Texas Instruments LMK61PD0A2-SIAR

Overview

LMK61PD0A2-SIAR from Texas Instruments is an ultra-low jitter, pin-selectable oscillator with integrated PLL and fractional VCO, generating seven factory-programmed reference frequencies (62.5–312.5 MHz) in LVPECL/LVDS/HCSL formats. It delivers 90 fs RMS typical jitter (>100 MHz), ±50 ppm total frequency tolerance, and -70 dBc PSRR for high-speed serial link timing in FPGA/ASIC-based systems.

For engineers reviewing the LMK61PD0A2-SIAR datasheet, LMK61PD0A2-SIAR pinout, LMK61PD0A2-SIAR application, or LMK61PD0A2-SIAR equivalent, this page provides verified pin-strapping configurations, output format selection logic, thermal derating guidance, and validated alternatives for 10G/25G Ethernet, optical transport, and high-performance computing clock trees.

Technical Context

The device integrates a 50 MHz crystal, fractional-N PLL with on-chip VCO, integer output divider, and universal differential output buffer-all controlled via FS[1:0] and OS pins. Its internal LDO-regulated power conditioning isolates analog and digital supplies to achieve robust supply noise immunity.

Frequency selection is implemented through LVCMOS-compatible FS[1:0] inputs (VDD/GND/NC), enabling seven discrete outputs including 100 MHz (PCIe), 125 MHz (1 GbE), 156.25 MHz (10 GbE), and 312.5 MHz (10 GbE). Output type (LVPECL/LVDS/HCSL) is selected independently via OS pin strapping, with OE enabling/disabling the output driver.

Key Specifications

Pinout & Package

8-pin QFM (SIA) package, 7.0 mm × 5.0 mm, thermally enhanced with exposed ground pad. Designed for low-inductance PCB mounting and optimal thermal dissipation via ≥3 thermal vias to internal ground plane.

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 AK212-01-100.0000T, the LMK61PD0A2-SIAR uniquely balances factory-programmed flexibility, zero-software configuration, and integrated PSRR-making it optimal for industrial and telecom hardware where reliability, thermal robustness, and deterministic startup behavior are prioritized over programmability.

Availability

LMK61PD0A2-SIAR is available at Aetrix Electronics and suitable for 10G Ethernet line cards, FPGA-based high-speed I/O timing, and optical transport unit systems requiring stable component supply, guaranteed long-term availability, and full traceability.

Supply support for LMK61PD0A2-SIAR 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, embedded processing, and clock solutions, with decades of leadership in precision timing and signal integrity.

The LMK61PD0A2 belongs to TI's PLLatinum™ oscillator family, engineered specifically for high-speed serial communication systems demanding ultra-low jitter, robust power supply rejection, and simplified board-level integration.

FAQ

What is the maximum allowable voltage droop on VDD during power-up?

The LMK61PD0A2-SIAR specifies a maximum allowable VDD droop of 0.1 V during startup, with threshold voltage defined between 2.72 V and 2.95 V. Exceeding this droop may cause unreliable oscillator lock or extended startup time beyond the specified 10 ms. Proper decoupling (10 µF/1 µF/0.1 µF) and controlled ramp rate (0.1–100 ms) are mandatory to meet this spec.

Can FS[1:0] pins be left floating?

No-FS[1:0] pins must be explicitly strapped to VDD, GND, or left unconnected (NC) per Table 1 in the datasheet; floating states are undefined and may result in invalid or unstable frequency selection. The device has no internal pull-ups/pull-downs on these pins, so external biasing is required for deterministic operation.

How does output format selection affect power consumption?

Power consumption varies by output format: LVPECL draws 162–208 mA, LVDS draws 152–196 mA, and HCSL draws 155–196 mA (all at VDD = 3.3 V). This difference arises from distinct output stage topologies-LVPECL's current-mode driver consumes more than LVDS's voltage-mode driver-and must be accounted for in thermal design and PDN sizing.

Is the LMK61PD0A2-SIAR RoHS compliant and MSL rated?

Yes-the LMK61PD0A2-SIAR is RoHS compliant and rated MSL3 per J-STD-020, with a floor life of 168 hours at ≤30°C/60% RH. Reflow peak temperature must not exceed 260°C, and the device requires baking if exposed beyond floor life before assembly.