Overview
The LMX2522LQ1635 from Texas Instruments is a highly integrated, high-performance, low-power frequency synthesizer system. It is optimized for Korean PCS (K-PCS) with GPS and is designed to generate very stable, low-noise local oscillator signals for up and down conversion in wireless communications devices. This device utilizes a proprietary digital phase locked loop technique and includes a RF voltage-controlled oscillator (VCO), a GPS VCO, a loop filter, and a fractional-N RF PLL based on a delta sigma modulator.
Key Specifications
| Parameter | Conditions | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| RF VCO Frequency Range | - | 1619.62 | - | 1649.62 | MHz |
| RF Output Power | OB_CRL [1:0] = 11 | -2 | 1 | 4 | dBm |
| Lock Time | - | - | 500 | - | µs |
| Operating Frequency (IF PLL) | IF_FREQ [1:0] = 10 | 440.76 | - | - | MHz |
| Charge Pump Current (IF PLL) | IF_CUR [1:0] = 00 | 100 | - | 800 | µA |
| Supply Voltage | - | 2.7 | 2.8 | 3.3 | V |
| Current Consumption | - | - | 17 | - | mA |
| Package Type | - | - | - | - | 28-Pin WQFN |
Key Features
- Highly integrated frequency synthesizer system with RF VCO, GPS VCO, loop filter, and fractional-N RF PLL based on a delta sigma modulator.
- Supports Korean PCS band with GPS and CDMA (1xRTT, IS-95) mobile handsets.
- Low spurious, low phase noise performance.
- 10 kHz frequency resolution.
- Programmable charge pump current levels.
- Fast lock time of 500 µs.
- Integrated IF PLL with 4-level programmable charge pump.
- Supports various reference oscillator frequencies (e.g., 19.20/19.68 MHz).
- Small 5.0 mm x 5.0 mm x 0.75 mm 28-Pin WQFN package.
- Power down mode to reduce power consumption.
- MICROWIRE serial interface for programming.
Applications
- Korean PCS (K-PCS) mobile handsets.
- Korean Cellular (K-Cellular) with GPS.
- CDMA (1xRTT, IS-95) mobile handsets.
- GPS systems.
- Wireless communications devices requiring stable, low-noise local oscillator signals.
Q & A
- What is the primary function of the LMX2522LQ1635?
The LMX2522LQ1635 is a highly integrated frequency synthesizer system that generates stable, low-noise local oscillator signals for wireless communications devices.
- What frequency bands does the LMX2522LQ1635 support?
The LMX2522LQ1635 supports the Korean PCS band with GPS and CDMA (1xRTT, IS-95) mobile handsets.
- What is the typical current consumption of the LMX2522LQ1635?
The typical current consumption is 17 mA at 2.8 V.
- What is the package type of the LMX2522LQ1635?
The device is packaged in a 28-Pin WQFN (NJB) package.
- How is the device programmed?
The device is programmed via a three-wire MICROWIRE serial interface (DATA, LE, CLK).
- What is the lock time of the LMX2522LQ1635?
The lock time is typically 500 µs.
- Does the LMX2522LQ1635 have a power down mode?
Yes, the device includes a power down mode to reduce power consumption.
- What is the frequency resolution of the LMX2522LQ1635?
The frequency resolution is 10 kHz.
- What types of VCOs are integrated into the LMX2522LQ1635?
The device includes a RF VCO and a GPS VCO.
- What is the operating supply voltage range of the LMX2522LQ1635?
The operating supply voltage ranges from 2.7 V to 3.3 V.
