Analog Devices Inc. LTC2357CLX-18#PBF

Overview

LTC2357CLX-18#PBF from Analog Devices (formerly Linear Technology) is an 18-bit, quad-channel simultaneous-sampling SAR ADC with buffered differential inputs, ±10.24V input range, 350ksps per channel throughput, and integrated 4.096V reference buffer. It operates from ±15V analog supplies and 5V digital supply, delivering 96.4dB SNR and ±3.5LSB INL in industrial power monitoring and PLC analog input modules.

For engineers reviewing the LTC2357CLX-18#PBF datasheet, LTC2357CLX-18#PBF pinout, LTC2357CLX-18#PBF application, or LTC2357CLX-18#PBF equivalent, key selection criteria include per-channel SoftSpan™ reconfigurable input ranges (±10.24V/0–10.24V/±5.12V/0–5.12V), picoamp-level input leakage (5pA max at 85°C), 128dB CMRR, LVDS/CMOS serial interface flexibility, and 48-lead LQFP package compatibility with high-voltage signal conditioning layouts.

Technical Context

The LTC2357CLX-18#PBF implements a true 4-channel simultaneous sampling architecture using independent track-and-hold circuits per channel, enabling synchronized acquisition across all inputs without inter-channel skew. Its picoamp-input analog buffers support rail-to-rail common-mode voltage operation from VEE + 4V to VCC – 4V (e.g., –11V to +34V with ±15V supplies), eliminating external level-shifting for wide-range sensor interfaces.

Conversion is controlled by a single CNV pulse triggering simultaneous sampling, with internal clock generation ensuring zero cycle latency. The SoftSpan™ configuration allows dynamic per-conversion selection of four bipolar/unipolar input ranges via SPI register writes, while the integrated reference buffer delivers 4.096V with 5ppm/°C tempco and supports external overdrive up to 5V.

Key Specifications

Pinout & Package

The LTC2357CLX-18#PBF uses a 48-lead plastic LQFP (LX package) with 0.5mm pitch and exposed thermal pad. Pin functions are defined per the official Linear/ADI pinout diagram (top view, LX package).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7606C-18 and ADS8684, the LTC2357CLX-18#PBF uniquely combines per-channel reconfigurable input ranges, simultaneous sampling with 150ps matching, and dual LVDS/CMOS interface - making it optimal for synchronized multi-sensor systems where input signal types vary across channels and EMI resilience is critical.

Availability

LTC2357CLX-18#PBF is available at Aetrix Electronics and suitable for industrial process control, power line monitoring, and programmable logic controller applications requiring stable component supply, long-term lifecycle support, and traceable sourcing for safety-critical deployments.

Supply support for LTC2357CLX-18#PBF 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 LTC2357 series was designed specifically for high-voltage, high-accuracy industrial data acquisition systems requiring simultaneous sampling, wide common-mode input tolerance, and flexible interface options - addressing limitations of legacy multichannel ADCs in PLC and power monitoring equipment.

FAQ

What is the operating temperature range for the LTC2357CLX-18#PBF?

The LTC2357CLX-18#PBF is specified for 0°C to 70°C ambient operation, as indicated by the 'C' grade suffix. This commercial temperature range suits indoor industrial control cabinets and laboratory test equipment where ambient conditions are regulated. The part maintains full 18-bit no-missing-codes performance and ±3.5LSB INL across this range, with zero-scale error drift of ±4μV/°C and full-scale error drift of ±2.5ppm/°C.

Does the LTC2357CLX-18#PBF support both CMOS and LVDS serial interfaces?

Yes, the LTC2357CLX-18#PBF supports pin-selectable CMOS and LVDS serial interfaces. Interface mode is determined by the voltage applied to the LVDS/CMOS pin: grounded for LVDS, tied to OVDD for CMOS. In CMOS mode, 1–4 data lanes (SDO0–SDO3) can be enabled to balance bus width and throughput; LVDS mode uses differential pairs for noise-immune high-speed communication up to 100MHz clock rates.

How does the SoftSpan™ feature work on the LTC2357CLX-18#PBF?

The SoftSpan™ feature on the LTC2357CLX-18#PBF allows independent, conversion-by-conversion configuration of each of the four input channels to accept ±10.24V, 0–10.24V, ±5.12V, or 0–5.12V signals via SPI register writes. This eliminates external gain-switching circuitry when interfacing mixed-sensor types (e.g., ±10V accelerometers and 0–10V pressure transducers) on the same ADC, preserving signal integrity and reducing PCB area.

What is the maximum input common-mode voltage range supported by the LTC2357CLX-18#PBF?

The LTC2357CLX-18#PBF supports a wide input common-mode voltage range of VEE + 4V to VCC – 4V. With typical ±15V analog supplies (VCC = +15V, VEE = –15V), this translates to –11V to +11V common-mode range - sufficient to directly digitize signals from industrial ±10V sensors without level-shifting. The 128dB CMRR at 200Hz ensures robust rejection of common-mode interference within this range.

Can the LTC2357CLX-18#PBF operate with external reference sources?

Yes, the LTC2357CLX-18#PBF supports external reference operation via the REFIN pin, which accepts 1.25V to 2.2V inputs. When using an external reference, the internal reference buffer must be disabled by setting REFIN = 0V. This enables integration with ultra-low-noise references or system-level reference distribution networks, though the internal 4.096V buffer (with 5ppm/°C tempco) is typically preferred for simplicity and stability in most industrial applications.