LTC6603

The LTC^®6603 is a dual, matched, programmable lowpass fi lter for communications receivers and transmitters. The
selectivity of the LTC6603, combined with its linear phase, phase matching and dynamic range, make it suitable for
fi ltering in many communications systems. With 1.5°phase matching between channels, the LTC6603 can be used in applications requiring pairs of matched fi lters, such as transceiver I and Q channels. Furthermore, the differential inputs and outputs provide a simple interface for most communications systems.

The sampled data fi lter does not require an external clock yet its cutoff frequency can be set with a single external resistor with an accuracy of 3.5% or better. The external resistor programs an internal oscillator whose frequency is divided prior to being applied to the fi lter networks.

This allows up to three cutoff frequencies that can be obtained for each external resistor value, allowing the cutoff frequency to be programmed over a range of more than six octaves. Alternatively, the cutoff frequency can be set with an external clock. The fi lter gain can also be programmed to 1, 2, 4 or 16.

The LTC6603 features a low power shutdown mode that can be programmed through the serial interface and is available in a 24-pin 4mm × 4mm QFN package.