Texas Instruments LMK61PD0A2-SIAT

Overview

LMK61PD0A2-SIAT from Texas Instruments is an ultra-low jitter (90 fs RMS typical at fOUT > 100 MHz), pin-selectable, integrated PLL-based oscillator generating seven factory-programmed reference frequencies (62.5–312.5 MHz) with ±50 ppm total frequency tolerance. It supports LVPECL/LVDS/HCSL differential outputs via OS pin control and operates from a single 3.3 V ±5% supply across –40°C to +85°C for high-speed serial link timing in FPGA/ASIC clock trees.

For engineers reviewing the LMK61PD0A2-SIAT datasheet, LMK61PD0A2-SIAT pinout, LMK61PD0A2-SIAT application, or LMK61PD0A2-SIAT equivalent, key selection criteria include output jitter performance below 200 fs RMS (12 kHz–20 MHz), PSRR of –70 dBc against 50 kHz–1 MHz supply ripple, pin-strapped frequency/format configuration, and QFM-8 (7.0 × 5.0 mm) package compatibility with high-density PCB layouts.

Technical Context

The LMK61PD0A2-SIAT integrates a 50 MHz crystal, fractional-N PLL with on-chip VCO, integer output divider, and universal differential output buffer-all configured via factory ROM and controlled by FS[1:0] and OS pins. Its internal LDO-regulated power network isolates analog and digital supplies to achieve robust PSRR.

Frequency selection is determined by FS[1:0] strapping (e.g., FS1=NC, FS0=NC → 156.25 MHz; FS1=0, FS0=0 → 100 MHz), while output format (LVPECL/LVDS/HCSL) is set by OS and OE pin states. Startup time is ≤10 ms after VDD reaches 3.135 V, and output enable/disable latency is 50 µs.

Key Specifications

Pinout & Package

LMK61PD0A2-SIAT uses an 8-pin QFM (SIA) package measuring 7.0 mm × 5.0 mm with exposed thermal pad. Pin 3 is GND, Pin 6 is VDD, Pins 4–5 form the differential output pair (OUTP/OUTN), Pins 7–8 are FS[1:0] frequency select inputs, Pin 1 is OE (output enable), and Pin 2 is OS (output type select).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low jitter oscillator applications.

Compared with Si5338A-D-GM and AK212-01-EVAL, the LMK61PD0A2-SIAT delivers optimal balance of ultra-low jitter, zero-software configuration, industrial qualification, and cost-effective fixed-frequency operation-making it ideal for high-volume, hardware-defined timing in networking and compute platforms.

Availability

LMK61PD0A2-SIAT is available at Aetrix Electronics and suitable for 10 Gbps Ethernet line cards, FPGA transceiver clocking, medical ultrasound imaging systems, and 5G baseband units requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for LMK61PD0A2-SIAT 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 headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets since 1930.

The LMK61PD0A2-SIAT belongs to TI's LMK family of high-performance clock generators and oscillators, designed specifically to replace quartz-based solutions in jitter-critical serial data applications such as 10/25/100 Gbps Ethernet and JESD204B/C converter interfaces.

FAQ

What is the startup time and output enable latency for LMK61PD0A2-SIAT?

The device achieves full output stability within 10 ms after VDD reaches 3.135 V. Output enable/disable latency is 50 µs measured from OE transition to VIH/VIL threshold to valid differential output swing. This enables precise power sequencing in multi-rail systems without requiring external reset coordination.

How does the LMK61PD0A2-SIAT achieve –70 dBc PSRR without external filtering?

It uses on-chip, partitioned LDO regulators-one for analog PLL/VCO blocks and another for digital control logic-providing >60 dB isolation between supply noise and sensitive timing paths. The PSRR is validated across 50 kHz–1 MHz with 50 mVpp ripple, eliminating need for ferrite beads or additional bulk capacitance.

Can FS[1:0] and OS pins be left unconnected (NC), and what is the default behavior?

Yes-FS[1:0] and OS support NC (no-connect) states per datasheet Table 1 and Table 2. FS[1:0]=NC/NC selects 156.25 MHz; OS=NC selects LVDS output. All control pins have internal biasing; floating is electrically safe but NC must be explicitly implemented as open circuit, not tied to VDD/GND unintentionally.

Is the LMK61PD0A2-SIAT RoHS-compliant and qualified for lead-free reflow?

Yes-the SIA package is RoHS-compliant and MSL3 rated per J-STD-020. It supports peak reflow temperatures up to 260°C with a maximum 30-second exposure above 220°C. Thermal resistance data (RθJA = 41.2°C/W at 400 LFM) confirms suitability for standard lead-free assembly processes.