SC2268

SC2268 SILAN | Alldatasheet

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/G3 HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD /G3 Rev: 1.0 2000.12.31/G3 REMOTE CONTROL ENCODER

DESCRIPTION

The SC2268 is a remote control encoder utilizing CMOS Technology specially designed for use with the SC2128. Using a special coding technique, SC2268 increases noise immunity to a very great extent. It is housed in 16-Pins DIP Package and has a maximum of eight input channels. Its high performance features makes SC2268 a must in every fan and other electrical home appliance remote control application.

FEATURES

• CMOS Technology * Low power consumption * Very high noise immunity * Wide range of operating voltage: Vcc=2.2 ~ 5.0 Volts * Transmits signals to a maximum of 8 channels * Start word custom code options available

APPLICATIONS

• Fan remote control * Air cleaner * Humidifier * Heater /G3 DIP-16 /G3 /G3 /G3/G3

ORDERING INFORMATION

Custom Cord C3=1SC2268 Custom Cord C3=0 /G3 PIN CONFIGURATION BLOCK DIAGRAM SC2268 Vcc OSCI OSCO Tx OUT Vss Key input scanning and sampling OSC Timing circuit Encoder 12 11 10 Output Waveform Generator 16 9 OSCI OSCO C4 C5 C6 Tx OUT Vcc Vss

/G3 HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD /G3 Rev: 1.0 2000.12.31/G3 ABSOLUTE MAXIMUM RATINGS Characteristic Symbol Value Unit Supply Voltage V CC 0~6 . 0 V Input/Output Voltage V IN/VOUT Vss-0.2V ~ VCC +0.3V V Power Dissipation P D 500 mW Operating Temperature Topr -20 ~ +70 °C Storage Temperature Tstg -55 ~ +125 °C ELECTRICAL CHARACTERISTICS(Tamb=0 ~ 70°C,VCC -VSS =3 – 10%V,Unless otherwise specified) Parameter Symbol Test conditions Min Typ Max Unit Operating Voltage V CC -- 2.2 3 5 V Operating Current(note) I OP OSC On, TxOUT is floating. -- 0.5 1 mA Standy-by Current I SB I1 ~ I8 = “L” OSC Stops. TxOUT is floating. 0.5 1 3 mA VOL =2.2V, VDD =3V 8 15 --Sinking Current of TxOUT I SINK VOL =1.5V, VDD =3V 4 6 -- mA High Level V IH -- 0.7V CC -- V CCInput Voltage of I1 ~I8 Low level V IL -- 0 -- 0.3V CC V Input Pull-Low Resistor R L -- 30 50 80 kW Input Pull-High Resistor R H -- 40 90 150 kW Oscillation frequency f OSC -- -- 455 -- kHz Note: For pins I1 ~ I8 : Any one of the said pins is set to HIGH while the others are set to LOW. PIN DESCRIPTION Pin No. Symbol I/O Function 1~8 I1 ~ I8 I Key input pins. These pins are used to connect a maximum of 8 keys. (each pin has a built-in pull-low resistor). 9 Vss -- Negative power supply. 11~12 C4~C5 I Select input pin for start word. These pins have internal pull-low resistor. 10 C6 I Select input pin for start word. This pins have internal pull-high resistor.

13 TxOUT O

Transmission output pin. This pin is an open drain (NMOS) output and is used to transmit signals. The carrier frequency is 38kHz.

15 OSCI I Oscillator Input Pin

14 OSCO O Oscillator Outpu Pin

These pins are used to externally connect a 455kHz ceramic resonator. 16 Vcc -- Positive power supply.

/G3 HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD /G3 Rev: 1.0 2000.12.31/G3 FUNCTIONAL DESCRIPTION 1. KEY INPUT Up to eight keys can be directly connected to pins I1 ~ I8. Please refer to the diagram right. Furthermore, SC2268 has a buit-in pull-low resistor of about 60K ~ 110K W which reduces the need for external components. SC2268 Vcc 2. OSCILLATOR An oscillation circuit can be constructed using the CMOS inverter and Built-in Feedback resistor, 455kHz crystal and two 220pf capacitors. The carrier frequency is 38kHz. Unless any of the 8 keys (I1~I8) is being operated, the oscillation is automatically stopped. Thus, power consumption is considerably reduced. OSCI 455kHz OSCO 220pf 220pf SC2268 15 14 3. TRANMISSION WAVEFORM When any of the 8 keys (I1 ~ I8) is set to “High”, the TxOUT outputs one start word followed by 2 identical data words and a space. The code will be continuously outputted until the key is released. If for any reason, the key was released during the code transmission process, the code that is being transmitted during the key release action will still be completely outputted. Please refer to the following diagram. Start Word Data Word Data Word Space Start Word Data Word Data Word Space Start Word Data Word Data Word Space 20ms 80ms

1 Frame = 80ms

I1 ~ I8 Tx OUT *OSC = 455kHz

/G3 HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD /G3 Rev: 1.0 2000.12.31/G3 4. TRANSMISSION CODE WAVEFORM The transmission waveforms of the Start Word and the different Data Words generated when a specific input key (I1~I8) is pressed are illustrated below (see also Transmission Code Pattern Sectioon): CLK start X 3X X=0.625ms 5. TRANSMISSION CODE PATTERN The transmission code pattern of SC2268 is given in the table below. L S B M S B Transmission C0 C1 C2 C3 C4 C5 C6 C7 Receiver S t a r t w o r d 0011001 1 B0 B1 B2 B3 B4 B5 B6 B7 D a t a W o r d W 1 ( I 1 ) 0011101 0 0 / p 1 (Key pressed) W2 (I2) 0 1 0 1 1 0 0 0 0/p2 W 3 ( I 3 ) 0110001 0 0 / p 3 W 4 ( I 4 ) 1001110 0 0 / p 4 W 5 ( I 5 ) 1010011 0 0 / p 5 W 6 ( I 6 ) 1011000 1 0 / p 6 W 7 ( I 7 ) 1100010 1 0 / p 7 W 8 ( I 8 ) 1101001 0 0 / p 8

/G3 HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD /G3 Rev: 1.0 2000.12.31/G3 6. START WORD CUSTOM CODE The start word custom code has the following format:

001 C 3 1 C4 C5 C6

Where: C3 = 1 (default value) = bonding option available C4 = “0” when floating or connected to Vss = “1” when connected to Vcc C5 = “0” when floating or connected to Vss = “1” when connected to Vcc C6 = “0” when connected to Vss = “1” when floating or connected to Vcc Note: C4 and C5 have internal pull-low resistors while C6 has an internal pull-high resistor. The start word custom code table is given below : C3=0 C3=1(default) C4 C5 C6 Custom Code (C0 to C7) Custom Code (C0 to C7) 0 0 0 00100001 00110001 0 0 1 00100011 00110011 0 1 0 00100101 00110101 0 1 1 00100111 00110111 1 0 0 00101001 00111001 1 0 1 00101011 00111011 1 1 0 00101101 00111101 1 1 1 00101111 00111111 OPERATION FLOW CHART Power on Stand by Key press? Enable oscillator Debounce Code correct? One frame code transmit Key released? No Yes No Yes No Yes

/G3 HANGZHOU SILAN MICROELECTRONICS JOINT-STOCK CO.,LTD /G3 Rev: 1.0 2000.12.31/G3 APPLICATION CIRCUIT SC2268 Vcc OSCI OSCO Tx OUT Vss IR LED 10 Ω 1kΩ 220pf 47µf* 455kHz 220pf battery Note: Please take note that C3(default value)=1. For more details, please refer to Start Word Custom Cord Section. * Place 47uf capacitor as near as possible to the SC2268 Vss pin. PACKAGE OUTLINE DIP-16-300-2.54 UNIT:mm 6.40 2.54 3.51 5.083.30 7.62 0.25 15 degree 0.46 19.4 1.50