Linear Technology announces the LTC5548, a double balanced mixer that operates either as an up- or downconverter with an exceptionally wide frequency range from 2 GHz to 14 GHz. The LTC5548 features integrated balun transformers at the RF and LO ports, providing 50 Ω match from 2 GHz to 13.6 GHz and from 1 GHz to 12 GHz at each port, respectively, while enabling single-ended operation. Additionally, the IF port is capable of DC to 6 GHz, supporting wideband transmitters and receivers at the baseband. The LTC5548 has high linearity of 24.4 dBm IIP3 at 5.8 GHz, and 21.4 dBm at 9 GHz.
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| The LTC5548 Typical Application. |
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| Conversion Loss and IIP3 (Low Side LO, IF = 240 MHz). |
The LTC5548 simplifies microwave transmitter and receiver designs with its integrated LO buffer, requiring only a 0 dBm drive, effectively eliminating an external high power LO amplifier circuit. Moreover, the LTC5548 has a selectable on-chip LO frequency doubler, enabling the device to use lower cost, commonly available low frequency synthesizers. The LTC5548 mixer features exceptional port-to-port isolation, minimizing undesirable LO leakage, easing external filtering requirements.
The LTC5548’s performance is ideal for a wide range of microwave applications, including broadband microwave backhaul, the emerging 5.8 GHz unlicensed band and 14 GHz LTE-Advanced broadband wireless services, satellite broadband transceivers, radar systems, X-band and Ku band transceivers, spectrum analyzers, RF test equipment and satellite modems.
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| Demonstration circuit 2461A is optimized for evaluation of the LTC5548. |
The LTC5548 has exceptionally robust ESD handling capability of 2,000 V ESD human body model (HBM) rating on all pins. The device comes in a tiny 12-lead 3 mm × 2 mm plastic QFN package, providing a compact solution footprint, requiring minimal external components. The device is rated for operation from –40 °C to 105 °C case temperature. The mixer is powered from a single 3.3 V supply, drawing a nominal supply current of 120 mA. Additionally, the LTC5548 has an enable pin to shut down the IC. When deactivated, the device draws only 100 μA maximum standby current. The enable pin can be driven directly to turn the device on and off rapidly in less than 0.2 μs, supporting time-division duplex (TDD) or burst mode type radios. The LTC5548 is priced starting at $9.50 each in 1,000-piece quantities. Samples and production quantities are available immediately.
Summary of Features: LTC5548
- Operating RF Frequency: 2 GHz to 14 GHz
- Up- or Downconversion
- IF Frequency Range: DC to 6 GHz
- High Input IP3:
- 24.4 dBm at 5.8 GHz
- 21.4 dBm at 9 GHz
- Low Conversion Loss: 7.1 dB at 5.8 GHz
- SSB Noise Figure: 8 dB
- Low LO Drive Level: 0 dBm
- Integrated Bypassable LO Frequency Doubler
