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WITH INTEGRATED 5 DIGIT LED DISPLAY DRIVER
FEATURES
SA9106A
SINGLE PHASE WATT MEASUREMENT IC
n Performs bidirectional power measure-
ment and directly drives a 5 digit (7
segment) LED display
n Accuracy better than 1% (± 1 count)
n Protected against ESD
n Total power consumption rating below
50mW
DESCRIPTION
The SAMES SA9106A Single Phase Watt
measurement integrated circuit has an
integrated Light Emitting Diode (LED) display driver for a 5 digit (7 segment) display.
The SA9106A performs the power calculations for active power.
The method of calculation takes the power
factor into account.
The measured power is displayed in Watts
and is updated approximately every 2 seconds, given an average power reading for
this period.
This innovative universal Watt measurement integrated circuit is ideally suited for
the display of the measured power in industrial and domestic power measurement
and multi plug sockets.
The SA9106A integrated circuit is available in 40 pin dual-in-line plastic (DIP-40)
as well as 44 pin plastic leaded chip carrier
(PLCC-44) package types.
n Adaptable to different types of current
sensors
n Operates over a wide temperature
range
n Precision voltage reference on-chip
PIN CONNECTIONS
V
SS
V
SSA
CIP
CIN
COP
CON
TP7
TP8
IVP
GND
TP11
IIN
IIP
VREF
TP15
CPON
CPOP
CPIN
CPIP
V
DDA
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
DR-00235
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
TP40
TP39
TP38
DIG[5]
DIG[4]
DIG[3]
DIG[2]
DIG[1]
DIG[0]
OSC1
OSC2
G
F
E
D
C
B
A
TP22
V
DD
Package: DIP-40
4008 PDS039-SA9106A-001 REV. D 10-08-1995
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SA9106A
PIN CONNECTIONS
COP
TP38
TP37
38
39 37 3536
CIN
CIP
34
SSA
V
V
SS
TP39
TP40
DIG[5]
3033 32 31
29
DIG[4]
BLOCK DIAGRAM
IIP
IIN
40
CON
41
TP7
42
IVP
43
GND
44
TP44
1
TP1
2
IIN
3
IIP
4
TP4
5
TP5
6
VREF
DR-00903
ANALOG
SIGNAL
7
CPON
CPOP
12
109811
CPIN
CPIP
V
TP12
TP9
POWER
INTEGRATOR
DDA
V
DD
151413
TP22
16
17
A
28
27
26
25
24
23
22
21
20
19
18
B
LED
DISPLAY
DRIVER
DIG[3]
DIG[2]
DIG[1]
DIG[0]
OSC1
OSC2
G
F
E
D
C
V
DD
V
SS
OUTPUTS
FOR LED
DISPLAY
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IVP
GND
DR-00236
PROCE-
SSING
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VOLTAGE
REF.
OSC
VREF OSC1
TIMING
OSC2
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SA9106A
ABSOLUTE MAXIMUM RATINGS*
Parameter Symbol Min Max Unit
Supply Voltage VDD -V
Current on any pin I
Storage Temperature T
Operating Temperature T
PIN
STG
O
SS
-0.3 6.0 V
-150 +150 mA
-40 +125 °C
-25 +85 °C
* Stresses above those listed under “Absolute Maximum Ratings” may cause perma-
nent damage to the device. This is a stress rating only. Functional operation of the
device at these or any other condition above those indicated in the operational sections
of this specification, is not implied. Exposure to Absolute Maximum Ratings for
extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
DD
and V
= 2.5V, VSS and V
DDA
= -2.5V, over the temperature range -10°C to +70°C
SSA
unless otherwise specified.)
Parameter Symbol Min Typ Max Unit Condition
Supply Voltage: Positive V
Supply Voltage: Negative V
Supply Current: Positive I
Supply Current: Negative I
2.25 2.75 V
DD
-2.75 -2.25 V
SS
DD
SS
510mA
510mA
Current Sensor Inputs (Differential)
Input Current Range I
II
-25 +25 µA Peak value
Voltage Sensor Input (Asymetric)
Input Current Range I
IV
-25 +25 µA Peak value
Display outputs
Digit Outputs I
Segment Drivers I
OL
OH
80 mA VOL = VSS + 0.5V
20 mA VOH = VDD - 0.5V
Oscillator Recommended crystal:
TV colour burst crystal f = 3.5795 MHz
#,
Pin VREF With R7 = 24kΩ
Ref. Current -I
Ref. Voltage V
#
Extended Operating Temperature Range available on request.
R
R
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45 50 55 µA connected to V
1.1 1.3 V Referred to V
SS
SS
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SA9106A
PIN DESCRIPTION
Pin Pin
PLCC DIP
43 10 GND Ground
14 21 V
13 20 V
33 1 V
34 2 V
42 9 IV P Analog input for Voltage
2 12 I IN Inputs for current sensor
3 13 IIP
24 31 OSC1 Connections for crystal or ceramic resonator
23 30 OSC2 (OSC1 = Input ; OSC2 = Output)
16 23 A Light Emitting Diode (LED) display segment
17 24 B outputs
18 25 C
19 26 D
20 27 E
21 28 F
22 29 G
25 32 DIG [0] Light Emitting Diode (LED) display digit outputs
26 33 DIG [1]
27 34 DIG [2]
28 35 DIG [3]
29 36 DIG [4]
30 37 DIG [5]
7 16 CPON Connections for outer loop capacitor of A/D
8 17 CPOP converter (Voltage)
10 18 CPIN Connections for inner loop capacitor of A/D
11 19 CPIP converter (Voltage)
35 3 CIP Connections for inner loop capacitor of A/D
36 4 CIN converter (Current)
39 5 COP Connections for outer loop capacitor of A/D
40 6 CON converter (Current)
6 14 VREF Connection for current setting resistor
41 7 TP7 Manufacturer's Test Pins (Leave unconnected)
11 TP11
15 TP15
15 22 TP22
38 TP38
Designation Description
DD
DDA
SS
SSA
8 TP8
Positive Supply Voltage
Negative Supply Voltage
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SA9106A
PIN DESCRIPTION (Continued)
Pin Pin
PLCC DIP
31 39 TP39 Manufacturer's Test Pins (Leave unconnected)
32 40 TP40
1 TP1
4 TP4
5 TP5
9 TP9
12 TP12
37 TP37
38 TP38
44 TP44
Designation Description
FUNCTIONAL DESCRIPTION
The SA9106A is a CMOS mixed signal Analog/Digital integrated circuit, which performs
bidirectional power calculations across a power range of 1000:1, to an overall accurancy
of better than 1% (± 1 count). An on-chip LED display driver directly drives a 5 digit (7
segment) LED display. The measured power is displayed in Watts.
The integrated circuit comprises of all the required functions 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.
1. Power Calculation
In the Application Circuit (Figure 1), the voltage drop across the shunt will be
between 0 and 50mV (0 to 80A through a shunt resistor of 625µΩ). This voltage is
converted to a current of between 0 and 16µA, by means of resistors R1 and R2.
The current sense input saturates at an input current of ±25µA peak.
For the voltage sense input, the mains voltage (230VAC) is divided down through
a divider to 14V. The resulting current into the A/D converter input is set at 14µA
at nominal mains voltage, via resistor R4 (1MΩ).
In this configuration, with a mains voltage of 230 V and a current of 80A, the
displayed power is 18 400 Watts.
2. LED Display Driver
The SA9106A has an on-chip LED display driver capable of driving 5 digit (7
segment) common cathode digits as well as a sign LED.
The sign LED is addressed by DIG [5], the most significant digit by DIG [4] and the
least significant digit by DIG [0].
The position of the segments a, b, c, d, e, f and g are shown in the diagram below:
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SA9106A
a
f
.
e
d
g
b
.
c
h
DR-00237
3. Analog Input Configuration
The input circuitry of the current and voltage sensor inputs are illustrated below.
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.
V
DD
IIP
V
CURRENT
SENSOR
INPUTS
SS
V
DD
A
I
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IIN
IVP
VOLTAGE
SENSOR
INPUT
DR-00505
V
SS
V
DD
V
SS
GND
A
V
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SA9106A
4. Electrostatic Discharge (ESD) Protection
The SA9106A integrated circuit inputs/outputs are protected against ESD according
to Mil-Std 883C, method 3015.
5. Power Consumption
The power consumption rating of the SA9106A integrated circuit is less than 50mW,
excluding the display.
TYPICAL APPLICATIONS
In the Application Circuits (Figures 1 and 2) the components required for power
measurement applications, are shown.
In Figure 1 a shunt resistor is used for current sensing. In this application, the circuitry
requires a +2.5V, 0V, -2.5V DC supply.
In the case of Figure 2, when using a current transformer for current sensing, a +5V, 0V
DC supply is sufficient.
The most important external components for the SA9106A integrated circuit are:
C1 and C2 are the outer loop capacitors for the two integrated oversampling A/D
converters. The value of these capacitors is 560pF.
The actual values determine the signal to noise and stability performance. The tolerances
should be within ±10%.
C3 and C4 are the inner loop capacitors of the A/D converters. The optimum value is
3.3nF. The actual values are uncritical. Values smaller than 0.5nF and larger than 5nF
should be avoided.
R2, R1 and RSH are the resistors defining the current level into the current sense input.
The values should be selected for an input current of 16µA into the SA9106A at maximum
line current.
Values for RSH of less than 200µΩ should be avoided.
R1 = R2 = (IL/16µA) * RSH/2
Where I
L
= Line current
RSH = Shunt resistor/termination resistor
R3, R6 and R4 set the current for the voltage sense input. The values should be selected
so that the input current into the voltage sense input (virtual ground) is set to 14µA.
R7 together with the trimpot RT defines all on-chip bias and reference currents. The bias
resistor value (RB = R7 + RT) may be varied within ±10% for calibration purposes. Any
change to RBwill affect the displayed value quadratically (i.e.: RB = +5%, Display value
= +10%).
XTAL is a colour burst TV crystal (f = 3.5795MHz) for the oscillator. The oscillator
frequency is divided down to 1.7897MHz on-chip to supply the digital circuitry and the
A/D converters.
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SA9106A
Figure 1: Application Circuit using a Shunt Resistor for Current Sensing.
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Parts List for Application Circuit: Figure 1
Item Symbol Description Detail
1 IC-1 SA9106A DIP-40/PLCC-44
2 D1 Light Emitting Diode
3 XTAL Crystal, 3.5795 MHz Colour burst TV
4 R1 Resistor, 1% metal Note 1
5 R2 Resistor, 1% metal Note 1
6 R3 Resistor, 390k, (230VAC) 1%, metal
7 R4 Resistor, 1M, 1/4W, 1% metal
8 R6 Resistor, 24k, 1/4W, 1% metal
9 R7 Resistor, 22k, 1/4W, 1% metal
10 R8 Resistor, (Segment G) Note 2
11 R9 Resistor, (Segment F) Note 2
12 R10 Resistor, (Segment E) Note 2
13 R11 Resistor, (Segment D) Note 2
14 R12 Resistor, (Segment C) Note 2
15 R13 Resistor, (Segment B) Note 2
16 R14 Resistor, (Segment A) Note 2
17 RT Potentiometer 4.7k Multi turn
18 C1 Capacitor, 560pF
19 C2 Capacitor, 560pF
20 C3 Capacitor, 3.3nF
21 C4 Capacitor, 3.3nF
22 C9 Capacitor, 100nF
23 C10 Capacitor, 100nF
24 C15 Capacitor, 820nF Note 3
25 RSH Shunt Resistor Note 4
SA9106A
Note 1: Resistor (R1 and R2) values are dependant upon the selected value of RSH.
Note 2: Resistors (R8 to R14) are current limiting resistors required to set the intensity
of the LED display segments.
Note 3: Capacitor (C15) to be positioned as close to Supply Pins (VDD & VSS) of IC-1 as
possible.
Note 4: See TYPICAL APPLICATIONS when selecting the value of RSH.
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SA9106A
Figure 2: Application Circuit using a Current Transformer for Current Sensing.
Note: Capacitor C11 may be selected for phase compensation and DC blocking.
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Parts List for Application Circuit: Figure 2
Item Symbol Description Detail
1 IC-1 SA9106A DIP-40/PLCC-44
2 XTAL Crystal, 3.5795MHz Colour burst TV
3 RSH Resistor Note 1
4 R1 Resistor, 1%, metal Note 2
5 R2 Resistor, 1%, metal Note 2
6 R3 Resistor, 390k, (230 VAC). 1%, metal
7 R4 Resistor, 1M, 1/4W, 1%, metal
8 R6 Resistor, 24k, 1/4W, metal
9 R7 Resistor, 22k, 1/4W, 1%, metal
10 R8 Resistor Note 3
11 R9 Resistor Note 3
12 R10 Resistor Note 3
13 R11 Resistor Note 3
14 R12 Resistor Note 3
15 R13 Resistor Note 3
16 R14 Resistor Note 3
17 R15 Resistor, 820Ω, 1/4W, 1%
18 R16 Resistor, 820Ω, 1/4W, 1%
19 D1 Light emitting diode
20 RT Potentiometer 4.7k Multi turn
21 C1 Capacitor, 560pF
22 C2 Capacitor, 560pF
23 C3 Capacitor, 3.3nF
24 C4 Capacitor, 3.3nF
25 C9 Capacitor, 100nF
26 C10 Capacitor, 100nF
27 C11 Capacitor Note 4
28 C15 Capacitor, 820nF Note 5
SA9106A
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SA9106A
Note 1: See TYPICAL APPLICATIONS when selecting the value of RSH.
Note 2: Resistor (R1and R2) values are dependant upon the selected value of RSH.
Note 3: Resistors (R10 to R16) are current limiting resistors required to set the
intensity of the LED display segments.
Note 4: Capacitor (C11) selected to minimize phase error introduced by current
transformer (typically 1.5µF).
Note 5: Capacitor (C15) to be positioned as close to Supply Pins (VDD & VSS) of
IC-1, as possible.
ORDERING INFORMATION
Part Number Package
SA9106APA DIP-40
SA9106AFA PLCC-44
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NOTES:
SA9106A
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SA9106A
Disclaimer: The information contained in this document is confidential and proprietary to South African Micro-
Electronic Systems (Pty) Ltd ("SAMES") and may not be copied or disclosed to a third party, in whole or in part,
without the express written consent of SAMES. The information contained herein is current as of the date of
publication; however, delivery of this document shall not under any circumstances create any implication that the
information contained herein is correct as of any time subsequent to such date. SAMES does not undertake to
inform any recipient of this document of any changes in the information contained herein, and SAMES expressly
reserves the right to make changes in such information, without notification,even if such changes would render
information contained herein inaccurate or incomplete. SAMES makes no representation or warranty that any
circuit designed by reference to the information contained herein, will function without errors and as intended by
the designer.
Any Sales or technical questions may be posted to our e-mail address below:
[email protected]
For the latest updates on datasheets, please visit out web site:
http://www.sames.co.za
South African Micro-Electronic Systems (Pty) Ltd
P O Box 15888, 33 Eland Street,
Lynn East, 0039 Koedoespoort Industrial Area,
Republic of South Africa, Pretoria,
Republic of South Africa
Tel: 012 333-6021 Tel: Int +27 12 333-6021
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Fax: 012 333-8071 Fax: Int +27 12 333-8071
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