STMicroelectronics VN21(012Y)

Overview

VN21(012Y) from STMicroelectronics is a high-side smart power solid-state relay in PENTAWATT in-line package, designed for automotive ISO-compliant load switching. It delivers 7 A nominal current (Tc = 85 °C, VCC = 13 V, VDS(on) ≤ 0.5 V), features 0.05 Ω RDS(on) at 25 °C, integrated thermal shutdown at 140 °C, open-drain diagnostic output, and –18 V inductive demagnetization voltage-used in engine control modules for solenoid and lamp drivers.

For engineers reviewing the VN21(012Y) datasheet, VN21(012Y) pinout, VN21(012Y) application, or VN21(012Y) equivalent, key selection criteria include ISO 7637-2 Pulse 5 Level II immunity (46.5 V), reverse battery protection capability, diagnostic timing (t1(on)/t1(off) = 1–10 ms), and junction-to-case thermal resistance of 1.35 °C/W.

Technical Context

The VN21(012Y) integrates a VIPower MOSFET with embedded protection logic and diagnostics. Its high-side architecture enables direct ground-referenced load control, while internal clamping limits VCC to 26 V and input VIH to ~6 V via internal clamp diodes. The device implements ISO-defined open-load detection with 5 ms filtering and fault-specific status delays (tpovl = 5–10 µs, tpol = 50–700 µs).

Thermal protection activates at 140 °C junction temperature and resets at 125 °C, enabling automatic recovery after short-circuit events. Fast demagnetization uses an internal negative voltage generator to clamp inductive flyback to –18 V (typ), reducing dissipation by >50% versus passive snubbers in 12 V automotive systems.

Key Specifications

Pinout & Package

PENTAWATT in-line package (5-pin, through-hole, vertical lead orientation per Figure 14); thermally optimized for PCB-mounted heatsinking via exposed metal tab (pin 3).

Key Features

Applications

Equivalent & Alternatives

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

Compared with STVN22(012Y), VN21(012Y) delivers 40% lower conduction loss at 7 A; versus BTS716G, it eliminates external clamp components and simplifies firmware by providing analog-compatible fault signaling with fixed timing windows.

Availability

VN21(012Y) is available at Aetrix Electronics and suitable for engine control units, body control modules, and transmission control modules requiring stable component supply across extended automotive temperature ranges and long production lifecycles.

Supply support for VN21(012Y) 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, specializing in automotive, industrial, and power management ICs with vertical manufacturing capabilities.

VN21 belongs to ST's VIPower M0-3 high-side driver product line, engineered specifically for ISO 16750-2 and ISO 7637-2 compliant automotive power distribution with integrated diagnostics and protection.

FAQ

What is the maximum safe operating voltage for VN21(012Y) during load dump events?

VN21(012Y) withstands ISO 7637-2 Test Pulse 5 Level II (46.5 V) without external components, as confirmed in Section 6 of the datasheet. At Level III (60 V), a 150 Ω resistor between pin 1 and ground plus a 1000 µF capacitor between pin 3 and ground is required for full functionality retention.

How does the open-drain STAT pin behave during overtemperature fault?

During overtemperature, the STAT pin pulls low immediately-no delay-as specified in Table 8 and Functional Description (page 6). Recovery occurs after junction temperature falls to 125 °C (TR), with STAT returning high after tpovl delay (5–10 µs), distinct from open-load recovery which uses tpol (50–700 µs).

Can VN21(012Y) drive inductive loads without external freewheeling components?

Yes-the device integrates a –18 V (typ) demagnetization clamp that actively sinks inductive energy during turn-off. This eliminates the need for external diodes or Zener networks in most 12 V automotive inductive applications, as verified in the "Inductive Load Fast Demagnetization" feature and Figure 7 waveforms.

What is the thermal resistance from junction to case, and how should it be used in heatsink design?

R_thj-case is 1.35 °C/W (max), measured from die junction to the exposed metal tab (pin 3). For thermal design, this value must be summed with heatsink-to-ambient resistance (R_thhs-amb) and ambient temperature to calculate maximum allowable power dissipation-e.g., at T_c = 85 °C and T_amb = 70 °C, P_max ≈ (85 − 70) / 1.35 ≈ 11.1 W before heatsink contribution.