Analog Devices Inc. LTC2191CUKG#PBF

Overview

LTC2191CUKG#PBF from Analog Devices (formerly Linear Technology) is a 16-bit, dual-channel, simultaneous-sampling analog-to-digital converter optimized for high-dynamic-range signal digitization at 40 Msps. It delivers 77 dB SNR and 90 dB SFDR with ultralow 0.07 ps_RMS aperture jitter, enabling undersampling of IF signals in communications infrastructure. Its serial LVDS outputs, 1.8 V single-supply operation, and 550 MHz full-power bandwidth make it suitable for cellular base stations and portable medical imaging systems.

For engineers reviewing the LTC2191CUKG#PBF datasheet, LTC2191CUKG#PBF pinout, LTC2191CUKG#PBF application, or LTC2191CUKG#PBF equivalent, key selection criteria include its 40 Msps sampling rate, ±2 LSB INL, differential LVDS serialization (1/2/4-lane), internal/external reference flexibility via SENSE pin, and QFN-52 package thermal performance for high-density RF data acquisition designs.

Technical Context

The LTC2191CUKG#PBF implements two independent 16-bit ADC cores with simultaneous sampling and shared clocking, supporting both differential and single-ended encode inputs (ENC+/ENC–). Its on-chip duty cycle stabilizer maintains AC performance across wide input clock duty cycles, while the integrated PLL ensures low-jitter sampling timing critical for undersampling architectures.

Digital output serialization uses LVDS drivers with programmable current (1.75 mA or 3.5 mA per lane) and optional internal 100 Ω termination. The SPI-compatible serial port (CS/SCK/SDI/SDO) enables real-time configuration of output mode, reference selection, and power states including Nap (50 mW) and Sleep (1 mW) modes.

Key Specifications

Pinout & Package

Package: 52-lead (7 mm × 8 mm) plastic QFN with exposed thermal pad (Pin 53 = GND), rated for 0°C to 70°C operating range (C-grade).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel, 16-bit ADC applications.

Compared with AD9269BCPZ-40 and LTC2261IUJ#PBF, the LTC2191CUKG#PBF uniquely combines 16-bit resolution, serial LVDS, ultralow jitter, and flexible reference control in a single 1.8 V supply-making it optimal for SWaP-constrained, high-fidelity RF and medical systems requiring guaranteed monotonicity and deterministic latency.

Availability

LTC2191CUKG#PBF is available at Aetrix Electronics and suitable for cellular base stations, software-defined radios, and portable medical imaging systems requiring stable component supply across extended production lifecycles.

Supply support for LTC2191CUKG#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, Inc. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing technologies, serving communications, industrial, automotive, and healthcare markets.

The LTC2191CUKG#PBF belongs to ADI's high-speed precision ADC product line, engineered specifically for demanding wideband digitization in infrastructure and instrumentation where dynamic range, timing accuracy, and power efficiency are co-optimized.

FAQ

What is the maximum sampling rate supported by the LTC2191CUKG#PBF?

The LTC2191CUKG#PBF is rated for a maximum sampling rate of 40 Msps, as confirmed in its ordering information and electrical specifications table. This speed grade distinguishes it from the LTC2192 (65 Msps) and LTC2190 (25 Msps) within the same family. Operation at 40 Msps is fully characterized for AC performance (77 dB SNR, 90 dB SFDR) and DC accuracy (±2 LSB INL) across the 0°C to 70°C temperature range.

Does the LTC2191CUKG#PBF support both internal and external voltage references?

Yes, the LTC2191CUKG#PBF supports flexible reference configuration via the SENSE pin (Pin 50). Tying SENSE to VDD selects the internal 1.25 V reference with ±1 V input range; grounding SENSE selects ±0.5 V range; applying an external 0.625 V to 1.3 V voltage sets the input range to ±0.8×V_SENSE. The internal reference exhibits ±25 ppm/°C drift and 1.225 V to 1.275 V output tolerance at 25°C.

What LVDS serialization modes does the LTC2191CUKG#PBF support, and how are they configured?

The LTC2191CUKG#PBF supports 1-lane, 2-lane, and 4-lane LVDS serialization per channel, configured via the CS and SCK pins in parallel programming mode (PAR/SER = VDD) or via SPI register writes in serial mode. Each lane carries time-multiplexed bits: 1-lane outputs 16 bits per frame, 2-lane outputs 8 bits per lane, and 4-lane outputs 4 bits per lane-reducing interface width while maintaining 40 Msps throughput.

How does the duty cycle stabilizer in the LTC2191CUKG#PBF improve system design?

The LTC2191CUKG#PBF's internal duty cycle stabilizer corrects encode clock asymmetry, allowing high AC performance even with non-50% duty cycle inputs (e.g., from crystal oscillators or dividers). This eliminates the need for external duty cycle correction circuits, reduces BOM cost, and simplifies clock tree design-particularly valuable in space-constrained base station and SDR platforms where clock sources may lack tight duty cycle control.

What are the thermal management requirements for the LTC2191CUKG#PBF in continuous operation?

The LTC2191CUKG#PBF uses a 7 mm × 8 mm QFN package with an exposed thermal pad (Pin 53) that must be soldered to the PCB ground plane using multiple thermal vias. With θ_JA = 29°C/W and max power dissipation of 146 mW at 40 Msps, junction temperature rise is ~4.2°C above ambient-enabling reliable operation without heatsinks in ambient temperatures up to 70°C, provided the thermal pad is properly implemented per AN136 guidelines.