SNAS624B March 2014 – May 2015 LMX2492 , LMX2492-Q1
PRODUCTION DATA.
- 1 Features
- 2 Applications
- 3 Description
- 4 Simplified Schematic
- 5 Revision History
- 6 Pin Configuration and Functions
- 7 Specifications
-
8 Detailed Description
- 8.1 Overview
- 8.2 Functional Block Diagram
- 8.3
Feature Description
- 8.3.1 OSCin Input
- 8.3.2 OSCin Doubler
- 8.3.3 R Divider
- 8.3.4 PLL N Divider
- 8.3.5 Fractional Circuitry
- 8.3.6 PLL Phase Detector and Charge Pump
- 8.3.7 External Loop Filter
- 8.3.8 Fastlock and Cycle Slip Reduction
- 8.3.9 Lock Detect and Charge Pump Voltage Monitor
- 8.3.10 FSK/PSK Modulation
- 8.3.11 Ramping Functions
- 8.3.12 Power on Reset (POR)
- 8.4 Device Functional Modes
- 8.5 Programming
- 8.6 Register Map
- 8.7 Register Field Descriptions
- 8.8 Lock Detect and Charge Pump Monitoring
- 8.9 TRIG1,TRIG2,MOD, and MUXout Pins
- 8.10 Ramping Functions
- 8.11 Individual Ramp Controls
- 9 Applications and Implementation
- 10Power Supply Recommendations
- 11Layout
- 12Device and Documentation Support
- 13Mechanical, Packaging, and Orderable Information
1 Features
- -227 dBc/Hz Normalized PLL Noise
- 500 MHz - 14 GHz Wideband PLL
- 3.15 - 5.25 V Charge Pump PLL Supply
- Versatile Ramp / Chirp Generation
- 200 MHz Max Phase Detector Frequency
- FSK / PSK Modulation Pin
- Digital Lock Detect
- Single 3.3 V Supply Capability
- Automotive 125°C Q100 Grade 1 Qualification
- Non-Automotive (LMX2492) Option
2 Applications
- Automotive FMCW Radar
- Military Radar
- Microwave Backhaul
- Test and Measurement
- Satellite Communications
- Wireless Infrastructure
- Sampling Clock for High Speed ADC/DAC
3 Description
The LMX2492/92-Q1 is a low noise 14 GHz wideband delta-sigma fractional N PLL with ramp and chirp generation. It consists of a phase frequency detector, programmable charge pump, and high frequency input for the external VCO. The LMX2492/92-Q1 supports a broad and flexible class of ramping capabilities, including FSK, PSK, and configurable piecewise linear FM modulation profiles of up to 8 segments. It supports fine PLL resolution and fast ramp with up to a 200 MHz phase detector rate. The LMX2492/92-Q1 allows any of its registers to be read back. The LMX2492/92-Q1 can operate with a single 3.3 V supply. Moreover, supporting up to 5.25 V charge pump can eliminate the need of external amplifier, leading to a simpler solution with improved phase noise performance.
Device Information
| PART NUMBER | PACKAGE | BODY SIZE (NOM) |
|---|---|---|
| LMX2492-Q1RTW | WQFN (24) | 4.00 mm x 4.00 mm |
| LMX2492RTW | WQFN (24) | 4.00 mm x 4.00 mm |
- For all available packages, see the orderable addendum at the end of the datasheet.
4 Simplified Schematic
