Analog Devices Inc. LTM2893IY#PBF

Overview

LTM2893IY#PBF from Analog Devices is a high-speed isolated μModule SPI interface IC optimized for 1Msps, 18-bit SAR ADCs such as the LTC2338 family. It provides galvanic isolation of conversion start (CNV→CNV2), busy signaling, and three multiplexer select lines with 30ps_RMS aperture jitter, 20ns latency, and 100MHz SPI-compatible I/O - enabling precision data acquisition in industrial process control and test equipment.

For engineers reviewing the LTM2893IY#PBF datasheet, LTM2893IY#PBF pinout, LTM2893IY#PBF application, or LTM2893IY#PBF equivalent, key selection criteria include its 6000V_RMS isolation rating, configurable 8–32-bit SPI word length, dual-voltage logic support (1.71–5.5V), and guaranteed timing performance across –40°C to +85°C.

Technical Context

The LTM2893IY#PBF implements coreless transformer-based isolator μModule technology, encoding digital signals into differential pulses across a reinforced insulation barrier. It integrates dedicated state machines for ADC handshake sequencing - including CNV edge transfer, BUSY/BUSY2 synchronization, and MISOA/MISOB data buffering - with independent configuration via CSC-controlled register.

It supports two operational modes: read-only isolation (LTM2893) and read/write isolation (LTM2893-1). The LTM2893IY#PBF variant is the industrial-grade (–40°C to +85°C), non–1 version, featuring fixed read-only operation, 3V–5.5V supply range on both sides, and 15mm × 6.25mm BGA package with 36-ball layout.

Key Specifications

Pinout & Package

36-pin BGA package (15mm × 6.25mm × 2.06mm), RoHS-compliant SAC305 ball finish, MSL Level 3. Pin functions are electrically isolated between logic side (VL/GND) and isolated side (VL2/GND2).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ADC isolation applications.

Compared with ADUM6401ARWZ and ISO7741FEDWR, the LTM2893IY#PBF delivers integrated ADC interface logic, guaranteed low-aperture-jitter CNV transfer, and autonomous SPI transaction management - reducing firmware burden and enabling higher-resolution, higher-speed isolated data acquisition in a single BGA package.

Availability

LTM2893IY#PBF is available at Aetrix Electronics and suitable for industrial process control, test and measurement equipment, and high-speed data acquisition systems requiring stable component supply, long-term lifecycle assurance, and certified reinforced isolation.

Supply support for LTM2893IY#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. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LTM2893IY#PBF belongs to Analog Devices' isolated μModule product line, designed specifically to simplify high-fidelity, high-speed ADC interfacing in safety-critical and noise-immune applications - eliminating discrete isolation + interface logic design effort.

FAQ

What is the primary function of the LTM2893IY#PBF?

The LTM2893IY#PBF is an isolated SPI interface μModule that bridges a host processor to isolated SAR ADCs. Its core function is to transfer conversion start (CNV), busy (BUSY), and data (MISOA/MISOB) signals across a 6000V_RMS galvanic barrier while maintaining ultra-low aperture jitter (30ps_RMS) and deterministic timing - enabling high-resolution, high-speed data acquisition in noisy industrial environments. The LTM2893IY#PBF implements this with integrated state machines and transformer-based isolation.

Does the LTM2893IY#PBF support both read and write operations to the ADC?

No, the LTM2893IY#PBF is the read-only variant of the LTM2893 family. It supports reading ADC conversion results via MISOA/MISOB but does not provide MOSI2 output for writing configuration data to the ADC. That capability is exclusive to the LTM2893-1 variants (e.g., LTM2893IY-1#PBF). The LTM2893IY#PBF is optimized for ADCs like the LTC2338 family that require only read access after conversion.

What is the significance of the 30ps_RMS CNV jitter specification for the LTM2893IY#PBF?

The 30ps_RMS CNV→CNV2 aperture jitter directly limits the achievable SNR in high-resolution SAR ADC systems. For an 18-bit ADC sampling at 1Msps, this jitter contributes <0.5 LSB of timing-induced noise - preserving >95dB measured SNR as verified with the LTC2338-18. This performance is essential for precision applications like power quality analysis and medical instrumentation where dynamic range must be maintained under real-world conditions. The LTM2893IY#PBF achieves this via proprietary coreless transformer encoding and low-skew internal routing.

Can the LTM2893IY#PBF interface with ADCs using non-standard SPI modes?

The LTM2893IY#PBF operates strictly in SPI mode (0,0): SCK idle low, data sampled on rising edge. It does not support mode (1,1), (0,1), or (1,0). Compatibility requires the ADC to meet setup/hold timing relative to SCK rising edges (e.g., tSUMISO2 ≤ 1.8ns, tHDMISO2 ≥ 1ns at 100MHz). ADCs like the LTC2328-18 and LTC2378-18 are validated; others must satisfy the documented timing windows and avoid using SCK as a continuous conversion clock - a requirement explicitly enforced by the LTM2893IY#PBF's fault detection logic.

How does the LTM2893IY#PBF handle multiple ADCs in parallel configurations?

The LTM2893IY#PBF supports parallel ADC configurations via its BUSYS input (P6), which accepts a secondary ADC's BUSY signal. When BUSYS is asserted, the device synchronizes readout across both ADCs, ensuring coherent sampling. Additionally, the three isolated select signals (SA2/SB2/SC2) can independently configure multiplexers or gain stages per ADC channel. This architecture enables tightly coupled multi-channel acquisition - for example, isolating four LTC2348 channels using one LTM2893IY#PBF per pair - without external timing arbitration logic.