GPS/GNSS Front-End Amplifier
Dual-Stage, Low-Noise Amplifier Solution Includes Gain-Step Control
说明The MAX2678 GPS/GNSS front-end amplifier IC is designed for automotive and marine GPS/GNSS satellite navigation antenna modules, or for any application that needs to compensate for cable losses from the antenna to receiver. Two unconditionally stable low-noise amplifier stages provide the high gain and integrated I/O matching to minimize the need for external matching components and eliminate the need for additional gain stages. The IC features the option to place a bandpass ceramic or surface acoustic wave (SAW) filter between the two amplifier stages for improved immunity to out-of-band interferers. Additionally, a 3.4dB-gain step is provided to compensate for cable loss variation between different applications.
The device is designed to operate across all GNSS frequency standards with a 35dB typical cascaded gain and a 25mA supply current. The two LNA stages allow the use of a wide range of GNSS filter types for maximum flexibility in system design. The final RF output pin, which drives the cable to the GNSS receiver, is also the power-supply connection that accepts a DC supply in the 3.0V to 5.25V range. Alternatively, the DC supply can be applied to pin 4.
This GPS/GNSS front-end amplifier is available in a lead-free, 10-pin TDFN surface-mount package (3mm × 3mm). Electrical performance is guaranteed over the extended -40°C to +105°C temperature range.
- First Amplifier Noise Figure: 0.9dB
- High Gain:* 35dB
- 3.4dB Gain Step
- Shared VCC and RFOUT2 Pin
- Integrated 50Ω Output Matching
- AMP 2 includes 50Ω Input Matching
- 3.0V to 5.25V Supply Voltage Range
- Small (3mm × 3mm) Low-Cost Package
- AEC-Q100 Qualified
- ESD Protected to ±2kV Human Body Model
- -40°C to +105°C Ambient Temperature Range
*First amplifier input is impedance matched (S11 = -10dB).
Second amplifier is set to high gain. Amplifiers are cascaded without interstage filter.
|Part Number||RF Freq.|
(mm x mm)
|MAX2678||1575||1575||1||34.8||-12||5||25||3.0 x 3.0|
- 925MHz to 2175MHz Frequency Range
- Monolithic VCO
- High Dynamic Range: -75dBm to 0dBm