Analog Devices Inc. DC1500A-C

Overview

LTC2391-16 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 both parallel and serial interfaces, targeting high-fidelity data acquisition in medical imaging and industrial process control.

For engineers reviewing the LTC2391-16 datasheet, LTC2391-16 pinout, LTC2391-16 application, or LTC2391-16 equivalent, key selection considerations include guaranteed 16-bit no-missing-codes operation, internal reference tempco (±20ppm/°C max), 250ksps throughput with zero cycle latency, and dual 48-lead LQFP/QFN package options rated to 125°C.

Technical Context

The LTC2391-16 employs a charge-redistribution SAR architecture with a precision internal 4.096V reference buffer and on-chip oscillator, eliminating external clocking requirements. Its fully differential input stage accepts ±VREF signals with 70dB CMRR and supports 50MHz –3dB input bandwidth.

Conversion is initiated by a falling edge on CNVST; acquisition time is 1485ns and conversion time is 2500ns, enabling full 250ksps throughput with no pipeline delay. Interface mode (parallel/serial) is selected via SER/PAR pin, and output format (offset binary/two's complement) is controlled by OB/2C.

Key Specifications

Pinout & Package

Available in two RoHS-compliant 48-lead packages: 7mm × 7mm plastic QFN (UK) and 7mm × 7mm plastic LQFP (LX), both with exposed thermal pad (GND). Pin functions are identical across packages; layout requires separate analog/digital ground planes and local 0.1μF + 10μF AVP/DVP bypassing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7606C-16 and ADS8860, the LTC2391-16 uniquely balances 250ksps single-channel throughput, ±4.096V differential input, integrated low-drift reference, and 94dB SNR-making it optimal for space-constrained, high-fidelity instrumentation where channel count is secondary to signal fidelity.

Availability

LTC2391-16 is available at Aetrix Electronics and suitable for medical imaging systems, industrial process controllers, automated test equipment, and high-speed data loggers requiring stable component supply across extended temperature ranges.

Supply support for LTC2391-16 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 semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LTC2391-16 belongs to ADI's precision SAR ADC product line, engineered for applications demanding high resolution, low noise, and guaranteed performance over temperature without calibration.

FAQ

What is the maximum operating temperature for the LTC2391-16?

The LTC2391-16 is qualified for operation up to 125°C in the H-grade (LTC2391HLX-16), with thermal resistance θJA = 55°C/W for the LQFP package. This rating enables use in under-hood automotive sensors and industrial motor drives where ambient temperatures exceed 85°C. The LTC2391-16 maintains ±2LSB INL and 94dB SNR specifications across this full range.

Does the LTC2391-16 require an external clock source?

No, the LTC2391-16 includes an internal oscillator that sets conversion timing, eliminating the need for an external clock. This simplifies system design and improves jitter immunity. External clocks are not supported-the SCLK pin functions only as a serial interface clock in SER/PAR = 1 mode, not as a master conversion clock.

Can the LTC2391-16 operate with a 3.3V I/O supply?

Yes, the LTC2391-16 supports OVP from 1.8V to 5V, allowing direct connection to 3.3V logic without level shifters. Pins RD, CS, BUSY, D0–D15, and serial interface pins (SDIN/SDOUT/SCLK) are all compatible with 3.3V signaling when OVP = 3.3V, while AVP and DVP remain at 5V for analog/digital core operation.

How does the internal reference of the LTC2391-16 connect to the ADC core?

The LTC2391-16 uses its internal 4.096V reference directly as the conversion基准-no external buffering or scaling is needed. When REFOUT and REFIN are tied together, the reference buffer drives the SAR DAC array with low output impedance (~2.6kΩ) and high PSRR, ensuring stable VREF despite supply ripple. REFSENSE is left floating in this configuration.

What is the purpose of the BYTESWAP pin on the LTC2391-16?

The BYTESWAP pin selects byte ordering for parallel output: when low, D15–D0 appear on pins 28–9 (MSB-first); when high, upper and lower bytes are swapped so D7–D0 appear on pins 28–21 and D15–D8 on pins 16–9. This matches legacy processor bus endianness requirements without requiring firmware reordering of received data.