Analog Devices Inc. LTC2188IUP#PBF

Overview

LTC2188IUP#PBF from Analog Devices (formerly Linear Technology) is a dual-channel, simultaneous-sampling 16-bit analog-to-digital converter optimized for high-frequency, wide-dynamic-range signal digitization in communications infrastructure. It delivers 77dB SNR, 90dB SFDR, and ultralow 0.07ps_RMS aperture jitter at 20Msps sampling rate, operating from a single 1.8V supply with 76mW total power consumption. It is deployed in cellular base stations and software-defined radios where precise IF undersampling and channel matching are critical.

For engineers reviewing the LTC2188IUP#PBF datasheet, LTC2188IUP#PBF pinout, LTC2188IUP#PBF application, or LTC2188IUP#PBF equivalent, key selection considerations include its dual-channel simultaneity, selectable CMOS/DDR-CMOS/DDR-LVDS output interface, 550MHz full-power bandwidth, ±2LSB INL, and support for differential or single-ended encode inputs with duty cycle stabilization.

Technical Context

The LTC2188IUP#PBF employs a shared-encode architecture enabling true simultaneous sampling across two independent 16-bit ADC cores, each with a 550MHz sample-and-hold front-end and integrated reference buffer. Its low-jitter design supports undersampling of IF signals up to 140MHz while maintaining 76.4dB SNR and 84dB SFDR at that frequency.

Digital output flexibility is implemented via programmable mode control registers accessed through a 4-wire SPI interface; output modes include full-rate CMOS (32 pins), DDR-CMOS (16 pins), or DDR-LVDS (16 differential pairs), with separate OVDD supply allowing CMOS swing adjustment from 1.2V to 1.8V and on-chip 100Ω LVDS termination.

Key Specifications

Pinout & Package

Package: 64-lead (9mm × 9mm) plastic QFN with exposed thermal pad (Pin 65 = GND, must be soldered to PCB ground plane).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel, 16-bit, 20Msps ADC applications.

Compared with AD9268BCPZ-20 and ADS52J90IRGCT, the LTC2188IUP#PBF uniquely combines single-supply 1.8V operation, integrated clock duty cycle stabilization, output randomization, and three parallel output interface options - making it optimal for compact, low-noise, mixed-signal systems where layout simplicity and deterministic timing are prioritized over serial interface density or marginal SNR gains.

Availability

LTC2188IUP#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 industrial temperature ranges (–40°C to +85°C).

Supply support for LTC2188IUP#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. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and digital signal processing technologies.

The LTC2188IUP#PBF belongs to Linear's high-speed precision ADC product line, engineered specifically for demanding communications and instrumentation applications requiring simultaneous sampling, low jitter, and flexible digital interfacing.

FAQ

What is the operating temperature range of the LTC2188IUP#PBF?

The LTC2188IUP#PBF is rated for industrial operation from –40°C to +85°C, as indicated by the "I" grade suffix in the part number. This is confirmed in the Absolute Maximum Ratings table and Order Information section, where LTC2188IUP#PBF is explicitly listed with the –40°C to 85°C temperature range. The device maintains full specification compliance-including 77dB SNR and ±2LSB INL-across this entire range.

Does the LTC2188IUP#PBF support both differential and single-ended analog inputs?

Yes, the LTC2188IUP#PBF supports differential analog inputs by default (AIN1+/AIN1–, AIN2+/AIN2–), with optimal performance achieved using 180° out-of-phase signals biased at VCM (VDD/2). It also supports single-ended input on AIN1+ (with AIN1– tied to VCM) for lower harmonic distortion sensitivity, though this degrades INL and SFDR while preserving DNL and noise performance, as documented in the Applications Information section.

How does the clock duty cycle stabilizer function in the LTC2188IUP#PBF?

The LTC2188IUP#PBF's optional clock duty cycle stabilizer corrects non-50% duty cycle encode clocks (ENC+/ENC–) to maintain full AC performance at 20Msps. When enabled via the SPI-controlled mode register, it allows high-fidelity sampling even with asymmetric clock sources-eliminating the need for external clock conditioning circuits. The stabilizer adds no pipeline latency and operates transparently in all output modes.

What digital output interface options does the LTC2188IUP#PBF provide?

The LTC2188IUP#PBF offers three configurable digital output modes: full-rate CMOS (32 single-ended outputs), double-data-rate CMOS (16 outputs, data on both CLKOUT edges), and double-data-rate LVDS (16 differential pairs). Output mode is selected via the SCK pin in parallel programming mode or SPI register in serial mode. Each mode uses separate OVDD (1.2–1.8V for CMOS; 1.7–1.9V for LVDS) and supports programmable termination and data randomization.

Can the LTC2188IUP#PBF operate with an external voltage reference?

Yes, the LTC2188IUP#PBF supports external reference operation via the SENSE pin. Applying a voltage between 0.625V and 1.3V to SENSE sets the input range to ±0.8 × V_SENSE. When SENSE is tied to VDD, the internal reference configures a ±1V range; when tied to GND, it selects ±0.5V. The internal 1.25V reference (VREF pin) remains available and can be bypassed with a 2.2µF capacitor for improved stability.