Analog Devices Inc. LTC2165IUK#PBF

Overview

LTC2165IUK#PBF from Analog Devices (formerly Linear Technology) is a 16-bit, 125Msps low-power analog-to-digital converter optimized for high-frequency undersampling in communications systems. It delivers 76.8dB SNR, 90dB SFDR, and ultralow 0.07ps_RMS aperture jitter, enabling clean digitization of IF signals up to 140MHz with 550MHz full-power bandwidth. Its single 1.8V supply, selectable CMOS/LVDS outputs, and –40°C to +85°C industrial temperature range make it suitable for cellular base stations and portable medical imaging.

For engineers reviewing the LTC2165IUK#PBF datasheet, LTC2165IUK#PBF pinout, LTC2165IUK#PBF application, or LTC2165IUK#PBF equivalent, key selection criteria include its 125Msps sampling rate, differential input support, SPI-configurable output modes, and thermal performance across extended temperature operation.

Technical Context

The LTC2165IUK#PBF employs a high-linearity pipeline ADC architecture with integrated sample-and-hold and on-chip reference buffers. Its 550MHz full-power bandwidth supports wideband RF/IF signal acquisition, while the optional clock duty cycle stabilizer maintains AC performance across non-50% clock inputs.

Digital interface flexibility includes full-rate CMOS, DDR CMOS, or DDR LVDS outputs-each configurable via SPI or parallel control pins. The device supports both internal and external reference modes, with VREF output at 1.25V ±1.2% and SENSE pin programmability for gain scaling.

Key Specifications

Pinout & Package

48-lead (7mm × 7mm) plastic QFN package with exposed thermal pad (Pin 49 = GND). Requires soldering of exposed pad to PCB ground plane for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed ADC applications.

Compared with AD9268BCPZ-125 and ADS54J60IRGCT, the LTC2165IUK#PBF offers the lowest power per effective bit (194mW / 12.5 ENOB ≈ 15.5mW/bit), unique clock duty cycle stabilization, and single 1.8V supply - making it optimal for thermally constrained, high-density, or clock-flexible systems where JESD204B or ultra-high speed are unnecessary.

Availability

LTC2165IUK#PBF is available at Aetrix Electronics and suitable for cellular infrastructure, portable medical imaging, software-defined radio, and multichannel data acquisition requiring stable component supply across extended temperature ranges.

Supply support for LTC2165IUK#PBF 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

Analog Devices acquired Linear Technology in 2017 and maintains its high-performance signal chain portfolio with rigorous automotive and industrial qualification standards.

The LTC2165IUK#PBF belongs to Linear's ultra-low-jitter, high-SFDR ADC family designed specifically for communications and instrumentation applications demanding wideband digitization without sacrificing power efficiency or thermal robustness.

FAQ

What is the operating temperature range of the LTC2165IUK#PBF?

The LTC2165IUK#PBF is rated for industrial operation from –40°C to +85°C. This extended range is confirmed in the Absolute Maximum Ratings table and applies across all specified DC and dynamic performance parameters, including INL, SNR, and SFDR. The device uses internal thermal compensation to maintain stability within this envelope, making it suitable for outdoor base stations and portable field equipment where ambient conditions vary widely.

Does the LTC2165IUK#PBF support both differential and single-ended clock inputs?

Yes, the LTC2165IUK#PBF supports both configurations via ENC+ and ENC– pins. In differential mode, it accepts LVDS/PECL-level signals with 0.2V minimum differential swing; in single-ended mode, ENC– is tied to GND and ENC+ accepts TTL/CMOS-compatible 1.8V logic. The datasheet specifies distinct VIH/VIL thresholds and input capacitance (3.5pF) for each mode, and timing parameters (t_L, t_H) are guaranteed under both configurations.

Can the LTC2165IUK#PBF be used with an external reference?

Yes, the LTC2165IUK#PBF supports external reference operation via the SENSE pin (Pin 46), which accepts 0.625V–1.3V inputs to scale the internal reference. When enabled, the device disables its internal 1.25V VREF output and uses the external voltage to set full-scale range - allowing precise gain matching in multichannel systems or improved noise performance with low-noise external references.

What output interface modes does the LTC2165IUK#PBF support?

The LTC2165IUK#PBF supports three digital output modes: full-rate CMOS, double-data-rate (DDR) CMOS, and DDR LVDS. Mode selection is controlled via PAR/SER pin state and SPI register settings. CMOS outputs support 1.2V–1.8V OVDD; LVDS outputs provide 100Ω on-chip termination and 247–454mV differential swing. All modes maintain identical pipeline latency (6–6.5 cycles) and timing skew specifications.

Is the LTC2165IUK#PBF pin-compatible with other members of the LTC216x family?

Yes, the LTC2165IUK#PBF shares identical 48-lead QFN packaging, pinout, and footprint with LTC2164IUK#PBF (105Msps) and LTC2163IUK#PBF (80Msps). All three variants use the same VCM, AIN+, AIN–, ENC+, ENC–, and digital I/O pin assignments. This allows drop-in speed scalability in existing PCB layouts - only clock frequency and power supply decoupling may require minor optimization for higher-speed operation.