LMX2572LP - 2GHz Low Power RF Synthesizer | Texas Instruments
MPN: LMX2572LP ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.5 | $12.50 |
| 10 | $11.25 | $112.50 |
| 100 | $10 | $1,000.00 |
| 500 | $9 | $4,500.00 |
| 1,000 | $8.1 | $8,100.00 |
LMX2572LP Overview
An RF synthesizer is a key building block in communication systems, generating precise local oscillator signals for frequency conversion. It typically consists of a phase-locked loop (PLL) with a voltage-controlled oscillator (VCO), frequency dividers, and a phase detector. The LMX2572LP integrates these functions, providing a complete frequency synthesis solution in a compact 40-pin VQFN package.
Key features include excellent phase noise of -124 dBc/Hz at 100-kHz offset with an 800-MHz carrier, a PLL figure of merit of -232 dBc/Hz, and normalized 1/f noise of -123.5 dBc/Hz. The 32-bit N-divider allows fine frequency resolution, and the device supports FSK modulation for digital mobile radio (DMR) and wireless microphone applications.
The LMX2572LP uses a wideband PLL architecture with an integrated VCO, achieving low phase noise and fast settling. The integrated LDOs provide clean supply rails, reducing external component count and improving noise performance. The device operates from a single 3.3-V supply, simplifying power supply design.
Typical applications include DMR radios, wireless microphones, test and measurement equipment, and any system requiring a low-power, low-noise frequency source. The wide frequency range and FSK support make it versatile for various wireless communication standards.
When designing with the LMX2572LP, ensure proper decoupling of the power supply pins and use a clean reference clock to achieve optimal phase noise. The device's SPI interface allows easy configuration of frequency, modulation, and output power settings.
Drop-in alternatives for LMX2572LP — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LMX2572LPRHAR
✅ Drop-In📋 Reference alternative (not in catalog)
LMX2572LPRHAT
✅ Drop-In📋 Reference alternative (not in catalog)
LMX2572
⚡ Same Package📋 Reference alternative (not in catalog)
LMX2571
⚡ Same Package📋 Reference alternative (not in catalog)
ADF4355
⚡ Same Package ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LMX2572LP Specifications
| Output Frequency Range | 12.5 MHz to 2 GHz |
| Supply Voltage | 3.3 V |
| Supply Current | 70 mA |
| Phase Noise at 100 kHz Offset | -124 dBc/Hz (800 MHz carrier) |
| PLL Figure of Merit | -232 dBc/Hz |
| PLL Normalized 1/f Noise | -123.5 dBc/Hz |
| N-Divider Resolution | 32-bit |
| Modulation | FSK |
| Package | 40-VFQFN Exposed Pad |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Integrated LDOs | Yes |
| Internal Doubler | No |
| Interface | SPI |
LMX2572LP Pin Configuration
| Pin 1 | VCC — Power supply (3.3V) |
| Pin 2 | GND — Ground |
| Pin 3 | RF_OUT — RF output |
| Pin 4 | RF_OUTB — Complementary RF output |
| Pin 5 | VCO_VCC — VCO power supply |
| Pin 6 | VCO_GND — VCO ground |
| Pin 7 | CP_OUT — Charge pump output |
| Pin 8 | VCO_IN — VCO input |
| Pin 9 | SCK — SPI clock |
| Pin 10 | SDI — SPI data input |
| Pin 11 | CSB — SPI chip select (active low) |
| Pin 12 | SDO — SPI data output |
Typical Applications
LMX2572LP is suitable for 6 applications: Digital Mobile Radio (DMR), Wireless Microphones, Test and Measurement Equipment, Portable RF Communication Devices, IoT and Smart Home Devices, Aerospace and Defense.
Digital Mobile Radio (DMR)
The LMX2572LP supports FSK modulation, making it ideal for DMR transceivers. Its low power consumption (70 mA) and wide frequency range (12.5 MHz to 2 GHz) enable compact, battery-operated designs. The integrated LDOs reduce external components, simplifying the RF front-end. With phase noise of -124 dBc/Hz, it ensures clear communication in demanding environments.
Recommended
Wireless Microphones
The LMX2572LP's FSK modulation and low phase noise make it suitable for wireless microphone systems. It operates from 12.5 MHz to 2 GHz, covering UHF bands. The low power consumption extends battery life, and the integrated LDOs ensure clean supply rails. The device's small 40-VFQFN package fits space-constrained designs.
Recommended
Test and Measurement Equipment
The LMX2572LP provides a stable, low-noise frequency source for signal generators and spectrum analyzers. Its wide frequency range and fine resolution (32-bit N-divider) enable precise frequency synthesis. The low phase noise improves measurement accuracy. The device's SPI interface allows easy integration into automated test systems.
Recommended
Portable RF Communication Devices
The LMX2572LP's low power consumption (70 mA) and small package make it ideal for handheld radios and portable transceivers. It supports frequencies up to 2 GHz, covering various communication bands. The integrated LDOs reduce external components, saving board space. The device's FSK modulation capability supports digital communication protocols.
Recommended
IoT and Smart Home Devices
The LMX2572LP can generate local oscillator signals for IoT transceivers operating in sub-GHz bands. Its low power consumption is crucial for battery-powered sensors. The wide frequency range allows flexibility in band selection. The integrated LDOs simplify power supply design, and the SPI interface enables easy configuration.
Recommended
Aerospace and Defense
The LMX2572LP's high performance and low power make it suitable for aerospace and defense applications such as UAV communication links and radar systems. Its wide frequency range and low phase noise ensure reliable signal generation. The device's small form factor is advantageous for space-constrained platforms.
Recommended
Recommended Products Summary
Engineering reference data for LMX2572LP — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LMX2572LPRHAR | LMX2572LPRHAT | LMX2572 | LMX2571 | ADF4355 |
|---|---|---|---|---|---|---|
| Package | 40-VFQFN Exposed Pad | 40-VFQFN Exposed Pad | 40-VFQFN Exposed Pad | 40-VFQFN Exposed Pad | 40-VFQFN Exposed Pad | 40-VFQFN Exposed Pad |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices |
| Output Frequency Range | 12.5 MHz to 2 GHz | 12.5 MHz to 2 GHz | 12.5 MHz to 2 GHz | 12.5 MHz to 6.4 GHz | 12.5 MHz to 3.6 GHz | 53 MHz to 6.8 GHz |
| Supply Current | 70 mA | 70 mA | 70 mA | 110 mA | 80 mA | 110 mA |
| Phase Noise at 100 kHz Offset | -124 dBc/Hz | -124 dBc/Hz | -124 dBc/Hz | -110 dBc/Hz | -110 dBc/Hz | -110 dBc/Hz |
| FSK Modulation | Yes | Yes | Yes | No | No | No |
| Integrated LDOs | Yes | Yes | Yes | Yes | Yes | No |
| Pin Compatibility | Reference | Yes | Yes | No | No | No |
Key Differentiators
- Low power consumption of 70 mA (vs LMX2572)
- FSK modulation support (vs LMX2572)
- Integrated LDOs (vs ADF4355)
Design Notes
The LMX2572LP integrates LDOs, but proper decoupling is still essential. Place 100 nF capacitors close to each VCC pin and a 10 uF bulk capacitor on the main supply. Use a clean 3.3-V supply to minimize noise coupling into the VCO.
For optimal phase noise, use a solid ground plane under the device and keep the RF output traces short and impedance-controlled (50 ohm). Avoid routing digital SPI lines near the VCO pins to prevent interference.
Ensure the reference clock is clean and stable, as phase noise is directly affected by the reference. Use a low-noise crystal oscillator and follow the layout guidelines in the datasheet. Also, verify the SPI configuration for correct frequency and modulation settings.
Compliance Information
RoHS compliance inferred from TI's standard compliance. Other compliance data not specified in provided sources.
