Analog Devices Inc. LTC2321IUFD-16#TRPBF

Overview

LTC2321IUFD-16#TRPBF from Analog Devices is a dual, 16-bit, 2 Msps successive approximation register (SAR) analog-to-digital converter with differential inputs, ±4 LSB INL (typ), 81 dB SNR at 500 kHz, and integrated 4.096 V temperature-compensated reference. It operates from a single 3.3 V or 5 V supply, supports CMOS or LVDS serial interface, and targets high-speed data acquisition in industrial and automotive systems requiring wide dynamic range and high common-mode rejection.

For engineers reviewing the LTC2321IUFD-16#TRPBF datasheet, LTC2321IUFD-16#TRPBF pinout, LTC2321IUFD-16#TRPBF application, or LTC2321IUFD-16#TRPBF equivalent, key selection criteria include guaranteed 16-bit no-missing-codes operation, 2 Msps per channel throughput with zero cycle latency, internal reference drift ≤20 ppm/°C, and support for –40°C to +85°C extended temperature operation.

Technical Context

The LTC2321IUFD-16#TRPBF implements two independent SAR ADC cores sharing a common reference architecture and digital interface. Each channel features a fully differential input stage with 8 V_P-P full-scale range and 85 dB CMRR at 500 kHz, enabling direct digitization of bipolar, unipolar, or pseudo-differential signals without external configuration.

Its SPI-compatible serial interface supports both CMOS (1.8 V–2.5 V I/O) and LVDS modes, with skew-matched CLKOUT output for timing-critical FPGA/DSP interfacing. The device includes nap and sleep modes, reducing power to 5 μW in sleep mode while maintaining reference wake-up time of 10 ms.

Key Specifications

Pinout & Package

Package: 28-lead (4 mm × 5 mm) plastic QFN (UFD) with exposed pad (Pin 29) soldered to PCB ground plane for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7606C-16 and ADS8924B, the LTC2321IUFD-16#TRPBF uniquely delivers dual-channel 2 Msps sampling with integrated reference and zero-latency operation in a compact 28-pin QFN - optimizing for space-constrained, timing-critical industrial and automotive signal chains.

Availability

LTC2321IUFD-16#TRPBF is available at Aetrix Electronics and suitable for high-speed motor control, industrial data acquisition, and automotive battery management requiring stable component supply, extended temperature qualification, and long-term production continuity.

Supply support for LTC2321IUFD-16#TRPBF 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. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, communications, automotive, and healthcare markets.

The LTC2321IUFD-16#TRPBF belongs to the LTC® high-speed precision SAR ADC product line, engineered for applications demanding simultaneous sampling, low latency, and guaranteed ac/dc performance across harsh environmental conditions.

FAQ

What is the maximum sampling rate supported by the LTC2321IUFD-16#TRPBF?

The LTC2321IUFD-16#TRPBF supports a maximum sampling rate of 2 Msps per channel, with zero cycle latency. This means each conversion completes within 500 ns, and the next conversion can begin immediately after readout. The timing is validated across the full –40°C to +85°C operating range and is independent of interface mode (CMOS or LVDS). At this rate, the LTC2321IUFD-16#TRPBF delivers sustained 16-bit no-missing-codes performance with ±4 LSB INL typical.

Does the LTC2321IUFD-16#TRPBF require an external reference?

No, the LTC2321IUFD-16#TRPBF integrates a precision 4.096 V temperature-compensated reference with ≤20 ppm/°C drift and 0.2% initial accuracy. REFOUT1 and REFOUT2 provide buffered outputs for each channel. An external reference may be used only if REFINT is grounded, allowing 1.25 V to VDD input - but doing so forfeits the drift and accuracy benefits of the internal reference. For most industrial applications, the internal reference eliminates calibration and reduces system cost.

How does the CMOS/LVDS pin (Pin 25) configure the digital interface of the LTC2321IUFD-16#TRPBF?

The CMOS/LVDS pin (Pin 25) selects the digital I/O standard: grounding it enables CMOS mode (1.8 V or 2.5 V logic levels); tying it to OVDD enables full-power LVDS mode; leaving it floating enables low-power LVDS mode. This pin directly controls driver strength, termination, and power consumption of SDO, CLKOUT, SCK, and CNV receivers. All three modes maintain functional compatibility with the same timing parameters, allowing flexible noise vs. power trade-offs without hardware redesign.

What is the purpose of the REFRTN1 and REFRTN2 pins on the LTC2321IUFD-16#TRPBF?

REFRTN1 (Pin 11) and REFRTN2 (Pin 27) are dedicated return paths for the internal reference buffers driving REFOUT1 and REFOUT2, respectively. They must be bypassed directly to their corresponding REFOUT pins using 0.1 µF and 10 µF ceramic capacitors - not tied to system ground. This Kelvin connection minimizes ground loop errors and ensures stable reference voltage regulation under dynamic load, preserving the 81 dB SNR and ±4 LSB INL performance. Incorrect routing degrades reference accuracy and increases noise coupling.

Can the LTC2321IUFD-16#TRPBF operate reliably at 125°C?

No - the LTC2321IUFD-16#TRPBF is rated for –40°C to +85°C (I-grade). For operation up to +125°C, the H-grade variant LTC2321HUFD-16#TRPBF must be used. While the datasheet notes "guaranteed operation to 125°C" in FEATURES, that specification applies exclusively to the H-grade part number. The I-grade LTC2321IUFD-16#TRPBF is not characterized or warranted beyond +85°C, and thermal derating or reliability risks apply above that limit.