DESCRIPTION
However, it does contain a ROM in which the codes that have to be transmitted are stored. The oscillator frequency may be optionally chosen as 432KHz. For 432KHz additional external capacitors must be connected. When a key in the key-matrix is pressed a driveline will be connected to a sense line. This causes the oscillator to start and a corresponding code will be generated conforming to the RC5 protocol. Seven drive lines ( DR0 to DR6 ) and eight sense lines (SN0 to SN7) may be connected via the key matrix to scan the keys. When two or more keys are activated simultaneously no transmission will take place. FEATURES
SOP-20-300-1.27 SOP-20-375-1.27 * Power-down and key wake-up * High output current ( 45mA) * Oscillator frequency of 432KHz * Multiple key protection * Option of 25% or 33% duty factor * RC5 protocol * Maximum of 56 keys (20-pin version) * Option of multi-system or single system transmitter -- Multi-system: maximum 8 system, selection by key -- Single system: maximum 8 different systems per IC, selection by jumper wire or switch.