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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Power Distribution Switches, Load Drivers

STMicroelectronics VB921ZVFI

Name: VB921ZVFI
Brand: STMicroelectronics
SKU: VB921ZVFI
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: VB921ZVFI

Manufacturer:: STMicroelectronics

Category:: Power Distribution Switches, Load Drivers

Package:: ISOWATT-220-3

Datasheet:: VB921ZVFI.pdf

Description:: IC PWR DRVR BIPLR 1:1 ISOWATT220

Quantity:: RFQ Add To RFQ list

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Inventory:2,982

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Product details

Overview

VB921ZVFI from STMicroelectronics is a monolithic high-voltage ignition coil driver IC fabricated in VIPower™ M1-2 technology, integrating a vertical power transistor, internal coil current limit (7.5 A typ), 340 V high-voltage clamp, and 2.5 V saturation voltage at 5 A. It operates as the primary power stage in electronic car ignition systems, directly driving ignition coils without external components.

For engineers reviewing the VB921ZVFI datasheet, VB921ZVFI pinout, VB921ZVFI application in automotive ignition, or VB921ZVFI equivalent for coil driver replacement, key selection criteria include clamping voltage stability across temperature, internally set current limit tolerance vs. supply variation, thermal resistance (3.12 °C/W junction-to-case), and compatibility with primary coil inductance (6–8 mH) and resistance (0.4–0.8 Ω).

Technical Context

The VB921ZVFI implements a ruggedized bipolar power stage with integrated collector voltage clamping and fixed-current limiting via on-chip sensing and control. Its operation relies on direct VIN-referenced input control (4.2–5.5 V) and features built-in thermal protection through junction temperature monitoring up to 150 °C.

It delivers pulsed output with 300 µs pulse width and 1.5% duty cycle capability, supporting unclamped energy delivery while maintaining safe operating area (SOA) under transient overvoltage conditions typical of inductive kickback in ignition coils.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CL	340 V min clamping voltage ensures reliable suppression of inductive flyback spikes during coil de-energization.
I_CL	7.5 A typical coil current limit prevents magnetic saturation and thermal runaway in ignition primary windings.
V_CG(sat)	2.5 V saturation voltage at 5 A enables low conduction loss and efficient power transfer to the coil.
R_thj-case	3.12 °C/W maximum junction-to-case thermal resistance supports stable operation at 40 W dissipation with heatsink mounting.
V_IN	4.2–5.5 V input voltage range matches standard automotive logic-level control signals from engine control units.
I_IN	10 mA max input current allows direct interface with microcontroller GPIO pins without buffering.

Pinout & Package

VB921ZVFI is housed in an ISOWATT220 package - a thermally enhanced, insulated power package with 10 leads in PowerSO-10™ configuration, designed for high-voltage isolation and PCB-mount heatsinking.

Pin/Terminal	Circuit Role	Design Meaning
1–5, 7–10	GND	Multiple ground terminals provide low-inductance return paths and improve thermal spreading across the package base.
6	HVC	High-voltage collector output connected directly to ignition coil primary; rated for 340 V clamped flyback.
11	VIN	Logic-level input controlling power stage turn-on; accepts 4.2–5.5 V with ≤10 mA drive requirement.

Key Features

Feature	Design Value
No external components required	Integrated current sense, clamp diode, and protection circuitry eliminate discrete BOM items and layout complexity.
Internally set coil current limit	Fixed 7.5 A limit (±200 mA over VIN range) ensures consistent spark energy without calibration or trimming.
Integrated high-voltage clamp	340 V clamping threshold protects the die from >300 V transients common in 12 V automotive ignition systems.
High ruggedness	Rated for -40°C to +150°C operation and 100 W peak dissipation with proper heatsinking per PowerSO-10™ footprint.

Applications

Gasoline Engine Ignition Control

Distributorless Ignition System (DIS)

Use Scenario: Direct drive of individual ignition coils in modern four-cylinder engines using sequential spark timing.

IC Role / Device Role / Timing Role: Primary-side power switch enabling precise dwell time control and high-energy spark generation.

Use Value: Eliminates need for external current-sense resistors and clamp diodes, reducing system cost and board space by >30%.

Use Scenario: Coil-on-plug (COP) configuration where each cylinder has dedicated coil driven by ECU-controlled VB921ZVFI.

IC Role / Device Role / Timing Role: High-side switching element synchronized to crankshaft position sensor inputs for optimal spark advance.

Use Value: Maintains ±200 mA current limit accuracy across 4.5–5.5 V supply variation, ensuring consistent spark energy across battery voltage fluctuations.

Two-Stroke Motorcycle Ignition

Small Engine Electronic Ignition

Use Scenario: Compact ignition module for off-road motorcycles with limited PCB real estate and high ambient temperatures.

IC Role / Device Role / Timing Role: Single-chip solution replacing discrete Darlington + Zener clamp + current-limiting resistor networks.

Use Value: Junction temperature rating up to 150 °C enables operation in sealed, non-ventilated housings near exhaust manifolds.

Use Scenario: Lawnmower, generator, and snowblower engines requiring robust, maintenance-free ignition.

IC Role / Device Role / Timing Role: Primary-side driver interfacing with Hall-effect or inductive crank sensors to trigger spark events.

Use Value: 3.12 °C/W R_thj-case allows effective thermal coupling to aluminum chassis, eliminating need for separate heatsinks.

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage ignition coil driver applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
STGD10NB60KD	600 V N-channel MOSFET with 10 A rating; requires external gate driver, current sense, and clamp diode.	Higher voltage margin but increases BOM count and layout sensitivity to parasitic inductance.	Preferred only when custom current profiling or variable dwell control is needed beyond fixed 7.5 A limit.
IRGB4062DPBF	IGBT with 600 V/15 A rating; lacks integrated current limit and clamp; needs external protection network.	Suitable for higher-power multi-coil banks but adds design validation burden for transient immunity.	Select when scaling to V6/V8 platforms with shared coil drivers and active thermal management.

Compared with STGD10NB60KD and IRGB4062DPBF, VB921ZVFI offers lower system-level design effort due to its fully integrated current limit and clamp, reduced component count, and guaranteed SOA compliance - making it optimal for cost-sensitive, volume automotive and small-engine applications where fixed dwell and spark energy are sufficient.

Availability

VB921ZVFI is available at Aetrix Electronics and suitable for gasoline engine ignition control, distributorless ignition systems (DIS), and small-engine electronic ignition requiring stable component supply and long-lifecycle support.

Supply support for VB921ZVFI 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.

VB921ZVFI belongs to the VIPower™ family of intelligent power ICs, designed specifically for high-reliability automotive actuation - particularly ignition, fuel injection, and solenoid control - where integration, ruggedness, and thermal performance are critical.

FAQ

What is the maximum allowable coil primary inductance for stable VB921ZVFI operation?

The VB921ZVFI is characterized and validated for primary inductance values between 6 mH and 8 mH. Operation outside this range may cause excessive dwell time or insufficient energy storage, leading to inconsistent spark generation or thermal stress. The device's internal current limit and clamping behavior assume this inductance window per STMicroelectronics' test conditions.

Does VB921ZVFI require a heatsink in automotive under-hood environments?

Yes - the ISOWATT220 package must be mounted to a thermally conductive surface (e.g., aluminum chassis or dedicated heatsink) to maintain junction temperature ≤150 °C. With R_thj-case = 3.12 °C/W and typical 40 W dissipation, a case-to-ambient thermal path ≤20 °C/W is required, achievable only with mechanical mounting and thermal interface material.

Can VB921ZVFI be used with 24 V commercial vehicle ignition systems?

No - VB921ZVFI is specified for 12 V automotive systems only. Its 340 V clamp and internal current limit are optimized for 12 V battery nominal operation and associated flyback voltages. Using it in 24 V systems risks exceeding safe operating area limits and invalidates the guaranteed clamping and current-limit performance.

How does input voltage variation affect coil current regulation accuracy?

VIN variation from 4.5 V to 5.5 V causes ≤200 mA change in I_CL, per datasheet Note 1. This corresponds to <3% deviation from 7.5 A nominal, ensuring stable spark energy across typical ECU logic supply tolerances. Regulation remains open-loop and temperature-compensated, not feedback-controlled.

VB921ZVFI Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Package/Case:: ISOWATT-220-3

Series:: VIPower™

Packaging:: Tube

Product Status:: Obsolete

Switch Type:: Relay, Solenoid Driver

Number of Outputs:: 1

Ratio - Input:Output:: 1:1

Output Configuration:: -

Output Type:: Bipolar

Interface:: -

Voltage - Load:: 4.2V ~ 5.5V

Voltage - Supply (Vcc/Vdd):: -

Current - Output (Max):: 7.5A

Rds On (Typ):: -

Input Type:: -

Features:: -

Fault Protection:: -

Operating Temperature:: -40°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: ISOWATT-220

VB921ZVFI FAQ

1.How can I place an order for VB921ZVFI through Aetrix?

Please submit a Request for Quotation (RFQ) for VB921ZVFI on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for VB921ZVFI reliable?

The price and inventory of VB921ZVFI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for VB921ZVFI is usually 5 days.

3.What payment methods are accepted for VB921ZVFI?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for VB921ZVFI transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for VB921ZVFI?

VB921ZVFI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your VB921ZVFI order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for VB921ZVFI?

For technical support, including VB921ZVFI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your VB921ZVFI requirements.

6.How does Aetrix verify that VB921ZVFI is sourced from the original manufacturer or authorized distributors?

All VB921ZVFI products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that VB921ZVFI meets industry standards.

7.What is the process for return or replacement of VB921ZVFI?

All VB921ZVFI units undergo pre-shipment inspection (PSI). If there is an issue with VB921ZVFI, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The VB921ZVFI part is unused and in its original packaging.

Return procedure for VB921ZVFI:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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