Analog Devices Inc. LTC2435-1IGN#PBF

Overview

LTC2435-1IGN#PBF from Analog Devices (formerly Linear Technology) is a 20-bit micropower delta-sigma ADC with differential input and reference, 87dB simultaneous 50Hz/60Hz normal-mode rejection, 120dB DC common-mode rejection, and 0.8ppm RMS noise - designed for high-precision sensor digitization in industrial instrumentation and weigh scales.

For engineers reviewing the LTC2435-1IGN#PBF datasheet, LTC2435-1IGN#PBF pinout, LTC2435-1IGN#PBF application, or LTC2435-1IGN#PBF equivalent, key selection criteria include its 13.75Hz output rate, SSOP-16 package, single-cycle settling for multiplexed sensors, internal oscillator eliminating external timing components, and flexible GND-to-VCC common-mode range for remote sensing.

Technical Context

The LTC2435-1IGN#PBF implements a decimating FIR digital filter synchronized to an internal oscillator or user-supplied external clock (5–2000kHz), enabling notch rejection at 49Hz–61.2Hz without external components. Its auto-calibration architecture performs full-scale correction every conversion cycle but omits per-cycle offset calibration to achieve doubled throughput versus LTC2430.

It operates in three distinct states - conversion, sleep (4µA), and data output - controlled solely by CS and SCK logic transitions, with no configuration registers required. The 3-wire SPI/MICROWIRE-compatible interface supports both internal and external SCK modes, determined dynamically at power-up or on CS falling edge.

Key Specifications

Pinout & Package

Package: 16-lead plastic SSOP (GN), 5.0mm × 6.2mm footprint compatible with SO-8 layouts. Thermal resistance θJA = 95°C/W; TJMAX = 125°C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS124S08IPWR and LTC2440CGN#PBF, the LTC2435-1IGN#PBF uniquely balances 20-bit precision, 13.75Hz throughput, 4µA sleep current, and guaranteed 87dB simultaneous 50/60Hz rejection in a compact SSOP-16 - making it optimal for portable, globally deployed instrumentation requiring zero-firmware regional adaptation.

Availability

LTC2435-1IGN#PBF is available at Aetrix Electronics and suitable for industrial process control, portable test equipment, and high-accuracy weigh scale designs requiring stable component supply across global manufacturing sites.

Supply support for LTC2435-1IGN#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. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors.

The LTC2435-1IGN#PBF belongs to Linear's precision delta-sigma ADC product line, engineered specifically for low-power, high-accuracy sensor digitization in harsh industrial environments with stringent EMI immunity requirements.

FAQ

What is the maximum output data rate of the LTC2435-1IGN#PBF?

The LTC2435-1IGN#PBF achieves a maximum output data rate of 13.75Hz when configured for simultaneous 50Hz/60Hz rejection using its internal oscillator. This rate is fixed for the LTC2435-1 variant and cannot be increased without sacrificing line-frequency rejection performance. External clocking does not increase the rate beyond this specification, as the digital filter structure is optimized for 49–61.2Hz notch placement.

Does the LTC2435-1IGN#PBF require external passive components for line-frequency rejection?

No, the LTC2435-1IGN#PBF requires no external passive components for line-frequency rejection. Its integrated oscillator and decimating FIR filter provide guaranteed ≥87dB normal-mode rejection across 49Hz–61.2Hz when FO is grounded. Unlike competing ADCs that rely on external RC networks or crystals, this eliminates BOM cost, layout sensitivity, and temperature drift concerns associated with discrete timing elements.

How does the LTC2435-1IGN#PBF handle offset drift over temperature?

The LTC2435-1IGN#PBF exhibits offset drift of ≤100nV/°C, verified over the full –40°C to +85°C operating range. This performance stems from its modulator architecture and absence of per-conversion offset calibration - which trades minor initial offset (≤5mV) for doubled throughput. The low drift enables stable zero-point accuracy in unattended field instruments without periodic recalibration.

Can the LTC2435-1IGN#PBF interface directly with a 3.3V microcontroller SPI bus?

Yes, the LTC2435-1IGN#PBF supports 3.3V logic levels natively. Its digital inputs (CS, FO, SCK) accept VIH ≥2.0V and VIL ≤0.6V at VCC = 2.7–3.3V, while SDO outputs VOH ≥VCC–0.5V and VOL ≤0.4V - fully compatible with standard 3.3V SPI peripherals. No level-shifting circuitry is required when VCC = 3.3V, simplifying interface design and reducing component count.

What is the purpose of the seven GND pins on the LTC2435-1IGN#PBF SSOP-16 package?

The seven GND pins (Pins 1, 7, 8, 9, 10, 15, 16) on the LTC2435-1IGN#PBF serve distinct analog and digital grounding functions. They provide low-impedance return paths for reference, input, and digital currents while minimizing ground bounce and crosstalk. All seven must be connected to a solid ground plane - splitting or omitting any compromises PSRR, CMRR, and noise performance, particularly the critical 120dB DC common-mode rejection specification.