3.6V, 1W RF Power Transistors for 900MHz Applications

The MAX2601/MAX2602 are RF power transistors optimized for use in portable cellular and wireless equipment that operates from three NiCd/NiMH cells or one Li-Ion cell. These transistors deliver 1W of RF power from a 3.6V supply with efficiency of 58% when biased for constant-envelope applications (e.g., FM or FSK). For NADC (IS-54) operation, they deliver 29dBm with -28dBc ACPR from a 4.8V supply.

The MAX2601 is a high-performance silicon bipolar RF power transistor. The MAX2602 includes a high-performance silicon bipolar RF power transistor, and a biasing diode that matches the thermal and process characteristics of the power transistor. This diode is used to create a bias network that accurately controls the power transistor’s collector current as the temperature changes.

The MAX2601/MAX2602 can be used as the final stage in a discrete or module power amplifier. Silicon bipolar technology eliminates the need for voltage inverters and sequencing circuitry, as required by GaAsFET power amplifiers. Furthermore, a drain switch is not required to turn off the MAX2601/MAX2602. This increases operating time in two ways: it allows lower system end-of-life battery voltage, and it eliminates the wasted power from a drain-switch device.

The MAX2601/MAX2602 are available in thermally enhanced, 8-pin SO packages, which are screened to the extended temperature range (-40°C to +85°C).

Applications

* 915MHz ISM Transmitters * AMPS Cellular Phones * CDPD Modems * Digital Cellular Phones * Land Mobile Radios * Microcellular GSM (Power Class 5) * Narrow-Band PCS (NPCS) * Two-Way Paging

* Low Voltage: Operates from 1 Li-Ion or 3 NiCd/NiMH Batteries

* DC-to-Microwave Operating Range

* 1W Output Power at 900MHz

* On-Chip Diode for Accurate Biasing (MAX2602)

* Low-Cost Silicon Bipolar Technology

* Does Not Require Negative Bias or Supply Switch

* High Efficiency: 58%