Power Integrations CAP200DG-TL

Overview

CAP200DG-TL from Power Integrations is a CAPZero-2 zero-loss automatic X capacitor discharge IC designed for AC-DC converters, power adapters, home appliances, industrial power supplies, and low-standby-power switch-mode power supply designs. It automatically disconnects the X capacitor discharge path while AC input is present, then reconnects the discharge resistors when AC power is removed, helping the system meet safety discharge requirements without wasting standby power.

According to the CAP200DG-TL datasheet, the device supports X capacitor values from 100 nF to 6 µF, uses an internal 1000 V MOSFET structure, and is supplied in an SO-8 package. For engineers designing EMI filters in AC input stages, CAP200DG-TL helps reduce bleeder-resistor power loss while allowing larger X capacitor values for improved differential-mode EMI performance.

Technical Context

In an AC-DC power supply signal and power path, CAP200DG-TL is placed across the AC input X capacitor discharge network. During normal AC operation, the IC blocks current through the safety discharge resistors, reducing standby dissipation. When AC voltage is disconnected, the IC detects line removal and connects the external resistor path so the X capacitor can discharge safely.

This makes CAP200DG-TL especially useful in offline converters where standby power, no-load consumption, EMI filtering, and safety discharge timing must be balanced. Instead of using permanently connected bleeder resistors that continuously waste energy, CAP200DG-TL allows the designer to maintain fast X capacitor discharge while reducing power loss to less than 5 mW at 230 VAC.

Key Specifications

Pinout & Package

The CAP200DG-TL pinout uses a compact SO-8 package. Although the IC uses only two electrical terminals internally, multiple pins are assigned to D1 and D2 to improve creepage, clearance, and safety behavior. The package provides more than 4 mm creepage on the package and PCB when the recommended layout is followed.

Key Features

• Automatic X capacitor discharge: activates the discharge path when AC input is removed, helping adapters, appliances, and offline converters meet safety discharge requirements.
• Zero-loss standby architecture: blocks current through discharge resistors during normal AC operation, reducing no-load power consumption in energy-sensitive power supplies.
• Wide X capacitor support: covers 100 nF to 6 µF, allowing designers to use larger EMI filter capacitors for better differential-mode noise reduction without increasing standby loss.
• 1000 V internal MOSFET capability: improves suitability for high-voltage AC input environments and surge-aware designs when MOV placement and resistor selection are properly handled.
• Self-supplied operation: requires no external bias supply, simplifying the AC input circuit and reducing the number of auxiliary components.
• Two-terminal functional design: simplifies schematic integration because the IC works directly with the external resistor and X capacitor discharge path.
• SO-8 surface-mount package: supports automated assembly and compact PCB layouts for mass-produced power adapters, chargers, appliances, and power modules.

Applications

AC-DC Converter Input Stage Use Scenario: Used in offline flyback, forward, and other AC-DC converter input circuits with EMI X capacitors. IC Role: CAP200DG-TL disconnects the discharge resistor path during AC operation and reconnects it after AC removal. Use Value: It helps reduce standby power while maintaining safe X capacitor discharge behavior in the power input stage.

Power Adapters and Chargers Use Scenario: Applied in adapters, chargers, and external power supplies that must meet low no-load power regulations. IC Role: The IC removes unnecessary bleeder-resistor loss while keeping the X capacitor discharge function available when unplugged. Use Value: It helps improve energy efficiency and supports compact adapter designs with compliant EMI filtering.

Home Appliance Power Supply Use Scenario: Used in appliances requiring low standby power and reliable AC input safety behavior. IC Role: CAP200DG-TL manages the X capacitor discharge path in the appliance EMI filter section. Use Value: It allows designers to optimize EMI filtering with larger X capacitors while avoiding continuous bleeder-resistor power loss.

Industrial Power Supply and Control Equipment Use Scenario: Used in industrial control power modules, embedded AC input supplies, and equipment requiring long-term reliability. IC Role: The IC provides automatic X capacitor discharge without requiring an auxiliary power supply or control signal. Use Value: It simplifies the AC input protection and EMI filter design while helping reduce standby energy consumption.

Equivalent & Alternatives

When searching for a CAP200DG-TL equivalent, engineers should compare X capacitor range, breakdown voltage, package, standby loss, discharge timing, safety requirements, and PCB creepage design. Because CAP200DG-TL is used in the high-voltage AC input stage, replacement should always be verified against the final safety, surge, and EMI design.

Selection Recommendation: CAP200DG-TL is the preferred choice when the design needs a proven SO-8 automatic X capacitor discharge IC for 100 nF to 6 µF EMI capacitors and ultra-low standby power. For designs requiring additional zero-crossing signal capability, CAP300DG should be reviewed. For purchasing and PCB documentation, confirm whether the production order should specify CAP200DG-TL tape-and-reel packaging.

Quality

For reliable production use, CAP200DG-TL should be sourced as an original Power Integrations component with traceable lot information, correct package markings, manufacturer labeling, and proper reel packaging. Incoming quality inspection can include visual inspection, label verification, date code confirmation, quantity check, solderability inspection, and electrical testing when required.

Because CAP200DG-TL is used in the AC input and high-voltage EMI filter area, ESD handling, moisture control, and process traceability are important during storage, SMT placement, reflow, and rework. For safety-sensitive power supplies, additional inspection such as X-ray, package marking comparison, and supplier traceability review can help reduce counterfeit and reliability risk.

Availability

CAP200DG-TL is available at Aetrix Electronics and is suitable for engineering samples, prototype builds, small-batch production, and volume production of AC-DC power supplies. Tape-and-reel packaging supports automated SMT assembly, making it practical for adapter, appliance, and industrial power supply manufacturing.

For stable supply planning, buyers should confirm current inventory, factory lead time, date code, packaging condition, RoHS status, traceability documents, and batch delivery capability. Long-term supply planning is recommended because changing the X capacitor discharge IC can require safety, EMI, and standby power verification in the final product.

Manufacturer

Power Integrations is a recognized semiconductor manufacturer focused on high-voltage power conversion, energy-efficient power management, offline switcher ICs, gate drivers, and power supply technologies. Its CAPZero product family is designed to reduce unnecessary power loss in AC input X capacitor discharge networks, helping power supply designers meet standby power and safety requirements with fewer external design compromises.

FAQ

What is CAP200DG-TL used for?

CAP200DG-TL application areas include AC-DC converters, power adapters, chargers, home appliances, industrial power modules, and any offline converter design that uses an X capacitor and requires low standby power.

Where can I find the CAP200DG-TL datasheet download?

The CAP200DG-TL datasheet download is available from Power Integrations under the CAP200DG CAPZero-2 datasheet. It includes X capacitor range, resistor selection, package details, pin configuration, electrical characteristics, thermal ratings, and layout guidance.

What should be considered in CAP200DG-TL pinout design?

For CAP200DG-TL pinout design, pins 2 and 3 should be tied together as D1, pins 6 and 7 should be tied together as D2, and the PCB layout should preserve creepage and clearance around the AC input and X capacitor discharge network.

Is CAP200DG-TL equivalent to CAP200DG?

CAP200DG is the base part number, while CAP200DG-TL usually refers to the tape-and-reel ordering option. For a CAP200DG-TL equivalent, engineers should verify packaging, ordering format, electrical ratings, and production availability before substitution.

What is the difference between CAP200DG-TL and CAP300DG?

CAP200DG-TL vs CAP300DG mainly depends on the application requirement. CAP200DG-TL is suitable for standard zero-loss automatic X capacitor discharge, while CAP300DG belongs to the newer CAPZero-3 family and may be preferred when zero-crossing signal functionality or newer discharge features are required.

Does CAP200DG-TL need an external bias supply?

No. CAP200DG-TL is self-supplied and does not require an external bias supply, which simplifies the AC input circuit and reduces auxiliary component count.

How does CAP200DG-TL reduce standby power?

During normal AC operation, CAP200DG-TL blocks current through the X capacitor discharge resistors. This prevents continuous bleeder-resistor loss and helps reduce standby power consumption to less than 5 mW at 230 VAC.