Analog Devices Inc. DC1370A-L

Overview

LTC2258-12 from Analog Devices (formerly Linear Technology) is a 12-bit, 65 Msps ultralow-power analog-to-digital converter optimized for undersampling high-frequency IF signals in communications infrastructure. It delivers 71.1 dB SNR, 88 dB SFDR, and 0.17 psRMS aperture jitter with single 1.8 V supply operation, enabling high-fidelity digitization in cellular base stations and software-defined radios.

For engineers reviewing the LTC2258-12 datasheet, LTC2258-12 pinout, LTC2258-12 application, or LTC2258-12 equivalent, key selection criteria include its 800 MHz full-power bandwidth, selectable CMOS/LVDS DDR outputs, SPI-configurable modes (randomizer, duty cycle stabilizer), and pin-compatible family scaling across 65/40/25 Msps variants.

Technical Context

The LTC2258-12 employs a pipelined ADC architecture with integrated sample-and-hold, correction logic, and configurable output drivers. Its ENC+/ENC– differential clock interface supports sine wave, PECL, LVDS, TTL, or CMOS inputs, and the optional duty cycle stabilizer ensures consistent timing performance across wide input duty cycles.

Digital outputs are configurable as full-rate CMOS, double-data-rate CMOS, or double-data-rate LVDS - with separate OVDD supply enabling 1.2 V to 1.8 V CMOS swing or 100 Ω on-chip LVDS termination. The SPI port allows runtime configuration of randomization, nap/sleep modes, and output polarity.

Key Specifications

Pinout & Package

40-lead (6 mm × 6 mm) plastic QFN package (UJ), exposed pad soldered to PCB ground for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD9230-65 and ADS5463, the LTC2258-12 offers superior SFDR (88 dB vs ≤85 dB), lower power (79 mW vs ≥1.2 W), and unique features like duty cycle stabilization and SPI-configurable randomization - making it optimal for cost- and power-sensitive IF sampling where LVDS/CMOS parallel interfacing is preferred over JESD204B.

Availability

LTC2258-12 is available at Aetrix Electronics and suitable for cellular infrastructure, portable medical imaging, and multi-channel data acquisition requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for LTC2258-12 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 DSP technologies, serving communications, industrial, automotive, and healthcare markets.

The LTC2258-12 belongs to Linear's ultralow-power, high-SFDR ADC family designed specifically for demanding IF sampling applications in wireless infrastructure and instrumentation where jitter, power, and configurability are critical.

FAQ

What is the maximum analog input frequency supported by the LTC2258-12?

The LTC2258-12 features an 800 MHz full-power bandwidth, meaning it can accurately digitize analog input signals up to 800 MHz in amplitude - enabling direct undersampling of IF signals in cellular and radar applications without external bandpass filtering. This specification is verified under standard test conditions with a 2 V_P-P differential input and 65 Msps sampling.

Does the LTC2258-12 support both internal and external voltage references?

Yes, the LTC2258-12 supports flexible reference configuration via the SENSE pin (Pin 39). Tying SENSE to VDD selects the internal 1.25 V reference with ±1 V input range; grounding SENSE selects ±0.5 V range; applying 0.625–1.3 V externally configures ±0.8×V_SENSE range. Internal reference drift is ±25 ppm/°C, and external reference input leakage is ±6 µA.

How does the duty cycle stabilizer function in the LTC2258-12?

The LTC2258-12's optional duty cycle stabilizer (enabled via CS pin in parallel mode or SPI register) corrects non-50% clock duty cycles on ENC+/ENC– inputs, ensuring consistent sampling aperture timing and minimizing timing-induced distortion. It operates across full 1–65 MHz encode rates and maintains <0.3 ns skew between rising/falling edge sampling points.

What are the power consumption differences between CMOS and LVDS output modes on the LTC2258-12?

In CMOS output modes (full-rate or DDR), the LTC2258-12 consumes 79 mW at 65 Msps with 1.8 V VDD and 1.2 V OVDD. In DDR LVDS mode with 3.5 mA drive strength, power increases to 152.6 mW due to higher output stage current - a trade-off for improved noise immunity and reduced EMI in dense PCB layouts.

Is the LTC2258-12 pin-compatible with other members of the LTC225x-12 family?

Yes, the LTC2258-12 is fully pin-compatible and register-compatible with the LTC2257-12 (40 Msps) and LTC2256-12 (25 Msps), sharing identical 40-pin QFN (6 mm × 6 mm) packaging, pin functions, and SPI command structure - enabling drop-in speed scalability without PCB redesign or firmware changes.