Analog Devices Inc. LTM2895HY#PBF

Overview

LTM2895HY#PBF from Analog Devices (formerly Linear Technology) is a galvanically isolated µModule SPI transceiver with integrated DAC control signaling, designed to isolate LTC/LTC-compatible general-purpose DACs (e.g., LTC2642-16) and generic mode-(0,0) SPI interfaces. It delivers 100MHz SPI-compatible I/O, supports 8–32-bit configurable word length, provides three isolated select signals (SA2/SB2/SC2), and features <30ps RMS LOAD-to-LOAD2 jitter for precision DAC update timing in industrial process control systems.

For engineers reviewing the LTM2895HY#PBF datasheet, LTM2895HY#PBF pinout, LTM2895HY#PBF application, or LTM2895HY#PBF equivalent, key selection criteria include its 6000VRMS isolation rating, −40°C to 125°C operating range, dual-voltage logic interface (1.71V–5.5V), high common-mode transient immunity (>50kV/µs), and support for two isolated chip selects in compact 15mm × 6.25mm BGA packaging.

Technical Context

The LTM2895HY#PBF implements transformer-based isolator µModule technology with differential pulse encoding across a reinforced insulation barrier, enabling bidirectional signal translation without optical coupling. It operates as a slave on the logic side and master on the isolated side, reconstructing SPI waveforms-including SCK2, MOSI2, MISO2, SS2, and LOAD2-with precise timing alignment.

Its architecture includes configuration registers (0x30H/0x83H) that set SCK2 frequency (up to 100MHz) and word length, while dedicated low-jitter LOAD path and three isolated select channels (SA/SB/SC → SA2/SB2/SC2) enable synchronized DAC updates and external multiplexer control-critical for multi-channel precision analog output systems.

Key Specifications

Pinout & Package

36-ball BGA package (15mm × 6.25mm × 2.06mm) with exposed thermal pad; ball pitch 0.8mm; moisture sensitivity level (MSL) 3; RoHS-compliant SAC305 finish.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar isolated SPI interface applications.

Compared with ADUM3481CRWZ and SI8641ED-B-IS, the LTM2895HY#PBF integrates SPI protocol translation, low-jitter LOAD2 generation, and three isolated select channels in one BGA package-reducing BOM count, PCB area, and timing validation effort for DAC-centric isolated systems.

Availability

LTM2895HY#PBF is available at Aetrix Electronics and suitable for industrial process control, test and measurement equipment, medical instrumentation, and ground-loop mitigation systems requiring stable component supply across extended temperature ranges and high-reliability isolation.

Supply support for LTM2895HY#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, serving industrial, automotive, communications, and healthcare markets.

The LTM2895HY#PBF belongs to Analog Devices' µModule isolated interface product line, engineered specifically for robust, drop-in SPI isolation in precision analog systems-emphasizing timing integrity, safety certification, and simplified system integration over generic digital isolation.

FAQ

What is the maximum SCK2 frequency supported by the LTM2895HY#PBF?

The LTM2895HY#PBF supports up to 100MHz SCK2 frequency, configurable via its internal registers (0x30H/0x83H). This enables high-speed communication with fast DACs like the LTC2642-16 while maintaining mode-(0,0) SPI compliance. At 100MHz, tSCK2L is guaranteed ≥9.1ns, and LOAD2 pulse width is ~40ns-critical for minimizing DAC update latency in real-time control loops.

Does the LTM2895HY#PBF require external configuration to operate in basic SPI mode?

No, the LTM2895HY#PBF operates as a plug-and-play SPI isolator at default settings: SCK2 = 50MHz, word length = 16 bits, and mode-(0,0) timing. External configuration (via 0x30H/0x83H writes) is only needed to adjust SCK2 frequency, word length (8–32 bits), or enable dual-DAC support using SSB2. Basic 4-wire SPI isolation works immediately after power-up with ON and ON2 asserted.

How does the LOAD-to-LOAD2 path achieve low jitter in the LTM2895HY#PBF?

The LTM2895HY#PBF uses a dedicated, hardwired analog timing path-not SPI-reconstructed logic-to transfer the LOAD falling edge across the isolation barrier. This path bypasses digital serialization/deserialization, achieving <30ps RMS jitter on LOAD2. The resulting narrow pulse (20–80ns width, dependent on SCK2 frequency) directly drives DAC LDAC inputs, ensuring deterministic output updates without software or clock-domain dependencies.

What safety certifications apply to the LTM2895HY#PBF?

The LTM2895HY#PBF carries UL 1577 (6000VRMS, File #255632), CSA (IEC/UL 60950-1, 62368-1, 60601-1), and reinforced insulation ratings. It meets 2 MOPP for medical use (287.5VRMS), 455VRMS reinforced insulation for industrial applications, and has CTI ≥600 VRMS with 0.2mm distance through insulation-validated per IEC 60112 and IEC 60601-1.

Can the LTM2895HY#PBF interface with 1.8V logic systems?

Yes, the LTM2895HY#PBF supports 1.71V–5.5V logic interface supplies (VL and VL2) on both sides, making it fully compatible with 1.8V microcontrollers and DACs. Input thresholds scale with VL/VL2 (VIH = 0.8×VL, VIL = 0.2×VL), and output drive strength (VOH/VOL) is specified across the full range-enabling seamless level-shifting between 1.8V, 3.3V, and 5V domains without external translators.