STMicroelectronics VN31SP-E

Overview

VN31SP-E from STMicroelectronics is a high-side smart power solid-state relay built with VIPower M0-3 technology, designed for automotive-grade switching of resistive or inductive loads with one side grounded. It delivers 31 A continuous output current at Tc = 85 °C, features 60 V V(BR)DSS, 0.03 Ω RDS(on) at 11.5 A, integrated thermal shutdown, open-drain diagnostic output, and -18 V fast demagnetization for inductive loads - used in body control modules and lighting drivers.

For engineers reviewing the VN31SP-E datasheet, VN31SP-E pinout, VN31SP-E application, or VN31SP-E equivalent, key selection criteria include ISO-compliant nominal current (11.5 A), diagnostic timing parameters (tpol = 50–700 µs), load-dump immunity (ISO 7637-2 Pulse 5 Level II), reverse-battery protection architecture, and PowerSO-10 thermal resistance (Rthj-case = 1.2 °C/W).

Technical Context

The VN31SP-E integrates a vertical power MOSFET with embedded protection logic, current sensing, temperature monitoring, and open-load detection circuitry - all monolithically realized in ST's VIPower process. Its diagnostic output responds to four fault conditions: open load (off/on state), short-to-VCC, overtemperature (>140 °C), and undervoltage (<5 V), with programmable filtering (t1(on)/t1(off) = 1–10 ms) compliant with ISO 16750-2 and ISO 21848 standards.

Switching behavior is optimized for automotive battery environments: turn-off includes active clamp at −18 V (typ.) to accelerate inductive energy dissipation, while input logic thresholds (VIH = 2 V min, VIL = 0.8 V max) ensure robust 5 V microcontroller interfacing. Protection triggers are hardware-based with no software dependency - thermal reset occurs at 125 °C, and short-circuit response is sub-microsecond due to on-die thermal sensor placement.

Key Specifications

Pinout & Package

Package: PowerSO-10 - exposed die-pad surface-mount package with 10 terminals, optimized for high-current routing and thermal transfer to PCB copper pour.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-side automotive switch applications.

Compared with STVN32SP and BTS716G, the VN31SP-E provides superior load-dump resilience (46.5 V), lowest RDS(on) in its class, and tighter open-load timing control - making it optimal for thermally dense, safety-critical 12 V automotive nodes where diagnostic integrity and transient robustness are non-negotiable.

Availability

VN31SP-E is available at Aetrix Electronics and suitable for headlamp drivers, fuel injector controllers, body control module relay replacements, and electric power steering precharge circuits requiring stable component supply across automotive production lifecycles.

Supply support for VN31SP-E 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, Switzerland, designing and manufacturing silicon solutions for automotive, industrial, and consumer markets since 1987.

The VN31SP-E belongs to ST's VIPower high-side switch product line, engineered specifically for ISO-compliant automotive power distribution - emphasizing diagnostic reliability, transient immunity, and thermal survivability in under-hood environments.

FAQ

What is the maximum allowable PCB copper area for thermal performance?

The VN31SP-E achieves its rated 54 W power dissipation at Tc = 85 °C using the minimum recommended FR-4 pad size specified in the mechanical drawing (E2 = 7.2–7.6 mm, D1 = 7.4–7.6 mm). Increasing copper area beyond this improves Rthj-amb but does not reduce Rthj-case - which remains fixed at 1.2 °C/W. For ambient-limited designs, thermal vias under the exposed pad are essential.

Can the STAT pin drive an LED directly without a current-limiting resistor?

No. The STAT pin is an open-drain output rated for ±10 mA sink/source, with VOL = 0.4 V at ISTAT = 1.6 mA. Driving an LED requires an external pull-up resistor (e.g., 4.7 kΩ to 12 V) and series current-limiting resistor (e.g., 1 kΩ) to limit forward current to ≤10 mA and prevent latch-up during overtemperature events.

Does the VN31SP-E support PWM operation at frequencies above 1 kHz?

Yes - with verified performance up to 5 kHz for inductive loads. Turn-off delay (td(off) = 140 µs) and fall time (tf = 50 µs) enable clean commutation at 5 kHz (200 µs period), provided PCB layout minimizes parasitic inductance and the −18 V demagnetization clamp is not compromised by excessive trace length.

How does the device behave during ISO 7637-2 Pulse 5a (load dump)?

During ISO 7637-2 Pulse 5a (46.5 V, 100 ms), the VN31SP-E remains fully functional: VCC clamping activates internally, output stays latched in its prior state, and STAT continues reporting valid diagnostics. No external TVS or Zener is needed - unlike competitive devices rated only to 40 V - and all electrical characteristics are guaranteed post-pulse.