Analog Devices Inc./Maxim Integrated VT1697SBFQX+CN9

Overview

VT1697SBFQX+CN9 from Maxim Integrated is a smart slave IC for multiphase synchronous buck voltage regulators, designed to operate with seventh-generation Maxim master controllers. It integrates per-phase current sensing (±79.1A to ±80A clamp), die temperature monitoring (0°C to 150°C range), and protection circuits including VX short detection, VDDH UVLO/OVLO, and overtemperature shutdown at 140°C–165°C. It supports 300kHz–1.3MHz switching and enables phase shedding in high-current CPU/GPU VR applications.

For engineers reviewing the VT1697SBFQX+CN9 datasheet, VT1697SBFQX+CN9 pinout, VT1697SBFQX+CN9 application, or VT1697SBFQX+CN9 equivalent, key selection criteria include its FCQFN-16 package with top-side thermal pad, SMBus-enabled per-phase telemetry, integrated lossless current reconstruction, and compatibility with coupled inductors in VR12.0/VR12.5 systems.

Technical Context

The VT1697SBFQX+CN9 implements a monolithic synchronous buck power stage with integrated high- and low-side MOSFET drivers, lossless current-sense reconstruction, and analog temperature sensing. Its PWM input accepts three-state logic (high/mid/low) to enable diode emulation, phase shedding, and DCM operation under master control.

Protection is implemented via dedicated circuits: instantaneous OCP clamping (±64.7A to ±80A), VDDH OVLO/UVLO (14.95V–16.41V / 3.90V–4.40V), BST UVLO (1.32V–1.66V), and VX short-to-rail detection. Faults trigger TS_FAULT assertion and immediate shutdown, except for cycle-by-cycle OCP which does not assert TS_FAULT.

Key Specifications

Pinout & Package

The VT1697SBFQX+CN9 is housed in a 16-pin FCQFN (Fine-Pitch Chip-Scale Quad Flat No-Lead) package with an exposed top-side thermal pad electrically tied to VSS. This top-side cooling architecture reduces junction-to-ambient thermal resistance to 0.42°C/W and enables higher power density without requiring bottom-side heatsinking.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar smart slave IC applications.

Compared with VT1697SBFQX+CN9, VT1695SBFQX+CN9 offers identical form-factor and interface but reduced OCP headroom, while ISL95816IRZ-T requires full firmware and thermal redesign due to incompatible protocol and thermal architecture.

Availability

VT1697SBFQX+CN9 is available at Aetrix Electronics and suitable for high-current voltage regulators, microprocessor power delivery, and GPU/ASIC VR applications requiring stable component supply and long-term lifecycle support.

Supply support for VT1697SBFQX+CN9 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 power management ICs for demanding industrial, computing, and communications applications.

The VT1697SBFQX+CN9 belongs to Maxim's seventh-generation smart slave product line, engineered specifically for high-density, high-efficiency multiphase VRs in server CPUs, GPUs, and networking ASICs with emphasis on telemetry, protection, and thermal performance.

FAQ

What is the primary function of the VT1697SBFQX+CN9 in a multiphase VR system?

The VT1697SBFQX+CN9 serves as a smart slave IC that implements one phase of a synchronous buck converter, integrating power FET drivers, lossless current sensing, die temperature monitoring, and comprehensive fault protection. It operates under command from a Maxim master IC and reports per-phase current and temperature via SMBus. Its role is to execute switching, enforce safety limits, and provide real-time telemetry-making VT1697SBFQX+CN9 essential for high-accuracy, high-reliability VR designs.

Does the VT1697SBFQX+CN9 require external power FETs, or are they integrated?

The VT1697SBFQX+CN9 integrates both high-side and low-side power MOSFETs within the monolithic FCQFN package-no external FETs are required. It is a complete smart power stage, combining gate drivers, current/temperature sensors, protection logic, and power switches into a single device. This integration eliminates external FET layout complexity and parasitic losses, directly enabling the compact footprint (<1600mm² for 150A) cited in VT1697SBFQX+CN9 documentation.

How does the VT1697SBFQX+CN9 handle overcurrent conditions, and what happens to the TS_FAULT pin?

The VT1697SBFQX+CN9 implements two-tier overcurrent protection: cycle-by-cycle clamping (±64.7A to ±80A) that regulates peak current without asserting TS_FAULT, and a latching OCP shutdown level that pulls TS_FAULT low and disables the device until power cycle. TS_FAULT serves dual purpose-under normal operation it outputs analog temperature voltage; upon detection of latching faults (OTP, VX short, VDDH OVLO/UVLO), it is actively driven low to signal the master. This behavior is explicitly defined in VT1697SBFQX+CN9's Table 1 and Electrical Characteristics.

Can the VT1697SBFQX+CN9 be used with coupled inductors, and what benefit does that provide?

Yes, the VT1697SBFQX+CN9 supports coupled-inductor mode via proprietary signaling from the Maxim master IC. In this mode, the slave adjusts switching behavior to minimize circulating currents in inactive phases during phase shedding-reducing conduction losses and improving light-load efficiency. This capability is confirmed in the "Phase Configuration" and "Design Considerations" sections of the VT1697SBFQX+CN9 datasheet and is a distinguishing feature versus non-coupled alternatives.

What is the significance of the top-side thermal pad on the VT1697SBFQX+CN9 package?

The top-side thermal pad on the VT1697SBFQX+CN9 FCQFN package provides a dedicated thermal path to ambient air, achieving a junction-to-case thermal resistance of just 0.42°C/W. Unlike conventional QFNs relying solely on bottom-side conduction, this design lowers junction temperature under airflow (e.g., 200LFM), reduces PCB heating, and enables higher sustained current density. The pad is electrically connected to VSS but is intended exclusively for thermal conduction-not electrical routing-per VT1697SBFQX+CN9 layout guidelines.