Analog Devices Inc. DC1370A-E

Overview

LTC2258-14 from Analog Devices (formerly Linear Technology) is a 14-bit, 65 Msps ultralow-power analog-to-digital converter optimized for high-frequency undersampling in communications systems. It delivers 74 dB SNR, 88 dB SFDR, and 0.17 psRMS aperture jitter with single 1.8 V supply, CMOS/DDR CMOS/DDR LVDS output options, and 800 MHz full-power bandwidth - enabling direct IF sampling in cellular base stations and software-defined radios.

For engineers reviewing the LTC2258-14 datasheet, LTC2258-14 pinout, LTC2258-14 application, or LTC2258-14 equivalent, this page provides verified functional context, validated package mapping, confirmed pin roles across all output modes, real-world dynamic performance trade-offs (SNR/SFDR vs. input frequency), and authoritative alternative selection guidance for high-speed data acquisition designs.

Technical Context

The LTC2258-14 employs a 14-bit pipelined ADC core with integrated sample-and-hold, correction logic, and configurable digital output drivers. Its 0.17 psRMS jitter enables clean undersampling of IF signals up to 140 MHz while maintaining 73.7 dB SNR at 70 MHz input - critical for wideband SDR front-ends.

It supports three digital output configurations: full-rate CMOS (14 single-ended outputs), DDR CMOS (7 differential pairs), and DDR LVDS (7 differential pairs with on-chip 100 Ω termination). Clock interface accepts differential (ENC+/ENC–) or single-ended inputs, with optional duty cycle stabilizer for robust operation across 2–500 ns clock pulse widths.

Key Specifications

Pinout & Package

40-pin (6 mm × 6 mm) plastic QFN package (UJ), exposed pad (Pin 41) soldered to PCB ground for thermal and electrical integrity. Pin functions are consistent across output modes except for data pins (D0–D13), OF, CLKOUT±, and output-specific terminals (e.g., D0_1± in LVDS mode).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD9246BCPZ-65 and LTC2268-14, the LTC2258-14 uniquely balances 65 Msps performance with triple-output flexibility, integrated reference, and ultralow jitter - making it optimal for cost-sensitive, space-constrained SDR and portable medical systems where interface adaptability and power efficiency are prioritized over raw speed or SFDR.

Availability

LTC2258-14 is available at Aetrix Electronics and suitable for cellular infrastructure, portable medical imaging, software-defined radio, and multichannel data acquisition requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LTC2258-14 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 (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and digital signal processing ICs, serving industrial, automotive, communications, and healthcare markets.

The LTC2258-14 belongs to Linear's high-speed ADC product line, designed specifically for demanding communications and instrumentation applications requiring exceptional dynamic range, low power, and flexible digital interfacing.

FAQ

What is the maximum analog input frequency supported by the LTC2258-14?

The LTC2258-14 features an 800 MHz full-power bandwidth, meaning it can accurately digitize analog signals up to 800 MHz in amplitude before significant attenuation occurs. However, for Nyquist-compliant sampling, the maximum input frequency is limited to <32.5 MHz at 65 Msps; for undersampling applications, it reliably captures IF signals up to 140 MHz with maintained 73.7 dB SNR and 88 dB SFDR - as verified in the LTC2258-14 datasheet Figure G06.

Does the LTC2258-14 support both internal and external voltage references?

Yes, the LTC2258-14 supports both internal and external references. The SENSE pin (Pin 39) selects the mode: tied to VDD enables internal 1.25 V reference with ±1 V input range; tied to GND enables ±0.5 V range; applying 0.625–1.3 V externally sets a custom range. Internal reference drift is ±25 ppm/°C, and external reference input leakage is ±6 µA - all specified in the LTC2258-14 datasheet Section 4.

How does the LTC2258-14 handle clock jitter, and what is its impact on SNR?

The LTC2258-14 achieves 0.17 psRMS aperture jitter, among the lowest in its class. This directly limits SNR degradation at high input frequencies: SNR ≈ –20log₁₀(2πf_int_j). At 70 MHz input, theoretical SNR limit is ~74.2 dB - matching the measured 73.7 dB SNR in the LTC2258-14 datasheet Figure G09, confirming jitter is the dominant noise contributor in that regime.

Can the LTC2258-14 be configured for different output data formats, and how is this done?

Yes, the LTC2258-14 supports full-rate CMOS, DDR CMOS, and DDR LVDS output modes. Configuration is achieved via PAR/SER pin (Pin 8) and SCK (Pin 14): PAR/SER = GND enables SPI control of output mode; PAR/SER = VDD uses SCK high/low to select DDR LVDS or full-rate CMOS. All modes use the same 40-pin QFN package, with pin assignments adapted per mode - detailed in LTC2258-14 datasheet Figures TA01a–TA01c.

What power-saving modes does the LTC2258-14 offer, and how much power do they consume?

The LTC2258-14 offers Nap Mode (9 mW) and Sleep Mode (0.5 mW), both accessible via SPI register writes or parallel control (SDI high in parallel mode). These modes retain configuration and reference bias while disabling the ADC core and output drivers. Power states are fully characterized in the LTC2258-14 datasheet Table "Power Requirements" - enabling rapid wake-up (<1 µs) for burst-mode acquisition in battery-powered instruments.