Unraveling the Wonders of CAP200DG - TL: A Zero - Power X - Capacitor Auto - Discharge IC

Overview

CAP200DG-TL from Power Integrations is a CAPZero-2 zero-loss automatic X capacitor discharge IC for AC-DC power supplies and offline converters. The device blocks current through the X-capacitor discharge resistor path while AC is present and automatically connects the discharge path after AC is removed, helping designers meet safety discharge requirements without adding continuous standby loss.

As part of the Power Integrations CAPZero-2 family, CAP200DG-TL combines two-terminal operation, self-powered high-voltage switching, 1000V internal MOSFET capability, very low consumption at 230VAC, and support for X capacitor values from 100nF to 6uF. For engineers reviewing the CAP200DG-TL datasheet, CAP200DG-TL pinout, CAP200DG-TL application, or CAP200DG-TL equivalent, this IC is commonly used in adapters, appliances, chargers, LED drivers, power supplies, and other AC input systems that require low no-load power.

Technical Context

In an offline AC-DC converter, the X capacitor in the EMI filter must be discharged after the mains input is disconnected. A traditional resistor-only discharge network creates continuous loss while the product is connected to AC power. CAP200DG-TL solves this by interrupting the discharge resistor current during normal operation and reconnecting the path when the AC line is removed.

The device is especially useful where standby power regulations, EuP Lot 6 targets, or low no-load consumption requirements are important. Its two-terminal structure also keeps the circuit simple because no auxiliary bias winding, microcontroller command, or ground reference is required.

CAP200DG-TL is typically placed around the X capacitor discharge network in adapters, open-frame power supplies, consumer appliances, industrial AC-DC modules, chargers, and LED power products where EMI filter flexibility and standby power reduction must be balanced.

Key Specifications

Parameter	Value and Actual Design Meaning
Device Type	Zero-loss automatic X capacitor discharge IC for AC input EMI filter networks.
Family	Power Integrations CAPZero-2 series for low-standby-power AC-DC converter designs.
Breakdown Voltage	1000V internal MOSFET rating supports high-voltage mains-connected discharge paths.
X Capacitor Range	Designed for X capacitor values from 100nF to 6uF depending on selected discharge resistor values.
Standby Loss	Less than 5mW consumption at 230VAC for supported X capacitor values.
Total Series Resistance	External discharge resistance range supports the required safety discharge time constant.
Package	SO-8 surface-mount package with creepage support for AC input safety spacing.
Certifications	CAPZero-2 family documentation references NEMKO and CB certification support for safety-related designs.

Pinout & Package

The CAP200DG-TL pinout is intentionally simple because the IC behaves as a two-terminal high-voltage switch placed in series with the X capacitor discharge resistor network. The SO-8 package supports the creepage and layout spacing needed around mains-connected nodes.

For PCB layout, the discharge resistor path, X capacitor terminals, and AC input spacing should follow the safety requirements of the end product. The CAP200DG-TL package and resistor network should be placed so the high-voltage nodes remain separated from low-voltage control and SELV circuitry.

Pin / Function	PCB Design and Circuit Role
Terminal 1	Connects to one side of the X capacitor discharge resistor path.
Terminal 2	Connects to the opposite side of the controlled discharge path.
Internal MOSFETs	Block resistor current while AC is applied and reconnect the path after AC removal.
SO-8 Body	Provides surface-mount assembly format and spacing suitable for AC input circuitry.
External Resistors	Set the discharge time constant according to X capacitor value and safety standard requirements.

Key Features

• Automatic X capacitor discharge function reduces standby loss from conventional resistor-only networks.
• Two-terminal, self-supplied operation simplifies implementation in AC input EMI filters.
• Supports X capacitor values from 100nF to 6uF for flexible differential-mode EMI design.
• 1000V internal MOSFET capability supports robust mains-connected applications.
• Less than 5mW consumption at 230VAC supports low no-load power supply requirements.
• SO-8 package supports compact surface-mount power supply layouts.

Applications

AC-DC Adapters	Appliance Power Supplies
Use Scenario: Used in external adapters and chargers requiring low standby power. IC Role: CAP200DG-TL controls the X capacitor discharge resistor path. Use Value: Helps reduce no-load power while preserving discharge compliance after unplugging.	Use Scenario: Used in household appliance power boards with EMI filter X capacitors. IC Role: The IC disconnects resistor loss during AC operation and reconnects it after line removal. Use Value: Supports standby regulation targets without compromising input filter design.
LED Drivers	Industrial Offline Supplies
Use Scenario: Used in LED power supplies that must meet energy efficiency requirements. IC Role: The device enables larger X capacitors without continuous resistor power loss. Use Value: Improves EMI filter flexibility in compact lighting supplies.	Use Scenario: Used in offline control modules and AC-powered embedded equipment. IC Role: CAP200DG-TL provides automatic discharge management for the mains input capacitor. Use Value: Reduces heat and standby waste in always-connected systems.

Equivalent & Alternatives

When evaluating a CAP200DG-TL equivalent, engineers should compare X capacitor range, internal high-voltage rating, standby consumption, package creepage, safety certification status, and resistor-value design rules.

Alternative Part	Technical Difference	Application Difference	Selection Advice
CAP002DG-TL	Same CAPZero-2 family with different X capacitor and resistance range coverage.	Used when the EMI filter uses a different X capacitor value range.	Choose according to the actual X capacitor value and discharge resistor calculation.
CAP004DG-TL	Related CAPZero-2 option with different supported capacitance/resistance combination.	Used in similar AC input discharge circuits requiring a different family member.	Compare the CAPZero-2 component table before substituting.

Compared with resistor-only discharge solutions, CAP200DG-TL reduces continuous AC-line power loss. CAP200DG-TL vs other CAPZero-2 variants should be selected from the official component table according to the X capacitor and total series resistance used in the design.

Quality

CAP200DG-TL should be sourced as original Power Integrations components through traceable supply channels. Quality checks may include SO-8 package inspection, top-mark validation, solderability testing, moisture handling review, and verification against the official CAPZero-2 datasheet.

Production validation should include X capacitor discharge timing, no-load input power, surge and safety spacing review, thermal behavior, and compliance testing under the target AC input and safety standard conditions.

Availability

CAP200DG-TL available at Aetrix Electronics and is suitable for AC-DC adapters, appliances, LED drivers, chargers, and offline converters requiring automatic X capacitor discharge and very low standby loss.

Supply support may include volume procurement planning, scheduled delivery arrangements, traceable sourcing management, and long-term support for power supply manufacturers and OEM programs.

For production builds, confirming the CAPZero-2 family member, SO-8 footprint, X capacitor value, discharge resistor range, lead time, lifecycle status, and sourcing continuity helps reduce design and procurement risk.

Manufacturer

Power Integrations is a semiconductor manufacturer focused on high-voltage power conversion ICs and power supply technologies for offline conversion, LED lighting, motor drives, adapters, appliances, and industrial power systems.

The company's product families support energy-efficient AC-DC and high-voltage power designs using integrated switching, protection, control, and power-management functions.

FAQ

What is CAP200DG-TL used for?

CAP200DG-TL is used to automatically discharge X capacitors in AC input EMI filters while reducing standby power loss during normal AC operation.

Where can I find the CAP200DG-TL datasheet download?

The CAP200DG-TL datasheet is available from Power Integrations as part of the CAPZero-2 family datasheet and includes the component table, operating description, package information, and application guidance.

What should be considered in CAP200DG-TL pinout design?

Designers should treat the device as a mains-connected two-terminal discharge control IC and maintain proper creepage, clearance, resistor ratings, and AC input safety spacing.

Does CAP200DG-TL need an external bias supply?

No. CAP200DG-TL is self-supplied and does not require an external bias supply or ground reference.

What are common CAP200DG-TL equivalent solutions?

Common alternatives include other Power Integrations CAPZero-2 family members such as CAP002DG-TL or CAP004DG-TL selected according to X capacitor value and discharge resistor requirements.