BL0921

BL0921 BELLING | Alldatasheet

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BL0921 BL0921 BL0921 BL0921 http://www.belling.com.cn - 1 - 3/15/2007 Total 13 Pages Single Phase Energy Meter IC Single Phase Energy Meter IC Single Phase Energy Meter IC Single Phase Energy Meter IC with Integrated Oscillator with Integrated Oscillator with Integrated Oscillator with Integrated Oscillator /rhombus6 FEATURES /wheel High accuracy, less than 0.1% error over a dynamic range of 500: 1 /wheel On-chip oscillator as clock source /wheel Exactly measure the real power in the positive orientation and negative orientation, calculate the energy in the same orientation /wheel Two current monitors continuously monitor the phase and neutral currents in two-wire distribution systems. Uses the larger of two currents to bill, even during a Fault condition /wheel A PGA in the current channel allows using small value shunt and burden resistance /wheel The low frequency outputs F1 and F2 can directly drive electromechanical counters and two phase stepper motors and the high frequency output CF, supplies instantaneous real power, is intended for calibration and communications /wheel Two logic outputs REVP and FAULT can be used to indicate a potential orientation or Fault condition /wheel On-Chip power supply detector /wheel On-Chip anti-creep protection /wheel On-Chip voltage reference of 2.5V±8% /wheel Single 5V supply /wheel Low static power (typical value of 25mW). The technology of SLiM (Smart–Low–current– Management) is used. /wheel Credible work, working time is more than twenty years Interrelated patents are pending /rhombus6 DESCRIPTION The BL0921 is a low cost, high accuracy, high stability, simple peripheral circuit electrical energy meter IC. The meter based on the BL0921 is intended for using in single-phase, two-wire distribution systems. It can exactly measure the real power in the positive orientation and negative orientation and calculate the energy in the same orientation. The BL0921 incorporates a novel fault detection scheme that both warns of fault conditions and allows the BL0921 to continue accurate billing during a fault event. The BL0921 does this by continuously monitoring both the phase and neutral (return) currents. PIN12 (FAULT) indicates Fault condition, when these currents differ by more than 12.5%. Billing is continued using the larger of the two currents when the difference is greater than 14%. The BL0921 supplies average real power information on the low frequency outputs F1 (Pin16) and F2 (Pin15). These logic outputs may be used to directly drive an electromechanical counter and two-phase stepper motors. The CF (Pin14) logic output gives instantaneous real power information. This output is intended to be used for calibration purposes or interface to an MCU. BL0921 thinks over the stability of reading error in the process of calibration. Bulk test data indicate that in the condition of small signal 5%Ib (Ib=5A), the error of CF is less than 0.1%. An internal no-load threshold ensures that the BL0921 does not exhibit any creep when there is no load. /rhombus6 BLOCK DIAGRAM 8 9 VDD V1A V1B V1N V2N V2P VREF GND S1 REVP CF BL0921 BL0921 BL0921 BL0921 11 G FAULT current sampling voltage sampling analog to digital high pass filter digital multiplic ation digital to frequency and output low pass filter V1A V1A V1A V1A V1N V1N V1N V1N V1B V1B V1B V1B V2P V2P V2P V2P V2N V2N V2N V2N REVP REVP REVP REVP CF CF CF CF F1 F1 F1 F1 F2 F2 F2 F2 BL0921 BL0921 BL0921 BL0921 VDD VDD VDD VDD power detector voltage reference VREF VREF VREF VREF analog to digital input contron logic contron GG GG S0 S0 S0 S0 S1 S1 S1 S1 FAULT FAULT FAULT FAULT high pass filter internal oscillator SOP 16

BL0921 BL0921 BL0921 BL0921 http://www.belling.com.cn - 2 - 3/15/2007 Total 13 Pages Single Phase Energy Meter IC Single Phase Energy Meter IC Single Phase Energy Meter IC Single Phase Energy Meter IC with Integrated Oscillator with Integrated Oscillator with Integrated Oscillator with Integrated Oscillator /rhombus6 PIN DESCRIPTIONS Pin Symbol DESCRIPTIONS 1 VDD Power Supply (+5V). Provides the supply voltage for the digital circuitry. It should be maintained at 5 V ±5% for specified operation. 2,3 V1A,V1B Inputs for Current Channel. These inputs are fully differential voltage inputs with a maximum signal level of ±660 mV with respect to pin6 (V1N) for specified operation. 4 V1N Negative Input Pin for Differential V oltage Inputs V1A and V1B. 5,6 V2N,V2P Negative and Positive Inputs for V oltage Channel. These inputs provide a fully differential input pair. The maximum differential input voltage is ±660 mV for specified operation. 7 VREF On-Chip V oltage Reference. The on-chip reference has a nominal value of 2.5V ± 8% . An external reference source may also be connected at this pin. 8 AGND Ground Reference. Provides the ground refere nce for the circuitry. 9,10 S1,S0 Output Frequency Select. These logic inputs are used to select one of four possible frequencies for the digital-to-frequency conversion. This offers the designer greater flexibility when designing the energy meter. 11 G Gain Select. These logic inputs are used to select one of four possible gains for current channel. The possible gains are 1 and 16.

12 FAULT

Fault Indication. Logic high indicates fault condition. Fault is defined as a condition under which the signals on V1A and V1B differ by more than 12.5%. The logic output will be reset to zero when fault condition is no longer detected.

13 REVP

Negative Indication. Logic high indicates negative power, i.e., when the phase angle between the voltage and current signals is greater that 90 °. This output is not latched and will be reset when positive power is once again detected. 14 CF Calibration Frequency. The CF logic output gives instantaneous real power information. This output is intended to use for calibration purposes. 15,16 F1,F2 Low-Frequency. F1 and F2 supply average real power information. The logic outputs can be used to directly drive electromechanical counters and 2-phase stepper motors. /rhombus6 ABSOLUTE MAXIMUM RATINGS ( T = 25 ℃ ) Parameter Symbol Value Unit Power V oltage VDD VDD -0.3~+7(max) V Input V oltage of Channel 2 to GND V (V) VSS+0.5 ≤V(v)≤VDD-0.5 V Input V oltage of Channel 1 to GND V (I) VSS+0.5 ≤V(i)≤VDD-0.5 V Operating Temperature Range Topr -40~+75 ℃ Storage Temperature Range Tstr -55~+150 ℃ Power Dissipation 400 mW

BL0921 BL0921 BL0921 BL0921 http://www.belling.com.cn - 3 - 3/15/2007 Total 13 Pages Single Phase Energy Meter IC Single Phase Energy Meter IC Single Phase Energy Meter IC Single Phase Energy Meter IC with Integrated Oscillator with Integrated Oscillator with Integrated Oscillator with Integrated Oscillator /rhombus6 ELECTRONIC CHARACTERISTIC PARAMETER (T=25 ℃, VDD=5V ，On-Chip Oscillator ，On-Chip voltage reference) Parameter Symbol Test Condition Measure Pin Min Value Typica l Value Max Value Unit

1 Power Supply I DD Pin1 5 mA

2 Logic Input Pins

S1, S0, G , Pin 9, 10, 11 Input High V oltage V IH 2 V Input Low V oltage V IL VDD=5V 1 V Input Capacitance C IN 10 pF

3 Logic Output Pins F1,

F2, CF, REVP, FAULT Pin16,15 ,14,13,12 Output High V oltage V OH1 I H =10mA 4.4 V Output Low V oltage V OL1 I L=10mA 0.5 V 4 On-chip Reference Vref VDD=5V Pin7 2.3 2.5 2.7 V Temperature coefficient 30 60 ppm/ °C

5 Analog Input Pins

V1A, V1B, V1N, V2N, V2P Pin 2,3,4,5,,6 Maximum Input V oltage V AIN ±1 V DC Input Impedance 330 Kohm Input Capacitance 6 10 pF

6 Accuracy

Gain=1 ENL1 Pin14 0.1 % Gain=16 ENL16 Both channels with Full-Scale signal ±660mV over a dynamic range 500 to 1 Pin14 0.1 % Phase Error between Channels Channel 1 Lead 37 ° (PF=0.8 Capacitive) Pin14 0.1 ° Channel 1 Lags (PF=0.5 Inductive) Pin14 0.1 ° 7 Start Current I START Ib=5A, C=3200 Pin14 0.2%Ib A

8 Positive and Negative

Real Power Error (%) ENP Vv= ±110mV ,V(I)=2mV , cos ϕ=1 /uniF030/uniF020 Vv= ±110mV ,V(I)=2mV , cos ϕ=-1 Pin14 0.1 0.3 %

9 Gain Error Gain error Pin14 ±5 %

BL0921 BL0921 BL0921 BL0921 http://www.belling.com.cn - 4 - 3/15/2007 Total 13 Pages Single Phase Energy Meter IC Single Phase Energy Meter IC Single Phase Energy Meter IC Single Phase Energy Meter IC with Integrated Oscillator with Integrated Oscillator with Integrated Oscillator with Integrated Oscillator 10 Gain Error Match Pin14 0.2 1 % /rhombus6 TERMINOLOGY 1) Measurement Error The error associated with the energy measurement made by the BL0921 is defined by the following formula: %100 0921 Re ×−= Energy True Energy True BL the gisteredby Energy Error Pencebtage 2) Nonlinear Error The Nonlinear Error is defined by the following formula: eNL% ＝[(Error at X-Error at Ib) / (1+Error at Ib )]*100% When V(v)= ±110mV , cos ϕ=1, over the arrange of 5%Ib to 800%Ib, the nonlinear error should be less than 0.1%. 3) Positive And Negative Real Power Error When the positive real power and the negative real power is equal, and V(v) = ±110mV , the test current is Ib, then the positive and negative real power error can be achieved by the following formula: eNP%=|[(eN%-eP%)/(1+eP%)]*100%| Where: eP% is the Positive Real Power Error, eN% is the Negative Real Power Error. 4) Phase Error Between Channels The HPF (High Pass Filter) in Channel 1 has a phase lead response. To offset this phase response and equalize the phase response between channels, a phase correction network is also placed in Channel 1. The phase correction network matches the phase to within ±0.1 °over a range of 45 Hz to 65 Hz and ±0.2 °over a range 40Hz to 1KHz. 5) Gain Error The gain error of the BL0921 is defined as the difference between the measured output frequency (minus the offset) and the ideal output frequency. It is measured with a gain of 1 in channel V1. The difference is expressed as a percentage of the ideal frequency. The ideal frequency is obtained from the BL0921 transfer function. 6) Gain Error Match The gain error match is defined as the gain error (minus the offset) obtained when switching between a gain of 1 and a gain of 16. It is expressed as a percentage of the output frequency obtained under a gain of 1. This gives the gain error observed when the gain selection is changed from 1 to 16. 7) Power Supply Monitor BL0921 has the on-chip Power Supply monitoring The BL0921 will remain in a reset condition until the supply voltage on VDD reaches 4 V . If the supply falls below 4 V , the BL0921 will also be reset and no pulses will be issued on F1, F2 and CF.

BL0921 BL0921 BL0921 BL0921 http://www.belling.com.cn - 5 - 3/15/2007 Total 13 Pages Single Phase Energy Meter IC Single Phase Energy Meter IC Single Phase Energy Meter IC Single Phase Energy Meter IC with Integrated Oscillator with Integrated Oscillator with Integrated Oscillator with Integrated Oscillator /rhombus6 TIMING CHARACTERISTIC (VDD=5V , GND=0V , On-Chip Reference, Integrated Oscillator, Temperature range: -20~+70 °C) Parameter Value Comments t1 144ms F1 and F2 pulse-width (Logic Low). When th e power is low, the t1 is equal to 144ms; when the power is high, and the output period falls below 550ms, t1 equals to half of the output period. t2 F1 or F2 output pulse period. t3 ½ t2 Time between F1 falling edge and F2 falling edge. t4 CF Pulse Period. See Transfer Function section. t5 71ms CF pulse-width (Logic high). When the power is low, the t5 is equal to 71ms; when the power is high, and the output period falls below 180ms, t5 equals to half of the output period. t6 CLKIN/4 Minimum Time Between F1 and F2. Notes: 1) CF is not synchronous to F1 or F2 frequency outputs. 2) Sample tested during initial release and after any redesign or process change that may affect this parameter. /rhombus6 THEORY OF OPERATION /rhombus6 Principle of Energy Measure In energy measure, the power information varying with time is calculated by a direct multiplication of the voltage signal and the current signal. Assume that the current signal and the voltage signal are cosine functions; V and I are the peak values of the voltage signal and the current signal; ωis the angle frequency of the input signals; the phase difference between the current signal and the voltage signal is expressed as Ф. Then the power is given as follows: )cos( )cos( )( Φ+×= wt Iwt Vtp

BL0921 BL0921 BL0921 BL0921 http://www.belling.com.cn - 6 - 3/15/2007 Total 13 Pages Single Phase Energy Meter IC Single Phase Energy Meter IC Single Phase Energy Meter IC Single Phase Energy Meter IC with Integrated Oscillator with Integrated Oscillator with Integrated Oscillator with Integrated Oscillator Φ =0: )2cos( 1 (2)( wt VI tp += ≠Φ 0: [ ] )sin( )2sin( 2)cos( )) 2cos( 1 (2 )sin( )sin( )cos( )cos( )) 2cos( 1 (2 )sin( )sin( )cos( )cos( )cos( )cos( )cos( )( Φ+Φ+= Φ+Φ+= Φ+Φ×= Φ+×= wt VI wt VI wt wt VI wt VI wt wt Iwt V wt Iwt Vtp p(t) is called as the instantaneous power signal. The ideal p(t) consists of the dc component and ac component whose frequency is 2 ω. The dc component is called as the average active power, that is: cos( ) 2 VI P ϕ= The average active power is related to the cosine value of the phase difference between the voltage signal and the current signal. This cosine value is called as Power Factor (PF) of the two channel signals. Figure1. The Effect of phase When the signal phase difference between the voltage and current channels is more than 90 °, the average active power is negative. It indicates the user is using the electrical energy reversely. /rhombus6 Operation Process In BL0921, the two ADCs digitize the voltage signals from the current and voltage transducers. These ADCs are 16-bit second order sigma-delta with an over sampling rate of 900 kHz. This analog input structure greatly simplifies transducer interfacing by providing a wide dynamic range for direct connection to the transducer and also simplifying the anti-alias filter design. A programmable gain stage in the current channel further facilitates easy transducer interfacing. A high pass filter in the current channel removes any dc component from the current signal. This eliminates any inaccuracies in the real power calculation due to offsets in the voltage or current signals. The real power calculation is derived from the instantaneous power signal. The instantaneous power signal is generated by a direct multiplication of the current and voltage signals. In order to extract the real power component (i.e., the dc component), the instantaneous power signal is low-pass filtered. Figure 2 illustrates the instantaneous real power signal and shows how the real power information can be extracted by low-pass filtering the instantaneous power signal. This

channel can be matched completely, and the performance when PF equal 0.5C or 0.5L is improved. stable, and the ripple of the typical output signal is less than 0.05%. electric power whose frequency is 60Hz. connected to the BL0921 Voltage Channel. Figure 4. Voltage Channels BL0921 can be driven with common-mode voltages of up to 100 mV with respect to GND. However, best results are achieved using a common mode equal to GND. of carrying out a gain calibration on the meter.

Figure 7. Typical Connections for Current Channels full-scale input range. This will eliminate false detection of a fault due to noise at light loads. is still greater than V1B, billing is maintained on VIA, i.e., no swap to the V1B input will occur. V1A remains the active input.

BL0921 BL0921 BL0921 BL0921 http://www.belling.com.cn - 12 - 3/15/2007 Total 13 Pages Single Phase Energy Meter IC Single Phase Energy Meter IC Single Phase Energy Meter IC Single Phase Energy Meter IC with Integrated Oscillator with Integrated Oscillator with Integrated Oscillator with Integrated Oscillator low-pass filters this product to extract real power information. This real power information is then converted to a frequency. The frequency information is output on F1 and F2 in the form of active low pulses. The pulse rate at these outputs is relatively low. It means that the frequency at these outputs is generated from real power information accumulated over a relatively long period of time. The result is an output frequency that is proportional to the average real power. The average of the real power signal is implicit to the digital-to-frequency conversion. The output frequency or pulse rate is related to the input voltage signals by the following equation. ) ()(5 . 3 REF V Fz Gain iVvVFreq ××××= Freq ——Output frequency on F1 and F2 (Hz) V(v)——Differential rms voltage signal on Channel 1 (volts) V(i) ——Differential rms voltage signal on Channel 2 (volts) Gain ——1 , 16 depending on the PGA gain selection, using logic inputs G Vref ——The reference voltage (2.4 V ±8%) (volts) Fz ——One of four possible frequencies selected by using the logic inputs S0 and S1. S1 S0 Fz(Hz) 0 0 1.7 0 1 3.4 1 0 6.8 1 1 13.6 /rhombus6 Frequency Output CF The pulse output CF (Calibration Frequency) is intended for use during calibration. The output pulse rate on CF can be up to 128 times the pulse rate on F1 and F2. The following Table shows how the two frequencies are related, depending on the states of the logic inputs S0, S1 and SCF. Mode S1 S0 CF/F1 (or F2) 1 0 0 64 2 0 1 32 3 1 0 16 4 1 1 8 Because of its relatively high pulse rate, the frequency at this logic output is proportional to the instantaneous real power. As is the case with F1 and F2, the frequency is derived from the output of the low-pass filter after multiplication. However, because the output frequency is high, this real power information is accumulated over a much shorter time. Hence less averaging is carried out in the digital-to-frequency conversion. With much less averaging of the real power signal, the CF output is much more responsive to power fluctuations. /rhombus6 Gain Selection By select the digital input G0 and G1 voltage (5V or 0V), we can adjust the gain of current

BL0921 BL0921 BL0921 BL0921 http://www.belling.com.cn - 13 - 3/15/2007 Total 13 Pages Single Phase Energy Meter IC Single Phase Energy Meter IC Single Phase Energy Meter IC Single Phase Energy Meter IC with Integrated Oscillator with Integrated Oscillator with Integrated Oscillator with Integrated Oscillator channel. We can see that while increasing the gain, the input dynamic range is decreasing. G Gain Maximum Differential Signal 1 1 ±660mV 0 16 ±41mV /rhombus6 Analog Input Range The maximum peak differential signal on Voltage Channel is ± 660 mV, and the common-mode voltage is up to 100 mV with respect to GND. The analog inputs V1A, V1B, and V1N have the same maximum signal level restrictions as V2P and V2N. However, The Current Channel has a programmable gain amplifier (PGA) with user-selectable gains of 1,16. These gains facilitate easy transducer interfacing. The maximum differential voltage is ±660 mV and the maximum common-mode signal is ±100 mV.The corresponding Max Frequency of CF/F1/F2 is shown in the following table. Max Frequency of F1, F2 (Hz) CF Max Frequency (Hz) S1 S0 Fz DC AC DC AC /rhombus6 Package Dimensions SOP16 Notice ： Sample tested during initial release and after any redesign or process change that may affect parameter. Specification subjects to change without notice. Please ask for the newest product specification at any moment.