Overview
The LMX2522LQ1635/NOPB is a highly integrated frequency synthesizer system developed by Texas Instruments. This device is optimized for Korean PCS (K-PCS) and Korean Cellular (K-Cellular) with GPS, as well as CDMA (1xRTT, IS-95) mobile handsets. It incorporates a proprietary digital phase-locked loop technique to generate stable, low-noise local oscillator signals for up and down conversion in wireless communications devices.
Key Specifications
| Parameter | Symbol | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| Supply Voltage | VCC, VDD | 2.7 | 3.3 | 3.6 | V |
| Ambient Temperature | TA | -30 | 25 | 85 | °C |
| Total Supply Current | ICC + IDD | 17 | 19 | mA | |
| RF PLL Total Supply Current | ICC + IDD | 16 | 18 | mA | |
| Power Down Current | IPD | 20 | µA | ||
| Reference Oscillator Input Frequency | fOSCin | 19.20 | 19.68 | MHz | |
| RF VCO Frequency Range | fRFout | 1619.62 | 1649.62 | MHz | |
| RF Output Power | pRFout | -9 | -6 | -3 | dBm |
| Lock Time | 500 | 800 | µs | ||
| Phase Noise @100 kHz offset | L(f) | -113 | -112 | dBc/Hz |
Key Features
- Integrated RF and GPS VCOs: The device includes both RF and GPS voltage-controlled oscillators (VCOs) for comprehensive frequency synthesis.
- Fractional-N RF PLL: Based on an 11-bit delta sigma modulator, this feature supports 10 kHz channel spacing and fast lock times.
- Integer-N IF PLL: Includes a 4-level programmable charge pump for flexible loop filter designs.
- Low Spurious and Phase Noise: Offers low spurious and phase noise characteristics, enhancing signal quality.
- Programmable Frequencies: Supports various reference oscillator frequencies and programmable charge pump current levels.
- Small Form Factor: Available in a small 5.0 mm x 5.0 mm x 0.75 mm 28-Pin WQFN package.
- MICROWIRE Interface: Uses a three-signal MICROWIRE serial interface for programming the device.
- Power Down Mode: Reduces power consumption by powering down the RF and IF circuitry individually or together.
Applications
- Korean PCS (K-PCS) and Korean Cellular (K-Cellular): Optimized for these wireless communication standards with GPS support.
- CDMA (1xRTT, IS-95) Mobile Handsets: Suitable for use in CDMA mobile handsets requiring stable and low-noise local oscillator signals.
- GPS Systems: Integrated GPS VCO supports GPS applications, ensuring accurate and stable frequency synthesis.
- Wireless Communications Devices: General use in various wireless communication devices requiring high-performance frequency synthesizers.
Q & A
- What is the primary function of the LMX2522LQ1635/NOPB?
The primary function is to generate stable, low-noise local oscillator signals for up and down conversion in wireless communications devices.
- What types of wireless communication standards is the LMX2522LQ1635/NOPB optimized for?
It is optimized for Korean PCS (K-PCS), Korean Cellular (K-Cellular) with GPS, and CDMA (1xRTT, IS-95) mobile handsets.
- What is the package type and size of the LMX2522LQ1635/NOPB?
The device is available in a 5.0 mm x 5.0 mm x 0.75 mm 28-Pin WQFN package.
- What is the typical supply voltage range for the LMX2522LQ1635/NOPB?
The typical supply voltage range is 2.7 V to 3.6 V.
- How does the device support power management?
The device includes a power down mode that can reduce power consumption by powering down the RF and IF circuitry individually or together.
- What is the lock time for the RF PLL in the LMX2522LQ1635/NOPB?
The lock time for the RF PLL is typically between 500 µs and 800 µs.
- What is the phase noise performance of the LMX2522LQ1635/NOPB at a 100 kHz offset?
The phase noise at a 100 kHz offset is typically -113 dBc/Hz.
- How is the device programmed?
The device is programmed via a MICROWIRE serial interface using three signal pins: CLK, DATA, and LE.
- What are the key components integrated into the LMX2522LQ1635/NOPB?
The device includes integrated RF and GPS VCOs, a fractional-N RF PLL, an integer-N IF PLL, and a loop filter.
- What are the supported reference oscillator frequencies?
The device supports reference oscillator frequencies of 19.20 MHz and 19.68 MHz.
