900MHz Image-Reject Receivers with Transmit Mixer
DescriptionThe MAX2424/MAX2426 highly integrated front-end ICs provide the lowest cost solution for cordless and ISM-band radios operating in the 900MHz band. Both devices incorporate a receive image-reject mixer (to reduce filter cost) as well as a versatile transmit mixer. The devices operate from a +2.7V to +4.8V single power supply, allowing direct connection to a 3-cell battery stack.
The receive path incorporates an adjustable-gain LNA and an image-reject downconverter with 35dB image suppression. These features yield excellent combined downconverter noise figure (4dB) and high linearity with an input third-order intercept point (IIP3) of up to +2dBm.
The transmitter consists of a double-balanced mixer and a power amplifier (PA) predriver that produces up to 0dBm (in some applications serving as the final power stage). It can be used in a variety of configurations, including BPSK modulation, direct VCO modulation, and transmitter upconversion. For devices featuring transmit as well as receive image rejection, refer to the MAX2420/MAX2421/MAX2422/MAX2460/MAX2463 data sheet.
The MAX2424/MAX2426 have an on-chip local oscillator (LO), requiring only an external varactor-tuned LC tank for operation. The integrated divide-by-64/65 dual-modulus prescaler can also be set to a direct mode, in which it acts as an LO buffer amplifier. Four separate power-down inputs can be used for system power management, including a 0.5µA shutdown mode.
The MAX2424/MAX2426 come in a 28-pin SSOP package.
- Receive Mixer with 35dB Image Rejection
- Adjustable-Gain LNA
- Up to +2dBm Combined Receiver Input IP3
- 4dB Combined Receiver Noise Figure
- Optimized for Common Receiver IF Frequencies:
- 10.7MHz (MAX2424)
- 70MHz (MAX2426)
- PA Predriver Provides up to 0dBm
- Low Current Consumption:
- 23mA Receive
- 20mA Transmit
- 9.5mA Oscillator
- 0.5µA Shutdown Mode
- Operates from Single +2.7V to +4.8V Supply
- Cordless Phones
- Spread-Spectrum Communications
- Two-Way Paging
- Wireless Networks
- Wireless Telemetry
|Device||Fab Process||Technology||Sample size||Rejects||FIT at 25°C||FIT at 55°C||Material Composition|
- 925MHz to 2175MHz Frequency Range
- Monolithic VCO
- High Dynamic Range: -75dBm to 0dBm