SAA3007

The SAA3007 transmitter IC for infrared remote control systems has a capacity for 1280 commands arranged in 20 subsystem address groups of 64 commands each.The subsystem address may be selected by press-button or slider switches, or be hard-wired.Commands are transmitted in patterns of pulses coded by the pulse spacing. The pulses can be infrared flashed (single pulse) or modulated. Flashed infrared transmissions require a wideband preamplifier at the receiver, but modulated transmissions allow a narrow band receiver to be used for improved noise rejection. The modulation frequency of the SAA3007 is 455 kHz which allows disturbance-free infrared operation in the presence of 10 -100 kHz fluorescent lamps.

The SAA3007 has the following features including:(1)flashed or modulated transmission modes; (2)immune from fluorescent lamp disturbance in modulated mode ; (3)supply voltage range 2 V to 6,5 V; (4)40 mA output current capability; (5)requires few additional components.When more than one connection is made to ADRM then all connections should be decoupled using diodes.Lines DRVON to DRV6N are driven by open drain N-channel transistors (conductive in standby mode).The sense lines go to P-channel pull-up transistors, so that they are HIGH until they are HIGH until they are pulled LOW by key contact with a driver line. This key operation initiates a code transmission.

The absolute maximum ratings of the SAA3007 are:(1)supply voltage range:-0.3 to +7V;(2)output voltage range:-0.3 to Vdd+0.3V;(3)power disspation:50mW; (4)storage temperature range:-20 to 120; (5)input voltage range:-0.3 to Vdd+0.3V.When a key is pressed the transmitter becomes active, 'pull-down' is switched off, 'pull-up' is switched on and the driver line signals are sensed for the subsystem address coding.The subsystem address is sensed only within the first scan cycle, whereas the command code is sensed in every scan.The transmitted subsystem address remains unchanged if the subsystem address selection is changed while the command key is pressed. A change of the subsystem address does not start a transmission.