ETC FIC98648

an ISO9001 company
TECHNICAL INFORMATION FOR FIC98648
Technical Information for FIC98648--microprocessor for
use with TGS4160 in automatic CO2 monitors
The FIC98648 is a microprocessor
for handling signals from the
TGS4160 carbon dioxide sensor.
This microprocessor enables
maintenance-free automation of
the air quality control in buildings
when connected with appliances
such as ventilation fans, air
cleaning systems, etc.
Page
Introduction.........................................................................................2
Features................................................................................................2
Basic Function...............................................................................................3
Pin Arrangement...........................................................................................3
Pin Functions
Pins for the initial setting of operational conditions....................................3
Gas sensor signal Vg input .........................................................................5
Internal thermistor signal VT input ...........................................................5
Bias signal output......................................................................................5
Manual benchmark reset signal input........................................................5
Sensor signal output....................................................................................5
LED display signal output..........................................................................6
Malfunction signal output.........................................................................6
Benchmark renewal status signal output........................................................6
Line test mode...........................................................................................7
Electrical Circuits for FIC98648........................................................................7
Hardware Specifications....................................................................................12
IMPORTANT NOTE: OPERATING CONDITIONS IN WHICH FIGARO SENSORS ARE USED WILL VARY
WITH EACH CUSTOMER’S SPECIFIC APPLICATIONS. FIGARO STRONGLY RECOMMENDS
CONSULTING OUR TECHNICAL STAFF BEFORE DEPLOYING FIGARO SENSORS IN YOUR APPLICATION
AND, IN PARTICULAR, WHEN CUSTOMER’S TARGET GASES ARE NOT LISTED HEREIN. FIGARO
CANNOT ASSUME ANY RESPONSIBILITY FOR ANY USE OF ITS SENSORS IN A PRODUCT OR
APPLICATION FOR WHICH SENSOR HAS NOT BEEN SPECIFICALLY TESTED BY FIGARO.
Revised 08/03
1
TECHNICAL INFORMATION FOR FIC98648
Introduction
The FIC98648 is a microprocessor for handling signals
from the TGS4160 carbon dioxide sensor, enabling
maintenance-free automation of air quality control
in buildings when connected with appliances such
as ventilation fans, air cleaning systems, etc.
The microprocessor takes in the output voltage, or
electromotive force (EMF), from the TGS4160 sensor
and outputs a signal which corresponds to a
concentration of CO2 in the environment. CO2
concentrations are calculated in the microprocessor
based on ∆EMF, which is the change in the value of
EMF from the value in a normal clean environment.
The microprocessor also contains software to
compensate the sensor ’s signal for changes in
temperature and basic environmental factors.
1. Features
1-1 Automatic calibration
The FIC98648 uses the concept of a benchmark value
of EMF in order to provide automatic calibration. The
1
XOUT
benchmark value is assumed to be equal to the level
of CO2 which exists in ambient air (approx. 400ppm).
CO2 concentrations are calculated periodically by
determining the change of EMF from the benchmark
level (∆EMF). In order to offset the effects of sensor
signal drift which are caused by environmental
temperature and air contaminants, the microprocessor automatically renews the benchmark level
to the current EMF value whenever a lower CO2
concentration than the current benchmark is
calculated. Using this method of automatic calibration, very stable characteristics can be expected for
the sensor, allowing for reliable monitoring of CO2
levels and long term maintenance-free ventilation
control.
1-2 High CO2 sensitivity and wide detectable range of
400~3000ppm
By programming the microprocessor to take into
consideration the unique performance characteristics
of the TGS4160, reliable readings of CO2 concentrations within a wide range (400~3000ppm) can be
achieved, satisfying the requirements of building
ventilation control applications.
VDD
28
X-TAL
Input port for +4.4V
Input port for manual
benchmark reset
2 XIN
KEO 27
Input port for
microprocessor reset
3 RESET
R92
26
Output port for benchmark
renewal status signal
Input port for
test mode
4 R70
R91
25
Output port for CO2
concentration signal
Input port for +4.4V
5 R71
R90
24
Output port for
bias signal
Input port for +3.8V
6 VAREF
R83
23
GND
Gas sensor signal
input port
7 AIN0
R82
22
GND
Thermistor signal
input port
8 AIN1
R81
21
GND
Input port for damper
control thresholds
9 AIN2
R80
20
GND
Input port for setting
warm up period
10
R43
R63
19
Output port for green LED
Input port for setting
benchmark renewal (VL)
11
R50
R62
18
Output port for red LED
Input port for setting
benchmark renewal (TK)
12
R51
R61
17
Output port for malfunction signal
Input port for automatic
benchmark reset (Tr)
13
R52
R60
16
Output port for damper
control signal
14
VSS
R53
15
GND
GND
Figure 1 - Pin arrangement for FIC98648
Revised 08/03
2
TECHNICAL INFORMATION FOR FIC98648
1-3 Two output signals
FIC98648 generates two separate output signals:
a) For calculating CO2 concentrations, a pulse width
modulated (PWM) signal is output.
b) An On/Off signal is generated as a control signal
for devices such as ventilation fans, dampers, etc.
4-1 Pins for the initial setting of operational conditions
To optimize sensor performance, the following pins
are provided for setting operational conditions at the
time of power-on. No change can be made to
operational conditions after the initial setting without
powering off and then repowering the device.
Notes:
1) The microprocessor is designed to assume the
highest value of EMF reading is representative of
400ppm of CO2 (ambient air levels). As a result, an
accurate reading cannot be expected if the sensor is
used in an environment where CO2 constantly exists
at higher concentrations than can be found in a
normal clean environment.
2) This device is not suitable for usage in life saving
equipment.
4-1-1 Input signal for setting the sensor’s initial warmup time (Pin No. 10)
Initial warm-up time, which is necessary to stabilize
the sensor’s output signal after an unpowered period,
is set by input of a signal to port R43 (see Table 2).
No signal can be taken from the microprocessor’s
output ports during initial warm-up time.
2. Basic Functions
2-1 Initial setting of operational conditions
In order to achieve optimal performance of the sensor,
manual preset of operational conditions is provided.
2-2 Automatic operation
Once power is supplied, an initial warm-up timer is
activated. When the initial warm-up time is finished,
the microprocessor will automatically begin
operation and commence generating the two output
signals mentioned above.
2-3 Line test
The microprocessor has the ability to perform a line
test for checking the functionality of the
microprocessor and the surrounding circuits. This
allows users to eliminate tool testing which is
normally done on the production line after assembly.
3. Pin Arrangement
Pin arrangement of FIC98648 is shown in Figure 1.
4. Pin Functions
The basic pin functions of FIC98648 are shown in
Table 1 (shown on Page 4).
Revised 08/03
Signal Input
Setting
Initial warm-up
time (T1)
"H"
"L"
30 minutes
120 minutes
Table 2 - Initial warm-up time setting (AM-4 default = "L")
4-1-2 Input signals VL and TK for benchmark adjustment
(Pins No. 11 and 12)
The benchmark level is normally set at the lowest
value of the sensor’s signal (Vg), which is considered
as 400ppm of CO2 (ambient levels). The benchmark
level Vg is renewed whenever a lower signal voltage
than the present benchmark level is read from the
sensor (as described in Sec. 1-Automatic calibration).
If the benchmark level Vg is not renewed for a preset period of time (TK), it is automatically adjusted
upward by a pre-set voltage (VL) which corresponds
to an equivalent concentration of CO2. Table 3 shows
the user-determined settings for VL and TK which
can be selected by applying a signal to Ports R50 and
R51 respectively.
Terminal
Signal input
Setting
Symbol
Pin No.
"H"
"L"
Benchmark
adjustment level
(V L )
R50
11
5ppm
equivalent
20ppm
equivalent
Benchmark
adjustment time
(TK)
R51
12
1 day
7 days
Table 3 - Benchmark adjustment level and timer setting
(AM-4 default = 20ppm equiv. and 1 day)
3
TECHNICAL INFORMATION FOR FIC98648
Terminal
Category
Power
Pin
No.
Power supply
VDD
28
Connect to +4.4V power supply
Ground
VSS
14
Connect to ground
Reference voltage
VAREF
6
Connect to 3.8V power supply (Reference voltage for A/D
converter)
Reset
RESET
3
Microprocessor reset when "L" is input for one machine
cycle or longer
XIN
2
XOUT
1
Initial warm-up time
R43
10
Benchmark adjustment
level (VL)
R50
11
Benchmark adjustment
time (TK)
R51
12
Auto reset time
R52
13
Gas sensor signal (Vg)
AIN0
7
Input gas sensor signal (Vg)
See Sec. 4-2 - Gas sensor signal Vg input
Thermistor signal (VT)
AIN1
8
Thermistor signal (VT) for temperature compensation circuit
See Sec. 4-3 - Internal thermistor signal VT input
Control signal threshold
AIN2
9
Calibration of CO2 levels for damper control
See Sec. 4-1-4 - Input signal for damper control
Manual benchmark
reset
KEO
27
See Sec. 4-5 - Manual benchmark reset signal input
Bias signal
R90
24
See Sec. 4-4 - Bias signal output
Damper control signal
R60
16
See Sec. 4-6-2 - Damper control signal output
CO2 concentration
signal
R91
25
See Sec. 4-6-1 - PWM signal output for CO2 concentration
Green LED
R63
19
See Sec. 4-7 - LED display signal output
Red LED
R62
18
See Sec. 4-7 - LED display signal output
Test mode (Input)
R70
4
See Sec. 4-10 - Line test mode
Malfunction (Output)
R61
17
See Sec. 4-8 - Malfunction signal output
Benchmark renewal
status (Output)
R92
26
See Sec. 4-9 - Benchmark renewal status signal output
Microprocessor
control
Clock in
Clock out
Switch input
Signal output
Other
Connect to ceramic oscillator of 4.19MHz
(ports to internal clock circuit)
Input optional "H" or "L" signal
See Sec. 4-1 - Pins for initial setting of operation conditions
Settings
Analog signal
input
Functions
Symbol
Name
Table 1 - Pin functions of FIC98648
Revised 08/03
4
TECHNICAL INFORMATION FOR FIC98648
4-1-3 Input signal Tr for automatic benchmark reset (Pin
No. 13)
Whenever the benchmark level Vg has only been
adjusted (Sec. 4-1-2) and has not been renewed (Sec.
1-1) for a pre-set period of time (Tr), it should be automatically reset at the current output signal in ambient
air. Table 4 shows the time intervals (Tr) which can
be pre-set by applying a signal to Port R52.
Signal Input
Setting
Auto reset time
(Tr)
"H"
"L"
7 days
30 days
Table 4 - Auto reset timer setting (AM-4 default = 7 days)
4-1-4 Input signal for damper control (Pin No. 9)
Concentration levels of CO2 at which the damper
control signals are activated are selected by inputting
a voltage signal to port AIN2. Sensor output voltage
is first AD converted within the microprocessor. The
relationship between these AD converted values and
CO2 concentrations is shown in Table 5. Whenever a
CO2 concentration exceeds the threshold level for
opening the damper (Cd1), a low signal (L) is output
from port R60. A high signal (H) is output for closing
the damper when the CO2 concentration drops
beneath the Cd2 level. Figure 11 shows the circuit
for damper control signal threshold. Please note that
a high signal (H) is designed to be output during the
sensor’s initial warm-up period and also whenever
the malfunction signal is activated.
Signal input
Cd1 (ppm)
Cd2 (ppm)
0 - 48
800
720
49 - 96
1000
800
97 - 144
1500
1300
145 - 192
2000
1800
193 - 255
3000
2700
(AD converted: 0-255*)
Cd1: Threshold for OPEN signal
Cd2: Threshold for CLOSE signal
* 8-bit - Least significant byte=3.8V/256
output voltage is reversed, amplified and adjusted
(please refer to Figure 3, Sec. 4-4, and Sec. 5-1 for
details). The result of this process is a gas sensor signal
Vg with good resolution and which increases/
decreases as CO2 concentration increases/decreases.
This gas sensor signal Vg is input to port AIN0.
4-3 Internal thermistor signal VT input (Pin No. 8)
To compensate for the temperature dependency of
CO 2 sensor, a signal from the sensor ’s internal
thermistor (VT) is input to port AIN1. This thermistor
also monitors the sensor’s built-in heater from 30
minutes after powering and after. By detecting a
sharp drop in the sensor’s internal temperature
indicative of a broken heater, the thermistor can cause
a malfunction signal to be generated by the
microprocessor.
4-4 Bias signal output (Pin No. 24)
A PWM signal, of which the pulse width is variable,
is output from port R90. To optimize the resolution
of Vg readings, this signal is introduced to the
differential circuit after being converted to an analog
voltage, and adjusts the benchmark level Vg to fall
between 25 and 51 counts at AD converted value, or
0.38 ~ 0.75V at 3.8V full scale. The bias signal starts
from 128 counts (1.9V at 3.8V full scale) when the
power is switched on, and reduces the count stepwise
along with the sensor’s initial action until Vg falls
and then stabilizes at the above stated level.
4-5 Manual benchmark reset signal input (Pin No. 27)
The benchmark level can be reset manually at any
time by inputting an “L” pulse to port KEO. This
manual benchmark reset should be done in a clean
atmosphere where the CO2 concentration is about
400ppm (please refer to Sec. 5-6 - Benchmark reset
circuit).
Note: If the benchmark level is manually reset under
a high CO2 concentration environment, the device’s
sensitivity would be decreased and calculated CO2
concentration values would be less than the actual
concentration.
Table 5 - Thresholds for damper OPEN/CLOSE signal
4-2 Gas sensor signal Vg input (Pin No. 7)
Since the raw sensor output voltage (EMF) actually
decreases as CO2 concentration increases, the sensor’s
Revised 08/03
4-6 Sensor signal output
4-6-1 PWM signal output for CO2 concentration (Pin No. 25)
A PWM signal is output from port R91 to show CO2
5
TECHNICAL INFORMATION FOR FIC98648
concentration readings. The pulse width against a
cycle corresponds to the CO2 concentration as shown
in Figure 2. This pulse width is then converted to an
analog output voltage between 0 ~ 3V by the circuit
(please refer to Sec. 5-4 - CO2 concentration circuit).
4-6-2 Damper control signal output (Pin No. 16)
The output from port R60 is set to “H” under normal
conditions in a clean environment, indicating that the
damper should be closed. When a CO2 reading
exceeds the preset level of the Open Damper
Threshold (Cd1) as shown in Table 2, an “L” signal is
output from port R60 as a signal for opening the
damper. When CO2 drops below the preset level of
the Close Damper Threshold (Cd2), the output from
port R60 returns to an “H” signal for closing a
damper. “H” is also output from port R60 during
initial warm-up time and whenever a malfunction
signal is output.
4-7 LED display signal output (Pin Nos. 18 & 19)
The following LED display signals are output from
port R62 (red LED) and port R63 (green LED):
4-7-1 Initial warm-up time
During the initial warm-up period (see Sec. 4-1-1),
an alternating H/L signal is output from port R63
every 0.5 seconds, causing the green LED to alternate
between on and off every 0.5 seconds. “L” is output
continuously from R62 during this period.
4-7-2 Normal operation mode
When the CO2 concentration is lower than the preset
threshold level for the damper control (Cd1), “L” is
output from port R62 and “H” is output from the
R63, causing the green LED to be lit continuously.
Conversely, if the CO2 concentration is higher than
the preset threshold level for the damper control
(Cd1), “H” is output from port R62 and “L” is output
from port R63, causing the red LED to be lit
continuously.
4-7-3 Malfunction mode
When a malfunction has been detected (see Sec. 4-8),
an alternating H/L signal is output from port R62
every 0.5 seconds, causing the red LED to alternate
between on and off every 0.5 seconds. “L” is output
continuously from R63 during this period.
Revised 08/03
H
L
A
B
C
A: [(CO2 concentration) / 3000 ] x C
Approx. 65 msec.
B: C - [(CO2 concentration) / 3000] x C
C: approx. 65msec.
Figure 2 - PWM signal for CO2 concentration
4-8 Malfunction signal output (Pin No. 17)
An “H” signal is output from port R61 under normal
operation conditions. When a malfunction is detected on
the gas sensor’s heater and/or the benchmark level Vg,
an “L” signal is output from port R61. The following
conditions would generate a malfunction signal:
(a) Sensor heater breakage—when the thermistor’s
signal (VT) remains at a level equivalent to 50°C
or lower for over 10 seconds, the heater can be
considered to have malfunctioned. Monitoring of
this condition commences 30 minutes after
powering on.
(b) Benchmark level Vg malfunction—when the
benchmark level Vg (gas sensor’s signal) cannot
be adjusted in the range between 25 and 51 counts
at AD converted value within 10 minutes after
the adjustment is started, a malfunction is
considered to have occurred.
The relationship between signal output ports and
their output signals under malfunction mode can be
seen in Table 6.
Terminal
Signal
Indication
CO2 concentration
signal (R91)
“L” signal
0ppm
Damper control
signal (R60)
“H” signal
Close
Red LED (R62)
Alternate H/L signal
(0.5 sec./0.5 sec.)
On/Off
Green LED (R63)
“L” signal
Off
Bias signal (R90)
Hold the level
Off
Table 6 - Malfunction signal
4-9 Benchmark renewal status signal output (Pin No. 26)
When the benchmark level has been renewed, an “L”
signal is output from port R92 for one second to
indicate the status. An “H” signal is normally output
from this port.
6
TECHNICAL INFORMATION FOR FIC98648
4-10 Line test mode (Pin No. 4)
A line test mode can be activated by the input of an
“L” signal to port R70 at the moment of power supply.
Operation of the microprocessor and the surrounding
circuits will be tested according to the schedule
shown in Table 7. After powering on, signal outputs
change from Step 1 to Step 4 according to the table,
with Steps 1-3 lasting 5 seconds each. Afterwards,
Step 4 outputs will be maintained continuously until
the power is shut off.
Terminal
Signal Output
Name
Symbol
Pin No.
Step 1
Step 2
Step 3
Step 4
CO2 concentration
signal
R91
25
Cd1 (ppm)
Note *1
Cd1 (ppm)
Cd1 (ppm)
Cd1 (ppm)
Bias signal
Note *2
R90
24
0
255
128
128
Green LED
R63
19
L
H
(Note 3)
H
Red LED
R62
18
H
L
(Note 4)
H
Damper control
signal
R60
16
H
L
(Note 5)
H
Malfunction
R61
17
H
L
(Note 6)
H
Benchmark
renewal status
R92
26
H
L
H
H
Notes:
(1) Please refer to Sec. 4-1-4 - Input signal for damper control
(2) Please refer to Sec. 4-4 - Bias signal output
(3) H or L, as input to Pin #10 for initial warmup setting - refer to Sec. 4-1-1
(4) H or L, as input to Pin #11 for benchmark adjustment - refer to Sec. 4-1-2
(5) H or L, as input to Pin #12 for benchmark adjustment - refer to Sec. 4-1-2
(6) H or L, as input to Pin #13 for benchmark reset - refer to Sec. 4-1-3
(7) Outputs shown are held until power is shut off
Table 7 - Line test mode
5. Electrical Circuit for FIC98648
The following peripheral circuits are suggested when
using the FIC98648 with the TGS4160 sensor.
5-1 Circuit for driving sensor and for processing sensor signals
The block/circuit diagrams for driving the sensor and
processing its signals are shown in Figure 3 (below)
+3.8V
+5V
Thermistor
signal (VT)
Heater
voltage
(VH)
FIC98648
Sensor
voltage
(EMF)
Bias signal (PWM signal)
Convert to DC
and Figure 4 (Page 8) respectively. Please note the
following items:
a) +5.0V should be applied to Pin No. 6 for the heater
of TGS4160.
b) +3.8V is the specified voltage to sensor pin No. 5
for the built-in thermistor which is connected in
series with an 8.2kΩ resistor. Output voltage across
the 8.2kΩ resistor is designed to be input to port
4.5 times
Buffer +
amplification
circuit
circuit
10 times
Regulation
amplification +
circuit
circuit
Buffer
circuit
Figure 3 - Block diagram for driving sensor and processing sensor signal
Revised 08/03
7
TECHNICAL INFORMATION FOR FIC98648
FIC98648
AIN0
10k
7
10µ
104
+5V
+3. 8V
TLC271CP 8
3
6
5
2
3
7
220k
22k
6
9
10
4
LM324N
SENSOR
AIN1
8
2
30k
4
1
R90
8.2k
10k
24
47k
30k
10k 100p
103
+ 4.4V
8
6
7
100k
5
1M
104
LM324N
1m
Figure 4 - Circuit for driving sensor and processing sensor signal
AIN1 (Pin No. 8) as a thermistor signal for the
temperature compensation circuit.
c) As a first stage, the sensor’s output (pin No. 3),
which is of very high impedance, should be
amplified by 4.5 times with a high impedance
(100MΩ or higher) operational amplifier, such as
Texas Instrument’s Model No. TLC271. This
amplified signal is designed to be further amplified
by ten times in the second stage. The output from
the amplifier is input into port AIN0 (Pin No. 7)
after being adjusted by a regulator (differential
circuit) with a bias signal.
5-2 Power supply circuit
As illustrated in Figure 5, the circuit is designed to
be operated by +5V. The sensor’s heater, which
requires a large current, is powered directly by +5V.
The microprocessor is powered by +4.4V (downstream from a diode). A diode is connected between
the power supply and the microprocessor to protect
the microprocessor from a surge current. Taking the
saturation voltage of the operational amplifiers into
consideration, the analog reference voltage (VAREF)
is set at +3.8V. Voltage is provided downstream from
another diode.
FIC98648
+4.4V
+5V
1SS176
28
+3.8V
1SS176
6
5V
103
104
220 µ
6. 2V
220 µ
VDD
VAREF
2. 2k
14
VSS
Figure 5 - Power supply circuit
Revised 08/03
8
TECHNICAL INFORMATION FOR FIC98648
5-3 System reset circuit
Under normal operating conditions, an “H” signal is
continuously applied to the RESET port (Pin #3).
When an “L” signal is applied to the RESET port for
a period of one machine cycle or longer, the internal
logic circuit of FIC98648 and the micro-processor’s
program return to the same condition which exists
just after powering on the unit, effectively resetting
the system.
+4.4V
FIC98648
2SA1015Y
28
VDD
1k
104
3
RESET
3.9k
4. 7 k
103
14
To perform the above described system reset function
automatically, a circuit such as that shown in Figure
6 is suggested. This kind of automatic system reset
circuit is useful in circumstances such as just after
powering on, after a momentary power interruption,
at the moment of recovery after a sudden drop of
voltage, etc. The microprocessor’s program sometimes does not run correctly in these cases due to a
malfunction of the internal logic circuit in the
processor. Manual resets help to assure normal
operation of the microprocessor’s program.
Figure 6 - Reset circuit
DC. A delay of several seconds is anticipated in the
DC voltage concentration signal because a C-R
combination is used in the circuit. A 100Ω resistor is
connected in series to protect the external circuit from
excessive current.
5-5 Circuit for damper control signal
Figure 8 shows an example circuit in which an H/L
signal which is output from port R60 (Pin No. 16)
and converted to an On/Off signal for controlling
the opening/closing of a damper. A 100Ω resistor is
connected in series to protect the external circuit from
excessive current.
5-4 CO2 concentration signal circuit
Port 91 (Pin No. 25) outputs a PWM signal which
represents a CO2 concentration in the range between
400 and 3000ppm. Figure 7 illustrates a sample circuit
for converting a PWM signal to a linear output of 0~3V
1M
FIC98648
2
10k
R91
VSS
1
25
1M
22k
3
100
10µ LM 324N
Analog output (0~3V)
for CO2 concentration
6.2V
Figure 7 - CO2 concentration signal circuit
10k
FIC98648
R60
2SA1015Y
16
100
1k
Damper control signal
10k
6. 2V
Figure 8 - Damper control circuit
Revised 08/03
9
TECHNICAL INFORMATION FOR FIC98648
5-6 Circuit for manual benchmark reset
A circuit designed to allow for manual benchmark
reset is shown in Figure 9.
+4.4V
FIC98648
10k
27
KEO
Figure 9 - Manual benchmark reset circuit
5-7 Circuit for clock signal generator
When a ceramic oscillator is connected with the
clock in and out ports, Xin and Xout (Pins No. 2
and 1 respectively), a clock signal is activated in
FIC98648 by a built-in clock signal generator. A
sample circuit for connecting such an oscillator is
shown in Figure 10. Murata Electronics model
CST4.19MGW is a well-matched ceramic oscillator
for FIC98648. Before using a different oscillator,
please consult with Figaro or the oscillator
manufacturer.
FIC98648
XIN
XOUT
2
1
CST4. 19 MGW
Figure 10 - Clock signal generator circuit
+3. 8V
5-8 Circuit for damper control signal threshold
A recommended circuit design for setting the damper
control signal threshold can be seen in Figure 11.
1k
JP
5-9 Sample circuit of damper control with TGS4160 and
FIC98648
A sample application circuit for damper control when
using a TGS4160 CO 2 sensor and a FIC98648
microprocessor is shown in Figure 12. Please refer to
Technical Information for AM-4 for details.
4. 3k
JP
10k
JP
24k
JP
100k
FIC98648
9
AIN2
10k
103
Figure 11 - Damper control signal threshold circuit
Revised 08/03
10
Revised 08/03
2
CN1
B2B-XH-A
0V
5V
1
R6
C14
104
C13
C1
104 220m
ZD1
6.2V
D1
1SS176
C2
220m
JP8
R2
4.7k
R1
1k
R4
2.2k
C5
103
R3
4.7k
C3
103
2SA1015Y
Q1
C4
104
D2 1SS176
R13
100k
JP7
R14
10k
R16 10k
R12
24k
R7 R8
R15 10k
R11
10k
JP6
JP1 JP2 JP3 JP4
R5
10k ~4
R24(8/8)
10k
LED2
LED1
R24(2/8) 10k
R10
4.3k
SW1
SKHHAJ
R19 750
JP5
R9
1k
R24(1/8)
10k
R18 470
2
X1
CST4.19MGW
14
3
28
6
13
12
11
10
9
5
4
26
17
27
18
19
FIC98648
(IC4 TMP47C243N)
1
15
23
16
25
R27
47k
24
8
7
20
21
22
5
R35
8.2k
1
C15
104
3
R20
10k
3
C6
10m
5
6
R37
30k
2
5
3
2
C16
104
IC2 1/4
LM324N
ZD3
6.2V
3
2
1
11
0V
14
IC2 4/4
4
CN2
B3B-XH-A
R23 100
12
13
104
C12
IC2 3/4
8
R40 220k
R21 100
ZD2
6.2V
1
R26 1M
IC2 2/4
7
C7
1m
9
R39
22k 10
R45
100k
6
C11 104
VR1
30k
C9
100p
4
8 7
IC3
93LC468
8
Sensor pins 2,5 : thermistor
"
"
1,6 : heater
"
"
3,4 : sensor
2SA1015Y
Q2
R43 10k
1
2
R36
10k
4
4
3
TLC271CP
IC1
R24(7/8)
10k
R22 1M
R24(4/8)
10k
R25
1M
R24(4/8)
10k
R44 1k
R28
22k
C8
103
2
6
R50 10k
SENSOR1
C10
10m
R24(5/8)
10k
R24(6/8)
10k
TECHNICAL INFORMATION FOR FIC98648
Figure 12 - Application circuit
11
TECHNICAL INFORMATION FOR FIC98648
*8-bit successive approximate type A/D converter
with sample and hold
- 8 analog inputs
- Conversion time: 24µs (at 8MHz)
*Serial Interface with 8-bit buffer
- Simultaneous transmission and reception
capability
- 8/4-bit transfer, external/internal clock, and
leading/trailing edge shift mode
*Zero-cross detector (and external interrupt handler)
*Pulse output
- Buzzer drive/Remocon carrier
*High current outputs
- LED direct drive capacity: typ. 20mA x 8 bits
(Ports R5, R6)
*Reset function
- Watchdog timer reset
*Hold function
- Battery/Capacitor back-up
6. Hardware Specifications
6-1 Features
*4-bit single chip microcomputer
*Instruction execution time: 1.0µs (at 8MHz)
*Low voltage operation: 2.2V (at 4.2MHz)
*Basic instructions: 92
- ROM table look-up instructions
- 5-bit to 8-bit data conversion instruction
*Subroutine nesting: 15 levels maximum
*6 interrupt sources (External: 2, Internal: 4)
- All sources each have independent latches, and
multiple interrupt control is available
*I/O port (23 pins)
*Two 12-bit Timer/Counters
- Timer, event counter, and pulse width measurement mode
*Interval Timer
*Emulation pod: BM47C443
6-2 DC characteristics (see Table 8)
Parameter
Symbol
Pins
Conditions
Min.
Typ.
Max.
Unit
Hysteresis
voltage
VHS
Hysteresis input
-
-
0.7
-
V
IIN1
RESET, HOLD
VDD = 5.5V, VIN = 5.5V/0V
-
-
IIN2
Open drain ports
±2
µA
Input
resistance
RIN
RESET
-
100
220
450
kΩ
Output
leakage
current
ILO
Open drain
output ports
VDD = 5.5 V, VOUT = 5.5 V
-
-
2
µA
Output low
voltage
Ports
R4, R7, R8, R9
VDD = 4.5V, IOL = 1.6mA
-
-
0.4
VOL
VDD = 2.2V, IOL = 20µA
-
-
0.1
Output low
current
IOL
Ports R5, R6
VDD = 4.5V, VOL = 1.0V
7
20
-
VDD = 5.5V, fc = 4MHz
-
2
4
VDD = 3.0V, fc = 4MHz
-
1
2
VDD = 3.0V, fc = 400kHz
-
0.5
1
VDD = 5.5V
-
0.5
10
Input
current
Supply
current
(NORMAL
operating
mode)
IDD
Supply
current
(HOLD
operating
mode)
IDDH
-
-
V
mA
mA
µA
Table 8 - DC characteristics
(Vss = 0, Topr = -30~+70˚C)
Revised 08/03
12
TECHNICAL INFORMATION FOR FIC98648
6-3 A/D conversion characteristics (Table 9)
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Unit
Analog reference voltage
VAREF
(Mask option)
VDD - 1.5
-
VDD
V
Analog reference
voltage range
∆VAREF
VAREF - Vss
2.7
-
-
V
Analog input voltage
VAIN
-
Vss
-
VDD
V
Analog supply current
IREF
-
-
0.5
1.0
mA
-
-
±1
-
-
±1
-
-
±1
-
-
±2
Nonlinearity error
Zero point error
-
Full scale error
VDD = 2.7 ~5.5V
VAREF = VDD ± 0.001V
Vss = 0.000V
Total error
LSB
Table 9 - A/D conversion characteristics
(Topr = -30~+70˚C)
6-4 AC characteristics (Table 10)
Parameter
Instruction Cycle Time
High level clock pulse width
Low level clock pulse width
Symbol
tcy
tWCH
tWCL
Condition
Min.
VDD = 2.7~5.5V
1.0
VDD = 2.2~5.5V
1.9
in RC oscillation
3.2
For external
clock
(XIN input)
VDD≥2.7V
60
VDD<2.7V
120
VDD≥2.7V
60
VDD<2.7V
120
Typ.
Max.
Unit
-
20
µs
-
-
ns
A/D Conversion Time
tADC
-
-
24tcy
-
A/D Sampling Time
tAIN
-
-
2tcy
-
Shift data Hold Time
tSDH
-
0.5tcy-300
-
-
µs
ns
Table 9 - A/D conversion characteristics
(Vss = 0, Topr = -30~+70˚C)
Revised 08/03
13
TECHNICAL INFORMATION FOR FIC98648
6-5 Dimensions
Dimensions of FIC98648 are shown in Figure 13.
15
1
14
0.25
+0.1
-0.05
10.16
8.8±0.2
0-15˚
28
26.1 Max.
1.243 Typ
1.0±0.1
0.46±0.1
0.18
3.0±0.3
3.8±0.3
0.3 Min.
3.3±0.2
25.6 ± 0.2
M
1.778
Figure 13 - Dimensions of FIC98648
Figaro Engineering Inc. (Figaro) reserves the right to
make changes without notice to any products herein
to improve reliability, functioning or design.
Information contained in this document is believed
to be reliable. However, Figaro does not assume any
liability arising out of the application or use of any
product or circuit described herein; neither does it
convey any license under its patent rights, nor the
rights of others.
Figaro's products are not authorized for use as critical
components in life support applications wherein a
failure or malfunction of the products may result in
injury or threat to life.
FIGARO GROUP
Revised 08/03
HEAD OFFICE
OVERSEAS
Figaro Engineering Inc.
1-5-11 Senba-nishi
Mino, Osaka 562 JAPAN
Tel.: (81) 72-728-2561
Fax: (81) 72-728-0467
email: [email protected]
Figaro USA Inc.
3703 West Lake Ave. Suite 203
Glenview, IL 60025 USA
Tel.: (1) 847-832-1701
Fax.: (1) 847-832-1705
email: [email protected]
14