STMicroelectronics STEVAL-ISQ009V1

Overview

STEVAL-ISQ009V1 from STMicroelectronics is a demonstration board for load-sharing control in parallel DC-DC converter systems, built around the L6615 current-sharing controller and three L6910-synchronized buck modules. It delivers 3.3 V / 5 A per channel from a +5 V input, supports 2+1 redundancy, enables hot-plug capability, and uses MOSFETs for both OR-ing and current sensing via R_DS(on).

For engineers reviewing the STEVAL-ISQ009V1 datasheet, STEVAL-ISQ009V1 pinout, STEVAL-ISQ009V1 application, or STEVAL-ISQ009V1 equivalent, this board serves as a validated reference for high-reliability, current-balanced multi-phase 3.3 V power delivery in telecom and industrial server applications where fault tolerance and dynamic reconfiguration are critical.

Technical Context

The motherboard implements analog current sharing using the L6615's differential current-sense amplifier and gate-drive outputs to regulate MOSFET conduction across up to three identical daughterboards. Each daughterboard integrates an L6910 synchronous buck controller driving external power stages with remote voltage sensing.

Failure isolation is achieved through dedicated enable/disable switches and L6615-controlled MOSFET gate sequencing, ensuring no output overvoltage during section removal or negative voltage drop during insertion - verified under live 3.3 V / 10 A load conditions.

Key Specifications

Availability

STEVAL-ISQ009V1 is available at Aetrix Electronics and suitable for telecom power systems, industrial server PSUs, and high-availability embedded computing platforms requiring stable component supply, rapid prototyping validation, and production-ready reference design reuse.

Supply support for STEVAL-ISQ009V1 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing microcontrollers, power ICs, sensors, and analog/mixed-signal solutions for industrial, automotive, and consumer markets.

The STEVAL evaluation board series targets power system designers needing turnkey, application-validated hardware for ST's proprietary controllers - specifically enabling fast verification of current-sharing, redundancy, and fault-handling architectures in multi-rail DC-DC systems.

FAQ

What is the primary function of the L6615 on this board?

The L6615 acts as the core current-sharing controller, measuring per-channel current via MOSFET R_DS(on) voltage drops and dynamically adjusting gate drive to balance output currents across up to three parallel buck converters. It also manages OR-ing MOSFET sequencing during hot-plug events to prevent backfeeding and output transients.

Can the board operate with only two daughterboards installed?

Yes - the motherboard supports 1-, 2-, or 3-daughterboard configurations. With two sections active, each supplies 5 A to meet a 10 A total load. The L6615 automatically recalibrates current sharing, and the disable/enable switches allow safe insertion or removal without disrupting output regulation or causing overcurrent in remaining channels.

Is remote voltage sensing implemented, and how is it connected?

Yes - each daughterboard includes dedicated remote sense traces (VSENSE+, VSENSE−) routed to the motherboard header. These connect directly to the load point, enabling precise 3.3 V regulation independent of PCB trace resistance, and are compatible with any L6615-based supply meeting its absolute maximum input voltage rating.

Does the board support thermal monitoring or overtemperature protection?

No - the STEVAL-ISQ009V1 reference design does not integrate thermal sensors or overtemperature shutdown circuitry. Protection relies on external system-level monitoring; the L6615 itself provides only current balancing and OR-ing control, with no built-in thermal sensing or shutdown functionality per ST's L6615 datasheet specifications.