Silan
Semiconductors
FUNCTIONAL DESCRIPTION
1. CONTROL KEYS
SC2128A
Up to seven function keys – SPEED, MODE, TIMER, SW1, SW2, LIGHT and OFF/MEMS – may be used on
the control panel of fan to access SC2128A to its full versatility. OFF/MEMS key input pin serves further as buzzer
output BUZZ pin. All key inputs are internally pulled-high in SC2128A.
SPEED key controls the fan speed. TIMER key adjusts off-timer. MODE key sets fan into various modes of
operation. SW1 and SW2 keys control the head swing of fan. LIGHT key toggles the LIT output ON and OFF.
OFF/MEMS key resets the fan to idle state when fan is ON. It starts fan into memory mode if pressed when fan is
OFF, provided memory option is enabled. LIT output is not affected by OFF key.
2. SPEED KEY
SPEED key is used to (1) turn on the fan (2) change speed of the fan. OFF/MEMS may also be used to turn on
the fan into memory mode, provided memory mode is enabled. SLEEP key my turn on the fan from remote
control handset. All the other keys can NOT turn on the fan. All the other keys, except LIGHT key, can NOT
operate until fan is turned on. The diagram shows the state transition of SC2128A for successive pressing of
SPEED key.
S
ED
PE
KE
Y
MI start
LO=Z
MI=L
ST=Z
EE
SP
D
KE
Y
MID
LO=L
MI=Z
ST=Z
SPEED KEY
E
SP
ED
K
EY
OFF
LO=Z
MI=Z
ST=Z
LOW
LO=L
MI=Z
ST=Z
Z=high impedence
L=low voltage
SPEED KEY
D
EE
SP
STR
LO=L
MI=Z
ST=Z
Y
KE
not middle wind start-up optioned
3. TIMER KEY
TIMER key is used to set time schedule after which SC2128A will automatically restore off
state(off-timer). When the fan is on, pressing TIMER key sets up the off-timer. Each pressing of TIMER
key increases the timer by one step. Each time increment step is determined by various timer options.
Either 0.5 or 1 hour per step may be selected, and either 3 levels or 4 levels timer may be selected.
Please see TIMER section for details.
HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD
Rev: 1.0
2000.12.31
6
SILAN [ SILAN MICROELECTRONICS JOINT-STOCK ]
