MC145173 Overview
Key Features
- linear transfer functions (no dead zones)
- An external crystal ties across on–chip circuitry which drives a completely–programmable reference counter
- Thus, a broad range of tuning resolution is possible
- The crystal oscillator is buffered and fed to an open–drain output which is active in the HF mode only
- The serial port is byte–oriented to facilitate control via an MCU
- Tuning across a band is accomplished with a two–byte transfer to the N register
- The 6–bit analog–to–digital converter (ADC) has two input channels
- The converter is read via a one–byte transfer which includes an end–of–conversion (EOC) bit
- A 22–stage frequency counter is provided and accepts two IF (intermediate frequency) signals
- Primary use for the frequency counter is for the seek or scan function on broadcast radio receivers
