Analog Devices Inc./Maxim Integrated MAX3786UTJ

Overview

MAX3786UTJ from Maxim Integrated is a 1.5Gbps Serial ATA-compatible multiplexer/buffer IC designed for redundant SATA I/O channel switching in storage controllers. It integrates receive equalization (EQ) and transmit preemphasis (PE) on dual controller-side channels, supports loss-of-signal detection on all three high-speed inputs, and enables loopback on the nonselected channel. It operates from a single +3.3V supply and is used in enterprise RAID controllers requiring failover-capable SATA signal routing.

For engineers reviewing the MAX3786UTJ datasheet, MAX3786UTJ pinout, MAX3786UTJ application, or MAX3786UTJ equivalent, key selection criteria include differential jitter performance (<50ps_P-P with EQ/PE enabled), 100Ω internal input termination, CML-compatible I/O architecture, and support for SATA out-of-band signaling with sub-5ns output enable/disable timing.

Technical Context

The MAX3786UTJ implements a triple-mux architecture with independent LVCMOS control of channel selection (SEL), loopback enable (LB_EN), and per-channel EQ/PE activation (EQ0EN/EQ1EN/PE0EN/PE1EN). Its LOS detectors monitor RX, IN0, and IN1 with 50–150mV_P-P thresholds and drive output disable logic with <5ns response time.

All high-speed I/Os use CML signaling with internally terminated 100Ω differential inputs and 50Ω single-ended-to-V_CC outputs. EQ and PE are calibrated to compensate for ~2.5dB path loss-matching typical 20in FR-4 stripline attenuation at 750MHz.

Key Specifications

Pinout & Package

The MAX3786UTJ is housed in a 5mm × 5mm, 32-lead thin QFN package with exposed pad (T3255-2), requiring soldering of the EP pad to PCB ground for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SATA mux/buffer applications.

Compared with MAX3785UTJ, the MAX3786UTJ adds essential EQ/PE for marginal channel conditions without increasing pin count or footprint; versus DS100DF410, it offers targeted 1.5Gbps SATA functionality at lower cost, power, and design complexity-ideal for cost-sensitive, space-constrained redundancy implementations.

Availability

MAX3786UTJ is available at Aetrix Electronics and suitable for RAID controller redundancy, SATA hot-swap validation, and high-density storage backplane applications requiring stable component supply and long-term industrial lifecycle support.

Supply support for MAX3786UTJ 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

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and high-speed interface ICs for industrial, communications, and computing markets.

The MAX3786UTJ belongs to Maxim's high-speed serial interface product line, engineered specifically for SATA infrastructure applications demanding low-jitter signal routing, OOB compatibility, and hardware-based redundancy management.

FAQ

What is the operating temperature range for the MAX3786UTJ?

The MAX3786UTJ is specified to operate from 0°C to +85°C ambient temperature. This industrial-grade range ensures reliable performance in server chassis, storage enclosures, and network-attached storage units where airflow and thermal management are constrained. The device's thermal design leverages the exposed pad for efficient heat dissipation into the PCB ground plane.

Does the MAX3786UTJ require external termination resistors?

No, the MAX3786UTJ does not require external termination resistors. Its high-speed inputs feature internal 100Ω differential termination, and outputs provide internal 50Ω single-ended-to-V_CC termination. External AC coupling capacitors are still required, but the integrated terminations eliminate 10 discrete resistors typically needed in SATA signal path designs.

How does the loopback function work on the MAX3786UTJ?

The MAX3786UTJ enables loopback on the nonselected I/O channel via the LB_EN pin. When LB_EN is driven low, the inactive channel (e.g., IN1/OUT1 when SEL = low) routes its input directly to its output, forming a local diagnostic path. This allows real-time validation of signal integrity and PHY layer functionality without engaging the primary data path or requiring external test hardware.

Can the MAX3786UTJ support SATA II (3Gbps) or SATA III (6Gbps) data rates?

No, the MAX3786UTJ is rated exclusively for 1.5Gbps operation. Its electrical specifications-including jitter, bandwidth, and EQ/PE calibration-are characterized and guaranteed only at SATA I speed. Attempting 3Gbps or 6Gbps operation exceeds design limits and will result in excessive jitter, closed eye diagrams, and link failure. For higher speeds, consider retimers like the DS100DF410.

What is the purpose of the CM0 and CM1 pins on the MAX3786UTJ?

The CM0 and CM1 pins provide access to the common-mode voltage nodes of the IN0 and IN1 differential inputs. Though normally left unconnected, each can be tied to V_CC via a 1.0µF capacitor to establish a low-impedance AC path for common-mode noise rejection-improving immunity to board-level EMI and power-supply noise without affecting differential signal integrity.