Analog Devices Inc. LTC2391ILX-16#PBF

Overview

LTC2391ILX-16#PBF from Analog Devices (formerly Linear Technology) is a 16-bit, 250ksps successive approximation register (SAR) analog-to-digital converter with ±4.096V fully differential input range, ±2LSB INL (max), 94dB SNR (typ), and integrated 4.096V reference. It operates from a single 5V supply and supports 1.8V–5V I/O, making it suitable for high-dynamic-range data acquisition in industrial instrumentation and medical imaging systems.

For engineers reviewing the LTC2391ILX-16#PBF datasheet, LTC2391ILX-16#PBF pinout, LTC2391ILX-16#PBF application, or LTC2391ILX-16#PBF equivalent, key selection considerations include guaranteed 16-bit no-missing-codes operation, internal reference tempco (±20ppm/°C max), parallel/serial interface flexibility, nap/sleep power-down modes, and –40°C to +85°C extended temperature grade.

Technical Context

The LTC2391ILX-16#PBF implements a charge-redistribution SAR architecture with precision internal 4.096V reference and on-chip reference buffer. Its fully differential input stage accepts ±VREF swing, enabling maximum signal utilization without external level-shifting. The device uses an internal oscillator for conversion timing, eliminating external clock dependency.

It supports dual interface modes: 16-bit parallel output (D0–D15) with CS/RD/BUSY handshaking, and serial SPI-compatible mode (SDIN/SDOUT/SCLK) with MSB-first transfer. Conversion starts on CNVST falling edge, completes in 2.5μs, and delivers data with zero cycle latency-no pipeline delay affects real-time control loops.

Key Specifications

Pinout & Package

Package: 48-lead 7mm × 7mm plastic LQFP, exposed pad (Pin 49) connected to GND. Thermal resistance θ_JA = 55°C/W. Operating junction temperature up to +150°C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS8860IRGET and AD7606BSTZ, the LTC2391ILX-16#PBF uniquely combines single-channel 250ksps performance, fully differential ±4.096V input, integrated low-drift reference, and zero-latency parallel/serial interfaces - reducing BOM count and layout complexity in high-fidelity DAQ systems.

Availability

LTC2391ILX-16#PBF is available at Aetrix Electronics and suitable for medical imaging data acquisition, industrial process monitoring, and automated test equipment requiring stable component supply across extended temperature ranges.

Supply support for LTC2391ILX-16#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 industrial, automotive, communications, and healthcare markets.

The LTC2391ILX-16#PBF belongs to ADI's precision SAR ADC product line, engineered for applications demanding high resolution, low noise, and deterministic timing - including portable instrumentation, factory automation, and diagnostic equipment.

FAQ

What is the operating temperature range of the LTC2391ILX-16#PBF?

The LTC2391ILX-16#PBF is specified for operation from –40°C to +85°C ambient temperature. Its junction temperature can reach +150°C, supported by θ_JA = 55°C/W in the 48-lead LQFP package. This extended industrial grade makes it suitable for deployment in harsh environments such as factory floors or outdoor instrumentation enclosures where thermal management is constrained.

Does the LTC2391ILX-16#PBF require an external clock source?

No, the LTC2391ILX-16#PBF does not require an external clock source. It incorporates an internal oscillator that sets the conversion time to 2.5μs, ensuring consistent 250ksps throughput regardless of supply or temperature variation. This eliminates timing jitter from external clocks and simplifies system-level clock tree design - a key advantage over many competing SAR ADCs that mandate precise external timing.

How does the internal reference of the LTC2391ILX-16#PBF perform over temperature?

The internal reference of the LTC2391ILX-16#PBF has a guaranteed temperature coefficient of ±20ppm/°C (max) and initial accuracy of ±0.5%. Measured data shows typical drift of ±4ppm/°C, delivering stable 4.096V output across –40°C to +85°C. This performance eliminates the need for external trimming in most industrial applications, while still allowing connection to higher-accuracy references like LT1790-4.096 if tighter spec is required.

Can the LTC2391ILX-16#PBF interface directly with a 1.8V FPGA?

Yes, the LTC2391ILX-16#PBF supports 1.8V–5V I/O voltage on its OVP supply rail (Pin 18), enabling direct connection to 1.8V FPGA I/O banks without level shifters. Digital outputs (D0–D15, BUSY, RD, etc.) are compatible with 1.8V logic thresholds when OVP = 1.8V, and input thresholds scale accordingly. This feature reduces component count and signal integrity risk in mixed-voltage systems.

What power-saving modes does the LTC2391ILX-16#PBF support?

The LTC2391ILX-16#PBF supports two low-power states: Nap mode (25μA typical supply current) and Sleep mode (125μA typical). Both are activated via the PD pin (Pin 33). In Nap mode, the reference remains active for fast wake-up; in Sleep mode, reference and oscillator are disabled for lowest power. Recovery time from Nap is <1μs, making it ideal for duty-cycled DAQ systems where rapid resumption is critical.