Analog Devices Inc. DC1350A-A

Overview

LTC2246H from Analog Devices (acquired Linear Technology) is a 14-bit, 25Msps low-power pipelined ADC designed for high-dynamic-range signal digitization in demanding imaging and broadband communication systems. It operates from a single 3V supply, delivers 74.5dB SNR and 90dB SFDR at 5MHz input, supports –40°C to 125°C automotive/industrial environments, and features flexible ±0.5V to ±1V differential input range with internal 1.5V VCM reference.

For engineers reviewing the LTC2246H datasheet, LTC2246H pinout, LTC2246H application, or LTC2246H equivalent, key selection considerations include its 48-pin LQFP package, clock duty cycle stabilizer capability, shutdown/nap modes, 1LSB RMS transition noise, and compatibility with transformer- or amplifier-based differential analog drive circuits.

Technical Context

The LTC2246H implements a six-stage CMOS pipelined architecture with 5-cycle pipeline latency and synchronous sampling triggered on the rising edge of a single-ended CLK input. Its sample-and-hold uses 4pF sampling capacitors and achieves 575MHz full-power bandwidth with <0.2psRMS aperture jitter.

It integrates a programmable reference system: SENSE pin selection configures ±0.5V or ±1V input range; MODE pin selects offset binary/2's complement output format and enables/disables the internal clock duty cycle stabilizer PLL; REFH/REFL pins require dual-capacitor bypassing (0.1μF + 2.2μF) for optimal SFDR performance.

Key Specifications

Pinout & Package

48-pin (7mm × 7mm) plastic LQFP package with exposed pad (LX), θ_JA = 53°C/W, TJ_MAX = 150°C. Pin 1 marked by dot; pins numbered counterclockwise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD9246BCPZ-25, LTC2246H offers superior SFDR and integrated reference/biasing; compared with LTC2226H, it delivers 2 extra bits of resolution at identical speed and footprint-critical for medical imaging and radar where ENOB directly impacts diagnostic accuracy or range resolution.

Availability

LTC2246H is available at Aetrix Electronics and suitable for medical imaging systems, wireless infrastructure equipment, automotive ADAS modules, and industrial motor drives requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LTC2246H 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 LTC2246H belongs to ADI's high-speed precision ADC product line, engineered specifically for wide-dynamic-range digitization in harsh-environment applications where AC performance, thermal stability, and low power must coexist.

FAQ

What is the maximum input frequency supported by the LTC2246H before aliasing occurs?

The LTC2246H has a 25Msps sampling rate, so its Nyquist frequency is 12.5MHz. Signals above 12.5MHz will alias into the baseband unless filtered by an anti-aliasing filter. Its 575MHz full-power bandwidth ensures minimal amplitude roll-off below Nyquist, preserving signal integrity for IF sampling applications up to 12.5MHz.

Can the LTC2246H operate with a single-ended analog input?

Yes, the LTC2246H supports single-ended input: drive AIN+ with the signal and tie AIN– to VCM (1.5V). However, this degrades harmonic distortion and INL; SNR and DNL remain unchanged. For optimal performance, differential drive is strongly recommended per the datasheet's application circuits.

How does the MODE pin affect the LTC2246H's output format and clock functionality?

The MODE pin selects both output coding and clock duty cycle stabilization: grounded → offset binary, stabilizer off; 1/3VDD → offset binary, stabilizer on; 2/3VDD → 2's complement, stabilizer on; VDD → 2's complement, stabilizer off. This dual function simplifies system-level clock sourcing flexibility without external logic.

What is the purpose of the SENSE pin on the LTC2246H, and how should it be configured?

The SENSE pin programs the LTC2246H's input range: tied to VCM → ±0.5V differential range; tied to VDD → ±1V differential range; driven with 0.5V–1V external voltage → ±V_SENSE range. It must be bypassed with 1μF ceramic capacitor to ground if externally driven, and placed close to the pin to avoid noise coupling.

Does the LTC2246H require external reference components, or is the reference fully integrated?

The LTC2246H integrates a 1.5V bandgap reference and VCM output, eliminating need for external reference ICs. However, REFH and REFL pins require external bypassing (0.1μF + 2.2μF ceramics) to maintain AC performance. An external reference can be applied via SENSE for custom ranges, but the internal reference suffices for standard ±0.5V/±1V operation.