20 dB gain block cover 20 MHz to 2 GHz

April 14, 2014 // By Jean-Pierre Joosting
The LTC6431-20, a 20 MHz to 2 GHz single-ended input and output fixed gain amplifier from Linear Technology offers 46.2 dBm OIP3 (Output Third Order Intercept) and 2.6 dB noise figure.

Its OP1dB (Output 1 dB Compression Point) is a best-in-class 22 dBm. Two grades are offered, including the A-grade version that is 100% tested and guaranteed to have a minimum of 42.2 dBm OIP3 at 240 MHz, and the B-grade version offering a typical OIP3 of 45.7 dBm at the same frequency. Both input and output are internally 50Ω matched from 20 MHz to 1.4 GHz, with a frequency response of 20 dB power gain and a flatness of better than 0.5 dB.

Internal 50Ω matching simplifies design and enables easy cascading, using minimum external components. Each amplifier needs only an input and output DC blocking capacitor, plus a choke to bias its open collector output.

Fabricated using an advanced SiGe BiCMOS process, the LTC6431-20 offers exceptionally stable performance, while tolerating power supply voltage variations and temperature changes. The device is specified for operation over a case temperature range from -40°C to 85°C.

The LTC6431-20 is ideal for amplifying IF and RF signals in low distortion transmitters or receivers at frequencies up to 1.5 GHz. It is also suitable for digital predistortion receivers whose performance depends on maintaining low distortion in the signal path. In addition, the amplifier is suitable for a wide range of broadband and narrowband radios that operate in the VHF/UHF bands such as broadcast radios, cable networks, white space data services, low-band LTE base station infrastructure and public safety radios.

The LTC6431-20 comes in a 4mm x 4mm QFN package. It is powered from a single 5 V supply at 93 mA supply current.