R7 - 1MW is chosen. Substituting the values result in: RB = 21.526kW RA = RB x (230V / 14V -1) RA = 332.12kW. Standard resistor values for R1, R2 and R3 are chosen to be 100kW, 100kW and 120kW. The capacitor C1 is used to compensate for phase shift between the voltage sense inputs and the current sense inputs of the device, in cases where CTs with phase errors are used. The phase shift caused by the CT may be corrected by inserting a capacitor in the voltage divider circuit. T o compensate for a phase shift of 0.18 degrees the capacitor value is calculated as follows: C = 1 / (2 x p x Mains frequency x R5 x tan (Phase shift angle)) C = 1 / ( 2 x p x 50 x 1MW tan (0.18 degrees )) C = 1.013µF Reference Voltage Bias resistor R6 defines all on chip and reference currents. With R6 = 24kW optimum conditions are set. Calibration should be done in the micro controller software. PRELIMINARY
Figure 8: Application circuit showing metering section 8/10http://www.sames.co.za samessamesSA2007H R1 R2 R3 R8 R10 R11 VSS LIVE NEUTRAL LIVE NEUTRAL CT1 CT2 R12 R13R9 L 14V + C5 p s Vin1 GND2 Vout 3 R14 R15 + C6 VDD VDD VSS GNDTZ1 GND IIP24 VREF5 RP7 OMODE6 VDD8 FMO9 TCLK10 IIN23 IIP12 IIN11 GND 20 IVP 19 D1 18 P1 17 D2 16 TEST 15 VSS 14 P2 13 INT 12 SA2007H VSS VSS RST Interrupt Zero Crossings Inrerrupt Energy Pulse CH2 Energy Pulse CH1 Energy Dir CH1 Energy Dir CH1 Micro GND GND Controller PRELIMINARY
http://www.sames.co.za Item Description Detail SA2007H DIP-20/SOIC-20 Parts List for Application Circuit: Figure 8 Note 1: Resistor (R10, R11, R12 and R13) values are dependent upon the selected value of R8 and R9 Note 2: See TYPICAL APPLICATION when selected the value of R8 and R9. Note 3: Capacitor (C4) to be positioned as closed to Supply Pins (V & V ) of U-1, as possible.DD SS Note 4: Capacitor (C1) selected to minimize phase error introduced by current transformer (typically 1.5µF for normal CTs) Symbol R10 R11 R12 R13 R14 R15 CT1 CT2 Diode, Silicon 1N4148 Diode, Silicon 1N4148 Diode, Silicon 1N4148 Resistor, 100k, 1/4W, 1%, metal Resistor, 100k, 1/4W, 1%, metal Resistor, 120k, 1/4W, 1%, metal Resistor, 10W, 2W, Wire wound Resistor, 24k, 1/4W, 1%, metal Resistor, 24k, 1/4W, 1%, metal Resistor, 1M, 1/4W, 1%, metal Resistor, 3.6W, 1/4W, 1%, metal Resistor, 3.6W, 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, 1k, 1/4W Resistor, 1k, 1/4W Capacitor Capacitor, 220nF Capacitor, 220nF Capacitor, 2200µF, 25V, electrolytic Capacitor, 820nF Capacitor, 100µF, 16V, electrolytic Current Transformer Current Transformer Transformer, 230V/9V 78LC05, Voltage regulator 400V, Metal oxide varistor Note 1 Note 1 Note 3 Diode, Silicon 1N4148 TZ1 Note 4 Note 1 Note 1 Note 2 Note 2 or Similar or Similar or Similar or Similar PRELIMINARY
samessamesPM9607AP samessamesSA2007H 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 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 P O BOX 15888
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KOEDOESPOORT INDUSTRIAL AREA PRETORIA REPUBLIC OF SOUTH AFRICA http://www.sames.co.za PRELIMINARY