TSA5059A

The TSA5059A is a single chip PLL frequency synthesizer designed for satellite tuning systems up to 2.7 GHz.

The RF preamplifier drives the 17-bit main divider enabling a step size equal to the comparison frequency, for an input frequency up to 2.3 GHz covering the complete satellite zero-IF frequency range. A fixed divide-by-two additional prescaler can be inserted between the preamplifier and the main divider for a frequency between 2.3 and 2.7 GHz. In this case, the step size is twice the comparison frequency.

The comparison frequency is obtained from an on-chip crystal oscillator that can also be driven from an external source. Either the crystal frequency or the comparison frequency can be switched to the XT/COMP output pin to drive the reference input of another synthesizer or the clock input of a digital emodulation IC.

Both divided and comparison frequency are compared into the fast phase detector which drives the charge pump. The loop amplifier is also on-chip, excepted an external NPN transistor to drive directly the 33 V tuning voltage.

Control data is entered via the I2C-bus; five serial bytes are required to address the device, select the main divider ratio, the reference divider ratio, program the four output ports, set the charge pump current, select the prescaler by two, select the signal to switch to the XT/COMP output pin and select a specific test mode. Three of the four output ports can also be used as input ports and a 5-level ADC is provided. Digital information concerning the input ports and the ADC can be read out of the TSA5059A on the SDA line (one status byte) during a READ operation. A flag is set when the loop is 'in-lock' and is read during a READ operation, as well as the Power-on reset flag. The device has four programmable addresses, programmed by applying a specific voltage at pin AS, enabling the use of multiple synthesizers in the same system.