AS8118_1 [AMSCO]

Single Phase Instantaneous Energy Metering IC with On-Chip Calibration, Stepper Motor Drive and LED Output; 单相瞬时电能计量IC,具有片内校准,步进电机驱动器和LED输出
AS8118_1
型号: AS8118_1
厂家: AMS(艾迈斯)    AMS(艾迈斯)
描述:

Single Phase Instantaneous Energy Metering IC with On-Chip Calibration, Stepper Motor Drive and LED Output
单相瞬时电能计量IC,具有片内校准,步进电机驱动器和LED输出

驱动器 电机
文件: 总30页 (文件大小:283K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
AS8118  
Single Phase Instantaneous Energy Metering IC  
with On-Chip Calibration, Stepper Motor Drive and LED Output  
DATA SHEET  
control block and non-volatile calibration memory for the  
on-chip programming. The on-chip programming enables  
the setting of the current input gain, the anti-creep  
threshold, the output pulse rates and the system  
calibration. The high level of integration ensures a  
minimum number of non-critical external components are  
required.  
Features  
-
Extremely accurate, surpassing the accuracy  
requirements of the IEC 1036 Specification less than  
0.1% error over a 600 : 1 dynamic range  
On-chip programmable current input gain suitable for  
use with low-resistance shunt resistor or current  
transformer  
-
The on-chip anti-creep circuit ensures that the AS8118  
does not output pulses when the meter is in a no-load  
condition and that the IEC1036 anti-creep test  
requirements are fully complied with, for both direct or  
transformer connection meters.  
-
-
On-chip programming for output pulse rate selection  
On-chip calibration eliminates the need for an external  
resistor network or trim-potentiometer  
Programmable on-chip creep prevention under no-load  
condition  
All on-chip programmable functions may be  
reprogrammed a second time  
Outputs directly drive an electromechanical counter or  
counters with a two phase stepper motor and  
consumption LED indicator  
-
-
-
The AS8118 offers three different pulse outputs. A stepper  
motor drive output for directly driving a stepper motor  
display, a LED output for energy consumption indication  
and a dedicated high frequency output for fast single point  
system calibration.  
-
-
-
Fast calibration pulse output for high speed manual or  
automated calibration  
On-chip voltage reference and power supply  
monitoring  
Bi-directional or unidirectional energy measurement,  
with direction indication output available  
The AS8118 is available in either surface mount SOIC-18  
or dual-in-line DIP-18 packages.  
Block Diagram  
Description  
Non-volatile  
Calibration  
AGND  
Buffer  
The AS8118 is a very accurate single-phase bi-directional  
instantaneous energy measurement integrated circuit,  
which surpasses all the accuracy requirements for  
IEC1036 alternating current static watt-hour meters. The  
measured energy is converted into pulses with the number  
of output pulses being proportional to the measured  
energy.  
VP  
VN  
Digital  
Filter  
Σ∆-mod  
Power  
Calculation  
IP  
IN  
Digital  
Filter  
Σ∆-mod  
VREF  
The AS8118 is ideal for use in ‘stand alone’ kWh meter  
applications, where the IC directly drives an  
electromechanical counter with a two-phase stepper  
motor, or for more complex meter applications, the  
AS8118 interfaces directly to a micro-controller.  
CAL  
LED  
MON  
MOP  
XIN  
XOUT  
Crystal  
Osc  
Control  
POR  
The highly integrated AS8118 design includes all the  
required functional blocks. The blocks comprise of analog  
to digital converters (ADC) for the voltage and current  
channels, digital filters, a digital signal processing block, a  
Figure 1  
Block diagram of the AS8118  
Revision 1.8, 15-Feb-05  
Page 1 of 30  
Data Sheet AS8118  
Typical Connection Circuit  
Load  
VDD (5V)  
VDDA VDDD  
IP  
Calibration  
PROG  
Programming  
Shunt  
TM  
IN  
LED  
LED Output  
VN  
Calibration  
CAL  
DIRI  
Pulse Output  
VP  
MOP  
MON  
Stepper Motor  
Outputs  
XIN  
DIRO  
XOUT VSSA VSSD  
VSS  
Voltage  
VDD (5V)  
VSS  
Regulator  
N
L
Figure 2  
Typical connection circuit for the AS8118  
Pin Configuration  
1
18  
17  
16  
15  
14  
IN  
IP  
VP  
2
VN  
3
TM  
DIRI  
VDDA  
XIN  
4
5
VSSA  
PROG  
VSSD  
DIRO  
6
7
13  
12  
11  
10  
XOUT  
VDDD  
8
9
CAL  
LED  
MON  
MOP  
Figure 3 Pin configuration of the AS8118  
Revision 1.8, 15-Feb-05  
Page 2 of 30  
Data Sheet AS8118  
Pin Description  
Pin No. Pin Name Description  
1
2
3
VP  
VN  
TM  
Positive input for the voltage channel. VP is a differential input with VN. The differential voltage  
should be set at ±150mV peak for rated voltage conditions. VP is an analog input pin.  
Negative input for the voltage channel. VN is a differential input with VP. VN is usually tied to 0V  
potential (VSSA). VN is an analog input pin.  
On ‘power up’, the test mode input defines the operation mode of the device. Either ‘Normal  
Operation’, or ‘Calibration’ modes may be selected. TM has an on-chip pull down resistor and  
should be left unconnected during ‘Normal Operation’. TM must be set to logic ‘1’ at ‘power up’ to  
set the device in ‘Calibration’ mode.  
4
5
VSSA  
PROG  
Negative analog supply. VSSA is the ground reference for the analog circuitry.  
Programming pin for calibration procedure. PROG is an analog input pin which must be left  
unconnected during normal operation. Note: PROG must not be connected to VSS.  
Negative digital supply. VSSD is the ground reference for the digital circuitry.  
Direction output provides indication of the direction of current flow through the current sensor.  
This digital input/output has an on-chip pull down resistor and provides logic ‘0’ for positive  
power and logic ‘1’ for negative power. DIRO is used as an input during the programming cycle.  
This output may be directly connected to a LED and is capable of driving 4mA.  
Fast energy pulse output for calibration. CAL pulse rate is programmable and dependent upon  
the selected MON/MOP frequency.  
6
7
VSSD  
DIRO  
8
9
CAL  
MOP  
Positive motor drive signal. MOP and MON are low frequency outputs for directly driving a two  
phase stepper motor. The frequency of the MOP/MON outputs is programmable to suite all  
industry standards and is capable of driving 10mA.  
10  
11  
MON  
LED  
Negative motor drive signal. MON and MOP are low frequency outputs for directly driving a two  
phase stepper motor. The frequency of the MOP/MON outputs is programmable to suite all  
industry standards and is capable of driving 10mA.  
This output may be connected to an LED to display energy consumption. LED is a digital output,  
which is programmable to a desired pulse rate. All the industry standard pulse rates are  
available. This output is capable of driving 10mA.  
12  
13  
14  
VDDD  
XOUT  
XIN  
Positive digital supply. VDDD provides the supply voltage for the digital circuitry. The required  
supply voltage is 5V ±10%.  
See XIN below, for the connection of a crystal or ceramic resonator. When an external clock is  
applied to XIN, XOUT is not connected.  
A 3.579545 MHz crystal or ceramic resonator may be connected across XIN and XOUT without  
the need for external load capacitors. Alternatively, an external clock signal may be applied to  
XIN.  
15  
16  
VDDA  
DIRI  
Positive analog supply. VDDA provides the supply voltage for the analog circuitry. The required  
supply voltage is 5V ±10%.  
Direction input pin for selecting unidirectional or bi-directional energy measurement mode. When  
DIRI is at logic ‘0’, the IC is set in unidirectional mode. When DIRI is at logic ‘1’ the IC is in bi-  
directional mode. In default mode, when DIRI is not connected, the IC is in bi-directional mode.  
DIRI is a digital input with an on-chip pull-up resistor.  
17  
18  
IP  
IN  
Positive input for the current channel. IP is a differential input with IN. The input gain is  
programmable depending on the desired current sensor. The maximum differential voltage is  
±150mV peak (Gain = 4). IP is an analog input pin.  
Negative input for the current channel. IN is a differential input with IP. The input gain is  
programmable depending on the desired current sensor. IN is usually at 0V potential. IN is an  
analog input pin.  
Revision 1.8, 15-Feb-05  
Page 3 of 30  
Data Sheet AS8118  
AS8118 Performance Graphs  
0,8  
0,6  
0,4  
0,8  
0,6  
0,4  
0,2  
0
- 40°C  
GAIN 16  
0,2  
+ 85°C  
+ 25°C  
0
-0,2  
-0,2  
-0,4  
-0,6  
-0,8  
GAIN 4  
GAIN 20  
-0,4  
-0,6  
-0,8  
0,01  
0,1  
1
10  
100  
0,01  
0,1  
1
10  
100  
I [A]  
I [A]  
Graph 1: Error as a % of reading for gain settings 4, 16 and 20 at 25°C  
Graph 4: Error as a % of reading at temperature limits and PF = 0.5  
0,8  
0,6  
0,8  
0,6  
VDD_5.5V  
VDD_5.0V  
0,4  
0,2  
0
0,4  
0,2  
0
- 40°C  
+ 85°C  
+ 25°C  
-0,2  
-0,4  
-0,6  
-0,8  
-0,2  
-0,4  
-0,6  
-0,8  
VDD_4.5V  
0,01  
0,1  
1
10  
100  
0,01  
0,1  
1
10  
100  
I [A]  
I [A]  
Graph 5: Error as a % of reading with variation in VDD  
Graph 2: Error as a % of reading at temperature limits and PF = 1  
0,8  
0,6  
0,4  
0,8  
0,6  
0,4  
- 40°C  
V_MAIN_264.5  
0,2  
0
0,2  
+ 85°C  
0
V_MAIN_230  
V_MAIN_184  
+ 25°C  
-0,2  
-0,4  
-0,6  
-0,8  
-0,2  
-0,4  
-0,6  
-0,8  
0,01  
0,1  
1
10  
100  
0,01  
0,1  
1
10  
100  
I [A]  
I [A]  
Graph 6: Error as a % of reading with mains voltage variation  
Graph 3: Error as a % of reading at temperature limits and PF = 0.8  
Revision 1.8, 15-Feb-05  
Page 4 of 30  
Data Sheet AS8118  
0 ,8  
0 ,6  
0 ,4  
0 ,2  
0
-0 ,2  
-0 ,4  
-0 ,6  
-0 ,8  
4 5  
5 0  
5 5  
6 0  
6 5  
F
[H z )  
Graph 7: Error as a % of reading with mains frequency variation  
Functional Description  
The AS8118 is a CMOS mixed signal integrated circuit that measures electrical power over a dynamic range of 600:1, to an  
accuracy of better than 0.1%.  
The AS8118 comprises of standard functional blocks including two sigma/delta modulators, which convert the analog voltage  
and current input signals into digital signals. The voltage and current signals are then digitally filtered, which eliminates  
offsets thus enabling a single point calibration cycle. A power calculation block calculates the active energy value. An on-chip  
voltage reference (±30ppm/K typical), oscillator and non-volatile calibration registers and control block for programming the  
AS8118 completes the core functional elements.  
Programming of the AS8118 enables the device to be configured to suite the users specific input and output requirements  
and allows for fast and efficient calibration. The AS8118 device provides the user with two complete opportunities to  
programme the device. The following parameters may be programmed via the on-chip non-volatile memory:  
-
-
-
-
-
-
Current channel input gain  
Calibration pulse output frequency  
Stepper motor output drive frequency  
LED output frequency  
Anti-creep threshold  
Calibration constant  
A detailed description of the versatility of the AS8118 is given below.  
Current Inputs for Energy Calculation  
The current channel input consisting of inputs IP and IN is differential and connected to a low resistance shunt or current  
transformer, in series with the load. The current input signal level may be programmed by means of an on-chip  
programmable gain amplifier (PGA). The gain is selected through the programming of 2 bits in the on-chip memory as  
follows:  
Parameter: Gain  
Setting  
Voltage Input Voltage  
Comments  
Gain  
1 1  
20  
16  
Shunt mode  
CT mode  
-30mVpeakVIP30mVpeak  
-38mVpeakVIP38mVpeak  
1 0  
0 1  
0 0  
4
CT mode  
-150mVpeakVIP150mVpeak  
Revision 1.8, 15-Feb-05  
Page 5 of 30  
Data Sheet AS8118  
For optimum operating conditions, the input signal at the Maximum Current (IMAX) condition should be set at ±30mV peak,  
when the input Gain = 20, or ±150mV peak, when the input Gain = 4.  
The default gain, namely the AS8118 setting which is available without any programming required, is Gain = 20.  
The value of an ideal shunt resistor, may be calculated as follows:  
Assuming an IMAX rating of 60A (rms) 84.85A (peak), then a shunt value of 350µwould be suitable.  
30mVpeak  
Rshunt  
=
= 350µΩ  
84.85Apeak  
The mains current is sampled at 1.7478kHz, assuming that the recommended crystal oscillator frequency of 3.5795MHz, is  
used.  
Voltage Input for Energy Calculation  
The voltage channel input consists of inputs VP and VN, which are is differential, with VP connected to the tap of a resistor  
divider circuit of the line voltage and VN connected to Ground. For optimum operating conditions, the input signal at VP with  
respect to VN, should be set at 150mV peak for the rated line voltage condition.  
The maximum voltage on VP for the specified operation is 210mV with respect to VSS. The maximum allowed voltage signal  
at VP, which ensures that pulses are still provided at the output, is 300mV with respect to VSS. Both VP and VN have  
internal ESD protection and an over-voltage of ±7V can be sustained on these pins without risk of permanent damage to the  
device.  
The resistor values for an ideal voltage divider, may be calculated as follows:  
Assuming a Vmains of 230V (rms) 325V (peak) and according to the voltage divider shown below, the value for  
R2 = 820, the value of R1A+R1B may be calculated as follows:  
Vmains  
R1A+R1B  
R2  
Vin  
(Vmains( peak ) VIP max  
)
325V 150mV  
150mV  
R1A + R1B = R2*  
= 820*  
= 1.77MΩ  
VIP max  
The mains voltage is sampled at 1.7478kHz, assuming that the recommended crystal oscillator frequency of 3.5795MHz is  
used.  
Revision 1.8, 15-Feb-05  
Page 6 of 30  
Data Sheet AS8118  
Digital Filters  
The current and voltage channels have been identically implemented with digital high pass filters in both channels, thus  
eliminating offsets.  
The filters ensure that there are no phase errors introduced between the voltage and current channels, enabling single point  
calibration.  
Energy to Pulse Output Conversion  
The energy value is accumulated in the energy accumulator and compared with the default or programmed threshold level,  
following each sample. The threshold represents the pulse equivalent energy value. If the energy value goes above the  
threshold, a pulse is generated and presented to the output. Each time a pulse is generated the threshold value is subtracted  
from the contents of the energy accumulator.  
The remaining energy, namely the energy value above the threshold value is retained in the accumulator. Further measured  
energy is added to the retained value in the accumulator and a pulse is again generated and presented to the output, when  
the value again exceeds the threshold value. Thus no energy is lost during the energy to pulse output conversion process.  
The voltage and current signals are sampled at 1.7478kHz. The sample rate is derived from the main clock (FMCLK) as  
follows:  
3.57945 MHz / 8*256 =  
1.7478 kHz  
The number of measured harmonics is defined by the sample rates of the voltage and current input signals. The maximum  
bandwidth, which is half the sample frequency, is calculated as follows:  
1.7478/2 kHz = 873.9 Hz  
Thus, depending on the mains frequency, the measured energy is up to the following harmonics:  
50Hz mains = 17th harmonic  
60Hz mains = 14th harmonic  
Energy Pulse Outputs  
The AS8118 has three different pulse outputs. All the outputs are derived directly from the measured energy; thus, the  
outputs can be used for energy accumulation and for calibration purposes. The output options include the following:  
-
-
-
CAL: A higher pulse rate output for fast calibration  
MOP/MON: Low pulse rate outputs for directly driving a stepper motor  
LED: A low pulse rate output which may be used to directly drive a LED for displaying power consumption  
Calibration Pulse Output (CAL): The CAL output is a high frequency output, the frequency of which is proportional to the real  
power measured.  
The output pulse rate is programmable via the on-chip memory and allows for 4 pulse rate options:  
Parameter: F_cal_sel  
Setting CAL Output Pulse Rate  
00  
01  
10  
11  
MON/MOP x  
8
MON/MOP x 16  
MON/MOP x 32  
MON/MOP x 64  
Revision 1.8, 15-Feb-05  
Page 7 of 30  
Data Sheet AS8118  
The default pulse rate of CAL is MON/MOP x 16. The default pulse rate is the pulse rate available at the output, without any  
programming required to the AS8118.  
(Note: As the default pulse rate of MON/MOP is 400 imp/kWh, the actual CAL default pulse rate is 400 x 16 = 6,400  
imp/kWh)  
As an example, the maximum selectable pulse rate of CAL is 64 * 800 = 51,200 imp/kWh (See MON/MOP below)  
The CAL pulse width is fixed at 1ms and is shown in the Timing Diagram and Timing Parameters that follow.  
Stepper Motor Drive Outputs (MON & MOP): The MON and MOP outputs may be used to directly drive an electromechanical  
counter or a stepper motor counter. The output frequencies are proportional to the real power measured. The required format  
of the signal for driving a mechanical counter, activated by a 2-phase stepper motor is provided by the difference between  
the MON and MOP outputs.  
The output pulse rate is programmable via the on-chip memory, with 4 pulse rate options being available:  
Parameter: F_mon_sel  
Setting MON/MOP Output Pulse Rate  
00  
01  
10  
11  
100 imp/kWh  
200 imp/kWh  
400 imp/kWh  
800 imp/kWh  
The default MON/MOP pulse rate is set at 400 imp/kWh. The default pulse rate is the pulse rate available at the output,  
without any programming required to the AS8118.  
The MON and MOP outputs shown in Figure 4 are capable of driving 10mA at VOH = 4.0V and VOL = 0.4V.  
The widths of the MON/MOP pulses are 200ms for all settings up to 800imp/kWh. Above 800imp/kWh, the MON/MOP pulse  
widths maintain a constant 50% duty cycle and is shown in the Timing Diagram and Timing Parameters that follows.  
LED Driver Pulse Output (LED): The LED output is a low frequency output, the frequency of which is proportional to the real  
power measured. The pulse rate is programmable via the on-chip memory the selected pulse rate is independent of the  
settings of both the selected CAL and the MON/MOP settings.  
Parameter: F_led_sel  
Setting LED Output Pulse Rate  
000  
001  
010  
011  
100  
101  
110  
100 imp/kWh  
200 imp/kWh  
400 imp/kWh  
800 imp/kWh  
1600 imp/kWh  
3200 imp/kWh  
6400 imp/kWh  
The default LED pulse rate is set at 3200 imp/kWh. The default frequency is the frequency available at the output, without  
any programming required to the AS8118.  
The LED output is capable of driving 10mA at VOH = 4.0V and VOL = 0.4V.  
The width of the LED pulse is 80 ms for all settings except where the LED stream is shorter than 160ms. In this case, a 50%  
duty cycle is maintained. The format of the LED signal is shown in the Timing Diagram and Timing Parameters below.  
Revision 1.8, 15-Feb-05  
Page 8 of 30  
Data Sheet AS8118  
Anti-Creep Threshold Setting  
The anti-creep threshold is programmable to ensure that the set threshold lies between the anti-creep current, a current level  
at which no pulses must be generated and the start current. The programmable threshold levels have been set to  
accommodate the various specified base currents (IB) of the meter and if the meter is direct connection (shunt resistor) or  
connection is through a current transformer. The formulae for calculating the appropriate thresholds are as follows:  
4* IB  
1000  
1
5
1
5
Shunt:  
ac _th =  
ac _th =  
*
*
= IStart  
*
*
2* IB  
1000  
1
5
1
5
Current Transformer:  
= IStart  
Parameter: Acreep_sel  
(All values are given in mA, unless otherwise specified)  
Setting  
Ithreshold  
IB (A)  
IMAX(A)  
IMAX(A)  
Ianticreep Istarting  
Ianticreep  
CT  
Istarting  
CT  
(IB*4)  
(IB*6)  
Shunt  
Shunt  
2.3  
2.3  
7.4  
14.8  
14.8  
29.7  
29.7  
1.5  
2.5  
5
10  
15  
20  
30  
6
10  
20  
40  
60  
80  
120  
9
15  
30  
60  
90  
120  
n/a  
1.2  
2
4
6
10  
20  
40  
60  
80  
100  
0.6  
1
2
4
6
3
5
00  
01  
10  
10  
20  
30  
40  
50  
8
12  
16  
20  
8
10  
11  
The default Anti-Creep threshold (ac_th) is set at 7.4mA, best suited to a 30A (IB*6) or 20A (IB*4) meter. The default Anti-  
Creep is the programmed threshold setting, without any programming required to the AS8118.  
Summary of Programmable Parameters  
The AS8118 programming options, along with the default settings have been summarised in the table below:  
I Gain  
CAL  
MON/MOP  
LED  
Anti-Creep Threshold  
20  
8
100  
100  
2.32mA  
16  
4
16  
32  
64  
200  
400  
800  
200  
400  
800  
7.43mA  
14.90mA  
29.70mA  
1600  
3200  
6400  
Note: The default settings have been highlighted.  
Revision 1.8, 15-Feb-05  
Page 9 of 30  
Data Sheet AS8118  
Timing Diagram  
t1  
MON  
MOP  
t2  
t3  
t4  
t5  
t6  
CAL  
LED  
Figure 4  
Timing diagram for AS8118 frequency outputs  
Timing Parameters  
Parameter Values  
Unit  
ms  
ms  
Pulse rate  
100,200,400 imp/kWh  
800 imp/kWh  
Comments  
t1  
200  
For all currents up to 120A ; 230V  
Imax < 97.8 A ; 230 V  
200  
50% duty cycle  
800 imp/kWh  
Imax > 97.8 A ; 230 V  
t2  
t3  
t4  
t5  
t6  
Tosc*4  
t1+t2  
2 * t3  
1
80  
80  
50% duty cycle  
80  
50% duty cycle  
50% duty cycle  
80  
50% duty cycle  
50% duty cycle  
50% duty cycle  
ms  
ms  
ms  
ms  
ms  
ms  
Minimum time between MON and MOP  
100,200,400,800 imp/kWh  
50,100,200,400 imp/kWh  
100,200,400,800 imp/kWh  
1600 imp/kWh  
1600 imp/kWh  
3200 imp/kWh  
3200 imp/kWh  
3200 imp/kWh  
6400 imp/kWh  
6400 imp/kWh  
6400 imp/kWh  
6400 imp/kWh  
For all currents up to 120A ; 230V  
For currents below 61.14A ; 230V  
For currents above 61.14A ; 230V  
For currents below 30.57A ; 230V  
For currents above 30.57A ; 230V  
For currents above 61.14A ; 230V  
For currents below 15.28A ; 230V  
For currents above 15.28A ; 230V  
For currents above 30.57A ; 230V  
For currents above 61.14A ; 230V  
ms  
ms  
Revision 1.8, 15-Feb-05  
Page 10 of 30  
Data Sheet AS8118  
Direction Input (DIRI)  
The direction input pin (DIRI) is used to program the AS8118 for either bi-directional energy measurement, or unidirectional  
measurement.  
Bi-directional measurement mode ensures that all energy is measured regardless of the direction of the current through the  
current sensor. In unidirectional energy measurement mode, all negative going energy is suppressed and thus excluded from  
the accumulated energy value.  
The programming conditions for the DIRI pin are given below:  
DIRI Pin  
Mode  
0
1
Unidirectional  
Bi-directional  
The default condition, when the DIRI pin is not connected is bi-directional energy measurement, as the DIRI pin has an on-  
chip pull-up resistor.  
Direction Output (DIRO)  
The Direction Output pin (DIRO) is a logic output providing information on the direction of the current flow through the current  
sensor. The DIRO output may be used to directly drive an LED to indicate a reversal in the direction of current flow.  
The timing diagram below demonstrates the operation of the DIRO output and the pulse outputs (MOP/MON, CAL and LED)  
relative to the sign of the measured energy and the setting of the DIRI input.  
For illustration purposes, the timing diagram below only shows the LED output.  
1
2
4
3
VP  
IP  
DIRI  
LED  
DIRO  
Figure 5  
Timing diagram for the DIRI and DIRO functions  
The timing diagram above demonstrates the state of both the LED and DIRO output pins depending on the input conditions:  
1.  
The voltage input (VP) and current input (IP) are in phase and the direction input DIRI is set to ‘Unidirectional’ mode.  
Pulses are available at the LED output and DIRO indicates a positive energy flow.  
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Data Sheet AS8118  
2.  
3.  
The voltage input (VP) and current input (IP) are in phase and the direction input DIRI is set to ‘Bidirectional’ mode.  
Pulses are available at the LED output and DIRO indicates a positive energy flow.  
The voltage input (VP) and current input (IP) are out of phase and the direction input DIRI is set to ’Unidirectional’  
mode. Pulses are no longer available at the LED output as negative going energy is not measured. The direction  
output DIRO indicates a change in direction of the input current at IP.  
4.  
The voltage input (VP) and current input (IP) are out of phase. The direction input DIRI is set to ‘Bidirectional’ mode.  
Pulses are again available at the LED output and the direction output DIRO indicates a change in direction of the  
input current at IP.  
Crystal Oscillator  
The AS8118 has an on-chip crystal oscillator, with the recommended 3.5795MHz crystal connected to the XIN (Crystal Input)  
and XOUT (Crystal Output) pins. The 3.5795MHz crystal is recommended, as it is a standard low cost component.  
Alternatively, an external clock signal may be applied to XIN. In this case, XOUT should not be connected.  
Test Mode (TM)  
On ‘power up’, the test mode input defines the mode of operation of the device. Either ‘Normal Operation’, or ‘Programming’  
modes may be selected. TM has an on-chip pull down resistor and should be left unconnected during ‘Normal Operation’. TM  
must be set to logic ‘1’ at ‘power up’ to set device in ‘Programming’ mode.  
The AS8118 programming procedure is defined in detail in the following paragraphs.  
Power Supply Monitor  
The AS8118 has an on-chip power supply monitor (PSM) which resets the complete device once the supply voltage drops  
below the specified threshold of 3.5V ±5%.  
Programming the AS8118  
The AS8118 is a programmable device, which uses on-chip zener diodes to permanently program specific data such as  
current input channel gain, pulse-level, meter constant settings and system calibration. This programming operation is also  
called ‘burn’ which relates to the permanent physical change of the on-chip zener diodes electrical behavior. Another term for  
‘permanent programming’ is OTP (One-Time-Programming).  
Two banks of zener diodes are available in the AS8118 in order to allow a second calibration. By programming the 2nd bank  
of zener diodes, this bank will subsequently be used (bank-select-bit). During power-up of AS8118, a readout of all zener  
diodes occurs and the data of the active bank is used.  
The AS8118 may also be used with the default operating parameters, which have been defined earlier in this document. If  
the user wishes to alter the operating parameters, the AS8118 may simply be programmed to provide the required operating  
parameters. Fast meter system calibration may also be carried out as part of the AS8118 programming procedure, providing  
long term meter system stability.  
The AS8118 can be operated in one of two modes. The two modes are:  
-
Normal Operation Mode: Normal operation is the mode in which the device operates to perform the kWh metering  
function, for which the device is designed.  
-
Programming Mode: Programming is the mode in which the AS8118 is set to perform the programming operations. When  
in Programming mode, two different operations may be carried out:  
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Data Sheet AS8118  
-
-
Test Write: Test Write enables the writing of data to a register in the device and for the resultant chip behaviour to be  
investigated, before the data is written permanently to the non-volatile PROM (programmable read only memory)  
memory.  
Burn: Burn is the programming cycle that ensures that the required data is permanently written to the non-volatile  
PROM (programmable read only memory).  
During Programming mode all pulse outputs (MOP/MON, CAL and LED) can be accessed.  
The AS8118 may only be set up in one of these two modes during the ‘power up’ cycle of the device. The mode is selected  
by programming the TM and DIRO at ‘power up’ as shown in the table below:  
Mode of Operation  
Normal Operation  
Programming  
TM  
0
DIRO  
X
0
1
Note: Pin DIRO has an on-chip internal pull-down resistor, thus the pin may be left open or tied ‘low’ for both Normal  
Operation and Programming modes. The default mode is thus Normal Operation mode, with the AS8118 only being set to  
Programming mode when TM is pulled high during power up.  
The analog input pin PROG is also required for the programming of the AS8118. During Test-Write PROG is used to transfer  
digital data to the internal register. During Burn it is used to change the states of the internal PROM cells.  
When in Programming mode, the AS8118 must be powered down before the device can enter Normal Operation mode.  
PROM Definition and Contents  
The table below provides a definition of the internal PROM cells. As shown, sets of PROM cells form binary words, which  
represent, for example, a defined pulse rate.  
Parameter  
Description  
Number  
of bits  
Register bits  
Settings  
Default  
Bank 0  
[34:33]  
Bank 1  
Gain  
Select current  
channel gain  
2
2
2
2
[67:66]  
[65:64]  
[63:62]  
[61:60]  
00 : 4  
01 : 16  
10 : 16  
11 : 20  
11  
Acreep_sel  
F_mon_sel  
F_cal_sel  
Select anti creep  
threshold  
[32:31]  
[30:29]  
[28:27]  
00 : 2.32mA  
01 : 7.43mA  
10 : 14.9mA  
11 : 29.7mA  
00 : 100  
01 : 200  
10 : 400  
11 : 800  
00 : 8  
01  
10  
01  
Select MOP/MON  
pulse rate  
[imp/kWh]  
Select multiplier for  
CAL pulse rate  
related to  
01 : 16  
10 : 32  
MOP/MON pulse  
rate  
11 : 64  
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Data Sheet AS8118  
Parameter  
Description  
Number  
of bits  
3
Register bits  
Settings  
Default  
F_led_sel  
Select LED pulse  
rate [imp/kWh]  
[26:24]  
[59:57]  
000 : 100  
001 : 200  
010 : 400  
011 : 800  
100 : 1600  
101 : 3200  
110 : 6400  
101  
Pulse_lev  
Bank01  
Sel_def  
Central pulse_level  
value  
Select PROM bank  
0 or 1  
Select default or  
programmed values  
22  
1
[23:2]  
[1]  
[56:35]  
0x6A6D4  
0 : Bank 0  
1 : Bank 1  
0 : default  
1 : programmed  
Value  
0
0
1
[0]  
Not used  
2
[69:68]  
00  
Total  
70  
The “Default” values are hard coded on-chip outside the PROM block. Only once the Sel_def bit has been set, are the PROM  
parameters selected by the AS8118.  
Two PROM banks are defined as ‘Bank 0’ and ‘Bank 1’. This feature allows for a complete reprogramming cycle if necessary.  
The required bank is selected with the bit called Bank01.  
The calibration of the AS8118 adjusts the specific pulse-level (Pulse_lev), which defines exactly the energy level when a  
pulse has to be generated and presented to the output. This pulse-level is used to define a very fast internal pulse rate from  
which the external pulse outputs are derived. Therefore, the AS8118 is extremely flexible in defining pulse output rates as  
required for a specified kWh meter.  
The parameters F_mon_sel, F_cal_sel and F_led_sel are used to define the pulse rates for the pins MOP/MON, CAL and  
LED.  
The Acreep_sel bit defines the threshold for the current for when no pulses should be transmitted.  
Calculations for Calibration  
This paragraph describes how to successfully calibrate the AS8118 device. The parameter Pulse_lev is the main parameter  
to determine the basic internal (very fast) frequency. This frequency relates to the measured power and is the basis from  
which all the output pulse rates namely, MOP/MON, CAL and LED are derived.  
Prior to system calibration, the appropriate value for the parameter Pulse_lev must be calculated to produce the required  
output pulse rates for MOP/MON, CAL and LED. The calibration exercise must accommodate all system non-idealities that  
are present in the meter system.  
There are two calibration methods available to find the appropriate value of Pulse_lev, namely:  
-
-
Defined current and calibration time method  
Comparison method  
It is also possible to perform:  
Calibration without on-chip programming  
-
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Data Sheet AS8118  
Defined Current and Calibration Time Method  
The AS8118 generates a pulse whenever the internal energy accumulator contains a value, which is greater than a  
programmed threshold. This threshold is the parameter Pulse_lev. This parameter depends on the basic meter properties,  
the mains voltage Vmains and the maximum current to be measured, Imax. Furthermore, it is assumed that through a resistor  
divider Vmains is scaled down to match the maximum input range of the VP input.  
Firstly, an ideal value for Pulse_lev is calculated. This is the value, which would have to be programmed into the AS8118  
device if the meter system was perfect.  
The following formula calculates this ideal value of Pulse_lev:  
230V 20A  
Pulse _lev(ideal ) =  
*
* 435924  
Vmains Imax  
A calibration is performed to compensate for system non-idealities like resistor tolerances etc. The effect of these non-  
idealities is that with the ideal Pulse_lev value the pulse rates will not be correct. In order to calibrate the meter, a new  
Pulse_lev value has to be found. Figure 6 shows the basic calibration setup. CAL pulses from a meter built with the AS8118  
are counted during a defined time period tc, while an accurately defined calibration current Ical, is being measured.  
AS8118  
Meter  
time  
tc  
base  
Ical  
Calboard  
Figure 6  
Basic calibration setup for defined current and calibration time method  
Again, if the system was perfect we would expect a certain number of pulses to be counted, the ideal number of pulses, Ni:  
PR * tc * Vmains * Ical  
Ni =  
3600* 1000  
where tc is in seconds.  
PR is the pulse rate on pin CAL, which can be calculated from the PROM parameters F_mon_sel and F_cal_sel:  
PR = Fmon* Fcal  
where Fmon [imp/kWh] is the pulse rate selected by F_mon_sel and Fcal is the multiplier selected by F_cal_sel.  
If pin LED is used for calibration then PR is the pulse rate on pin LED (selected by F_led_sel).  
The corrected value for Pulse_lev can now be calculated using the following formula:  
Nr  
Pulse _lev(corrected ) = Pulse _lev(ideal )*  
,
Ni  
where Nr is the real number of pulses, i.e. the number of pulses counted during tc.  
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Data Sheet AS8118  
A logical flow of the described calculations, is shown below:  
System Properties  
Vmains  
Imax  
ideal Pulse_lev  
Calibration Setup  
Correction  
Number of pulses to  
expect (ideal), Ni  
Ical  
tc  
Nr  
Ni  
Pulse _ lev = Pulselev(ideal) *  
Pulse Counting  
real number of  
pulses, Nr  
System Nonidealities  
Example  
Calibrate a meter with Vmains = 230V, Imax = 40A and Ical = 10A. Calibration time is 20 seconds, the PROM settings for the  
pulse rates are: Fmon: 200 imp/kWh, Fcal: 64  
230V 20A  
Pulse _lev(ideal ) =  
*
* 435924 = 217962  
230V 40A  
The ideal number of pulses during 20 seconds of calibration is:  
200imp / kWh* 64* 20s * 230V * 10A  
Ni =  
= 163.56imp 164imp  
3600* 1000  
Thus 164 pulses are expected during the 20 seconds calibration time. (For this example it is not important what error is  
introduced with this setting!).  
Assuming that 170 pulses were actually counted. The real pulse level may then be calculated:  
170  
Pulse _lev(real ) = 217962*  
= 225936.2 225936  
164  
This pulse level must then be written to the PROM so that Nr equals Ni.  
Comparison Method  
Most common, is the comparison of energy reading of the meter under test against a standard or reference meter. Normally,  
the standard, or reference meter has a considerably higher pulse rate than the meter under calibration. In this case, the  
absolute calibration time is not important for the calculations. The basic calibration setup is shown below:  
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Data Sheet AS8118  
Reference  
Meter  
AS8118  
Meter  
Calboard  
I
Figure 7  
Basic calibration setup for comparison calibration method  
The standard or reference meter pulses are counted between two or more pulses from the meter to be calibrated. Ideally the  
sum of the pulses would exactly be the ratio between standard meter pulse rate and the pulse rate of the meter under test.  
From the deviation the corrected Pulse_lev may be calculated.  
Ni  
Pulse _lev(corrected ) = Pulse _lev(ideal )*  
,
Nr  
Where Nr is the number of pulses counted from the standard or reference meter and Ni is the ratio between the pulse rates,  
which is always >1. The formula for Ni is as follows:  
PR(ref )  
Ni =  
,
Fmon* Fcal  
This is assuming that the CAL pulse output is used for calibration. If the LED pulse output is used for calibration, the following  
formula should be used:  
PR(ref )  
Ni =  
Fled  
The Pulse_lev (ideal) is calculated using the following formula:  
230V 20A  
Pulse _lev(ideal ) =  
*
* 435924  
Vmains Imax  
It is important to note that the formula for Pulse_lev (corrected) above should not be confused with the formula in the  
previous method of calibration for ‘Defined Current and Calibration Time’ method, where Ni and Nr are reversed.  
Example  
The reference meter has a pulse rate, which is 10,000 times greater than the pulse rate of the AS8118 CAL output. During a  
calibration cycle we measure 11,000 pulses between two CAL pulses. Therefore the ideal pulse-level has to be changed by a  
factor of 10,000/11,000 = 0.909.  
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Data Sheet AS8118  
Calibration without On-Chip Programming  
It is also possible to calibrate a kWh meter using the AS8118 by means of an external resistor network or trim-potentiometer.  
In this case, the parameters for the required pulse outputs are programmed into the device, along with the ideal value for  
Pulse_lev as defined in the formula above. A resistor network may then be used in the voltage divider for the voltage input  
setting, which is then trimmed until the measured pulse rate matches the ideal pulse rate.  
In the case for kWh meter designs, which include a µ-controller and non-volatile memory, again, the parameters for the  
required pulse outputs are programmed into the device, along with the ideal value for Pulse_lev as defined in the formula  
above. The calibration may then be performed in the µ-controller.  
Defining the Programmed Word  
The AS8118 allows for all on-chip programmable functions to be reprogrammed a second time. It is important to always use  
the Bank ‘0‘ as the first programming option. This is necessary as once Bank ‘1‘ has been selected and this selection has  
been permanently ‘Burned‘ into the AS8118 device, Bank ‘0‘ can no longer be selected.  
When programming the AS8118, the Bank that is NOT selected should have all ‘0‘ values as the programmed values.  
Confirmation of this is shown in the example below, where Bank ‘0‘ has been selected for programming. All the programme  
bits of Bank ‘1‘ have been programmed as ‘0‘.  
Important: The value of Bit [0] must always be ‘1‘ when programming the AS8118, regardless of the memory bank being  
programmed. The Bits [69:68] are not used and are thus ‘Don’t Care‘ bits. The programmed value may be ‘1‘ or ‘0‘.  
An example of the word to be programmed to the AS8118 should look as follows:  
Bit Number  
[69:68]  
[67:66]  
[65:64]  
[63:62]  
[61:60]  
[59:57]  
[56:35]  
[34:33]  
[32:31]  
[30:29]  
[28:27]  
[26:24]  
[23:2]  
Bit Value  
Description  
00  
00  
00  
00  
00  
Not used bits  
Bank 1: Gain  
Bank 1: Anticreep threshold  
Bank 1: F_mon  
Bank 1: F_cal  
000  
0x000000  
00  
Bank 1: F_led  
Bank 1: Pulse_lev  
Bank 0: Gain = 4 (CT mode)  
Bank 0: Anticreep threshold = 7.43mA  
Bank 0: F_mon: 100 imp/kWh  
Bank 0: F_cal: Fmon x 32  
Bank 0: F_led: 3200 imp/kWh  
01  
00  
10  
101  
0x06A6D4 Bank 0: Pulse_lev: 435924  
[1]  
[0]  
0
1
Select Bank 0  
Select programmed values  
After selecting all PROM parameters as required a complete 70-bit word (including two overhead bits) is formed, which must  
be written to the PROM.  
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Data Sheet AS8118  
Testwrite  
Testwrite means that the word to be programmed is simply written to an on-chip shift register so that the resulting behavior of  
the AS8118 device may be examined. Once the PROM word is confirmed correct, it may be burned into the device. i.e.  
Irreversibly written to the AS8118.  
Until the data has been burned into the device, in other words, if only a Testwrite procedure has been performed, the data  
will be lost when the supply is removed from the AS8118 device.  
Due to the respective on-chip processing it is required to testwrite the inverse of the word to be programmed. Continuing with  
the above example the word defined in the example should be as follows:  
69  
1
68 67 66  
65  
1
64  
1
63  
1
62  
1
61  
1
60  
1
59  
1
58  
1
57  
1
56  
1
55  
1
54  
1
53  
1
52  
1
51  
1
1
1
1
50  
1
34  
1
33  
1
32  
1
31  
0
30  
1
29  
1
28  
0
27  
1
26  
0
25  
1
24  
0
23  
1
22  
1
21  
1
20  
0
19  
0
18  
1
17 16 15  
14  
1
13  
1
12  
0
11  
0
10  
1
9
0
8
0
7
1
6
0
5
1
4
0
3
1
2
1
1
1
0
0
0
1
0
The Testwrite procedure is carried out as described in the following timing diagram:  
Startup  
2
4
1
0
69  
68  
67  
3
High  
Low  
TM  
f1  
High  
Low  
DIRO  
PROG  
t2  
H
t3  
3V-3.5V  
0V  
x
x
L
H
H
H
L
Imax:  
500µA  
start  
define  
testwrite testwrite  
mode  
(DIRO=0)  
Note: High and Low refers to VDD and VSS respectively.  
On the first falling TM edge the mode (Testwrite) is defined. On the next rising TM edge the procedure is started. Afterwards  
70 clocks have to be sent to DIRO. As can be seen the logic level on PROG prior to the positive DIRO edges defines the  
state to be shifted into the internal register.  
Important timing parameters are:  
f1: Maximum frequency, must not exceed 50kHz  
t2: Data setup time, minimum is 100ns  
t3: Data storage time: the programmed bit is stored after approximately 20ns  
Burn  
The Burn procedure irreversibly writes data to the PROM. To do this, the 1s in the original word to be programmed must be  
burned.  
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Data Sheet AS8118  
Continuing with the above example, the defined word to be burned will be as follows:  
69 68  
67  
0
66  
0
65  
0
64  
0
63  
0
62  
0
61  
0
60  
0
59  
0
58  
0
57  
0
56  
0
55  
0
54  
0
53  
0
52  
0
51  
0
0
0
50  
0
34  
0
33  
0
32  
0
31  
1
30  
0
29  
0
28  
1
27  
0
26  
1
25  
0
24  
1
23  
0
22  
0
21  
0
20  
1
19  
1
18 17  
16  
0
15  
1
14  
0
13  
0
12  
1
11  
1
10  
0
9
1
8
1
7
0
6
1
5
0
4
1
3
0
2
0
1
0
0
1
0
1
The following timing diagram shows how the burn procedure is carried out:  
Startup  
2
67  
1
0
69  
68  
4
3
High  
Low  
TM  
t3  
t1  
t2  
f1  
L
High  
Low  
DIRO  
Vburn  
0V  
x
x
H
L
L
L
H
PROG  
start  
burn  
define  
burn  
mode  
(DIRO=1)  
Note: High and Low refers to VDD and VSS respectively.  
The first falling and rising edges on TM define the burn mode and starts it (as can be seen DIRO must be set to logic ‘high’ at  
the falling edge, but must be low at the rising edge). Then the first PROM cell is selected. After each rising clock edge on  
DIRO the next PROM cell is selected going from MSB to LSB. While one of the PROM cells is selected a defined (low-active)  
pulse on TM must be applied to “burn” the respective PROM cell, i.e. write a permanent logic-1 to it.  
Important specifications are:  
Tburn: Temperature during burn cycle: 25°C ± 10°C  
Vburn: 7.50 ± 0.25V (at the AS8118 PROG pin)  
f1: Maximum DIRO clock frequency is 100kHz  
t1: The burn pulse must have a delay of at least 1µs after the previous positive DIRO clock edge  
t2: After one burn pulse there must be a delay of at least 1µs before the next PROM cell is selected  
t3: The burn pulse width is defined to be 1.0 ± 0.2µs. The rise and fall time of the burn pulses on TM must be less than 50ns.  
After a burn cycle has been completed, a read cycle must be initiated so that the actual data is loaded. (After “burn” the data  
in the internal register is inverted!)  
Read  
The conditions for ‘burn’ are specified very tightly. In order to be certain that the ‘burn’ process was successful this process  
has to be verified. There are 2 modes of readout, a digital readout and analog readout.  
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Data Sheet AS8118  
Digital readout uses the threshold of the comparator internal to the AS8118. Thus, the result, which can be observed on the  
CAL pin, is the same as that used internally by the AS8118. Digital readout does NOT allow the quality of the ‘burn’ to be  
evaluated.  
Analog readout does allow for the verification of the analog value of the zener diodes. With analog readout, the quality of the  
‘burn’ can be verified.  
In order to verify the ‘burn’ process, an ‘analog readout’ of the zener diodes voltages has to be performed as the last step  
after calibration. This can be done during the ‘read’ process, which may be started during calibration mode. The goal is to  
verify that burned diodes show a voltage level of not more than 0.5V during the analog readout and the ‘unburned’ diodes a  
voltage level of more than 2.4V.  
Digital Readout  
The AS8118 offers the customer the ability to read the PROM data. For example, it may be necessary to examine if a device  
has been calibrated already and what value is correctly stored in the PROM. For the read mode the same two digital inputs  
(TM and DIRO) are used as for ‘testwrite’ and ‘burn’. As can be seen in the following timing diagram the read mode is  
selected by setting DIRO=1 while there is a rising edge on TM. (This assumes that one of the 3 modes has been completed  
or the chip has just been powered up, i.e. the chip expects to enter a new mode.)  
The following timing diagram shows the digital readout of the zener diodes:  
end  
read  
2
67  
1
69  
68  
66  
0
High  
Low  
TM  
DIRO  
PROG  
CAL  
f1  
t2  
High  
Low  
High  
Low  
t3  
High  
Low  
define  
read  
mode  
(DIRO=1)  
Note:  
1. High and Low refers to VDD and VSS respectively.  
2. In this case, the term ‘digital’ means that there is an on-chip comparator, which decides on the values of the bits, 0 or 1,  
relative to a certain threshold; it neither guarantees the burned zener diodes voltage level to be below 0.5V (ZVB) nor a  
value for unburned zener diodes of higher than 2.4V (ZVUB) as shown in the Operating Conditions.  
After starting read mode with each rising edge on DIRO one of the PROM cells is selected. Its content is stored in a separate  
internal flip-flop, the output of which can be watched on pin CAL (only during read!). With one additional rising edge on TM  
the read mode is left and pin CAL shows the normal pulse output again.  
Important: The bits displayed on CAL are the inverse of the PROM contents, i.e. they have to be inverted to match with the  
previous PROM contents table.  
Important timings are:  
f1: Maximum read frequency, for reliable reading this should not be higher than 100kHz.  
t2: Delay between the two rising edges: >100ns  
t3: Depending on the loading on pin CAL the delay between rising edge on TM and change of data on CAL may vary. A  
typical value is 50 ns.  
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Data Sheet AS8118  
Analog Readout  
The analog readout can be performed by disconnecting the PROG pin from the calibration board and starting a ‘read’  
sequence. At specific points in time the voltage level on the PROG pin must be sampled. These time points are shown in the  
following timing diagram.  
end  
read  
2
67  
1
69  
68  
66  
0
High  
Low  
TM  
High  
Low  
DIRO  
PROG  
5V  
2.4V  
0.5V  
High  
Low  
CAL  
measure  
zener diode  
voltage:  
68  
67  
66  
65  
0
69  
The numbers at the bottom of this timing diagram indicate the sample points of the bits in the PROM table, at which the zener  
diode voltage level can be measured and compared against the limits for burned and unburned zener diodes.  
In general this readout is most important, when a new calibration system is installed. Variations on the burn voltage or even  
the length of the cable connected to the AS8118 PROG pin may have an influence on the quality of the burn process.  
Revision 1.8, 15-Feb-05  
Page 22 of 30  
Data Sheet AS8118  
Application Circuit  
LOAD  
VDD  
VDD  
C12  
C11  
C9  
C10  
R3  
R4  
R5  
R6  
XTAL  
C3  
C2  
C5  
C4  
AS8118  
LED  
MON  
C13  
C14  
R1A  
R1B  
C7  
R2  
MOP  
CAL  
C1  
R7  
D2  
VDD  
1
IC1  
DIRO  
C6  
3
VAR  
VI  
VO  
+
PROG  
GND  
2
C8  
D1  
GND  
N
L
POWER IN  
Note:  
1. There must be proper ground connection between the calibration hardware and the meter under calibration during  
‘Calibration Mode’. This ensures that the programming procedure is not effected by spurious signals. Such spurious  
signals could originate from load switching during calibration.  
2. When using a low resistance shunt for current sensing, a small parasitic inductance introduced by the shunt can have  
negative effects on the measurement accuracy. The filters on the current inputs designated by the components R5, C5  
and R6, C4 provide a cancellation effect on the parasitic shunt inductance. The filters assume a typical inductance of  
between 1nH and 2nH.  
Revision 1.8, 15-Feb-05  
Page 23 of 30  
Data Sheet AS8118  
Parts List  
Designation  
Value  
Unit  
Description  
AS8118  
Rshunt  
R1A  
R1B  
Single Phase Average Energy Metering IC  
Precision Resistor, ±5%  
Resistor, 0.6W, ±10%  
Resistor, 0.6W, ±10%  
SMD Resistor, ±1%  
SMD Resistor, ±1%  
Resistor, 1W, ±5%  
SMD Capacitor, ±5%  
300  
820  
750  
820  
680  
470  
68  
µOhm  
kOhm  
kOhm  
Ohm  
Ohm  
Ohm  
nF  
R2  
R3, R4, R5, R6  
R7  
C1  
C2, C3, C4, C5  
33  
nF  
SMD Capacitor, ±5%  
C6  
C7  
C8  
C9, C10  
C11  
C12  
C13, C14  
IC1  
XTAL  
D1  
D2  
10  
nF  
nF  
µF  
nF  
µF  
µF  
nF  
Capacitor (Polypropylene), 1000VDC/250VAC, ±10%  
Capacitor (Polypropylene), 1000VDC/250VAC, ±10%  
Capacitor (Electrolytic), ±20%  
SMD Capacitor, ±5%  
Capacitor (Electrolytic) , ±10%  
Capacitor (Electrolytic) , ±20%  
SMD Capacitor, ±10%  
LM78L05 Voltage Regulator, ±5%  
Quartz Crystal or Ceramic Resonator, 20ppm/K  
BZV85-C15 Zener Diode, 1.3W, 15V, ±5%  
1N4007 Diode  
470  
470  
100  
10  
220  
100  
3.579545  
MHz  
VAR S20K275  
Varistor, VRMS = 275V, VDC = 350V  
Revision 1.8, 15-Feb-05  
Page 24 of 30  
Data Sheet AS8118  
Electrical Characteristics  
Absolute Maximum Ratings *  
Parameter  
Symbol  
Min  
Max  
Unit  
Note  
DC Supply Voltage  
VDD  
Vin  
Iin  
-0.3  
7.0  
V
Input Pin Voltage  
-0.3  
-100  
-65  
5
VDD + 0.3  
+100  
V
mA  
°C  
%
Input Current on any Pin  
Storage Temperature  
Humidity Noncondensing  
Electrostatic Discharge  
Lead Temperature  
25°C  
Tstrg  
H
+150  
85  
1000  
V
1)  
2)  
°C  
1) MIL STD883 method 3015.7 ‘Human Body Model‘ (R = 1.5k; C = 100pF)  
2) IEC61760-1, soldering conditions  
* Stresses above those listed may cause permanent damage to the device. This is a stress rating only and  
functional operation of the device at these or any other conditions above those indicated in the operational  
sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended  
periods may affect device reliability (eq. hot carrier degradation).  
Operating Conditions  
Parameter  
Symbol  
Min Typ Max Unit  
Note  
Positive Analog Supply Voltage  
AVDD  
4.5  
5.0  
5.5  
V
Referred to AVSS  
Typical ±10%  
Negative Analog Supply Voltage  
Difference of Supply  
AVSS  
A - D  
0
V
V
-0.1  
4.5  
0.1  
5.5  
AVDD – DVDD  
AVSS – DVSS  
Referred to DVSS  
Typical ±10%  
Positive Digital Supply Voltage  
DVDD  
5.0  
0
V
Negative Digital Supply Voltage  
Supply Current  
DVSS  
Isupp  
Tamb  
fmeas  
fclk  
V
4
mA  
°C  
Hz  
Ambient Temperature  
Measured Frequency  
System Clock Frequency  
-40  
45  
25  
85  
65  
3.56 3.58 3.60 MHz Variations result in gain errors  
which are calibrated out  
Measurement Bandwidth  
BW  
870  
Hz  
V
PROM Zener Voltage Unburned  
ZVUB  
2.4  
Measured during analog  
readout  
PROM Zener Voltage Burned  
ZVB  
0.5  
V
Measured during analog  
readout  
Revision 1.8, 15-Feb-05  
Page 25 of 30  
Data Sheet AS8118  
DC Characteristics  
Digital Input with Pull-down (TM)  
Parameter  
Min  
Max  
Note  
Vih  
Vil  
0.7 * VDD  
0.3 * VDD  
160µA  
NA  
Iih  
Iil  
30µA  
DI, cmos w/pull-down (1)  
DI, cmos w/pull-down  
NA  
1)  
Iih tested at VDD = 5.5V and Vin = 5.5V  
Digital Input with Pull-up (DIRI)  
Parameter  
Min  
Max  
Note  
Vih  
Vil  
0.7 * VDD  
0.3 * VDD  
NA  
Iih  
Iil  
NA  
DI, cmos w/pull-up (2)  
DI, cmos w/pull-up  
30µA  
160µA  
2)  
Iil tested at VDD = 5.5V and Vin = 0V  
Digital Input/Output with Pull-down (DIRO, CAL)  
Parameter  
Input  
Min  
Max  
Note  
Vih  
0.7 * VDD  
Vil  
0.3 * VDD  
160µA  
NA  
Iih  
30µA  
(1)  
Iil  
NA  
DI, cmos w/pull-down  
Output  
Voh  
Vol  
4.0V  
Ioh = -4mA  
Iol = 4mA  
0.4V  
1) Iih is tested at VDD = 5.5V and Vin = 5.5V  
Digital Output (MON, MOP, LED)  
Parameter  
Voh  
Min  
Max  
Note  
Ioh = -10mA  
Iol = 10mA  
4.0V  
Vol  
0.4V  
Revision 1.8, 15-Feb-05  
Page 26 of 30  
Data Sheet AS8118  
Package Dimensions  
PDIP-18  
(ALL DIMENSIONS IN INCH)  
0.900 (18 lead)  
0.756 (16 lead)  
SOIC-18  
(ALL DIMENSIONS IN INCH)  
COMMON DIMENSIONS  
SYMBOL  
MIN  
.097  
NOM  
MAX  
NOTE  
.040  
.050  
.035  
.045  
DIA.  
A
A1  
A2  
B
.101  
.104  
.0115  
.094  
h x 45°  
.0050  
.090  
.009  
.092  
.013  
.018  
PARTING LINE  
.014  
.016  
.019  
.045  
.055  
C
D
E
.0091  
.010  
.0125  
E
H
SEE VARIATIONS  
3
5
.292  
.296  
.299  
.034  
.040  
L
45°  
.018  
.024  
e
.050  
H
h
.400  
.010  
.024  
.406  
.410  
.016  
.040  
DETAIL A  
.013  
L
.032  
SEE VARIATIONS  
5°  
TOP VIEW  
N
0°  
8°  
h x 45°  
SEE DETAIL A  
e
B
X
.085  
.093  
VARIATIONS  
NOTE 3 (D)  
NOM  
.100  
C
A
A2  
NOTE 5  
(N)  
16  
SYMBOL  
AA  
MIN  
.402  
.451  
.500  
.602  
.701  
MAX  
.412  
.461  
.510  
.612  
.711  
D
.407  
SEATING PLANE  
A1  
SIDE VIEW  
END VIEW  
AB  
.456  
18  
AC  
.505  
20  
AD  
.607  
24  
AE  
.706  
28  
Ordering Information  
Part Number  
Package  
AS8118D18  
DIP-18  
AS8118S18  
AS8118 Evaluation Kit  
SOIC-18  
DIP-18  
Revision 1.8, 15-Feb-05  
Page 27 of 30  
Data Sheet AS8118  
Copyright  
Copyright 1997-2004, austriamicrosystems AG, Schloss Premstaetten, 8141 Unterpremstaetten, Austria - Europe.  
Trademarks Registered . All rights reserved. The material herein may not be reproduced, adapted, merged, translated,  
stored, or used without the prior written consent of the copyright owner.  
Disclaimer  
Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing in its  
Terms of Sale. austriamicrosystems AG makes no warranty, express, statutory, implied, or by description regarding the  
information set forth herein or regarding the freedom of the described devices from patent infringement. austriamicrosystems  
AG reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this  
product into a system, it is necessary to check with austriamicrosystems AG for current information. This product is intended  
for use in normal commercial applications. Applications requiring extended temperature range, unusual environmental  
requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are specifically  
not recommended without additional processing by austriamicrosystems AG for each application.  
The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However,  
austriamicrosystems AG shall not be liable to recipient or any third party for any damages, including but not limited to  
personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or  
consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical  
data herein. NO obligation or liability to recipient or any third party shall arise or flow out of austriamicrosystems AG  
rendering of technical or other services.  
Revision 1.8, 15-Feb-05  
Page 28 of 30  
Data Sheet AS8118  
Note:  
Revision 1.8, 15-Feb-05  
Page 29 of 30  
Data Sheet AS8118  
Contact  
Headquarters  
austriamicrosystems AG  
Suite 915, No. 1,  
austriamicrosystems AG  
A 8141 Schloss Premstaetten, Austria  
Phone: +43 3136 500 0  
Suhua Road,  
Suzhou Industrial Park,  
PR China 215021  
Phone: +86 512 6762 2590  
(6762 2593)  
Fax:  
+43 3136 525 01  
info@austriamicrosystems.com  
Fax:  
+86 512 6762 2594  
Sales Offices  
austriamicrosystems Germany GmbH  
Tegernseer Landstrasse 85  
D 81539 München, Germany  
Phone: +49 89 69 36 43 0  
austriamicrosystems AG  
Suite 811, Tsimshatsui Centre,  
East Wing, 66 Mody Road,  
Tsim Sha Tsui East,  
Fax : +49 89 69 36 43 66  
Kowloon, Hong Kong  
Phone: +852 2268 6899  
austriamicrosystems AG  
Klaavuntie 9 G 55  
Fax:  
+852 2268 6799  
FI 00910 Helsinki, Finland  
Phone: +358 9 72688 170  
austriamicrosystems Japan, AG  
AIOS Gotanda Annex 5th Fl.,  
1-7-11,  
Higashi-Gotanda,  
Shinagawa-ku,  
Tokyo 141-0022, Japan  
Phone: +81 3 5792 4975  
Fax : +81 3 5792 4976  
Fax:  
+358 9 72688 171  
austriamicrosystems France S.A.R.L.  
124, Avenue de Paris  
F 94300 Vincennes, France  
Phone: +33 1 43 74 00 90  
Fax : +33 1 43 74 20 98  
austriamicrosystems AG  
#805, Dong Kyung Bldg., 824-19,  
Yeok Sam Dong,  
austriamicrosystems AG  
Bivägen 3B  
S 19163 Sollentuna, Sweden  
Phone: +46 8 6231 710  
Kang Nam Gu, Seoul  
Korea 135-080  
Phones: +82 2 557 8776  
austriamicrosystems Switzerland AG  
Rietstrasse 4  
Fax:  
+82 2 569 9823  
CH 8640 Rapperswil, Switzerland  
Phone: +41 55 220 9008  
Fax : +41 55 220 9001  
austriamicrosystems AG  
83, Clemenceau Avenue,  
#02-01, UE Square,  
Singapore 239920  
austriamicrosystems AG  
88, Barkham Ride,  
Phone: +65 6 830 8305  
Fax: +65 6 234 3120  
Finchampstead, Wokingham,  
Berkshire RG40 4ET, United Kingdom  
Phone: +44 118 973 1797  
austriamicrosystems AG  
2nd Floor,  
Fax:  
+44 118 973 5117  
No. 31, Sec. 2  
Nam-Chang Road,  
Taipei, Taiwan  
austriamicrosystems USA, Inc.  
8601 Six Forks Road  
Suite 400  
Raleigh, NC 27615, USA  
Phone: +1 919 676 5292  
Fax : +1 509 696 2713  
Phone: +886 2 2395 6600 227  
Fax:  
+886 2 2395 7330  
Revision 1.8, 15-Feb-05  
Page 30 of 30  

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