BELLING BL6506 Single phase energy meter ic with integrated oscillator Datasheet

BL6506
FEATURES
Single Phase Energy Meter IC
with Integrated Oscillator
DESCRIPTION
High accuracy, less than 0.1% error over a
The BL6506 is a low cost, high accuracy, high
dynamic range of 500: 1
stability, simple peripheral circuit electrical energy
On-chip oscillator as clock source
meter IC. The meter based on the BL6506 is intended
Exactly measure the real power in the positive
for using in single-phase, two-wire distribution
orientation and negative orientation, calculate the
systems. It can exactly measure the real power in the
energy in the same orientation
positive orientation and negative orientation and
calculate the energy in the same orientation.
Two current monitors continuously monitor the
phase and neutral currents in two-wire distribution
The BL6506 incorporates a novel fault detection
systems. Uses the larger of two currents to bill, even
scheme that both warns of fault conditions and allows
during a Fault condition
the BL6506 to continue accurate billing during a fault
event. The BL6506 does this by continuously
A PGA in the current channel allows using small
value shunt and burden resistance
monitoring both the phase and neutral (return)
The low frequency outputs F1 and F2 can
currents. PIN15 (FAULT) indicates Fault condition,
directly drive electromechanical counters and two
when these currents differ by more than 12.5%.
phase stepper motors and the high frequency output
Billing is continued using the larger of the two
CF, supplies instantaneous real power, is intended for
currents when the difference is greater than 14%.
The BL6506 supplies average real power
calibration and communications
Two logic outputs REVP and FAULT can be used
information on the low frequency outputs F1 (Pin20)
to indicate a potential orientation or Fault condition
and F2 (Pin19). These logic outputs may be used to
On-Chip power supply detector
directly drive an electromechanical counter and
On-Chip anti-creep protection
two-phase stepper motors. The CF (Pin18) logic
On-Chip voltage reference of 2.5V±8%
output gives instantaneous real power information.
Single 5V supply
This output is intended to be used for calibration
Low static power (typical value of 25mW).
purposes or interface to an MCU.
The technology of SLiM (Smart–Low–current–
BL6506 thinks over the stability of reading
Management) is used.
error in the process of calibration. Bulk test data
indicate that in the condition of small signal 5%Ib
Credible work, working time is more than twenty
years
(Ib=5A), the error of CF is less than 0.1%. An internal
no-load threshold ensures that the BL6506 does not
Interrelated patents are pending
exhibit any creep when there is no load.
BLOCK DIAGRAM
SSOP 20
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3/15/2007
Single Phase Energy Meter IC
with Integrated Oscillator
BL6506
PIN DESCRIPTIONS
Pin
Symbol
Descriptions
1
VDD
Power Supply (+5V). Provides the supply voltage. It should be maintained at 5V±
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 Voltage Inputs V1A and V1B.
5,6
V2N
V2P
Negative and Positive Inputs for Voltage Channel. These inputs provide a fully
differential input pair. The maximum differential input voltage is ±660 mV for
specified operation.
7
NC
None connect.
8
GND
Provides the ground reference for the circuitry.
9
VREF
On-Chip Voltage Reference. The on-chip reference has a nominal value of 2.5V ±
8%.
10
SCF
Calibration Frequency Select. This logic input is used to select the frequency on
the calibration output CF.
11,12
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.
13,14
G1,G0
Gain Select. These logic inputs are used to select one of four possible gains for
current channel.
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.
15
Negative Indication. Logic high indicates negative power, i.e., when the phase
16
REVP
17
NC
None connect.
18
CF
Calibration Frequency. The CF logic output gives instantaneous real power
information. This output is intended to use for calibration purposes.
19,20
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.
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.
ABSOLUTE MAXIMUM RATINGS
( T = 25 ℃ )
Parameter
Symbol
Value
Unit
Power Voltage VDD
VDD
-0.3~+7(max)
V
Input Voltage of Channel 2 to GND
V (V)
VSS+0.5≤V(v)≤VDD-0.5
V
Input Voltage of Channel 1 to GND
V (I)
VSS+0.5≤V(i)≤VDD-0.5
V
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Single Phase Energy Meter IC
with Integrated Oscillator
BL6506
Operating Temperature Range
Topr
-40~+85
℃
Storage Temperature Range
Tstr
-55~+150
℃
400
mW
Power Dissipation
ELECTRONIC CHARACTERISTIC PARAMETER
(T=25℃, VDD=5V,On-Chip Oscillator,On-Chip voltage reference)
Parameter
Symbol
1 Power Current
Test Condition
IVDD
Measure
Pin
Min
Value
Pin1
2 Logic Input Pins
SCF, S0, S1, G1,G0
Typical
Value
Max
Value
5
Unit
mA
Pin 10, 11,
12, 13,14
Input High Voltage
VIH
VDD=5V
Input Low Voltage
VIL
1
V
Input Capacitance
CIN
10
pF
3 Logic Output Pins
F1, F2, CF, REVP, FAULT
VOH1
IH=10mA
Output Low Voltage
VOL1
IL=10mA
4.4
Vref
10
VDD=5V
Pin9
2.3
Temperature coefficient
5 Analog Input Pins
V1A, V1B, V1N, V2N, V2P
Maximum Input Voltage
V
0.5
IO1
4 On-chip Reference
V
Pin20,19,
18, 15,16
Output High Voltage
Output Current
2
V
mA
2.5
2.7
V
30
60
ppm/°C
±1
V
Pin2, 3, 4,
5, 6
VAIN
DC Input Impedance
330
Input Capacitance
6
Kohm
10
pF
6 Accuracy
Measurement Error
Channel 1 and 2
on
Gain=1
ENL1
Pin18
0.1
%
Gain=2
ENL2
Pin18
0.1
%
Gain=8
ENL8
Pin18
0.1
%
Gain=16
ENL16
Pin18
0.1
%
Channel 1 Lead 37°
(PF=0.8 Capacitive)
Pin18
0.1
%
Channel 1 Lags
(PF=0.5 Inductive)
Pin18
0.1
%
Phase
Error
Channels
7 Start Current
Both channels with
Full-Scale signal
±660mV over a
dynamic range 500 to 1
between
ISTART
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Ib=5A, C=3200
-3Total 14 Pages
Pin18
0.2%Ib
3/15/2007
A
BL6506
8 Positive and Negative
Real Power Error (%)
9 Gain Error
ENP
Vv=±110mV,
V(I)=2mV, cosϕ=1
Vv=±110mV,
V(I)=2mV, cosϕ=-1
Gain error
10 Gain Error Match
Single Phase Energy Meter IC
with Integrated Oscillator
Pin18
0.3
%
Pin18
±5
%
1
%
Pin18
0.2
TERMINOLOGY
1) Measurement Error
The error associated with the energy measurement made by the BL6506 is defined by the
following formula:
Pencebtage Error =
Energy Re gisteredby the BL6506 − True Energy
× 100%
True Energy
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, cosϕ=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 BL6506 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 BL6506 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.
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3/15/2007
BL6506
Single Phase Energy Meter IC
with Integrated Oscillator
7) Power Supply Monitor
BL6506 has the on-chip Power Supply monitoring The BL6506 will remain in a reset
condition until the supply voltage on VDD reaches 4 V. If the supply falls below 4 V, the BL6506
will also be reset and no pulses will be issued on F1, F2 and CF.
TIMING CHARACTERISTIC
(VDD=5V, GND=0V, On-Chip Reference, Integrated Oscillator, Temperature range: -20~+70°C)
Parameter
t1
Value
144ms
t2
t3
Comments
F1 and F2 pulse-width (Logic Low). When the power is low,
the t1 is equal to 144ms; when the power is high, and the
output period falls below 280ms, t1 equals to half of the
output period.
F1 or F2 output pulse period.
½ t2
t4
Time between F1 falling edge and F2 falling edge.
CF Pulse Period. See Transfer Function section.
t5
71ms
t6
CLKIN/4
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 140ms, t5 equals to half of the output
period.
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.
THEORY OF OPERATION
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
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BL6506
Single Phase Energy Meter IC
with Integrated Oscillator
current signal and the voltage signal is expressed asФ. Then the power is given as follows:
p (t ) = V cos( wt ) × I cos( wt + Φ )
Φ =0:
p (t ) =
Φ ≠ 0:
VI
(1 + cos(2 wt )
2
p (t ) = V cos( wt ) × I cos( wt + Φ )
= V cos( wt ) × [I cos( wt ) cos(Φ) + sin( wt ) sin(Φ )]
VI
(1 + cos(2 wt )) cos(Φ ) + VI cos( wt ) sin( wt ) sin(Φ)
2
VI
VI
=
(1 + cos(2 wt )) cos(Φ ) + sin(2 wt ) sin(Φ)
2
2
=
p(t) is called as the instantaneous power signal. The ideal p(t) consists of the dc component and ac
component whose frequency is 2ω. The dc component is called as the average active power, that
is:
P=
VI
cos(ϕ )
2
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.
Operation Process
In BL6506, 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
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Single Phase Energy Meter IC
with Integrated Oscillator
BL6506
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
scheme correctly calculates real power for non-sinusoidal current and voltage waveforms at all
power factors. All signal processing is carried out in the digital domain for superior stability over
temperature and time.
I
V
current
sampling
voltage
sampling
analog to
digital
high pass
filter
analog to
digital
digital
multiplication
high pass
filter
CF
low pass
filter
digital to
frequency
F1
F2
instantaneous real
power signal
instantaneous
power signal p(t)
V*I
integral
p(t)=i(t)*v(t)
v(t)=V*cos(wt)
i(t)=I*cos(wt)
V*I
2
p(t)=
V*I
2
V*I
2
[1+cos(2wt)]
t
t
Figure 2.
Signal Processing Block Diagram
Accumulating this real power information generates the low frequency output of the BL6506. This
low frequency inherently means a long accumulation time between output pulses. The output
frequency is therefore proportional to the average real power. This average real power information
can, in turn, be accumulated (e.g., by a counter) to generate real energy information. Because of its
high output frequency and hence shorter integration time, the CF output is proportional to the
instantaneous real power. This is useful for system calibration purposes that would take place
under steady load conditions.
Offset Effect
The dc offsets come from the input signals and the forepart analog circuitry.
Assume that the input dc offsets on the voltage channel and the current channel are Uoffset and Ioffset,
and PF equals 1 (φ=0).
p ( t ) = [U cos( ω t ) + U offset ] × [ I cos( ω t + Φ ) + I offset ]
=
UI
UI
+ I offset U cos( ω t ) + U offset I cos( ω t ) +
cos( 2ω t )
2
2
Figure 3.
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Effect of Offset
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BL6506
Single Phase Energy Meter IC
with Integrated Oscillator
As can be seen, for each phase input, if there are simultaneous dc offsets on the voltage channel
and the current channel, these offsets contribute a dc component for the result of multiplication.
That is, the offsets bring the error of Uoffset×Ioffset to the final average real power. Additionally,
there exists the component of Uoffset×I+U×Ioffset at the frequency of ω. The dc error on the real
power will result in measure error, and the component brought to the frequency of ω will also
affect the output of the average active power when the next low-pass filter cannot restrain the ac
component very completely.
When the offset on the one of the voltage and the current channels is filtered, for instance, the
offset on the current channel is removed; the result of multiplication is improved greatly. There is
no dc error, and the additional component at the frequency of ω is also decreased.
When the offsets on the voltage channel and the current channel are filtered respectively by two
high-pass filters, the component at the frequency of ω (50Hz) is subdued, and the stability of the
output signal is advanced. Moreover, in this case, the phases of the voltage channel and the current
channel can be matched completely, and the performance when PF equal 0.5C or 0.5L is improved.
In BL6506, this structure is selected. Though it is given in the system specification that the ripple
of the output signal is less than 0.1%, in real measure of BL6506, the calibration output is very
stable, and the ripple of the typical output signal is less than 0.05%.
Additionally, this structure can ensure the frequency characteristic. When the input signal changes
from 45Hz to 65Hz, the complete machine error due to the frequency change is less than 0.1%. In
such, the meter designed for the 50Hz input signal can be used on the transmission-line system of
electric power whose frequency is 60Hz.
Voltage Channel Input
The output of the line voltage transducer is connected to the BL6506 at this analog input. As
Figure4 shows that channel V2 is a fully differential voltage input. The maximum peak differential
signal on Channel 2 is ±660mV. Figure4 illustrates the maximum signal levels that can be
connected to the BL6506 Voltage Channel.
V1
V1A
+660mV
GAIN
Maximun input differential voltage
±660mV
+
V1
V2
V1N
-
V2
-660mV
GAIN
V1
Maximun input common-mode voltage
±100mV
V1B
+
AGND
Figure 4.
Voltage Channels
Voltage Channel must be driven from a common-mode voltage, i.e., the differential voltage signal
on the input must be referenced to a common mode (usually GND). The analog inputs of the
BL6506 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.
Figure5 shows two typical connections for Channel V2. The first option uses a PT (potential
transformer) to provide complete isolation from the mains voltage. In the second option, the
BL6506 is biased around the neutral wire and a resistor divider is used to provide a voltage signal
that is proportional to the line voltage. Adjusting the ratio of Ra and Rb is also a convenient way
of carrying out a gain calibration on the meter.
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Single Phase Energy Meter IC
with Integrated Oscillator
BL6506
RF
CT
VAP
+
CF
±660mV
RF
AGND
-
VN
CF
AGND
Phase Neutral
AGND
CF
Ra
Rb
AGND
Rv
AGND
±660mV
VAP
+
Phase Neutral
RF
AGND
-
VN
Ra >> RF
Rb+Rv=RF
Figure 5.
CF
AGND
AGND
Typical Connections for Voltage Channels
Current Channel Input
The voltage outputs from the current transducers are connected to the BL6506 here. As Figure6
shows that channel V1 has two voltage inputs, namely V1A and V1B. These inputs are fully
differential with respect to V1N. However, at any one time, only one is selected to perform the
power calculation.
V1
+660mV
V2P
Maximun input differential voltage
±660mV
+
V1
V2N
V2
-
V2
Maximun input common-mode voltage
±100mV
AGND
-660mV
Figure 6.
Current Channels
The analog inputs V1A, V1B and V1N have same maximum signal level restrictions as V2P and
V2N. However, Channel 1 has a programmable gain amplifier (PGA) with user-selectable gains of
1,2,8 or 16. These gains facilitate easy transducer interfacing. Figure illustrates the maximum
signal levels on V1A, V1B, and V1N. The maximum differential voltage is ±660 mV divided by
the gain selection. Again, the differential voltage signal on the inputs must be referenced to a
common mode, e.g., GND. The maximum common-mode signal is ±100 mV.
Figure7 shows a typical connection diagram for Channel V1. Here the analog inputs are being
used to monitor both the phase and neutral currents. Because of the large potential difference
between the phase and neutral, two CTs (current transformers) must be used to provide the
isolation. The CT turns ratio and burden resistor (Rb) are selected to give a peak differential
voltage of ±660 mV/gain.
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Single Phase Energy Meter IC
with Integrated Oscillator
BL6506
RF
CT
V1A
Rb
IP
IN
±660mV
GAIN
CF
+
-
V1N
AGND
Rb
±660mV
GAIN
-
CF
V1B
CT
+
RF
Phase Neutral
CF
Ra
Rb
Rv
Ra >> RF
Rb+Rv=RF
AGND
±660mV
V1A
AGND
IP
+
-
V1N
IN
AGND
Rb
±660mV
GAIN
-
CF
V1B
CT
+
RF
Phase Neutral
Figure 7.
Typical Connections for Current Channels
Fault Detection
The BL6506 incorporates a novel fault detection scheme that warns of fault conditions and allows
the BL6506 to continue accurate billing during a fault event. The BL6506 does this by
continuously monitoring both the phase and neutral (return) currents. A fault is indicated when
these currents differ by more than 12.5%. However, even during a fault, the output pulse rate on
F1 and F2 is generated using the larger of the two currents. Because the BL6506 looks for a
difference between the signals on V1A and V1B, it is important that both current transducers are
closely matched. On power-up the output pulse rate of the BL6506 is proportional to the product
of the signals on Channel V1A and Voltage Channel. If there is a difference of greater than 12.5%
between V1A and V1B on power-up, the fault indicator (FAULT) will go active after about one
second. In addition, if V1B is greater than V1A the BL6506 will select V1B as the input. The fault
detection is automatically disabled when the voltage signal on Channel 1 is less than 0.5% of the
full-scale input range. This will eliminate false detection of a fault due to noise at light loads.
If V1A is the active current input (i.e., is being used for billing), and the signal on V1B (inactive
input) falls by more than 12.5% of V1A, the fault indicator will go active. Both analog inputs are
filtered and averaged to prevent false triggering of this logic output. As a consequence of the
filtering, there is a time delay of approximately one second on the logic output FAULT after the
fault event. The FAULT logic output is independent of any activity on outputs F1 or F2. Figure 8
illustrates one condition under which FAULT becomes active. Since V1A is the active input and it
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.
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BL6506
Single Phase Energy Meter IC
with Integrated Oscillator
V1A
V1B
V1A
V1B
V1N
0V
FAULT
current
sampling
to ADC
V1B < 87.5% V1A
Figure 8. Fault Conditions for Inactive Input Less than Active Input
Figure 9 illustrates another fault condition. If V1A is the active input (i.e., is being used for billing)
and the voltage signal on V1B (inactive input) becomes greater than 114% of V1A, the FAULT
indicator goes active, and there is also a swap over to the V1B input. The analog input V1B has
now become the active input. Again there is a time delay of about 1.2 seconds associated with this
swap. V1A will not swap back to being the active channel until V1A becomes greater than 114%
of V1B. However, the FAULT indicator will become inactive as soon as V1A is within 12.5% of
V1B. This threshold eliminates potential chatter between V1A and V1B.
V1B
V1A
0V
V1A
V1B
V1N
FAULT
current
sampling
to ADC
V1A < 87.5% V1B
Figure 9. Fault Conditions for Inactive Input Greater than Active Input
Power Supply Monitor
The BL6506 contains an on-chip power supply monitor. If the supply is less than 4V±5% then
the BL6506 will go in an inactive state, i.e., no energy will be accumulated when the supply
voltage is below 4V. This is useful to ensure correct device operation at power up and during
power down. The power supply monitor has built-in hysteresis and filtering. This gives a high
degree of immunity to false triggering due to noisy supplies.
The trigger level is nominally set at 4V, and the tolerance on this trigger level is about ±5%. The
power supply and decoupling for the part should be such that the ripple at VDD does not exceed
5V±5% as specified for normal operation.
SLiM Technology
The BL6506 adopts the technology of SLiM (Smart Low current Management) to decrease the
static power greatly. The static power of BL6506 is about 15mW. This technology also decreases
the request for power supply design.
BL65XX series products used 0.35um CMOS process. The reliability and consistency are
advanced.
OPERATION MODE
Transfer Function
The BL6506 calculates the product of two voltage signals (on Channel 1 and Channel 2) and then
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BL6506
Single Phase Energy Meter IC
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.
Freq =
3.5 × V (v) × V (i ) × Gain × Fz
2
V REF
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 ,2,8 or 16, depending on the PGA gain selection, using logic inputs G1/G0
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
0
S0
0
Fz(Hz)
1.7
0
1
3.4
1
0
6.8
1
1
13.6
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
SCF
S1
S0
CF/F1 (or F2)
1
1
0
0
128
2
0
0
0
64
3
1
0
1
64
4
0
0
1
32
5
1
1
0
32
6
0
1
0
16
7
1
1
1
16
8
0
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
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3/15/2007
Single Phase Energy Meter IC
with Integrated Oscillator
BL6506
the digital-to-frequency conversion. With much less averaging of the real power signal, the CF
output is much more responsive to power fluctuations.
Gain Selection
By select the digital input G0 and G1 voltage (5V or 0V), we can adjust the gain of current
channel. We can see that while increasing the gain, the input dynamic range is decreasing.
G1
G0
Gain
Maximum
Differential Signal
1
1
1
±660mV
1
0
2
±330mV
0
1
8
±82mV
0
0
16
±41mV
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 1,2,8,16. 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.
SCF
S1
S0
Fz
Max Frequency
of F1, F2 (Hz)
DC
CF Max Frequency (Hz)
AC
DC
AC
1
0
0
1.7
0.45
0.22
128×F1,F2=57.6
128×F1,F2=28.8
0
0
0
1.7
0.45
0.22
64×F1,F2=28.8
64×F1,F2=14.4
1
0
1
3.4
0.90
0.45
64×F1,F2=57.6
64×F1,F2=28.8
0
0
1
3.4
0.90
0.45
32×F1,F2=28.8
32×F1,F2=14.4
1
1
0
6.8
1.80
0.90
32×F1,F2=57.6
32×F1,F2=28.8
0
1
0
6.8
1.80
0.90
16×F1,F2=28.8
16×F1,F2=14.4
1
1
1
13.6
3.60
1.80
16×F1,F2=27.6
16×F1,F2=28.8
0
1
1
13.6
3.60
1.80
8×F1,F2=28.8
8×F1,F2=14.4
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3/15/2007
BL6506
Single Phase Energy Meter IC
with Integrated Oscillator
Package Dimensions
1、DIP20
2、SSOP20
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.
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3/15/2007
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