My Inquiry
My Account
Texas Instruments LMK61A2-156M25SIAR
- Part No.:
- LMK61A2-156M25SIAR
- Manufacturer:
- Texas Instruments
- Category:
- Oscillators
- Package:
- 6-SMD Module
- Datasheet:
-
LMK61A2-156M25SIAR.pdf
- Description:
- SILICONE OSC XO 156.2500MHZ LVDS
- Quantity:
- Payment:
- Shipping:
Inventory:5,660
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LMK61A2-156M25SIAR from Texas Instruments is an ultra-low-jitter LVDS oscillator generating a factory-programmed 156.25 MHz reference clock with ±50 ppm total frequency tolerance, 90 fs RMS jitter (typical at >100 MHz), and robust –70 dBc PSRR. It operates from a single 3.3 V supply in industrial temperature range (–40°C to +85°C) and serves as a high-stability timing source for FPGA and processor clocking in telecom infrastructure.
For engineers reviewing the LMK61A2-156M25SIAR datasheet, LMK61A2-156M25SIAR pinout, LMK61A2-156M25SIAR application, or LMK61A2-156M25SIAR equivalent, key selection criteria include differential LVDS output compliance (300–480 mV swing, 125 Ω impedance), OE-controlled output enable/disable timing (50 µs), and 6-pin QFM package compatibility with industry-standard 7050 XO footprints.
Technical Context
The LMK61A2-156M25SIAR integrates a high-performance PLL-based oscillator core with internal power conditioning to suppress supply noise, enabling stable 156.25 MHz LVDS output without external crystal or loop filter components. Its architecture supports deterministic start-up (10 ms from VDD ≥3.135 V) and fast output control via LVCMOS OE input with internal pull-up.
It delivers differential LVDS signaling with guaranteed 45–55% duty cycle, 150–250 ps rise/fall time (20%–80%), and –162 dBc/Hz phase noise floor at 10 MHz offset-critical for SerDes and JESD204B interface timing integrity in baseband units and network line cards.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Frequency | 156.25 MHz - precisely factory-programmed for Ethernet, CPRI, and JESD204B reference applications. |
| Output Format | LVDS - differential signaling compliant with ANSI/TIA-644-A, requiring 125 Ω termination for optimal signal integrity. |
| RMS Phase Jitter (12 kHz–20 MHz) | 100–200 fs (typical) - meets stringent jitter budgets for 10G+ serial links and high-speed ADC/DAC sampling clocks. |
| Total Frequency Tolerance | ±50 ppm - includes initial calibration, temperature drift (–40°C to +85°C), voltage variation, solder reflow, and 10-year aging. |
| Supply Voltage | 3.3 V ±5% - single-rail operation simplifies power delivery; internal regulation decouples output stability from rail ripple. |
| PSRR | –70 dBc at 50 kHz–1 MHz - suppresses switching noise from adjacent DC/DC converters without additional filtering. |
| OE Response Time | 50 µs enable/disable - enables precise power-gating control in multi-clock domain systems during low-power states. |
Pinout & Package
LMK61A2-156M25SIAR uses a 6-pin QFM (7.0 mm × 5.0 mm) package, pin-compatible with standard 7050 XO footprints. The SIA package features exposed thermal pad connected to GND for enhanced thermal dissipation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - OE | Digital control input | LVCMOS-compatible output enable with internal pull-up; drives output pair to high-impedance when low. |
| 2 - NC | No connect | Unbonded pin; must remain unconnected per TI specification to avoid parasitic coupling or ESD path disruption. |
| 3 - GND | Analog/digital ground | Primary return path; requires ≥3 thermal vias to internal ground plane for thermal reliability and low-impedance reference. |
| 4 - OUTN | Differential output (negative) | LVDS-compliant complementary output; paired with OUTP to deliver 300–480 mVpp differential swing into 125 Ω load. |
| 5 - OUTP | Differential output (positive) | LVDS-compliant primary output; routing must maintain matched length and impedance with OUTN to preserve common-mode rejection. |
| 6 - VDD | Analog power supply | 3.3 V ±5% supply; requires local 10 µF / 1 µF / 0.1 µF bypass network with shortest possible trace to GND vias. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low jitter | 90 fs RMS typical (fOUT > 100 MHz) - enables reliable operation in 25+ Gbps SerDes lanes and sub-picosecond sampling systems. |
| Robust PSRR | –70 dBc across 50 kHz–1 MHz - eliminates need for dedicated low-noise LDOs in dense power domains. |
| Factory-programmed frequency | 156.25 MHz LVDS - eliminates external crystal, load capacitors, and trimming; reduces BOM count and layout area. |
| Industrial temperature range | –40°C to +85°C - qualified for deployment in uncontrolled environments such as outdoor base stations and industrial edge servers. |
| Pin-compatible 7050 footprint | 6-pin QFM (7.0 mm × 5.0 mm) - allows drop-in replacement of legacy XOs without PCB redesign or requalification. |
Applications
| Telecom Baseband Units (BBU) | FPGA Clock Distribution |
|---|---|
Use Scenario: Timing reference for multi-channel digital up/down converters and CPRI fronthaul interfaces in 4G/5G macro cells. IC Role / Device Role / Timing Role: Primary 156.25 MHz LVDS clock source synchronizing ADC/DAC sample clocks and JESD204B serializer/deserializer cores. Use Value: Sub-200 fs jitter ensures <1 LSB timing error in 16-bit ADCs and maintains <10–12 BER in 10G CPRI links. |
Use Scenario: High-reliability clock feeding multiple FPGA banks (I/O, transceiver, logic) in radar processing and AI inference accelerators. IC Role / Device Role / Timing Role: Single-point LVDS oscillator replacing multiple crystals and fanout buffers to reduce skew and power. Use Value: ±50 ppm stability over temperature and life avoids re-calibration; OE pin enables dynamic clock gating during idle cycles. |
| Network Switches & Routers | Medical Imaging Systems |
Use Scenario: Reference clock for packet processing ASICs and 25G/100G Ethernet PHYs in enterprise and data center switches. IC Role / Device Role / Timing Role: Low-phase-noise 156.25 MHz source meeting IEEE 802.3bj CAUI-4 jitter compliance for KR4 interfaces. Use Value: –162 dBc/Hz phase noise floor at 10 MHz offset suppresses crosstalk-induced bit errors in parallel lane architectures. |
Use Scenario: Master clock for ultrasound beamforming ASICs and MRI gradient controller FPGAs requiring deterministic latency. IC Role / Device Role / Timing Role: Ultra-stable LVDS oscillator providing synchronous sampling clocks across distributed sensor arrays. Use Value: 10 ms power-on startup and 50 µs OE response support real-time system boot and emergency mode transitions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar oscillator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LMK61E2-156M25SIAR | Same 156.25 MHz LVPECL output, identical ±50 ppm tolerance, but LVPECL format (1.0–1.2 V common-mode) vs. LVDS (1.2 V). | Requires 50 Ω termination to VCCO instead of 125 Ω differential load; higher power consumption (208 mA vs. 196 mA). | Select when interfacing with legacy LVPECL receivers or where higher output swing justifies added power and termination complexity. |
| Si510-156M25-AG | 156.25 MHz LVDS output, ±20 ppm stability, 1.2 ps RMS jitter (12 kHz–20 MHz), 3.3 V supply, same 7×5 mm package. | Tighter frequency tolerance but higher jitter; programmable via I²C (not factory-set); no OE pin for hardware disable. | Select when long-term aging margin is critical and software-configurable frequency is acceptable; not suitable for OE-driven power sequencing. |
Compared with LMK61A2-156M25SIAR, LMK61E2-156M25SIAR offers identical timing performance in LVPECL format for different receiver topologies, while Si510-156M25-AG trades lower jitter tolerance for programmability and tighter stability-making it preferable only in systems requiring field-adjustable frequencies or extended lifetime calibration.
Availability
LMK61A2-156M25SIAR is available at Aetrix Electronics and suitable for telecom infrastructure, FPGA-based embedded systems, and medical imaging equipment requiring stable component supply, consistent parametric performance, and long-lifecycle availability.
Supply support for LMK61A2-156M25SIAR 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 company specializing in analog and embedded processing technologies, with leadership in precision timing, power management, and signal chain solutions.
The LMK61XX family is designed for high-performance clock generation in data-intensive systems-targeting applications where ultra-low jitter, supply noise immunity, and factory-programmed reliability eliminate crystal-related design risks.
FAQ
What output format does the LMK61A2-156M25SIAR support?
The LMK61A2-156M25SIAR is factory-programmed for LVDS output only. It delivers a 156.25 MHz differential signal with 300–480 mVpp swing, 125 Ω differential impedance, and 45–55% duty cycle. Unlike some variants in the LMK61XX family, this specific part does not support LVPECL or HCSL formats.
Does the LMK61A2-156M25SIAR require an external crystal or loop filter?
No. The LMK61A2-156M25SIAR is a fully integrated oscillator with a factory-programmed PLL core. It requires no external crystal, load capacitors, or loop filter components-only proper 3.3 V supply decoupling (10 µF / 1 µF / 0.1 µF) and matched differential routing for OUTP/OUTN.
What is the function of the OE pin on the LMK61A2-156M25SIAR?
The OE (Output Enable) pin on the LMK61A2-156M25SIAR is an LVCMOS input with internal pull-up. When pulled low, it disables the LVDS output pair and places both OUTP and OUTN in high-impedance state within 50 µs. When left floating or driven high, the oscillator runs continuously.
Is the LMK61A2-156M25SIAR pin-compatible with standard 7050 crystal oscillator footprints?
Yes. The LMK61A2-156M25SIAR uses a 6-pin QFM package measuring 7.0 mm × 5.0 mm-the same footprint as industry-standard 7050 XO modules. This enables direct mechanical and layout compatibility without PCB redesign, though electrical interface (LVDS vs. clipped-sine) must be verified.
What is the maximum junction temperature rating for the LMK61A2-156M25SIAR?
The LMK61A2-156M25SIAR is rated for a maximum junction temperature of 125°C. Its thermal design uses ψJB = 37.7°C/W (no airflow), so maintaining PCB temperature ≤99°C under full load (0.68 W on-chip dissipation) ensures safe operation within spec.
LMK61A2-156M25SIAR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- LMK61XX
- Package/Case:
- 6-SMD Module
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Base Resonator:
- Silicon
- Type:
- XO (Standard)
- Frequency:
- 156.25 MHz
- Function:
- Enable/Disable
- Output:
- LVDS
- Voltage - Supply:
- 3.3V
- Frequency Stability:
- ±50ppm
- Absolute Pull Range (APR):
- -
- Operating Temperature:
- -40°C ~ 85°C
- Spread Spectrum Bandwidth:
- -
- Current - Supply (Max):
- 196mA
- Ratings:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 6-QFM (7x5)
- Size / Dimension:
- 0.276" L x 0.197" W (7.00mm x 5.00mm)
- Height - Seated (Max):
- 0.045" (1.15mm)
LMK61A2-156M25SIAR FAQ
1.How can I place an order for LMK61A2-156M25SIAR through Aetrix?
Please submit a Request for Quotation (RFQ) for LMK61A2-156M25SIAR 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 LMK61A2-156M25SIAR reliable?
The price and inventory of LMK61A2-156M25SIAR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LMK61A2-156M25SIAR is usually 5 days.
3.What payment methods are accepted for LMK61A2-156M25SIAR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LMK61A2-156M25SIAR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LMK61A2-156M25SIAR?
LMK61A2-156M25SIAR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LMK61A2-156M25SIAR 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 LMK61A2-156M25SIAR?
For technical support, including LMK61A2-156M25SIAR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LMK61A2-156M25SIAR requirements.
6.How does Aetrix verify that LMK61A2-156M25SIAR is sourced from the original manufacturer or authorized distributors?
All LMK61A2-156M25SIAR 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 LMK61A2-156M25SIAR meets industry standards.
7.What is the process for return or replacement of LMK61A2-156M25SIAR?
All LMK61A2-156M25SIAR units undergo pre-shipment inspection (PSI). If there is an issue with LMK61A2-156M25SIAR, 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 LMK61A2-156M25SIAR part is unused and in its original packaging.
Return procedure for LMK61A2-156M25SIAR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LMK61A2-156M25SIAR Tags
-
ECS-2333-160-BN-TR
ECS Inc.
-
ECS-2333-240-BN-TR
ECS Inc.
-
KC2016Z25.0000C1KX00
KYOCERA AVX
-0.035-Thick.jpg)
-
ECS-2033-250-BN
ECS Inc.
-
O 25,0-JO32-B-1V3-1-T1-LF
Jauch Quartz
-
SIT1533AI-H4-DCC-32.768E
SiTime
-
ECS-2333-500-BN-TR
ECS Inc.
-
COM1305-50.000-EXT-T-TR
Raltron Electronics
-
SG-210STF 24.0000ML0
EPSON
-
ECS-3225MV-320-CN-TR
ECS Inc.
-
ECS-2033-240-BN
ECS Inc.
-
ECS-2333-120-BN-TR
ECS Inc.
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…
