SA9602E
FUNCTIONAL DESCRIPTION
The SA9602E is a CMOS mixed signal integrated circuit,
which performs power/energy calculations across a power
range of 500:1, to an overall accuracy of Class 1.
For the voltage sensor input, the mains voltage (220VAC) is
divided down through a divider (R3, R4 and P1) to 14V. The
current into the A/D converter input is set at 14μARMS at
nominal mains voltage, via resistor R5 (1M). P1 may be
varied for calibration purposes.
The SA9602E in is a direct replacement for the SA9102E with
the advantage of no external loop capacitors.
In this configuration, with a mains voltage of 220V and a
current of 80A, the output frequency of the SA9602E power
meter chip on FOUT1 is 1160Hz. In this case, one pulse will
correspond to an energy consumption of 17.6kW/1160Hz =
15.17Ws. The output frequency on FOUT2 is FOUT1/290
(i.e. the frequency output at FOUT1 divided by 290).
The integrated circuit includes all the required functions for
single phase power and energy measurement such as two
oversampling A/D converters for the voltage and current
sense inputs, power calculation and energy integration.
Internal offsets are eliminated through the use of cancellation
procedures. The SA9602E generates pulses, the frequency
of which are proportional to the power consumption. Two
frequency outputs (FOUT1 and FOUT2) are available, with
additional frequency options available on request. The pulse
rate follows the instantaneous power consumption measured.
ANALOG INPUT CONFIGURATION
The input circuitry of the current and voltage sensor inputs is
illustrated in Figure 4. These inputs are protected against
electrostatic discharge through clamping diodes. The
feedback loops from the outputs of the amplifiers AI and AV
generate virtual shorts on the signal inputs. Exact
duplications of the input currents are generated for the analog
signal processing circuitry.
POWER CALCULATION
In the application circuit (see Figure 3), the voltage drop
across the shunt (RSH) will be between 0 and 16mVRMS (0 to
80A through a shunt resistor of 200μ). This voltage is
converted to a current of between 0 and 16μARMS, by means
of resistors R1 and R2. The current sense inputs saturate at
an input current of ±25μA peak.
VDD
IIP
VDD
N
VSS
CURRENT
CHANNEL
ADC
CURRENT
SENSOR
INPUT
Power
Supply
AI
VDD
L
VSS
GND
IIN
VDD
U1
IIN
RSH
R1
R2
VSS
VDD
VDD
OSC1
IIP
OSC2
FOUT1
FOUT2
TEST
R3
R5
IVP
IVP
Pulse Output 1
Pulse Output 2
VOLTAGE
SENSOR
INPUT
AGND
R4
VSS
GND
VOLTAGE
CHANNEL
ADC
AV
VREF
VSS
N
L
SA9602E
R6
P1
AGND
VSS
GND
Figure 3: Application Circuit
Figure 4: Internal analog input configuration
SPEC-3117 (REV. 5)
29-09-2017
4/10
SAMES [ SAMES ]
