SA2002H SAMES | Alldatasheet
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Technical content
FEATURES
+ Functionally compatible with the SA9602H with reduced external components + Bi-directional power and energy measurement + Meets the IEC 521/1036 Specification requirements for Class 1 AC Watt hour meters + Protected against ESD samessames Single Phase Bi-directional Power / Energy Metering IC with Instantaneous Pulse Output SA2002H 1/12SA2002H (REV. 5) 17-08-00 + Total power consumption rating below 25mW + Adaptable to different types of current sensors + Operates over a wide temperature range + Precision voltage reference on-chip + Precision oscillator on-chip
DESCRIPTION
The SAMES SA2002H is an enhancement of the SA9602H, as the circuit contains the oscillator on chip. The SAMES SA2002H single phase bi-directional power/energy metering integrated circuit generates a pulse rate output with a frequency proportional to the power consumption. The SA2002H performs a calculation for active power. The method of calculation takes the power factor into account. Energy consumption can be determined by the power measurement being integrated over time. This innovative universal single-phase power/energy metering integrated circuit is ideally suited for energy calculations in applications such as residential municipal metering and factory energy metering and control. The SA2002H integrated circuit is available in 8, 14 and 20 pin dual-in-line plastic (DIP) as well as 16 and 20 pin small outline (SOIC) package types. Figure 1: Block diagram IIP IIN IVP GND VREF DR-01147 FMO* POWER TO FREQUENCY DIR* FOUT VDD VSS POWER INTEGRATOR ANALOG SIGNAL PROCESSING TIMINGOSC VOLTAGE REF. *FMO and DIR not availble in DIP-8 package type
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 samessamesSA2002H 2/123http://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 Operating temp. Range Supply Voltage: Positive Current Sensor Inputs (Diffferential) Input Current Range Voltage Sensor Input (Asymmetrical) Input Current Range Pin FOUT, FMO, DIR Output High Voltage Output Low Voltage V µA µA V V TO VDD III IIV VOL VOH -25 -25 -25 2.25 V- 1DD V+ 1SS +25 +25 +85 2.75 Peak value Peak value ConditionUnitMaxTypMinSymbolParameter Supply Voltage: Negative VVSS -2.75 -2.25 Supply Current: Positive IDD 53 mA Supply Current: Negative ISS 53 mA Positive energy flow Negative energy flow Pulse Width FOUT µs µs tpp tpn 71.55 143.1 # Extended Operating Temperature Range available on request. Pulse Rate FOUT At rated input conditions Specified linearity Min and Max frequency Hz Hz Hz 1600 3000 1360 fp With R = 24kW connected to VSS Reference to VSS Pin VREF Ref. Current Ref. Voltage µA V 1.1 1.3 -IR VR
http://www.sames.co.za PIN DESCRIPTION Pin Pin Pin Pin Designation Description 8 14 16 20 GND Analog Ground. The voltage to this pin should be mid-way between V and V .DD SS 4 5 5 8 VDD 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. 6 10 9 14 VSS 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. 7 13 15 19 IVP Analog Input for Voltage. The current into the A/D converter should be set at 14µA at nominal mains voltage. The RMS voltage sense input saturates at an input current of ±25µA peak. 1, 2 1, 2 1, 2 1, 2 IIN, IIP Inputs for current sensor. The shunt resistor voltage from each channel is converted to a current of 16µA at rated conditions.RMS The current sense input saturates at an input current of ±25µA peak. 3 3 3 3 VREF This pin provides the connection for the reference current setting resistor. A 24kW resistor connected to V set the optimum SS operating condition. 5 8 6 12 FOUT Pulse rate output. Refer to pulse output format for a description of the pulse rate. 4 4 4 6 8 5 7 10 6 12 12 7 14 10 TP1 TP2 TP3 TP4 TP5 TP6 TP7 TP8 TP9 TP10 Leave pins unconnected. N.A. 9 7 13 DIR Direction output. The direction of the energy flow is indicated on this output. N.A. 11 11 15 FMO Voltage sense zero crossover. The FMO output generates pulses on energy rising edge of the mains voltage.
http://www.sames.co.za FUNCTIONAL DESCRIPTION The SA2002H 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 two 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 SA2002H generates pulses, the frequency of which is proportional to the measured power consumption. One frequency output (FOUT) is available. The pulse rate follows the instantaneous power consumption measured. POWER CALCULATION In the application circuit (figure 6), the voltage drop across the shunt will be between 0 and 16mV (0 to 80A through a shunt RMS resistor of 200µ W) The voltage is converted to a current of between 0 and 16uA , by means of resistors R1 and R2. The RMS current sense inputs saturates at an input current of ±25µA peak. For the voltage sensor input, the mains voltage (230VAC) is divided down through a divider (R3, R4 and P1) to 14V . The RMS current into the A/D converter input is set at 14µA at nominal RMS mains voltage, via resistor R5 (1M W). P1 may be varied for calibration purposes. In this configuration, with a mains voltage of 230V and a current of 80A, the output frequency measured on the FOUT pin is 1360Hz. In this case one pulse on FOUT correspond to an energy consumption of 18.4kW/1360Hz = 13.53Ws. ANALOG INPUT CONFIGURATION The input circuitry of the current and voltage sensor inputs is illustrated in figure 7. These inputs are protected against electrostatic discharge through clamping diodes. The feedback loops from the outputs of the amplifiers A and AIV generate virtual shorts on the signal inputs. Exact duplications of the input currents are generated for the analog signal processing circuitry. Figure 6: Application circuit Figure 7: Internal analog input configuration GND VDD DR-01148 VOLTAGE SENSOR INPUT IVP SSV IIN IIP CURRENT SENSOR INPUTS SSV SSV VDD DDV A V AI DR-01587 VDD VREF IIP IIN GND IVP VSS FOUT SA2002H L N L N RSH GND GND VSS VDD GND Supply VDD VSS Pulse output DIR FMO Fwd/Rev. Energy Zero crossing
8/12http://www.sames.co.za TYPICAL APPLICATION In figure 11, the components required for stand alone power metering application, is shown. The application uses a shunt resistor for the mains current sensing. The meter is designed for 220V/40A I operation. The most important external MAX components for the SA2002H integrated circuit are the current sense resistors, the voltage sense resistors as well as the bias setting resistor. BIAS RESISTOR R13 defines all on-chip and reference currents. With R13=24kW, optimum conditions are set. Device calibration is done on the voltage input of the device. SHUNT RESISTOR The voltage drop across the shunt resistor at rated current should be at least 20mV. A shunt resistor with a value of 625µW is chosen. The voltage drop across the shunt resistor is 25mV at rated conditions (Imax). The power dissipation in the current sensor is: P=(40A)² x 625µW = 1W. CURRENT SENSE RESISTORS The resistors R6 and R7 define the current level into the current sense inputs of the device. The resistor values are selected for an input current of 16µA on the current inputs of the SA2002H at rated conditions. According to equation described in the Current Sense inputs section: R6 = R7 = ( I / 16µA ) x RSH / 2L = 40A / 16µA x 625µW / 2 = 781.2W A resistor with value of 820W is chosen, the 5% deviation from the calculated value will be compensated for when calculating resistor values for the voltage path. VOLTAGE DIVIDER The voltage divider is calculated for a voltage drop of 14V + 5%(14.7V). Equations for the voltage divider in figure 9 are: RA = R1 + R2 + R3 RB = R12 || (R11+P1) Combining the two equations gives: (RA + RB) / 220V = RB / 14.7V A 5k trimpot will be used in the voltage channel for meter calibration. The center position on the pot is used in the calculations. P1 = 2.5kW and values for resistors R11 = 22kW and R12 =1MW is chosen. Substituting the values will result in: RB = 23.91kW RA = RB x (230V/14.7V - 1) = 333kW so the resistor values of R1, R2 and R3 are chosen to be 110kW.
9/12http://www.sames.co.za Figure 11: Application circuit using a shunt resistor for current sensing. +C3 C2 R1 R2 R3 +C4 C5R8 VREF3 IIP2 IIN1 GND 14 IVP 13 FOUT 8 TP14 VDD5 TP26 TP37 DIR 9 VSS 10 FMO 11 TP4 12 SA2002H R11 R12 R13 +2V5 -2V5 -2V5 +2V5 LIVE NEUTRAL LIVE NEUTRAL R10 FMO DIR FOUT dr-01588
http://www.sames.co.za Symbol Description Detail SA2002H Diode, Silicon, 1N4002 Diode, Silicon, 1N4002 Diode, Zener, 2.4V Diode, Zener, 2.4V Resistor, 110k, 1/4W, 1% metal Resistor, 110k, 1/4W, 1% metal Resistor, 110k, 1/4W, 1%, metal Resistor, 680, 1/4W, 1%, metal Resistor, 680, 1/4W, 1%, metal Resistor, 820, 1/4W, 1%, metal Resistor, 820, 1/4W, 1%, metal Resistor, 47R, 2W, 5%, wire wound Resistor, 22k 1/4W, 1%, metal Resistor, 1M, 1/4W, 1%, metal Resistor, 24k, 1/4W, 1%, metal Trim pot, 5k, Multi turn Capacitor, 220nF Capacitor, 220nF Capacitor, 100uF, 16V, electrolytic Capacitor, 100uF, 16V, electrolytic DIP-14 R10 R11 R12 R13 Shunt resistor Parts List for Application Circuit: Figure 10 Note 1: Resistor (R6 and R7) values are dependant on the selected shunt resistor (R14) value. Note 2: Capacitor C6 to be positioned as close as possible to supply pins. Note 1 Note 1 Capacitor, 330nF, 250VAC Capacitor, 820nF C6 Note 2
11/12http://www.sames.co.za NOTES:
samessamesPM9607AP samessamesSA2002H 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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