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STMicroelectronics E-L6565D
- Part No.:
- E-L6565D
- Manufacturer:
- STMicroelectronics
- Category:
- AC DC Converters, Offline Switches
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
E-L6565D.pdf
- Description:
- IC OFFLINE SWITCH FLYBACK 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,463
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Product details
Overview
L6565D from STMicroelectronics is a current-mode quasi-resonant (QR) zero-voltage-switching (ZVS) flyback controller IC for offline AC-DC power supplies. It features line voltage feedforward for constant power delivery across 88–264 VAC input, frequency foldback for <3.5 mA quiescent current at light load, and ±400 mA totem-pole gate drive. Used in 50 W TV SMPS and 40 W inkjet printer adapters compliant with Blue Angel and Energy Star.
For engineers reviewing the L6565D datasheet, L6565D pinout, L6565D application, or L6565D equivalent, this page delivers verified technical context on QR timing control, ZCD-triggered MOSFET turn-on, VFF-based current limit scaling, and hiccup-mode OCP - all critical for designing energy-efficient flyback converters with primary-side regulation.
Technical Context
The L6565D implements transformer demagnetization sensing via its ZCD pin (pin 5), triggering MOSFET turn-on on negative-going edges after arming at 2.1 V and threshold crossing at 1.6 V. Blanking time (≥3.5 µs) is dynamically adjusted by COMP voltage to enforce frequency foldback under light load.
Line feedforward operates through VFF (pin 3), scaling the current-sense clamp voltage (VCSx) inversely with input voltage - e.g., VCSx drops from 1.4 V at VVFF = 0 V to 0.2 V at VVFF = 3 V - enabling stable power delivery across universal mains. The error amplifier uses a 2.5 V ±1% internal reference for primary or optocoupler-coupled secondary regulation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Operating Range | 10.3–18 V - supports direct bulk-cap startup and stable operation across wide-input flyback designs. |
| Start-up Current | <70 µA - enables high-impedance resistor-start circuits without auxiliary winding dependency. |
| Quiescent Current | <3.5 mA - sustains Energy Star/Blue Angel standby compliance in printers and monitors. |
| ZCD Trigger Threshold | 1.6 V (negative edge) with 2.1 V arming - ensures noise-immune QR synchronization using only one auxiliary-winding resistor. |
| Gate Drive Peak Current | ±400 mA - directly drives STP7NB80FI/STP4NA80FP MOSFETs without external buffers in 40–50 W designs. |
| Current Sense Clamp | VCSx = 1.4 V (VVFF = 0 V) → 0.2 V (VVFF = 3 V) - enables precise line-compensated overcurrent protection. |
| Reference Voltage | 2.5 V ±1% @ 25°C - provides stable feedback setpoint for ±5% output regulation in primary-side schemes. |
Pinout & Package
Package: SO-8 (Small Outline Integrated Circuit, 150 °C/W junction-to-ambient thermal resistance).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (INV) | Inverting input of error amplifier | Accepts primary-side voltage divider or optocoupler feedback; grounded in secondary-feedback configurations. |
| 2 (COMP) | Error amplifier output | Drives compensation network or optocoupler LED; blanking time and frequency foldback depend on its voltage. |
| 3 (VFF) | Line voltage feedforward input | Scales current-limit threshold inversely with input voltage; grounding disables feedforward and sets max limit. |
| 4 (CS) | Current sense comparator input | Detects primary current via sense resistor; >2 V triggers hiccup-mode OCP shutdown. |
| 5 (ZCD) | Zero-current detection / sync input | Triggers MOSFET turn-on on negative edge after arming; also serves as disable input when pulled <150 mV. |
| 6 (GND) | Signal and gate driver ground | Common return for analog circuitry and 400 mA totem-pole driver; requires low-inductance layout. |
| 7 (GD) | Gate driver output | Directly drives MOSFET gate; includes UVLO pull-down to prevent spurious turn-on during startup. |
| 8 (VCC) | Supply input | Powered via startup resistor from bulk capacitor; regulated internally to 7 V for logic, while gate driver uses raw VCC. |
Key Features
| Feature | Design Value |
|---|---|
| Quasi-resonant ZVS control | Reduces switching losses by synchronizing MOSFET turn-on to transformer demagnetization zero-crossing. |
| Line feedforward compensation | Maintains constant output power across 88–264 VAC input by scaling current limit with line voltage. |
| Frequency foldback | Extends light-load efficiency by reducing switching frequency while preserving ZVS operation down to ~10% load. |
| Hiccup-mode OCP | Shuts down gate driver on sustained CS >2 V, then auto-restarts after VCC discharge below UVLO threshold. |
| Ultra-low start-up current | Enables resistor-only startup without auxiliary winding, simplifying board layout and reducing BOM count. |
Applications
| TV/Display SMPS | AC-DC Adapters |
|---|---|
Use Scenario: 50 W offline flyback supply for 14" LCD TV with 88–264 VAC input. IC Role / Device Role / Timing Role: Primary-side QR controller managing ZVS turn-on, line-compensated current limiting, and burst-mode standby. Use Value: Achieves >85% full-load efficiency and <300 mW no-load consumption per Energy Star v2.0 requirements. | Use Scenario: 40 W universal-input adapter for inkjet printers with variable output loads. IC Role / Device Role / Timing Role: Flyback controller implementing frequency foldback and hiccup-mode OCP for robust light-load and fault handling. Use Value: Eliminates need for secondary-side TL431 in some designs via primary regulation, reducing component count by 30%. |
| Consumer Digital Devices | Office Equipment SMPS |
Use Scenario: Compact 25 W power supply for set-top boxes with tight EMI constraints. IC Role / Device Role / Timing Role: QR controller using ZCD blanking and VFF feedforward to suppress input ripple sensitivity and improve PSRR. Use Value: Reduces conducted EMI by 8 dBµV in 150 kHz–30 MHz band compared to fixed-frequency alternatives. | Use Scenario: 35 W SMPS for fax machines and photocopiers requiring high reliability under surge conditions. IC Role / Device Role / Timing Role: Primary controller with dual-level OCP (pulse-by-pulse + hiccup) and UVLO-protected gate drive. Use Value: Survives 10× 10 kV/µs common-mode surges on AC input without latch-up or parameter drift. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quasi-resonant flyback controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ICE2QS03G | Integrated 650 V CoolMOS + QR controller in DSO-16; no external MOSFET needed. | Higher integration reduces PCB area but limits MOSFET selection and thermal design flexibility. | Prefer ICE2QS03G for space-constrained designs where 35 W output and fixed MOSFET specs are acceptable. |
| UCC28600DR | Programmable frequency foldback slope and adaptive burst mode; higher BOM cost. | Superior light-load regulation stability in variable-output systems like multi-rail adapters. | Choose UCC28600DR when output cross-regulation under dynamic load steps is critical. |
Compared with ICE2QS03G and UCC28600DR, the L6565D offers discrete MOSFET flexibility, lowest system cost for 40–50 W applications, and proven field reliability in TV/printer SMPS - making it optimal for cost-sensitive, high-volume consumer power supplies where design reuse is prioritized.
Availability
L6565D is available at Aetrix Electronics and suitable for TV/monitor SMPS, AC-DC adapters/chargers, and digital consumer electronics requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for L6565D 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, delivering silicon solutions for automotive, industrial, and power management applications.
The L6565D belongs to ST's legacy AC-DC controller product line, engineered specifically for quasi-resonant flyback topologies in universal-input consumer power supplies - emphasizing efficiency, regulatory compliance, and ease of primary-side regulation implementation.
FAQ
What is the minimum blanking time on the ZCD pin, and how does it affect QR operation?
The ZCD pin has a guaranteed minimum blanking time of 3.5 µs after GD transitions high-to-low. This prevents false triggering from leakage inductance ringing and enforces frequency foldback when required OFF-time falls below this threshold. As COMP voltage decreases under light load, blanking time increases - causing skipped ringing cycles and eventually transitioning to burst mode for ultra-low standby power.
Can the L6565D operate without an auxiliary winding for VCC supply?
Yes - the L6565D supports resistor-start operation using a high-value resistor from bulk capacitor to VCC (pin 8), enabled by its ultra-low 70 µA start-up current. However, an auxiliary winding is required for continuous operation once started, unless a dedicated bias supply is provided. The ZCD pin cannot substitute for VCC supply.
How does line feedforward (VFF) improve power regulation in wide-range inputs?
VFF scales the current-sense clamp voltage (VCSx) inversely with input voltage: at 88 VAC, VCSx ≈ 1.4 V enables higher peak current; at 264 VAC, VCSx ≈ 0.2 V lowers peak current. This compensates for the natural POUT ∝ VIN² relationship in flyback converters, delivering constant output power across universal mains without secondary feedback.
What happens during hiccup-mode OCP, and how does recovery occur?
When CS voltage exceeds 2.0 V, the gate driver is disabled and quiescent current drops to ~2.1 mA. Since no energy is delivered to the VCC capacitor, its voltage decays until reaching the UVLO turn-off threshold (~9.5 V). At that point, the IC fully resets and initiates a new start-up cycle - resulting in low-frequency intermittent operation that protects MOSFET and transformer from thermal overstress.
E-L6565D Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Output Isolation:
- Isolated
- Internal Switch(s):
- No
- Voltage - Breakdown:
- -
- Topology:
- Flyback
- Voltage - Start Up:
- 13.5 V
- Voltage - Supply (Vcc/Vdd):
- 10.3V ~ 18V
- Duty Cycle:
- -
- Frequency - Switching:
- -
- Power (Watts):
- -
- Fault Protection:
- Current Limiting
- Control Features:
- -
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 8-SOIC
- Mounting Type:
- Surface Mount
E-L6565D FAQ
1.How can I place an order for E-L6565D through Aetrix?
Please submit a Request for Quotation (RFQ) for E-L6565D 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 E-L6565D reliable?
The price and inventory of E-L6565D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for E-L6565D is usually 5 days.
3.What payment methods are accepted for E-L6565D?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for E-L6565D transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for E-L6565D?
E-L6565D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your E-L6565D 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 E-L6565D?
For technical support, including E-L6565D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your E-L6565D requirements.
6.How does Aetrix verify that E-L6565D is sourced from the original manufacturer or authorized distributors?
All E-L6565D 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 E-L6565D meets industry standards.
7.What is the process for return or replacement of E-L6565D?
All E-L6565D units undergo pre-shipment inspection (PSI). If there is an issue with E-L6565D, 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 E-L6565D part is unused and in its original packaging.
Return procedure for E-L6565D:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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