900MHz ISM-Band, 250mW Power Amplifiers with Analog or Digital Gain Control
DescriptionThe MAX2232/MAX2233 low-voltage, silicon RF power amplifiers (PAs) are designed for use in the 900MHz ISM band. They operate from a single +2.7V to +5.5V supply, allowing them to be powered directly from a 3-cell NiCd or a 1-cell Lithium-Ion battery. The devices typically deliver 250mW (+24dBm) of output power at 915MHz from a single +3.6V supply, or 150mW (+22dBm) from a single +2.7V supply. At +24dBm output power, power-added efficiency (PAE) is 44%.
The MAX2232/MAX2233 provide 24dB of gain, which is adjustable over a continuous 24dB span via the analog gain-control pin of the MAX2232 or in two 10dB steps via the 2-bit programmable gain-control DAC of the MAX2233. An external capacitor sets the RF output power envelope ramp time, reducing spurious emissions during power-up and power-down by providing a gradual change in output power (MAX2232).
The MAX2232/MAX2233 feature a low-power shutdown mode, which typically draws less than 1µA of supply current, saving power during "idle slots" in time-division multiple-access (TDMA) systems. The ΔVSWR of the RF input in shutdown mode relative to normal operation is 1.2:1. The devices also feature a thermal shutdown function, enabling the PA to protect itself from excessive temperature conditions that could damage the IC. A capacitor to ground limits thermal cycling by setting a thermal shutdown timeout period.
The MAX2232/MAX2233 are available in a space-saving, thermally enhanced 16-pin power-QSOP (PQSOP) package.
- 800MHz to 1000MHz Frequency Range
- 250mW (+24dBm) Output Power at 915MHz from +3.6V Supply
- +2.7V to +5.5V Single-Supply Operation
- 44% Power-Added Efficiency
- 24dB Power Gain
- 24dB Analog Gain-Control Range (MAX2232)
- Three Levels of Digitally Programmed Power Gain in 10dB Steps (MAX2233)
- Programmable RF Power Envelope Ramping (MAX2232)
- Thermal Shutdown
- Programmable Thermal Shutdown Timeout Period
- 0.2µA Low-Power Shutdown Mode
- Low ΔVSWR in Standby and Shutdown Modes
- 868MHz European ISM Band
- 900MHz ISM-Band Applications
- Digital Cordless Phones
- FM Analog Transmitters
- Wireless Data
|Efficiency (%)||Low Pwr. Shutdn||Footprint|
(mm x mm)
|MAX2232||800||1000||24||44||Yes||3.9 x 6.0|
|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