TSA5521

` Complete 1.3 GHz single chip system
` Four PNP band switch buffers (40 mA)
` 33 V output tuning voltage
` In-lock detector
` 15-bit programmable divider
` Programmable reference divider ratio (512, 640 or 1024)
` Programmable charge-pump current (60 or 280 mA)
` Varicap drive disable
` Universal bus protocol I2C-bus or 3-wire bus (the TSA5520/TSA5521 I2C-bus mode only includes the write mode; if both read and write modes are required the TSA5526/TSA5527 devices should be selected):
bus protocol for 18 or 19 bits transmission (3-wire bus)
extra protocol for 27 bits for test and features (3-wire bus)
address plus 4 data bytes transmission (I2C-bus)
three independent I2C-bus addresses
` Low power and low radiation.

The TSA5521 is a single-chip PLL frequency synthesizer designed for TV and VCR tuning systems. The circuit
consists of a divide-by-eight prescaler with its own preamplifier, a 15-bit programmable divider, a crystal
oscillator and its programmable reference divider and a phase/frequency detector combined with a charge-pump
which drives the tuning amplifier and the 33 V output. Four high-current PNP band switch buffers are provided
for band switching. Two PNP buffers can be switched on simultaneously. The sum of the collector currents is limited
to 50 mA.