LMX3305  Product Folder

The LMX3305 contains three Phase Locked Loops (PLL) on a single chip. It has a RF PLL, an IF Rx PLL and an IF Tx PLL for CDMA applications. The RF fractional-N PLL uses a 16/17/20/21 quadruple modulus prescaler for PCS application and a 8/9/12/13 quadruple modulus prescaler for cellular application. Both quadruple modulus prescalers offer modulo 1 through 16 fractional compensation circuitry. The RF fractional-N PLL can be programmed to operate from 800 MHz to 1400MHz in cellular band and 1200MHz to 2300 MHz in PCS band. The IF Rx PLL and the IF Tx PLL are integer-N frequency synthesizers that operate from 45 MHz to 600 MHz with 8/9 dual modulus prescalers. Serial data is transferred into the LMX3305 via a microwire interface (Clock, Data, & LE).

The RF PLL provides a fastlock feature allowing the loop bandwidth to be increased by 3X during initial lock-on.

The supply voltage of the LMX3305 ranges from 2.7V to 3.6V. It typically consumes 9 mA of supply current and is packaged in a 24-pin CSP package.

• Three PLLs integrated on a single chip
• RF PLL fractional-N counter
• 16/17/20/21 RF quadruple modulus prescaler for PCS application
• 8/9/12/13 RF quadruple modulus prescaler for cellular application
• 2.7V to 3.6V operation
• Low current consumption: I_CC = 9 mA (typ) at 3.0V
• Programmable or logical power down mode: I_CC = 10 µA (typ) at 3.0V
• RF PLL Fastlock feature with timeout counter
• Digital lock detect
• Microwire Interface with data preset
• 24-pin CSP package

• CDMA Cellular telephone systems