CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper I.C. Handling Procedures.
Copyright
Harris Corporation 1999
10-31
CA3228
Speed Control System with Memory
Description
The CA3228 is a monolithic integrated circuit designed as an
automotive speed-control system.
The system monitors vehicle speed and compares it to a
stored reference speed. Any deviation in vehicle speed
causes a servo mechanism to open or close the engine
throttle as required to eliminate the speed error. The refer-
ence speed, set by the driver, is stored in a 9-bit counter.
The reference speed can be altered by the ACCEL and
COAST driver commands. The ACCEL command causes
the vehicle to accelerate at a controlled rate; the COAST
command disables the servo, thereby forcing the vehicle to
slowdown. Application of the brake disables the servo and
places the system in the standby mode while the RESUME
command returns the vehicle to the last stored speed.
Vehicle speed and driver commands are inputs to the
integrated circuit via external sensors. Actuators are needed
to convert the output signals into the mechanical action
necessary to control vehicle speed.
The CA3228 is supplied in a 24 lead dual-in-line plastic
package (E suffix). Refer to AN7326 for application
information.
Features
Low Power Dissipation
I
2
L Control Logic
Power-On Reset
On-Chip Oscillator for System Time Reference
Single Input Line for Operator Commands
Amplitude Encoded Control Signals
Transient Compensated Input Commands
Controlled Acceleration Mode
Internal Redundant Brake and Low-Speed Disable
Braking Disable
Applications
Automotive Speed Control
Residential
and
Industrial
Heating
and
Cooling
Controls
Industrial AC and DC Motor Speed Control
Applications Requiring Acceleration and Deceleration
Control
File Number
1436.3
June 1999
Pinout
CA3228 (PDIP)
TOP VIEW
1
2
3
4
5
6
7
8
9
10
11
12
GND
NC
DRIVER COMMAND
COMMAND DELAY
OSCILLATOR
V MEMORY
CURRENT SENSE SPEED
SENSOR INPUT
F/V OUT
F/V FILTER
V
S
BRAKE INPUT
16
17
18
19
20
21
22
23
24
15
14
13
GND
VACUUM CONTROL
VENT CONTROL
CONTROL AMP+
CONTROL AMP OUTPUT
ALIGN
ACCELERATE CAPACITOR
ACCELERATE RESISTOR
V
CC
OUTPUT GATE
CONTROL AMP-
V ERROR
Ordering Information
PART
NUMBER
TEMPERATURE
PACKAGE
CA3228E
-40
o
C to +85
o
C
24 Lead Plastic DIP
OBSOLETE PR
ODUCT
NO RECOMMENDED REPLA
CEMENT
Call Central Applications 1-800-442-7747
or email: centapp@harris.com
10-32
Specifications CA3228
Absolute Maximum Ratings
Thermal Information
Supply Voltage, V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +9.0V
Supply Current, I
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30mA
Driver Command Input (I
CMD
), Pin 3 . . . . . . . . . . . . . . . . . . . . 2mA
Brake Input (I
BRAKE
), Pin 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . 2mA
Storage Temperature Range . . . . . . . . . . . . . . . . -65
o
C to +150
o
C
Maximum Junction Temperature. . . . . . . . . . . . . . . . . . . . .
+150
o
C
Thermal Resistance
JA
Plastic DIP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
o
C/W
Power Dissipation Per Package
For T
A
= -40
o
C to +70
o
C . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2mW
For T
A
Above +70
o
C . . . . . . . . . . . Derate Linearly at 15.4mW/
o
C
Lead Temperature (Soldering 10s) . . . . . . . . . . . . . . . . . . . +265
o
C
Operating Temperature Range . . . . . . . . . . . . . . . . -40
o
C to +85
o
C
CAUTION: Stresses above those listed in "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress only rating and operation
of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
Typical Switching Characteristics
Driver Command Input Hold Times (Based on 0.68
F on Pin 4):
ACCEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50ms
COAST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50ms
RESUME. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330ms
ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50ms
OFF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50ms
Internal Oscillator Frequency, F
OSC
. . . . . . . . . . . . . . . . . . . 10kHz
(Based on 0.001
F at Pin 5)
System Performance
F
OSC
= 50kHz, f
S
/Speed Ratio = 2.22Hz/mph
Speed Sensor Input Frequency Range, f
S
at Pin 8 . .62Hz to 222Hz
Speed Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.45 mph
Minimum Operating Speed. . . . . . . . . . . . . . . . . . . . . . . . . . 25 mph
Maximum Stored Speed . . . . . . . . . . . . . . . . . . . . . . . . . . 100 mph
Redundant Brake Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 mph
Electrical Specifications
T
A
= +25
o
C, V
CC
= 8.20V, Unless Otherwise Specified (Refer to Figures 2 and 3)
PARAMETERS
SYMBOLS
TEST PIN
TEST CONDITIONS
MIN
MAX
UNITS
Operating Voltage
V
CC
13
7.40
9.00
V
Speed Sensor Input Voltage Amplitude
T.P.B.
62Hz
f
S
222Hz
3.50
15.0
Vpp
V
CC
Supply Current
I
CC
13
7.50
30.0
mA
Current Sense Voltage
V
7
7
43k
to Ground
4.85
5.95
V
Align Voltage
V
17
17
41k
to Ground
4.00
4.20
V
Command Idle Voltage
V
3IDLE
3
S1, S2, S3, S4, S5
Open
7.6
7.9
V
RESUME Command Voltage
V
3RES
3
S2 Closed
5.95
6.56
V
ACCEL Command Voltage
V
3ACCEL
3
S3 Closed
3.95
4.91
V
COAST Command Voltage
V
3COAST
3
S4 Closed
1.22
2.23
V
OFF Voltage
V
3OFF
3
S5 Closed
0
0.77
V
ON Voltage
V
3ON
T.P.A.
S1 Closed
9.2
28
V
Brake Input Voltage
V
BRAKE
12
S6 Closed
5.4
28
V
OUTPUT VOTLAGE
Gate
V
OL
23
4.7k
to V
CC
-
300
mV
V
OH
8
-
V
VAC
V
OL
22
1.2k
to V
CC
-
400
mV
V
OH
8
-
V
VENT
V
OL
21
1.2k
to V
CC
-
400
mV
V
OH
8
-
V
10-35
CA3228
FIGURE 2. TYPICAL AUTOMOTIVE SPEED CONTROL APPLICATION
FIGURE 3. SOLENOID DRIVERS AND SERVO VACUUM CONTROL MECHANISM TYPICAL APPLICATION
SEE FIGURE 3
SWITCH
FUNCTION
VOLTAGE AT TERM. 3
RATIO TO V
CC
MIN
MAX
S1 - ON
1.12
-
S2 - RESUME
0.725
0.8
S3 - ACCEL
0.482
0.599
S4 - COAST
0.148
0.272
S5 - OFF
0
0.094
IDLE (Note 1)
0.93
0.96
NOTE: 1. All Switches Open
1M
10K
C
EXT
2.2
F
V
CC
10K
2.4M
R
EXT
10K
V
CC
VENT
VAC
GATE
+
2.2
F
0.001
F
0.68
F
0.047
F
150K
51K
10K
V
CC
43K
10K
0.1
F
RI
560
R2
10K
8.2K
0.05
F
T.P.A.
MOMENTARY
CONTACT
DRIVER
COMMAND
SWITCHES
S1
S2
S3
S4
S5
T.P.B.
V
BRAKE
ON
RESUME
SET/ACCEL
COAST
OFF
R3, 2.2K
R4,680
R5, 120
V
3
ON
SPEED INPUT
FREQUENCY, f
S
2.22 Hz/MPH
N
S
ALL RESISTANCE VALUES ARE IN OHMS
BRAKE LIGHT
BRAKE SWITCH
S6
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
CA3228E
CA3228E
(SEE FIGURE 2)
VALVE
SYSTEM MODE
ACCEL
CRUISE
COAST
VAC
Open
NC (Note 1)
NC
VENT
Close
Close (Note 1)
NC
NOTE:
1. Open or Closed as Required to Maintain Set Speed Error
ACCEL
CRUISE
COAST
BRAKE
REDUNDANT BRAKE
HI-SPEED DROPOUT
LO-SPEED DROPOUT
VAC (Pin 22)
H
L
L
L
L
L
L
VENT (Pin 21)
H
H
L
L
L
L
L
GATE (pin 23)
L
L
L
H
H
H
H
V
CC
VAC
VENT
GATE
0.22
F
+8.2V
1.2K
1.2K
4.7K
VOLT.
REG
620
0.5W
TO
AIR
+14.4V
N.O.
N.C.
VENT
VALVE
VAC
VALVE
TO VACUUM
SOURCE
DIAPHRAGM
VENT
SOLENOID
VACUUM
SOLENOID
TO THROTTLE
POSITON
FEED BACK
(OPTIONAL
TO PIN 20)
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