LMX2370TMX

Clock Generators, PLLs, Frequency Synthesizers Overview

The LMX2370 is a monolithic dual frequency synthesizer designed for RF personal communications. It integrates two phase-locked loops with selectable dual modulus prescalers (Main: 32/33 or 16/17; Aux: 16/17 or 8/9). The Main PLL operates up to 2.5 GHz, while the Auxiliary PLL supports frequencies up to 1.2 GHz. It features a low voltage MICROWIRE interface compatible with 1.8V baseband processors and offers selectable charge pump currents of 1.0 mA or 4.0 mA. The device operates on a single supply ranging from 2.7V to 5.5V, consuming typically 6.0 mA at 3V.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Dual independent phase-locked loops with integrated dual modulus prescalers for main and auxiliary synthesizers
• Low voltage MICROWIRE serial interface allowing programming with baseband controllers operating down to 1.8V
• FastLock mode capability that increases charge pump current fourfold to accelerate loop locking without stability loss
• Configurable lock detect output and multiplexed multifunction pin for status monitoring

Clock Generators, PLLs, Frequency Synthesizers Applications

• First and second local oscillators in dual mode or dual conversion transceivers
• Portable wireless communication systems including PCS, PCN, and cordless phones
• Spread spectrum communication systems such as CDMA
• Cable TV tuners requiring stable UHF and VHF signal generation

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify package availability as the component is offered in multiple formats including 24-pad PLGA, 24-pad TCSP, and 20-pin TSSOP. Confirm specific ordering suffixes match the required physical footprint and lead configuration for your PCB layout. Ensure ESD precautions are maintained during handling due to the sensitivity of the MOS gates within the BiCMOS process.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select the LMX2370 when a compact dual-synthesizer solution is needed for mobile applications. Choose this part over single-loop alternatives if space constraints prevent using two separate devices. Verify that the required input frequencies align with the prescaler limits, specifically ensuring the main input does not exceed 2.5 GHz and the auxiliary input remains within its designated range based on the selected modulo.

Clock Generators, PLLs, Frequency Synthesizers Part Context

The LMX2370 belongs to the PLLatinum family of dual frequency synthesizers manufactured by Texas Instruments. It shares architectural similarities with the LMX2371 and LMX2372, differing primarily in prescaler configurations and maximum operating frequencies. These devices utilize TI's 0.5um ABiCV silicon BiCMOS process to achieve low noise performance and high integration levels suitable for portable electronics.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

The LMX2371 serves as a direct functional replacement with identical specifications. The LMX2372 offers similar functionality but may require verification of prescaler compatibility. Check datasheet revisions to ensure register maps and timing parameters remain consistent across substitutions.