Linear announces active filters/ADC drivers

Linear Technology has introduced five single and dual, wide bandwidth low-pass active filter/ADC driver amplifier products for challenging filtering applications.

The range includes: the LTC6603 dual programmable 2.5MHz filter/ADC driver; the LTC6601-1 5MHz to 28MHz bandwidth low noise configurable 0.5 per cent tolerance filter/ADC driver; the LTC6605-7 dual matched 7MHz filter/ADC driver; the LTC6605-10 dual matched 10MHz filter/ADC driver; and the LTC6605-14 dual matched 14MHz filter/ADC driver.

The LTC6603 features a dual matched programmable 9th order switched capacitor linear-phase filter and ADC driver.

The filter's low-pass cut-off frequency up to 2.5MHz and its gain are adjustable via a serial SPI port, or can be fixed by pin-strapping.

Fine frequency control over a 100:1 frequency range can be implemented using an external DAC to vary the device's master reference clock.

The LTC6603's programmability, sharp filter roll-off frequency response, along with guaranteed phase and gain performance make it suitable as a baseband filter for I/Q demodulators in CDMA-2000, W-CDMA and LTE (long-term evolution) femto-cell basestations, repeaters, RFID readers, imaging, sonar scan receivers and a wide range of industrial signal processing instruments.

The LTC6603 comes in a 4mm x 4mm 24-lead QFN package.

The LTC6601-1 is a low noise 0.5 per cent tolerance low-pass active filter and ADC driver with configurable bandwidth from 5MHz to 28MHz.

The filter has a 2nd order linear phase Butterworth response.

It has differential inputs and outputs.

The filter's on-chip resistors and capacitors that form its cut-off frequency, Q (quality factor of a filter) and gain are laser trimmed at the factory to an absolute tolerance of 0.5 per cent typical.

These resistors and capacitors are pinned out, allowing users to pin strap wide combinations of filter response and gain.

Additionally, the amplifier's frequency response is also laser trimmed, resulting in an accurate and repeatable filter response from device to device.

Higher order filters can be attained by cascading multiple stages of the LTC6601-1.

Moreover, the amplifier has a robust output stage to directly drive many high sampling speed A/D converters.

Each filter comes in a 4mm x 4mm 20-lead QFN package.

The LTC6605-7, -10 and -14 are fixed frequency, 2nd order linear phase dual matched low-pass active filters with bandwidths of 7MHz, 10MHz and 14MHz respectively.

Each filter pair is tested and guaranteed to offer tight matching of phase and gain characteristics.

These filters are suitable for I/Q demodulator channel filtering in Wimax and broadband wireless access equipment including point-to-point microwave links.

The matched filter performance is also suitable for driving multi-channel signal processing and pre-filtering for high-speed ADCs.

The LTC6605 range comes in a 6mm x 3mm, 22-lead DFN package.

All filters in the range are available in C-grade specified for 0C to 70C, and I-grade specified for -40C to 85C operation.

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