GENERAL DESCRIPTION
SM3502 is a Fan Controller CMOS IC that
can be applied to a variety of consumer
products. SM3502 has three wind modes;
normal, rhythm and sleep-rhythm wind.
Four kinds of timer setting and one swing
head control or light control.
Memory function is available; the Speed,
Mode, Swing functions will operate as last
state in memory type. If the last state is
Sleep mode, press SPEED key enable fan
controller while memory functions will be
returned to the last state before Sleep Mode
operation.
FEATURES
* High performance CMOS technology.
* Four types of timer setting:
Ladder adder (1/2-1-2-4hrs)
Non-ladder adder (1-2-4-8hrs)
* One swing head control or light control.
* SPEED key can enable fan controller.
* 18 pin plastic DIP package.
* 455KHz oscillator.
APPLICATIONS
* Electronic Fan
* Heater Fan
* Air-Cleaner
* Dehumidifier
* Humidifier
* Kitchen Exhaust
* Dish Dryer
* Wall Fan
PIN ASSIGNMENTS
Page 1
LTO
VSS
OSC1
OSC2
BUZ
VDD
LOW
MEDIUM
STRONG
LIGHT
DI
OFF
TIMER
SPEED
MODE
COM1
COM2
COM3
SM3502-A 18PIN
1
18
2
17
3
16
4
15
5
14
6
13
7
12
8
11
9
10
SM3502
S
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Microelectronics Corp.
FAN CONTROLLER
V.1.0
VSS
OSC1
OSC2
BUZ
VDD
LOW
MEDIUM
STRONG
SHO
DI
OFF
TIMER
SPEED
MODE
COM1
COM2
COM3
SWING
SM3502-B 18PIN
1
18
2
17
3
16
4
15
5
14
6
13
7
12
8
11
9
10
Page 2
PANEL DISPLAY
SM3502
V.1.0
ON/SPEED
S
M
L
TIMER
4HR
2HR
1HR
1/2HR
OFF
MODE
NOR
SLP-RHY
RHY
SW/LIGHT
SHO/LTO
BLOCK DIAGRAM
BUZZER
SWING/LIGHT
CONTROL
OSCILLATOR
REMOTE CONTROL DECODER
SYSTEM TIMING GENERATOR
ZERO_CROSS
FAN FUNCTIONS CONTROL
SPEED/MODE/TIMER/MEMORY
SHO LTO
SWING
OSC2
OSC1
MODE
TIMER
SPEED
OFF
BUZ
COM1
COM2
VDD
VSS
DI
KEY INPUT
LED OUTPUT
SCAN_SIGNAL
LIGHT
COM3
ROM
TIMER
SPEED
OUTPUT
DRIVER
STRONG
MEDIUM
LOW
(8HR)
(4HR)
(2HR)
(1HR)
SM3502
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Microelectronics Corp.
FAN CONTROLLER
Page 3
PIN DESCRIPTIONS
13
14
15
16
17
18
19
20
No.
1
2
3
4
5
6
7
8
9
10
11
12
Pin Name
LIGHT
DI
OFF
TIMER
SPEED
MODE
COM1
COM2
COM3
SWING
I / O
I
I
I/O
I/O
I/O
I/O
O
O
O
I
Function
Light control input
Remote control input
Off function control input
Timer setting input
Wind grade selection input
Wind mode selection input
LED scanning common pin / Customer code
LED scanning common pin / Customer code
LED scanning common pin
Swing head control input / Customer code
SHO
STRONG
MEDIUM
LOW
VDD
BUZ
OSC2
OSC1
VSS
LTO
O
O
O
O
POWER
O
O
I
POWER
O
Swing head / tuner pulse output
Wind speed control output
Wind speed control output
Wind speed control output
Positive power supply
Trigger output to drive piezo
Crystal output
Crystal input
Negative power supply (Substrate)
Light control output
V.1.0
SM3502
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Microelectronics Corp.
FAN CONTROLLER
FUNCTION DESCRIPTION
SM3502 has FIVE control signal operations :
* Start-up by SPEED key
a. function turn off (OFF key)
b. wind mode selection (MODE key)
c. start-up function and wind speed selection(SPEED key)
d. timer setting (TIMER key)
e. swing head or light control (SW or LIGHT Key)
Only SPEED key can enable the fan controller, except for the light control. Wind mode, timer and
swing head inputs can not be accepted when fa
by timer and OFF key inputs.
When more than one key are pressed, controller will not accept the multi-key's control signal, if the
panel keys are pressed more than six seconds, controller will generate a " BI-BI-BI-BI" warning sound.
When fan is enabled by SPEED key, the initial state of fan controller is as follows:
* Memory function available
If Fan controller is OFF on sleep mode, all memory functions will be returned to the LAST STATE
BEFORE SLEEP MDOE operation.
a. Grade as last state but with starting medium wind for three seconds
b. The wind mode as last state except sleep mode
c. Swing function as last state
d. Timer setting off
e. Light is independent
Page 4
V.1.0
A. OFF KEY
When fan controller is on, press the OFF key, fan functions will be off except light output.
B. SPEED KEY
When fan control is off, press SPEED key, fan is turned on, initial state is LOW wind; when
memory function is available, the wind grade will operate as last state. Both conditions have
three seconds starting wind. Press the SPEED key again, the wind will be changed as
follows :
SPEED key used
Pulse is put into OFF pin
OFF LOW MEDIUM
STRONG
SM3502
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Microelectronics Corp.
FAN CONTROLLER
Page 5
C. MODE KEY
SM3502 has three types of wind mode: normal, rhythm, sleep + rhythm. Memory function is
available except on sleep mode.
1. OFF
SLP-RHY
RHY
NOR
: Press MODE key: normal setting
: Pulse is put into OFF pin
: SPEED key used
V.1.0
D. LIGHTING CONTROL KEY
The LIGHT key is independent and the output is toggle function. When the LIGHT key is
pressed on panel, operation is as follows :
: Press LIGHT key
OFF
Light output key
E. SWING KEY:
The swing key will not activate when fan controller is off. Memory function is available, the
swing output will operate as last state when press SPEED.
OFF
SHO enable
(Right / Left)
The SW key pressed
SM3502
S
AM
H
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Microelectronics Corp.
FAN CONTROLLER
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