The SP5510 is a single-chip frequency synthesiser designed for TV tuning systems. Control data is entered in the standard I2C BUS format. The device has four addressable currentlimited output ports (P0-P3) and four bi-directional opencollector ports (P4-P7), one of which (P6) is also a 3-bit 5-level ADC input. The information on these ports can be read via the I2C BUS. The SP5510S is a variant in a 16-lead miniature plastic package, without P0-P2 but functionally identical in other respects.