My Inquiry
My Account
Texas Instruments LMX2531LQE1312E/NOPB
- Part No.:
- LMX2531LQE1312E/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 36-WFQFN Exposed Pad
- Datasheet:
-
LMX2531LQE1312E/NOPB.pdf
- Description:
- IC FREQ SYNTH 36WQFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,469
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LMX2531LQE1312E/NOPB from Texas Instruments is a high-performance fractional-N delta-sigma PLL frequency synthesizer with integrated VCO, operating in the 1268–1360 MHz high-band and 634–680 MHz low-band. It delivers ultra-low phase noise (–95 dBc/Hz @ 10 kHz offset at 1314 MHz), supports 1.8-V MICROWIRE interface, and integrates LDOs for PLL/VCO supply-noise immunity. It serves as a local oscillator in wireless LAN transceivers requiring stable, low-spur RF signal generation.
For engineers reviewing the LMX2531LQE1312E/NOPB datasheet, LMX2531LQE1312E/NOPB pinout, LMX2531LQE1312E/NOPB application, or LMX2531LQE1312E/NOPB equivalent, key selection criteria include its dual-band VCO tuning range, FastLock capability with timeout, programmable fourth-order delta-sigma modulator, and 36-pin WQFN package with integrated loop filter support.
Technical Context
The LMX2531LQE1312E/NOPB implements a fully integrated delta-sigma PLL architecture with adjustable third/fourth poles and an on-die VCO featuring integrated tank inductor. Its charge pump output (CPout) drives an external passive loop filter connected to Vtune, enabling precise loop bandwidth control.
It uses a 1.8-V MICROWIRE serial interface (DATA/CLK/LE/CE) for register programming, supports divider-enabled (÷2) and divider-disabled output modes, and includes dedicated outputs for lock detection (Ftest/LD) and FastLock status (FLout), with internal LDOs regulating VregVCO, VregPLL1/2, and VregDIG rails.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Frequency Range | 1268–1360 MHz (high-band), 634–680 MHz (low-band); enables dual-band RF system design without external VCO switching |
| Phase Noise @ 10 kHz | –95 dBc/Hz at 1314 MHz (divider disabled); critical for EVM-sensitive WLAN and LTE uplink paths |
| Charge Pump Current | Programmable 90–1440 µA (16× gain steps); allows optimization of loop dynamics and reference spur suppression |
| VCO Tuning Sensitivity | 3–6 MHz/V typical; determines required loop filter capacitor sizing and tuning line voltage range |
| Power Supply Range | 2.8–3.2 V across all rails (VCCDIG/VCCVCO/VCCBUF/VCCPLL); ensures stable operation under ±100 mV supply variation |
| Operating Temperature | –40°C to +85°C; validated for industrial and base station environments with ≤90°C max allowable temp drift for continuous lock |
| Interface Voltage | 1.8-V MICROWIRE compatible (VIH ≤ 2.75 V); reduces I/O power and simplifies level-shifting in mixed-voltage systems |
Pinout & Package
LMX2531LQE1312E/NOPB is housed in a 36-pin 6 mm × 6 mm × 0.8 mm WQFN package (NJH0036D variant), with exposed thermal pad for enhanced heat dissipation in RF-intensive applications.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CE (Pin 11) | Chip Enable Input | CMOS input controlling power-up sequence; must be held high to activate internal regulators and enable lock acquisition |
| CLK (Pin 9) | MICROWIRE Clock | Rising-edge clock for serial data; requires tCWH/tCWL ≥ 25 ns for reliable register loading |
| DATA (Pin 8) | Serial Data Input | MSB-first shift register input; accepts 24-bit configuration words including R0 frequency calibration bits |
| LE (Pin 10) | Latch Enable | Transfers shift register contents into active latch registers; initiates reprogramming of PLL/VCO settings |
| Fout (Pin 21) | RF Output Buffer | 50-Ω buffered VCO output delivering +1 to +7 dBm (divider disabled); directly drives mixer LO ports |
| Vtune (Pin 23) | VCO Tuning Input | Analog input accepting filtered CPout voltage; sets instantaneous VCO frequency via varactor bias |
| CPout (Pin 24) | Charge Pump Output | Current-source output driving external loop filter; polarity and magnitude set by ICP register bits |
| Ftest/LD (Pin 30) | Lock Detect Output | CMOS-level indicator asserting high when PLL achieves phase lock; used for system readiness signaling |
Key Features
| Feature | Design Value |
|---|---|
| Fractional-N Delta-Sigma Modulator | Programmable up to fourth order, reducing fractional spurs and enabling fine frequency resolution (sub-Hz step size) |
| Integrated VCO Tank Inductor | Eliminates external inductor placement and tolerance sensitivity, improving production yield and board space efficiency |
| FastLock with Timeout | Reduces lock time by detecting and correcting cycle slips during acquisition, preventing indefinite unlock states |
| Dual Independent LDOs | VregVCO and VregPLL1/2 provide isolated, low-noise supplies-improving PSRR by >60 dB and stabilizing VCO/PLL performance across rail noise |
| Partially Integrated Loop Filter | On-chip third/fourth pole compensation simplifies external RC network, reducing component count and layout sensitivity |
Applications
| Cellular Base Stations | Wireless LANs |
|---|---|
Use Scenario: Local oscillator generation for 2.6 GHz LTE FDD/TDD transceivers in macrocell remote radio heads. IC Role / Device Role / Timing Role: Primary frequency synthesizer providing clean, agile LO signals to quadrature mixers with < –95 dBc/Hz phase noise @ 10 kHz. Use Value: Enables 256-QAM modulation fidelity by suppressing adjacent channel leakage ratio (ACLR) through ultra-low in-band phase noise. | Use Scenario: Dual-band 2.4/5 GHz Wi-Fi 6 AP radios requiring fast channel switching and low EVM. IC Role / Device Role / Timing Role: High-speed frequency agile LO source supporting OFDMA subcarrier alignment with < 50 µs lock time. Use Value: Achieves < 1.5% RMS EVM at 802.11ax 1024-QAM by minimizing close-in phase jitter and harmonic distortion. |
| Broadband Wireless Access | Satellite Communications |
Use Scenario: Point-to-multipoint fixed wireless access (FWA) units operating in 3.5 GHz CBRS band. IC Role / Device Role / Timing Role: Low-power synthesizer generating stable LO for wideband QPSK/16-QAM demodulation with 100 MHz IF bandwidth. Use Value: Maintains BER < 1e–6 over temperature via on-chip frequency calibration and 90°C max continuous-lock drift margin. | Use Scenario: L-band upconverter in VSAT terminals for maritime and aeronautical SATCOM links. IC Role / Device Role / Timing Role: Radiation-tolerant LO generator delivering 1.2–1.3 GHz output with < –140 dBc/Hz @ 1 MHz offset. Use Value: Supports narrowband FDMA channel spacing (25 kHz) by achieving < –40 dBc second-harmonic suppression. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar frequency synthesizer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LMX2594RHBR | Wider 10 MHz–15 GHz range, JESD204B SYSREF support, higher phase detector frequency (up to 200 MHz) | Targets high-speed data converter clocking and mmWave 5G NR; lacks integrated VCO tank inductors | Select for multi-GHz broadband systems needing ultra-wide tuning; avoid if board space or BOM cost constraints favor integrated VCO solutions |
| ADF4351BCPZ | 35 MHz–4.4 GHz range, integrated VCO but no on-die tank inductor; higher typical current draw (120 mA vs. 41 mA) | Preferred for test equipment and general-purpose lab synthesizers; less optimized for low-noise wireless LO | Choose for legacy designs or where Analog Devices toolchain compatibility is required; verify loop filter redesign due to different CP architecture |
Compared with LMX2531LQE1312E/NOPB, LMX2594RHBR offers broader frequency coverage and digital interface enhancements but requires external VCO components, while ADF4351BCPZ provides wider tuning than LMX2531LQE1312E/NOPB yet trades off phase noise performance and power efficiency in narrowband wireless applications.
Availability
LMX2531LQE1312E/NOPB is available at Aetrix Electronics and suitable for cellular base stations, wireless LAN infrastructure, and satellite communications equipment requiring stable component supply, consistent parametric performance across temperature, and long-term obsolescence management.
Supply support for LMX2531LQE1312E/NOPB includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies for industrial, automotive, and communications markets.
The LMX2531 product line delivers highly integrated, low-phase-noise PLL+VCO solutions targeting wireless infrastructure and high-fidelity RF signal generation where supply-noise immunity and compact footprint are critical.
FAQ
What frequency bands does the LMX2531LQE1312E/NOPB support?
The LMX2531LQE1312E/NOPB supports two distinct frequency bands: a low-band range of 634–680 MHz and a high-band range of 1268–1360 MHz. These ranges are factory-configured and fixed per device variant-LMX2531LQE1312E/NOPB cannot operate outside these bands. The high-band output is generated directly by the integrated VCO, while the low-band is derived via internal division or alternate VCO core activation depending on register configuration.
Does the LMX2531LQE1312E/NOPB require external loop filter components?
Yes, the LMX2531LQE1312E/NOPB requires external passive loop filter components connected between CPout and Vtune. Although it integrates third- and fourth-pole compensation, the primary RC network-including series resistor, loop filter capacitor(s), and optional zero capacitor-must be placed externally to set loop bandwidth, phase margin, and reference spur attenuation. TI provides recommended values in the datasheet's typical application section.
How does the FastLock feature function in the LMX2531LQE1312E/NOPB?
The FastLock feature in the LMX2531LQE1312E/NOPB detects cycle slips during PLL acquisition and dynamically adjusts the N-divider value to accelerate lock convergence. It operates with a configurable timeout counter that resets upon successful lock detection (via Ftest/LD). This prevents infinite lock attempts and reduces typical lock time to under 50 µs in optimized loop configurations-critical for TDD systems requiring rapid frequency hopping.
What is the maximum allowable temperature drift for continuous lock in the LMX2531LQE1312E/NOPB?
The LMX2531LQE1312E/NOPB specifies a maximum allowable temperature drift of ±90°C for continuous lock-meaning the ambient temperature may drift up to 90°C above or below the value present when the R0 register was last programmed, while maintaining lock. This specification applies specifically to LMX2531LQ1312E variants; exceeding this drift requires reloading R0 to trigger VCO recalibration and restore lock integrity.
Can the LMX2531LQE1312E/NOPB drive a 50-Ω load directly?
Yes, the LMX2531LQE1312E/NOPB's Fout pin provides a buffered RF output designed to drive a 50-Ω load directly. When operating in divider-disabled mode at 1314 MHz, it delivers +1 to +7 dBm output power into 50 Ω, with second-harmonic suppression of –30 to –20 dBc and third-harmonic suppression of –20 to –15 dBc. No external matching network is required for standard 50-Ω system interfaces.
LMX2531LQE1312E/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 36-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Frequency Synthesizer (RF)
- PLL:
- Yes
- Input:
- Clock
- Output:
- CMOS
- Number of Circuits:
- 1
- Ratio - Input:Output:
- 2:2
- Differential - Input:Output:
- No/No
- Frequency - Max:
- 1.36GHz
- Divider/Multiplier:
- Yes/No
- Voltage - Supply:
- 2.8V ~ 3.2V
- Operating Temperature:
- -40°C ~ 85°C
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 36-WQFN (6x6)
LMX2531LQE1312E/NOPB FAQ
1.How can I place an order for LMX2531LQE1312E/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LMX2531LQE1312E/NOPB on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LMX2531LQE1312E/NOPB reliable?
The price and inventory of LMX2531LQE1312E/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LMX2531LQE1312E/NOPB is usually 5 days.
3.What payment methods are accepted for LMX2531LQE1312E/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LMX2531LQE1312E/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LMX2531LQE1312E/NOPB?
LMX2531LQE1312E/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LMX2531LQE1312E/NOPB order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LMX2531LQE1312E/NOPB?
For technical support, including LMX2531LQE1312E/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LMX2531LQE1312E/NOPB requirements.
6.How does Aetrix verify that LMX2531LQE1312E/NOPB is sourced from the original manufacturer or authorized distributors?
All LMX2531LQE1312E/NOPB products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LMX2531LQE1312E/NOPB meets industry standards.
7.What is the process for return or replacement of LMX2531LQE1312E/NOPB?
All LMX2531LQE1312E/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LMX2531LQE1312E/NOPB, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LMX2531LQE1312E/NOPB part is unused and in its original packaging.
Return procedure for LMX2531LQE1312E/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LMX2531LQE1312E/NOPB Tags
-
CD74HCT4046AM96
Texas Instruments
-
MC14046BDWR2G
onsemi
-
501MILFT
Renesas
-
CD74HC7046AM
Texas Instruments
-
CDCVF2505PWR
Texas Instruments
-
RC19004A100GNL#KB0
Renesas
-
SI5351A-B-GTR
Skyworks Solutions Inc.
-
CY2305SXI-1T
Infineon Technologies
-
570BILFT
Renesas
-
CDCE913PWR
Texas Instruments
-
CY2305SXI-1HT
Infineon Technologies
-
DS1086LU+T
Analog Devices Inc./Maxim Integrated
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
