Evaluation Board for the SA9904B Energy
Metering IC
sames
PM9904BPD
FEATURES
+ Designed to
+
+
+
+
be used together with accompanying
software as fully functional three phase trivector meter.
Better than class 1 operation.
On board power supply.
Two on-board LED’s for active and reactive pulse output.
3 Phase 4 wire configuration.
+
+
+
+
+
On-board LCD display.
On-board current transformers.
Isolated connection to PC parallel port.
Easy accessible test pins.
Micro-controller plug-in support
DESCRIPTION
This application note describes the PM9904BPD evaluation
board and together with the SA9904B data sheet provides a
complete evaluation platform. The SA9904B is an accurate bidirectional power / energy measurement IC with serial (SPI)
interface measuring active as well as reactive power / energy,
RMS voltage and frequency. More detailed information
specific to the of SA9904B can be found in its datasheet.
The SA9904B forms the energy/power metering front-end of
the module and connects to the SPI bus. Sharing the SPI bus
is the SA8807A LCD driver which is capable of driving 96
segments on a 4 back plane LCD.
The PM9904BPD evaluation board is configured and
calibrated via the parallel port of a PC. The data interface
between the evaluation board and the PC is fully isolated.
The PM9904BPD module is designed for a three-phase fourwire applications, referenced to neutral. The mains voltages
easily connect to module by way of a Molex connector (SK1).
The 3 on-board current transformers measures the current in
each phase. A simple capacitive power supply supplies the
energy metering IC with power. The LM431 regulators are
used to generate a 5 V supply voltage for the on-board optocouplers. Provision has been made to connect an external 5V
power supply to drive the isolated opto-coupler.
The PM9904BPD module can easily be connected to a microcontroller. The SAMES micro-controller board connects to the
evaluation module by means of JP1 thereby creating a
complete power meter without the PC interface. Physically the
micro-controller board plugs into the evaluation module with its
opto-coupler facing the mains connector (SK1). It shares the
SPI bus with the SA8807A onboard LCD controller.
JP4
PCVSS
SK1
VDD
GND
Power
Supply
CT1
SK3
PCVDD
LCD
DISPLAY
GND
VSS
VDD
PCVSS
PCVDD
SA8807A
Resistor
Network
JP2
JP1
CT2
Resistor
Network
SA9904A
J12
F50
CT3
JP3
PCVSS
Resistor
Network
Test Pins
VDD
VSS
PCVSS
Test Pins
Figure 1: Block diagram
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PM9904BPD
JUMPER SETTINGS
Power supply jumpers
with the PM9904BPD module the jumpers must be closed, and
can be left closed in the case of the SAMES micro-controller
board. This board is capable of driving the SPI bus in this state.
Default Closed.
The power supply jumpers are used to disconnect the onboard power supply, allowing the metering section of the circuit
to be powered from an external power supply if required.
Jumper
J4
J5
J6
J7
Description
Connects VDD to the metering circuitry.
Default closed
Connects VSS to the metering circuitry.
Default closed
GND connection point.
An additional output from the module is made available to the
parallel port of the PC. The output can be selected to be the
SA9904B’s F50 output or it can be selected to be the modules
push button output.
Connection point between the power supply GND
(N) and the SA9904 GND. Default closed
Jumper
Voltage selection jumpers
J12
The following jumpers are used to select between 115V and
230V operation. When closed the series resistance in the
voltage divider circuits to the voltage sense inputs are halved.
Default Open.
Jumper
J1
230V
115V
OPEN
Closed
J2
OPEN
Closed
J3
OPEN
Closed
Description
PB (left connection) - Connects the push button
output through a opto-coupler to pin 13 of the
parallel port
F50 (right connection) - Connects pin 7 of the
SA9904 through a opto-coupler to pin 13 of the
parallel port
Parallel power supply jumper
Jumper JP4 is used to select the power source for the optocoupler U7. Power can be taken from the PC’s parallel port or
from an external 5 volt supply via SK3.
Jumper
Communication jumpers
Jumpers J8 to J11 connect pull up resistors to the SPI inputs
of the SA9904. The pull up resistors are required by the open
drain outputs of the HCPL2631 opto-couplers. If a PC is used
Right connection - Connects U7 to SK3. An
external power supply can be connected to
SK3 to power U7.
SK3
N
PH3
PH2
PH1
SK1
JP4
Description
Left connection - Power for U7 is taken from the
PC’s parallel port (pins 1, 14,16,17)
sames
PM9904AP
JP2
JP4
Micro board
J12
F50*
JP1
JP3
PB
J8
J9
J3
J2
J1
J10
J11
J7
J6
SK2
Push button
GND
J5
VSS
J4
VDD
*On some pcb’s this may be labled as PB / F150, however f50 and f150 is the same connection.
Figure 2: Jumper positions
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PM9904BPD
CONNECTOR DESCRIPTION
Jumper
SK1
SK2
SETTING UP THE PM9904AP MODULE
Figure 3 below shows a typical setup for the PM9904BPD
evaluation module. The three phase voltages are connected
directly to SK1 and each corresponding phase current is wired
through the on-board CT’s. An external power supply can be
connected to SK3 should the PC’s parallel port not be able to
source enough current for the module's opto-couplers.
Description
Connects the three phase 4 wire supply to the
module.
Female BD25pin connects the evaluation board to
the PC parallel port by a 1 to 1 cable. The module
is isolated from the PC by the opto-couplers.
SK3
5V supply to U7 opto coupler
JP1
This header strip can be used for measuring the
I/O pins of the SA9904B and SA8807. Note that
this connector is on the same potential as the
SA9904B. Provision is made for VDD and VSS
so that a board with a micro controller can be
easily fitted without any additional wiring. Signals
available on this connector are:
Figure 3 also shows the default jumper settings. The
PM9904BPD evaluation module is setup by default for 3x
230V/80A operation. For 3x 115V operation jumpers J1, J2
and J3 need to be closed. Also capacitors C12, C13, and C14
values must be changed to 1uF / 150 VAC.
When these hardware settings have been verified the user has
the choice of using the micro-controller board or a PC to
evaluate the SA9904B further. Please note when using the PC
the micro-controller board should be unplugged to prevent a
bus contention on the SPI bus, since the PC and microcontroller would be attempting to drive the bus simultaneously.
Pin number Signal SA9904 (U1) SA8807 (U2)
1
VDD
Pin 6
Pin 13
2
VSS
Pin 14
Pin 26
3
F50
Pin 7
NC
4
SCK
Pin 8
Pin 18
5
CS
Pin 13
NC
6
MISO
Pin 9
Pin 20
7
MOSI
Pin 12
Pin 19
8
CE
NC
Pin 21
Micro-controller board
Once the board has been plugged into the evaluation module
no further action is required, just apply power.
PC
After removing the micro-controller board the evaluation board
can connected to the PC’s parallel port using a 1 to 1 parallel
cable (not supplied). Once the evaluation board has been
connected to the PC and powered up, the supplied software
can be launched. Refer to the next section for the software
installation and setup details.
MISO - Master In Slave Out
MOSI - Master Out Slave In
N
Load
PH1
PH2
PH3
SK1
5V
CT3
CT2
CT1
JP4
J3
JP2
Supp Sel
J12
PB/F150
JP1
SK2
SPI Port
VSS
J4
VDD
OUT
JP3
J10
J11
GND
J5
J8
J9
To PC
Parallel port
J7
J6
Figure 3: PM9904AP setup and connection
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J2
J1
sames
PM9904BPD
PM9904BPD EVALUATION SOFTWARE
Getting the SA9904 to generate pulses proportional
to the energy measured.
Software for the SA9904AP module is supplied on one 3.5”
1.44MB floppy disk and is designed to communicate with the
SA9904AP module via the PC’s parallel port. The supplied
software is written for DOS. Additional Windows software will
be posted to the SAMES web site for downloading when
available. The source code, written in Turbo C, is also
included.
Figure 4 is a flow diagram showing how to generate pulses
proportional to energy measured by the SA9904A. The speed
of execution is not critical, although it will influence the
resolution of the pulses that is generated.
It is recommended that the flow diagram be implemented
together with a timer interrupt used for the creep timing. The
same flow diagram is applicable for the SA9604A, but reading
of the register values should be synchronized with changes in
bit D19 of its frequency register.
File description
The following files are included on the floppy disk:
9904mtr.c
This file contains the source for the functions that read the
SA9904 registers, store these values in integration registers,
check for any overflow and generate the corresponding
energy pulse for the PM9904BPD on-board LED’s. It makes
provision to measure unbalanced energy per phase or sum the
energy for each phase. The software does not make use of
timers and relies on counting the software loops to generate
reasonable delays for the LED outputs.
Read Active Register
Subtract previous value
Check and fix register value wrapping
pc_spi.c
This file contains the source for all the SPI interface routines
which are used to communicate between the PM9904BPD
module and th e PC’s parallel port.
Add to active energy integrator
pc_lcd.c
This file contains the source for all the functions relating to the
SA8807 LCD driver IC, as well as other functions to switch on
the LCD display icons.
If integrator > threshold
No
Wait for next measurement cycle
Do other functions on the meter
Yes
Subtract threshold from integrator
9904mtr.exe
This is the executable file.
Load creep timer
Running the software
The program is executed by running the 9904mtr.exe file with
the following arguments:
9904mtr.exe 1 10
Generate pulse
Figure 4: Pulse flow diagram
The first parameter specifies the LPT port address to use
where 1= 0x378 (LPT1) and 2 = 0x278 (LPT2).
Threshold and pulse rates
The second parameter is a loop delay. Larger values will slow
down the SPI communication speed to the PM9904BPD
module.
The active and reactive registers on the SA9904B increment at
a rate of 320 000 counts per second at rated metering
conditions for a sine wave. A single count of the active register
corresponds to an amount of energy expressed in Watt
seconds (Ws).
Energy per count is (Ws):
Epc = Vnom x Imax / 320 000
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PM9904BPD
where:
Vnom is the mains voltage and correspond to 14µA in the
voltage inputs of the SA9904B.
Imax is the maximum mains current to be measured and
correspond to 16µA on the current inputs of the SA9904B.
The simplest way to implement the creep threshold is to relate
it to the time between meter pulses. If the time between pulses
is more than the limit, the energy accumulator is cleared.
Pulse rate of meter at rated conditions (Hz):
Rf = ( Vnom x Imax / 1000 ) x ( Mpr / 3600 )
The pulse rate required for a meter is usually expressed in
pulses/kWh. A single pulse on the LED is mostly a fraction of a
kWh and is converted to energy in Ws/pulse
where:
Vnom is the mains voltage and correspond to 14µA in the
voltage inputs.
Imax is the maximum mains current to be measured and
correspond to 16µA on the current inputs of the device.
Mpr is the meter pulse rate in pulses/kWh.
Energy per LED pulse is (Ws/pulse):
Epp energy = 1000 x 3600 / Mpr
where:
Epp is energy per LED pulse
Mpr is the meter pulse rate or meter constant in pulses/kWh
Creep threshold time (s):
Ct = 1/(Cc / Imax) x Rf
The threshold is calculated by dividing the energy represented
by a LED pulse by the energy per register count.
where:
Cc is the specified creep current; energy below this value is
discarded.
Imax is the maximum mains current to be measured and
correspond to 16µA on the current inputs of the device.
Rf is the rated current frequency.
Active energy threshold = Epp / Epc
The threshold is thus the amount of energy to be measured
(accumulated / integrated) by the meter before a LED pulse is
generated.
The flow diagram (figure 6) for the timer interrupt shows how
the time between pulses is measured, if the time since the last
pulse is more than the time measured, the integrator is reset
and a new count down is started.
Integrator Amplitude
Pulse threshold
Threshold value subtracted
from integrator
Start Timer Interrupt
No
Integrator zero
Yes
If LED On
Decrement LED ON timer
Pulse LED
Yes
Pulse Generated
If LED ON Timer = 0
Reg 8 add to Integrator
Reg 4 add to Integrator
Reg 0 add to Integrator
Switch LED off
Figure 5: Implementation of an overflow integrator
No
Yes
If creep timer > 0
Decrement creep timer
Meter creep current
For the SA9904B meter creep must be taken care of in
software. From the explanation above on how to generate
pulses, the meter must also be prevented from pulsing in
cases where the energy measured is less than the creep
threshold as per the meter specification. The creep current is
defined as the limit for measured energy, any energy less than
the creep threshold is discarded, and energy above the creep
threshold is measured.
Yes
If creep timer = 0
Load creep timer
No
Exit Interrupt
Reset integrator
Figure 6: Interrupt flow diagram
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PM9904BPD
THE MICRO-CONTROLLER BOARD
OVERVIEW
Keys
Four keys are provided of which one is connected to the microcontroller’s reset pin. The other three are available to
implement an HMI (Human Machine Interface) in the firmware;
they’re labelled Up/Down and Enter on the printed circuit
board.
This section describes the plug-in micro-controller board and
should be read in conjunction with the evaluation software
section, where basic metering software is described. The
micro-controller’s software was developed according to this
section. The board plugs into the evaluation module as
described earlier in this application note.
Rate outputs
Two LEDs are provided for active and re-active energy
respectively. These pulse outputs can be coupled to an optocoupler via JP3/4 providing an output for external usage. This
output-pulse selection is accomplished with a jumper on JP3/4
as follows:
+
Jumper on board’s outside edge
= a ctive
+
Jumper on board’s centre pins
= re -active
+
Jumper on board’s inside edge
= not used
1
Miscellaneous
Connectors JP1 and JP2 are provided to ease debugging
during code development, all relevant signals are available. J1
in conjunction with SK2 are the two plug-in points to the
evaluation module, where SK2 is the SPI connector and J1
merely a stabilising holder. The micro-controller is
programmed via SK1 using the controller’s ICSP (in circuit
serial programming) capability, as described in the relevant
MICROCHIP datasheet. If the intention is to program the board
from MICROCHIP’s PICSTART-programmer a buffer needs to
be inserted in the VDD line to boost the programmer’s output
capability. An example of such a buffer is shown in Figure 8.
Figure 7: Micro-controller board
Hardware
The schematic is presented in Figure 18. As can be seen the
major elements are:
+
micro-controller,
+
eeprom,
+
keys,
+
rate LEDs / opto-isolated rate pulse output
+
and miscellaneous connectors.
>5V
820K
R1
Micro-controller
A PIC 16F876-20/so is used to generate the rate pulses, in this
application the micro uses a 20 MHz crystal (X1). This device
has 8kB Flash ROM (program memory) and 368 Byte RAM
(data memory). Detail information on the device can be
obtained in the appropriate MICROCHIP datasheet.
100R
R3
2N3906
EEPROM
A 93C46 EEPROM provides storage for non-volatile data,
such as calibration factors. This device has 1 kB space
available or stated differently 128 x 8bit words.
I/P
2N3819
O/P
1.2M
R5
820K
R2
0V
Figure 8: Typical buffer circuit
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PM9904BPD
Firmware
The micro-controller’s code was created according to the
guidelines set out in the evaluation software section. It is
presented as a kick-start to experimentation with the microcontroller module and as such shouldn’t be seen as the best
(or only) possible implementation. The code was generated
using Hi-Tech PIC C (v7.86PL4); the demo version on their
www site (www.htsoft.com) is sufficient for experimentation.
The program flow is presented in Figure 9.
method of deciding what the predefined value should be is to
measure the time between two pulses at the lowest
permissible load current, this is then expressed i.t.o basic
timer ticks.
User Interface
A simple interface has been implemented using two of the
three available keys. The Enter Key toggles display of
consumed kWh and kVARh units. The Down Key displays per
phase voltage and frequency data, each press shows the next
phase’s data.
SPI
Bit-banging SPI is used to aid portability to other micros, i.e.
three port pins under direct software control creates
SPI_CLOCK, MOSI and reads MISO. The SPI access of the
SA9904B is divided into two tasks namely, fast and slow
changing data. This is accomplished via an interrupt driven
time-slicing architecture, with a basic timer tick of 10ms.
Memory Usage
ROM:
4070 words
or 50% of the total capacity
RAM:
Bank0
Bank1
Bank2
Bank3
Rate LEDs / opto-outputs
The 10ms pulse widths on these outputs are derived from the
basic timer tick.
Creep
The creep algorithm is simply: - if the time between two
successive pulses is greater than a predefined maximum, the
respective energy accumulator is cleared. The simplest
86%
26%
83%
---
or 50% of the total capacity
Please refer to the readme. 1st file for any updated information
not contained in this application note. The mentioned file is
part of the source code that accompanies this module.
/* Switch Power on */
START
Setup Ctrler’s ports and interrupts
init()
Displays the start-up screens on LCD
boot_scrn()
Read voltage and
frequency registers.
Read energy
registers
User Interface
isr()
interrupt service routine:
10ms ticks
ctrl fast & slow tasks
ctrl pulsing of rate LEDs
Manage interrupt on keypress
process_a_data()
process_r_data()
END
Figure 9: Program flow
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/*Power off*/
sames
PM9904BPD
CIRCUIT DESCRIPTION
ANALOG SECTION
Voltage Divider
The analog (metering) interface described in this section is
designed for measuring 3 x 230V/80A with precision better
than Class 1.
Referring to figure 11 the connections for the voltage sense
input for one phase is shown. The current into the A/D
converter (IVP) is set 14µARMS at nominal mains voltage. This
voltage sense input saturates at approximately 17µARMS. A
nominal voltage current of 14µA allows for 20% over driving.
Each phase voltage is divided down by a voltage divider to
14V. The current into the voltage sense input is set at 14µA via
a 1MW resistor.
The most important external components for the SA9904B
integrated circuit are the current sense resistors, the voltage
sense resistors and the bias setting resistor. The resistors
used in the metering section are of the same type to minimize
any temperature effects.
The following equation is used to calculate the 14V voltage
drop:
RA = R22 + R23 + R24 +R25
RB = R8 || R13
Combining the two equations gives:
(RA + RB) / 230V = RB / 14V
A 24kW resistor is chosen for R13 and a 1MW resistor is used
for R8.
Substituting these values result in:
RB = 23.44kW
RA = RB x (230V / 14V - 1)
RA = 361.6kW
Bias Resistor
Pin VREF (SA9904B pin 15) is connected to Vss via R7 which
determines the on chip bias current. With R7=47kW optimum
conditions are set. VREF does not require any additional
circuitry.
CT Termination Resistor
The voltage drop across the CT termination resistors should
be at least 16mV at rated current (Imax). The on-board CT's
have low phase shifts and have a ratio of 1:2500. Each CT is
terminated with a 2.7W resistor resulting in a voltage drop of
86.4mV across each resistor at rated conditions.
Resistor values of R22, R24 are chosen to be 82kW and
resistors R23 and R25 is chosen to be 120kW each.
Current Sense Resistors
Referring to figure 10 the resistors R1 and R2 define the
current level into the SA9904B’s current sense inputs (phase
one IIP1 and IIN1). The resistor values are selected for an
input current of 16µA into the current inputs at rated
conditions.
The three voltage channels are identical so
R14= R16 =R17 = R18 = R20 = R22 = R24 = 82kW and
R15= R17 =R19 = R21 = R23 = R25 = 120kW
The capacitors C3, C4 and C5 is used to compensate for
phase shifts between the SA9904’s voltage sense inputs and
current sense inputs. The on-board CT's were characterized
and found to have a constant phase shift of 0.18 degrees. The
value of the phase shift compensation capacitors were
calculated as follows:
C = 1 / ( 2 x p x Mains frequency x R5 x tan (Phase shift angle))
C = 1 / ( 2 x p x 50Hz x 1MW tan (0.18 degrees ))
C = 1.013µF
According to equation described in the Current Sense inputs
section of the datasheet:
R1 = R2 = (I / 16µA) x RSH / 2
= 80A /2500 / 16µA x 2.7W / 2
= 2.7kW
where:
I = Line current / CT Ratio
The three current channels are identical so R1 = R2 = R3 =
R4= R5 = R6.
V1In
R1
CT1
R26
2.7R
V1 Out
2.7k
R2
TZ76
GND
J3
Pin 19
V1In
R23
R24
R25
82k
120k
82k
120k
C5
R13 1u
24k
Pin 18
2.7k
GND
Figure 11: Mains voltage divider
Figure 10: Current input configuration
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R8
1M
Pin 17
sames
PM9904BPD
Power Supply
Power Supply routing and de-coupling
Referring to figure 15, capacitor C10 is charged through D2
during the positive half of the sine wave from the R29, C12
mains voltage dropper. Identical charging circuitry exists for
the other two phases. During the negative sine wave, C11 is
charged through diode D1. The unregulated voltage charged
on C10 and C11 is limited to 47 V by means of zener diode D7.
Resistors R32 and R33 act as current limiting resistors that
feed the unregulated voltage to the positive and negative
voltage regulators U3 and U4. The voltage regulators need a
load capacitance of around 10µF (C8 and C9) to be in a stable
operating region. C15 acts as a supply voltage storage
capacitor.
The 5V supply is de-coupled and routed directly to the power
pins of the SA9904B by means of capacitor C15. Care was
taken not to have current flowing in the node that connects the
voltage reference resistor to VSS as it may introduce power
supply noise on the voltage reference circuit.
Jumpers J4, J5 and J7 allow the power supply to be completely
disconnected form the metering section from the device.
THE SA8807A LCD DRIVER
Signal Routing
The signal routing is done in such a manner that any signal
coupling in to the measured signal will be a common mode
noise signal and is subsequently rejected. Care should be
taken that the signals to the SA9904B not be influenced by
other sources such as electric fields from transformers etc.
OVERVIEW
PCB DESIGN
The PM9904AP evaluation module represents a Class 1
meter and is designed to demonstrate the functionality and
performance of the SA9904B metering integrated circuits. The
SA9904B is mainly the analog front end of a meter. The
SA9904B measures the energy, voltage and frequency which
are made available to an external micro-controller, by way of
JP1, or to a PC. When the meter ’s PCB is designed, it should
be remembered that the SA9904B inputs are analog and
special care need to be taken with the power supply and signal
routing to the SA9904B.
Protection
The SA9904B should be protected from the measuring
environment. This is achieved by using resistor dividers to
scale all the SA9904B’s input signals. MOV's Z1, Z2, Z3
together with resistors R29, R30, R31 protect the power
supply capacitors as well as the voltage sense inputs. The
current setting resistors on the current sense inputs attenuates
any common mode and asymmetrical transients.
Component placement
All the resistors on the SA9904B’s current sense inputs should
be placed as close as possible to the SA9904B. This
eliminates the possibility of any stray signals coupling into the
input signals.
Ground Plane
The GND pin of the SA9904B is connected to the neutral
phase, which is halfway between VDD and VSS. Note that
supply bypass capacitors C1 and C2 are positioned as close
as possible to the supply pins of the SA9904B, and is
connected to a solid ground plane. Capacitor C6 is also
positioned as close as possible to the supply pins of the
SA9904B for proper supply bypassing.
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The SAMES SA8807A Liquid Crystal Display (LCD) driver is
capable of driving up to 96 LCD segments and is designed for
displays having 3 or 4 track multiplexed back planes. The
SA8807A includes an on-chip oscillator and needs only a
single external capacitor. Communication to the SA8807A is
via the Serial Peripheral Interface (SPI) which is shared with
the SA9904B.
This LCD driver is ideal for any micro-controller based system
requiring a liquid crystal display of up to 12 seven-segment
digits.
USING THE SA8807A
Oscillator
The SA8807A includes an on-chip oscillator that is controlled
by a single external capacitor. Adjusting the capacitor value will
change operating frequency of the SA8807A. The back plane
multiplexing is a function of the SA8807A operating frequency.
It is thus important to select the frequency high enough that the
multiplexing of the display is not noticeable, but still within limits
of the LCD display reaction time.
f =7µF x 0.1Hz / C
f = Required oscillator frequency
f / 8 = back plane multiplex rate for a 4 back plane display
SPI Interface
The SA8807A shares the SPI interface with the SA9904B and
connects directly to the opto-couplers on the PM9904BPD
evaluation board. The CE signal enables the SPI interface for
the display driver and the CS signal enables the SPI interface
for the SA9904B.
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PM9904BPD
Commands
To write to the device the following address is passed:
1 0 A5 A4 A3 A2 A1 A0
The demonstration software uses a buffer in memory on the
PC to generate the complete display. The buffer is dumped to
the LCD driver device in one go. The data passed to the driver
IC is formatted with a starting address followed by the data for
all segments. The first 8 bits is interpreted as address byte and
the rest of the data is sequentially passed as data bytes. The
address counter on the driver IC is incremented every 8
clocks. The procedure is repeated until all of the LCD memory
is filled up.
Data
Data to the device is passed with MSB first
D7 D6 D5 D4 D3 D2 D1 D0
Were D7 and D3 map to pin VR[3] of driver and COM4 of LCD
Were D6 and D2 map to pin VR[2] of driver and COM3 of LCD
Were D5 and D1 map to pin VR[1] of driver and COM2 of LCD
Were D4 and D0 map to pin VR[0] of driver and COM1 of LCD
See SA8807A datasheet for more information.
Address
The address of the data is set up in the following manner
b
g
g
c
Cost
b
4
e
d
c
e
d
h
DR-01255
Pin1
COM2
COM3
COM4
h
»
T4
f
1
Pin2
BACKPLANES
Com
»
T3
f
»
Total
COM1
a
»
T2
a
»
T1
Cosf
»
Pin32
»
Pin35
»
Pin36
Pin5
COLUMNS
Figure 12: Mapping of a single character
Address
5
4
3
2
1
0
30
7
32
5
33
4
34
3
35
2
36
1
COM1, 17
5f
5a
4f
4a
3f
3a
2f
2a
1f
1a
Cosi
T1
COM2, 18
5g
5b
4g
4b
3g
3b
2g
2b
1g
1b
Total
T2
COM3, 19
5e
5c
4e
4c
3e
3c
2e
2c
1e
1c
Com
T3
COM4, 20
5d
5h
4d
4h
3d
3h
2d
2h
1d
1h
Cost
T4
LCD Pin
Table 1: LCD display memory map
Address
11
10
23
LCD Pin
8
9
7
6
21
16
22
15
24
13
26
11
28
9
COM1, 17
Blank
Blank
k1
k2
% Error
V
8f
8a
7f
7a
6f
6a
COM2, 18
Blank
Blank
Hz
W
imp/KWh
A
8g
8b
7g
7b
6g
6b
COM3, 19
Blank
Blank
~1
s
Wh/imp
r
8e
8c
7e
7c
6e
6c
COM4, 20
T1, T2, T3, T4
Total
~2
h
~3
h
8d
8h
7d
7h
6d
6h
Table 2: LCD display memory map (continued)
http://www.sames.co.za
10/22
sames
PM9904BPD
THE LIQUID CRYSTAL DISPLAY
4-R1.0
Hz ~3 ~2 ~1
k1 kWrh
kWsh
8h k2
Wh/imp
4.6
T1
2.8
Max.
1.1±0.1
DETAIL OF DIGIT (1 ~ 8)
d
.
e
4.0°
0.25±0.05
0.5
0.8
.
c
b
a
1
f
10.0±2.0
58.0
REAR GLASS
2.54±0.05
T2
.
.
.
.
REAR POLARIZER(Reflective)
60.0 ±0.8
12.3
T3
.
.
4
g
FRONT GLASS
FRONT POLARIZER
1.5
.
.
27.6
5.0
.
.
.
7
6
1.5
5
.2
3
2
.5
±
0
.2
2
0
.6
±
0
.6
16.8
.
c
b
g
2.13
1.4
1.0
Max.
1.9
1.0
Max.
DR-00902
t3
t1
t2
4.27
8.41
t4
4.3
7.18
T1Coso
T2Total
T3Com
T4Cost
.
e
16.45
d
a
1
f
3.4
1h
.
4.6
1.6
3.5
0
.6
±
0
.6
2
.5
±
0
.2
2.54±0.05
3.1
17 x 2.54 = 43.18±0.1
7.8
4.0
2
0.65
T4 TOTAL
.
8
.
imp/kWh
1.95 2.4
%Error
8.3
8.41
1.0
2
3
.
0
±
0
0.
7.5
8.0 Max.
4.5
7.5
14.0 Min. Viewing Area
4.5
Figure 13: All the Icons and Dimensions of LCD
Pin
36
35
34
33
32
COM1
cosf
1f
2f
3f
4f
5f
6f
7f
8f
%Error
k1
COM2
Total
1g
2g
3g
4g
5g
6g
7g
8g
imp/KWh
Hz
COM3
Com
1e
2e
3e
4e
5e
6e
7e
8e
Wh/imp
~1
COM4
Cost
1d
2d
3d
4d
31
T1
30
5d
29
T2
28
6d
27
T3
26
7d
25
T4
24
8d
23
22
21
23
COM3
~2
Total ~ 3
23
COM4
Table 3 : Mapping of display
Pin
1
2
3
4
5
COM1
T1
1a
2a
3a
4a
5a
6a
7a
COM2
T2
1b
2b
3b
4b
5b
6b
COM3
T3
1c
2c
3c
4c
5c
6c
COM4
T4
1h
2h
3h
6
4h
7
8
5h
9
10
6h
15
16
17
8a
V
k2
COM1
7b
8b
A
W
7c
8c
r
s
h
h
11
12
13
7h
Table 4 : Mapping of display (continued)
http://www.sames.co.za
11/22
14
8h
18
COM2
sames
PM9904BPD
SCHEMATIC
V3 In
C1 R15
82k
R16
120k
R18
PH2
B1 R19
82k
R22
PH1
82k
A1 R23
82k
A4
120k
U1
19
IIN1
GND
IVP1
TZ76
18
IIP1
2.7k
GND
IVP2
R3
CT2
R13
16
GND
R2
2
IIN2
IVP3
R8
C5
1u
20
1M
R9
3
1M
R10
1
F50
SCK
CS
DI
DO
IIP2
2.7k
GND
R5
CT3
C4
1u
C3
1u
1M
R4
TZ76
24k
17
2.7k
R27
2.7R
5
7
8
13
12
9
JP1
F50
SCK
CS
MOSI
MISO
SCK
CS
DI
DO
IIN3
1
2
3
4
5
6
7
8
VDD
SPI Port
R6
TZ76
4
IIP3
OSC1
10
2.7k
GND
J7
C2
220n
X1
3.5795MHz
R7
V3 Out
15
VREF
OSC2
11
GND
47k
GND
N
14
N Node
VDD
VSS
F50
SCK
CS
MISO
MOSI
CE
F50
2.7k
R28
2.7R
V1 Out
R25
2.7k
R26
2.7R
V2 Out
R12
24k
A3
82k
R1
CT1
B4
120k
JUMPS2
J3
R24
120k
R11
24k
R21
B3
A2
V1In
C4
120k
JUMPS2
J2
R20
120k
R17
C3
82k
B2
V2 In
JUMPS2
J1
C2
R14
PH3
VSS
VSS
VDD
6
C1
220n
C6
1u
VDD
SA9904B
VSS
Figure 14 : Schematic diagram of metering section
VP
PH1
C12
R29
LL1
N
PH2
1N4007
1N4007
470/1W
470/250VAC
SK1
PH1
PH2
PH3
N
D2
VD
VDD
+ C10
47
Z1
4
3
2
1
D1
J4
VDD
R32
+ C8
470/25V
D3
D4
1N4007
1N4007
10u
U3
TL431
S10/275
C13
R30
47
Z2
J6
LL2
D7
47V
470/250VAC
GND
N
MAINS
+ C11
N
PH3
S10/275
C14
R31
LL3
47
Z3
N
D5
1N4007
D6
R33
470/250VAC
VN
Figure 15: Schematic diagram of power supply
http://www.sames.co.za
12/22
10u
U4
TL431
1N4007
S10/275
+ C9
470/25v
470/1W
+ C15
470
J5
VSS
VS
VSS
R51
O2
4.7R
R50
O3
4.7R
R48
O4
4.7R
R49
PC_OUT
VDD
PCVDD
C16
100n
C17
100n
C18
100n
VSS
PCVSS
4.7R
SK3
5V
PCVSS
1
2
PC 5V
VDD
U5
R34
D6
1
VCC
13/22
Figure 16: Schematic diagram of Isolated interface
680R
JUMPS2
J8
8
5V
PCVDD
PC_OUT
MOSI
JUMPS2
J9
R35
D5
4
680R
SK2
1
14
2
15
3
16
4
17
5
18
6
19
7
20
8
21
9
22
10
23
11
24
12
25
13
O1
O2
VCC
680R
D0
D3
VDD
JUMPS2
J10
8
J11
3
D2
R37
D7
4
680R
D4
GND
R47
CS
5
JP2
I0
I1
I2
I3
I4
PCVSS
VSS
HCPL2631
PCVSS
LED
VDD
4.7k
6
D3
L2
CE
JUMPS2
D1
O3
R43
4.7k
2
O4
R46
PCVSS
LED
1k
7
I0
L1
SCK
VSS
U6
1
R42
1k
5
HCPL2631
R36
D4
GND
D2
R45
4.7k
6
Supp Sel
VDD
4.7k
3
JP4
R44
7
2
PC
PM9904BPD
http://www.sames.co.za
O1
1
2
3
4
5
6
IN
PCVSS
D5
JP3
PCVDD
D6
R41
D7
4.7k
I3
I4
I2
PCVSS
VCC
I1
R38
1
4.7k
2
J12
PB/F50
3
6
5
PB1
GND
VDD
R39
4
680R
HCPL2631
PCVSS
MISO
680R
7
R40
I2
I1
U7
8
VSS
D0
D1
D2
D3
D4
D5
D6
D7
O1
O2
O3
O4
PCVSS
1
2
3
4
5
6
7
8
9
10
11
12
13
OUT
SW-PB
F150
sames
PM9904BPD
http://www.sames.co.za
VDD
U2
25
VDD
RES
V1
CLK
C7
39n
26
23
27
GND
END
M3
VSS
SCK
MOSI
MISO
CS_D
18
19
20
21
COM3
COM2
COM1
COM0
33
32
31
30
SCK
MOSI
MISO
CE
VR[3]
VR[2]
VR[1]
VR[0]
VS[23]
VS[22]
VS[21]
VS[20]
VS[19]
VS[18]
VS[17]
VS[16]
VS[15]
VS[14]
VS[13]
VS[12]
VS[11]
VS[10]
VS[9]
VS[8]
VS[7]
VS[6]
VS[5]
VS[4]
VS[3]
VS[2]
VS[1]
VS[0]
17
16
15
14
11
10
9
8
7
6
5
4
3
2
1
43
42
41
40
39
38
37
36
35
LNC
LP23
LP21
LP16
LP22
LP15
LP24
LP13
LP26
LP11
LP28
LP9
LP30
LP7
LP32
LP5
LP33
LP4
LP34
LP3
LP35
LP2
LP36
LP1
LCD1
LP1
LP2
LP3
LP4
LP5
LP7
LP9
LP11
LP13
LP15
LP16
COM0
COM1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
OEL-7678
14/22
Figure 17: Schematic diagram of LCD and Driver
13
22
28
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
LP36
LP35
LP34
LP33
LP32
LNC
LP30
LNC
LP28
LNC
LP26
LNC
LP24
LP23
LP22
LP21
COM2
COM3
HR-LCD
SA8807AF
sames
sames
PM9904BPD
Figure 18: Silkscreen PCB layout
http://www.sames.co.za
15/22
sames
PM9904BPD
PCB LAYOUT
Figure 19: Top PCB layout
Figure 20: Bottom PCB layout
http://www.sames.co.za
16/22
sames
PM9904BPD
COMPONENT LIST (PM9904BPD BOARD)
Items
Part Type
Designator
Description
1
100n
C16, C17, C18
Capacitor Monolithic Ceramic
2
10µ / 16V
C8, C9
Capacitor Tantalum
1
1µ / 16V / No Polarity
C3, C4, C5
Capacitor Electrolytic Radial
2
1µ / 63V
C6
Capacitor Monolithic Ceramic
4
220n / 63V
C1, C2
Capacitor Monolithic Ceramic
3
22n / 63V
C7
Capacitor Monolithic Ceramic
5
470n / 250VAC
C12, C13, C14
Capacitor Polyester
6
470µ / 16V
C15
Capacitor Electrolytic Radial
5
470µ / 25V
C10, C11
Capacitor Electrolytic Radial
6
Tz76
CT1, CT2, CT3
7
1N4007
D1, D2, D3, D4, D5, D6
Rectifier Diode
9
47V
D7
Zener Diode
16
LED
L1, L2
LED 3mm Diameter
17
SW-PB
PB1
Micro switch
18
2.7k
R1, R2, R3, R4, R5, R6
¼ Watt, 1%, Metal Film Resistor
20
47k
R7
¼ Watt, 1%, Metal Film Resistor
20
1M
R8, R9, R10
¼ Watt, 1%, Metal Film Resistor
21
24k
R11, R12, R13
¼ Watt, 1%, Metal Film Resistor
22
4.7R
R48, R49, R50, R51
¼ Watt, 5%, Carbon Resistor
25
120k
R15, R17, R19, R21, R23, R25
¼ Watt, 1%, Metal Film Resistor
27
1k
R42, R43
¼ Watt, 5%, Carbon Resistor
26
2.7R
R26, R27, R28
¼ Watt, 1%, Metal Film Resistor
27
4.7k
R40, R41, R44, R45, R46, R47
¼ Watt, 5%, Carbon Resistor
29
470R / 1 Watt
R32, R33
1 Watt, 1%, Wire Wound Resistor
30
47R / 2 Watt
R29, R30, R31
2 Watt, 1%, Wire Wound Resistor
31
680R
R34, R35, R36, R37, R38, R39
¼ Watt, 5%, Carbon Resistor
33
82k
R14, R16, R18, R20, R22, R24
¼ Watt, 1%, Metal Film Resistor
35
MAINS
Sk1
7 Pin Molex, Center square pin, Friction Lock
37
PC
Sk2
Db25, PCB Mount, Female
36
PC 5V
Sk3
2 Pin Molex, Center square pin, Friction Lock
37
TL431
U3, U4
TO -92 Package
38
HCPL2631
U5, U6, U7
DIP 8 Package
39
3.5795 MHz
X1
Crystal
40
S10 / 275
Z1, Z2, Z3
Metal Oxide Varistor
41
SA9904B
U1
20 Pin IC Socket, Tulip Type
43
SA8807AF
U2
44 Pin PLCC IC Socket
http://www.sames.co.za
17/22
PM9904BPD
http://www.sames.co.za
SK1
1
2
3
4
5
6
J1
MCLR
VDD
VSS
RB3
RB6
RB7
N1
N2
N3
N4
N5
N6
N7
N8
8
7
6
5
4
3
2
1
ISP
JP1
VSS
Holder
VSS
C1
33p
C2
33p
X1
20
D1
1N4148
R2
RST
640R
1N4148
C4
100n
VSS
VDD
1k
MCLR
RA0
RA1
RA2
RA3
RA4
RA5
F50
RB1
RB2
RB3
RB4
9
1
2
3
4
5
6
7
21
22
23
24
25
Active
1k
10
11
12
13
14
15
16
17
18
26
27
28
R
CS_D
CS_A
CS_M
SCK
MISO
MOSI
RC6
RC7
RB5
RB6
RB7
VDD
SK2
C5
1u
RST
VSS
VDD
VSS
F50
SCK
CS_A
MISO
MOSI
CS_D
1
2
3
4
5
6
7
8
SPI Port
S1
UP
S2
DOWN
S3
ENTER
S4
RESET
VSS
L2
VDD
L
OSC1/CLKIN OSC2/CLKOUT
MCLR/VPP RC0/T1OSO/T1CKI
RA0/AN0
RC1/T1OSI
RA1/AN1
RC2/CCP1
RA2/AN2
RC3/SCK/SCL
RA3/AN3/VREF RC4/SDI/SDA
RA4/T0CKI
RC5/SDO
RA5/AN4/SS
RC6
RB0/INT
RC7
RB1
RB5
RB2
RB6
RB3
RB7
RB4
RA0
R4
RB7
RB6
RB5
RB4
RB3
RB2
RB1
F50
VDD
VSS
RC7
RC6
MOSI
MISO
1
2
3
4
5
6
7
8
9
10
11
12
13
14
PIC16F876-20/SO
L1
R3
JP2
MCLR
RA0
RA1
RA2
RA3
RA4
RA5
VSS
OSCI
OSCO
CS_D
CS_A
CS_M
SCK
U1
D2
VDD
R1
33k
VDD
VSS
VSS
C3
100n
OSCO
OSCI
20MHz
VDD
8
19
18/22
Figure 21: Micro-Controller Board Schematic
1
2
3
4
5
6
7
8
9
10
11
12
13
14
VSS
RA1
Reactive
U2
CS_M
SCK
MOSI
MISO
1
2
3
4
CS
SCK
DI
DO
93C46
VCC
NC
ORG
VSS
VDD
8
7
6
5
VSS
VDD
JP3
RA0
RA1
RA2
JP4
1
2
3
1
2
3
Q1
PNP
R6
10k
Out Select
SK3
1
2
R5
VSS1k
U3
4N35
Opto Out
sames
sames
PM9904BPD
MICRO-CONTROLLER BOARD
sames
R1
D1
C4
MCLR
R2
RA0
RA0
D2
U1
RA4
PA9904B2
R6
RESET
RB4
RB2
C1
VSS
RB1
F50
OSCI
VDD
OSCO
VSS
CS_D
RC7
CS_A
CS_M
C5
UP
S1
DOWN
S2
RC6
C2
R5
Active
MOSI
C3
U2
MISO
ENTER
Figure 22: Top PCB layout
Figure 23: Bottom PCB layout
http://www.sames.co.za
Opto Out
RB3
RA3
SCK
S4
RB6
RB5
RA2
RA5
RB7
Q1
R3
PA9904B2
ISP
19/22
S3
R4
Reactive
sames
PM9904BPD
sames
R1
D1
C4
MCLR
R2
ISP
RA0
RA0
D2
U1
RB4
RB2
C1
VSS
RB1
F50
OSCI
VDD
OSCO
VSS
CS_D
RC7
CS_M
C5
UP
R5
S1
JP3/4
DOWN
S2
RC6
C2
CS_A
PA9904B2
R6
RESET
R3
RA4
Active
MOSI
C3
U2
MISO
ENTER
S3
R4
Reactive
Figure 24: Silkscreen PCB layout (Micro-controller board)
http://www.sames.co.za
Opto Out
RB3
RA3
SCK
S4
RB6
RB5
RA2
RA5
RB7
Q1
20/22
sames
PM9904BPD
COMPONENT LIST (Micro-controller board)
Designator
Part Type
Footprint
Description
D1
1N4148
MELF-MINI-D
Si signal diode
D2
1N4148
MELF-MINI-D
Si signal diode
R5
1k
805
Resistor, 1%
R4
1k
805
Resistor, 1%
R3
1k
805
Resistor, 1%
C5
1u
3528
Capacitor, tantalum/10V
U3
4N35
DIP6
Opto-coupler, medium speed
R6
10k
805
Resistor, 1%
X1
20MHz
XTAL3
Crystal
R1
33k
805
Resistor, 1%
C2
33p
805
Capacitor, ceramic
C1
33p
805
Capacitor, ceramic
U2
93C46
SO-8
e2prom, 1kB
C3
100n
805
Capacitor, ceramic
C4
100n
805
Capacitor, ceramic
R2
100R....1kW
805
Resistor, 1%
L1
Active
LED3MM
3mm green
S2
DOWN
SW_PB_SMALL
Micro switch, push to make
S3
ENTER
SW_PB_SMALL
Micro switch, push to make
JP4
HEADER 3
SIP3
3 pin SIP pins
J1
Holder
SIP8
8 pin SIP socket
SK1
ISP
SIP6
6 pin SIP pins
JP1
L
SIP14
14 pin SIP pins
SK3
Opto Out
2PIN_MOLEX
2 Pin Molex, Centre square pin, Friction lock
JP3
Out Select
SIP3
3 pin SIP pins
U1
PIC 16F876-20/SO
SOL-28
Micro-controller
Q1
PNP
SOT-23
Any Si PNP, e.g. SMBT3906
JP2
R
SIP14
14 pin SIP pins
Micro switch, push to make
S4
RESET
SW_PB_SMALL
L2
Reactive
LED3MM
3mm red
SK2
SPI Port
SIP8
8 pin SIP socket
S1
UP
SW_PB_SMALL
Micro switch, push to make
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sames
PM9607AP
PM9904BPD
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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 our web site:
http://www.sames.co.za.
SOUTH AFRICAN MICRO-ELECTRONIC
SYSTEMS (PTY) LTD
Tel: (012) 333-6021
Tel: Int +27 12 333-6021
Fax: (012) 333-8071
Fax: Int +27 12 333-8071
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REPUBLIC OF SOUTH AFRICA
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