MAX7057
300MHz to 450MHz Frequency-Programmable ASK/FSK Transmitter
Transmit any Frequency in the 300MHz to 450MHz Band with One Crystal While Keeping Your Antenna Matched
Part Details
- Programmable Frequency Operation with Single Crystal
- Internal Variable Capacitor for Antenna Tuning with Single-Matching Network
- 100kbps Data Rate (NRZ)
- +2.1V to +3.6V Single-Supply Operation
- < 12.5mA (FSK), < 8.5mA (ASK) DC Current Drain
- < 1µA Standby Current
- ASK/FSK Modulation
- 47% Carrier Tuning Range Using One Crystal
The MAX7057 frequency-programmable UHF transmitter is designed to transmit ASK/FSK data at a wide range of frequencies from 300MHz to 450MHz. The MAX7057 has internal tuning capacitors at the output of the power amplifier that are programmable for matching to an antenna or load. This allows the user to change to a new frequency and match the antenna at the new frequency simultaneously. The MAX7057 transmits at a data rate up to 100kbps nonreturn-to-zero (NRZ) (50kbps Manchester coded). Typical transmitted power into a 50Ω load is +9.2dBm with a +2.7V supply. The device operates from +2.1V to +3.6V and typically draws under 12.5mA of current in FSK mode (8.5mA in ASK mode) when the antenna-matching network is designed to operate over the 315MHz to 433.92MHz frequency range. For narrower operating frequency ranges, the matching network can be redesigned to improve efficiency. The standby current is less than 1µA at room temperature.
The MAX7057 reference frequency from the crystal oscillator is multiplied by a fully integrated fractional-N phase-locked loop (PLL). The multiplying factor of the PLL is set by a 16-bit number, with 4 bits for integer and 12 bits for fraction; the multiplying factor can be anywhere between 19 and 28. The 12-bit fraction in the synthesizer sets a tuning resolution equal to the reference frequency divided by 4096; frequency deviation can be set as low as ±2kHz and as high as ±100kHz. The fractional-N synthesizer eliminates the problems associated with oscillator-pulling FSK signal generation. The MAX7057 has a serial peripheral interface (SPI) for selecting all the necessary settings.
The MAX7057 is available in a 16-pin SO package and is specified to operate in the -40°C to +125°C automotive temperature range.
Applications
- Gaming Machines
- Industrial Controllers
- System Monitoring
- White Goods
Documentation
Data Sheet 1
Reliability Data 1
Technical Articles 10
Evaluation Design File 1
This is the most up-to-date revision of the Data Sheet.
Hardware Ecosystem
| Parts | Product Life Cycle | Description |
|---|---|---|
| ISM RF Receivers < 1GHz 2 | ||
| MAX1473 | PRODUCTION | 315MHz/433MHz ASK Superheterodyne Receiver with Extended Dynamic Range |
| MAX1470 | PRODUCTION | 315MHz Low-Power, +3V Superheterodyne Receiver |
| ISM RF Transmitters < 1GHz 4 | ||
| MAX1479 | PRODUCTION | 300MHz to 450MHz Low-Power, Crystal-Based +10dBm ASK/FSK Transmitter |
| MAX7044 | PRODUCTION | 300MHz to 450MHz High-Efficiency, Crystal-Based +13dBm ASK Transmitter |
| MAX7058 | PRODUCTION | 315MHz/390MHz Dual-Frequency ASK Transmitter |
| MAX1472 | PRODUCTION | 300MHz-to-450MHz Low-Power, Crystal-Based ASK Transmitter |
Evaluation Kits
Evaluation Kit for the MAX7057
Resources
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