Can I contact factories directly on CNFX?

CNFX is an open directory. Each factory profile provides direct contact information.

Bootstrap Circuit Component – Electrical Equipment Manufacturing

Q: What happens if the bootstrap capacitor discharges too much?

Insufficient bootstrap capacitor charge causes under-voltage lockout (UVLO) protection to trigger, preventing high-side switching and potentially causing shoot-through or improper operation.

Q: How do I calculate bootstrap capacitor value?

Cboot = (Qg_total × N) / (ΔVboot - Vf - Vmin), where Qg_total is total gate charge, N is safety margin (2-3), ΔVboot is allowable voltage drop, Vf is diode forward drop, and Vmin is minimum required gate voltage.

Component Specifications

Definition

A bootstrap circuit is an auxiliary power supply circuit used in gate drive circuits to provide floating voltage to the high-side switch in half-bridge or full-bridge configurations. It typically consists of a bootstrap capacitor, diode, and resistor, creating a temporary voltage source referenced to the switching node to drive the high-side gate when the low-side switch is conducting.

Working Principle

When the low-side switch is turned on, the switching node voltage drops near ground, allowing the bootstrap capacitor to charge through the bootstrap diode from the low-voltage supply. When the low-side switch turns off and high-side needs to be driven, the charged capacitor provides floating gate drive voltage relative to the switching node, enabling proper high-side MOSFET/IGBT switching despite the floating reference.

Materials

Ceramic capacitors (X7R, X5R dielectric), fast recovery diodes (Schottky or ultra-fast silicon), PCB with appropriate creepage/clearance, copper traces

Technical Parameters

Voltage Rating ≥ (Vcc + Vmax + margin)
Operating Frequency Up to 500kHz
Reverse Recovery Time <50ns
Bootstrap Capacitor Value 0.1μF to 10μF
Bootstrap Diode Forward Current 1A to 3A

Standards

IEC 61800, UL 508, IEC 60747

Industry Taxonomies & Aliases

Commonly used trade names and technical identifiers for Bootstrap Circuit.

Parent Products

This component is used in the following industrial products

Gate Drive Circuit

Electronic circuit that controls the switching of power semiconductor devices (like IGBTs or MOSFETs) in power conversion systems.

View Product Details

Engineering Analysis

Risks & Mitigation

Capacitor discharge during extended high-side on-time
Diode reverse recovery causing voltage spikes
Insufficient creepage causing arcing
ESD damage to gate driver IC

FMEA Triads

Trigger: Bootstrap capacitor aging or degradation
Failure: Insufficient gate drive voltage causing high-side switch partial turn-on
Mitigation: Use high-reliability capacitors with derating, implement UVLO protection, periodic capacitance testing

Trigger: Bootstrap diode thermal stress
Failure: Diode short circuit causing continuous capacitor discharge
Mitigation: Proper heatsinking, current derating, use of Schottky diodes with lower Vf

Industrial Ecosystem

Compatible With

Interchangeable Parts

Compliance & Inspection

Tolerance

Capacitance: ±10% to ±20%, Voltage: +0%/-10% of rated voltage

Test Method

In-circuit testing of bootstrap voltage during operation, leakage current measurement, thermal cycling test per IEC 60068

Procurement Evaluation Criteria

Not customer reviews or live demand data. These dimensions support RFQ preparation and supplier evaluation.

Technical documentation

4/5

Manufacturing capability

4/5

Inspection readiness

5/5

Supplier transparency

3/5

These scores are example evaluation dimensions, not real customer ratings, country-specific buyer feedback, or live inquiry activity.

Related Components

Induction Coil

Induction coil is a critical component in electromagnetic induction heaters that generates alternating magnetic fields to induce eddy currents in conductive materials for precise, contactless heating.

Protective Housing

Protective housing for industrial wireless power transfer modules, providing environmental protection, EMI shielding, and thermal management.

Alignment System

Precision alignment system for industrial wireless power transfer modules ensuring optimal energy coupling efficiency.

Winding Spindle

A precision rotating shaft in transformer winding machines that holds and rotates the coil form during wire winding operations.

Frequently Asked Questions

What happens if the bootstrap capacitor discharges too much?

Insufficient bootstrap capacitor charge causes under-voltage lockout (UVLO) protection to trigger, preventing high-side switching and potentially causing shoot-through or improper operation.

How do I calculate bootstrap capacitor value?

Cboot = (Qg_total × N) / (ΔVboot - Vf - Vmin), where Qg_total is total gate charge, N is safety margin (2-3), ΔVboot is allowable voltage drop, Vf is diode forward drop, and Vmin is minimum required gate voltage.

Can I contact factories directly?

Yes, each factory profile provides direct contact information.

Data Basis

CNFX manufacturer profiles, technical classification, publicly available product information, and ongoing plausibility checks.

Preliminary Technical Classification

This page supports structured research, RFQ preparation, and supplier evaluation. It does not replace buyer-led supplier qualification, standards review, or technical approval.

Bootstrap Circuit