Three Phase Bidirectional Power/Energy Metering IC with Instantaneous Pulse Output sames SA2005F FEATURES n n n n n n n n n 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. http://www.sames.co.za 2/10 3 sames 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 http://www.sames.co.za 3/10 sames 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 http://www.sames.co.za DR-01288 Figure 3: Analog Input Internal Configuration 4/10 sames 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 http://www.sames.co.za 5/10 sames 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. http://www.sames.co.za 6/10 SA2005F http://www.sames.co.za 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 7/10 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 sames V1 Out 15 13 sames 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. http://www.sames.co.za 8/10 sames SA2005F NOTES: http://www.sames.co.za 9/10 sames 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 http://www.sames.co.za 10/10