DPA422GN

DPA423-426 DPA-Switch Family Highly Integrated DC-DC Converter ICs for Power over Ethernet & Telecom Applications Product Highlights Highly Integrated Solution • Eliminates up to 50 external components–saves space, cost • Integrates 220 V high frequency MOSFET, PWM control • Lower cost plastic DIP surface mount (G package) and through-hole (P package) options for designs ≤35 W • Thermally efficient TO-263-7C (R package) option for high power applications Superior Performance and Flexibility • Eliminates all external current sensing circuitry • Built-in auto-restart for output overload/open loop protection • Pin selectable 300/400 kHz fixed frequency • Wide input (line) voltage range: 16-75 VDC • Externally programmable current limit • Source connected tab reduces EMI • Line undervoltage (UV) detection: meets ETSI standards • Line overvoltage (OV) shutdown protection • UV/OV limits gate drive voltage for synchronous rectification • Fully integrated soft-start for minimum stress/overshoot • Supports forward or flyback topology • Cycle skipping: regulation to zero load without pre-load • Hysteretic thermal shutdown for automatic fault recovery • RoHS compliant P and G package options VO SENSE CIRCUIT VIN DPA-Switch L D CONTROL RESET/ CLAMP CIRCUIT S F X PI-2770-032002 Figure 1. Typical Forward Converter Application. Output Power Table 36-75 VDC Input Range (Forward)2 Total Device Dissipation3 2.5 W 4W 6W Max Power Output1 16 W - - - 18 W 23 W 35 W - - 35 W 23 W 32 W 50 W 62 W - 70 W 25 W 35 W 55 W 70 W 83 W 100 W 0.5 W 1W DPA423 12 W DPA424 16 W EcoSmart™ – DPA425 • DPA4265 • Energy Efficient Extremely low consumption at no-load Cycle skipping at light load for high standby efficiency Applications • PoE applications, VoIP phones, WLAN, security cameras • Telco central office equipment: xDSL, ISDN, PABX • Distributed power architectures (24 V/48 V bus) • Industrial controls Description The DPA-Switch™ IC family is a highly integrated solution for DC-DC conversion applications with 16‑75 VDC input. DPA-Switch uses the same proven topology as TOPSwitch™, cost effectively integrating a power MOSFET, PWM control, fault protection and other control circuitry onto a single CMOS chip. High performance features are enabled with three user configurable pins. Hysteretic thermal shutdown is also provided. In addition, all critical parameters (i.e. current limit, frequency, PWM gain) have tight temperature and absolute tolerance, to simplify design and reduce system cost. C Product4 36-75 VDC Input Range (Flyback)2 Total Device Dissipation3 0.5 W 0.75 W 1W 1.5 W Max Power Output1 Product4 DPA423 9W 13 W - - 13 W DPA424 10 W 14.5 W 18 W 24 W 26 W DPA425 - - - 25.5 W 52 W 6 6 6 Table 1. Output Power Table. Notes: 1. Maximum output power is limited by device internal current limit. 2. See Applications Considerations section for complete description of assumptions, and for output powers with other input voltage ranges. 3. For device dissipation of 1.5 W or below, use P or G packages. Device dissipation above 1.5 W is possible with R package. 4. Packages: P: DIP-8, G: SMD-8, R: TO-263-7C. For lead-free package options, see Part Ordering Information. 5. Available in R package only. 6. Due to higher switching losses, the DPA425 may not deliver additional power compared to a smaller device. www.power.com October 2022 This Product is Covered by Patents and/or Pending Patent Applications. DPA423-426 Section List Functional Block Diagram ........................................................................................................................................ 3 Pin Functional Description ....................................................................................................................................... 3 DPA-Switch Family Functional Description ............................................................................................................. 4 CONTROL (C) Pin Operation..................................................................................................................................... 4 Oscillator and Switching Frequency........................................................................................................................... 5 Pulse Width Modulator & Maximum Duty Cycle......................................................................................................... 5 Minimum Duty Cycle and Cycle Skipping.................................................................................................................. 6 Error Amplifier........................................................................................................................................................... 6 On-chip Current Limit with External Programmability................................................................................................. 6 Line Undervoltage Detection (UV).............................................................................................................................. 6 Line Overvoltage Shutdown (OV)............................................................................................................................... 6 Line Feed-Forward with DCMAX Reduction................................................................................................................. 6 Remote ON/OFF....................................................................................................................................................... 7 Synchronization......................................................................................................................................................... 7 Soft-Start.................................................................................................................................................................. 8 Shutdown/Auto-Restart............................................................................................................................................ 8 Hysteretic Over-Temperature Protection.................................................................................................................... 8 Bandgap Reference.................................................................................................................................................. 8 High-Voltage Bias Current Source............................................................................................................................. 8 Using Feature Pins ...................................................................................................................................................... 8 FREQUENCY (F) Pin Operation................................................................................................................................. 8 LINE-SENSE (L) Pin Operation.................................................................................................................................. 9 EXTERNAL CURRENT LIMIT (X) Pin Operation.......................................................................................................... 9 Typical Uses of FREQUENCY (F) Pin ....................................................................................................................... 11 Typical Uses of LINE-SENSE (L) and EXTERNAL CURRENT LIMIT (X) Pins ........................................................ 11 Application Examples ............................................................................................................................................... 14 Key Application Considerations ............................................................................................................................... 16 DPA-Switch Design Considerations......................................................................................................................... 16 DPA-Switch Layout Considerations......................................................................................................................... 18 Quick Design Checklist........................................................................................................................................... 19 Design Tools........................................................................................................................................................... 19 Product Specifications and Test Conditions ......................................................................................................... 20 Typical Performance Characteristics ................................................................................................................... 27 Package Outlines ..................................................................................................................................................... 31 Part Ordering Information ....................................................................................................................................... 32 2 www.power.com Rev. V 10/22 DPA423-426 VC CONTROL (C) 0 DRAIN (D) ZC INTERNAL SUPPLY 1 SHUNT REGULATOR/ ERROR AMPLIFIER - 5.8 V + IFB + 5.8 V 4.8 V SOFT START - INTERNAL UV COMPARATOR VI (LIMIT) CURRENT LIMIT ADJUST SOFT START VBG + VT 1V OV/UV LINE SENSE DCMAX CONTROLLED TURN-ON GATE DRIVER STOP SOFTSTART DMAX DCMAX CLOCK 300/400 kHz FREQUENCY (F) CURRENT LIMIT COMPARATOR HYSTERETIC THERMAL SHUTDOWN STOP LOGIC VBG + SHUTDOWN/ AUTO-RESTART EXTERNAL CURRENT LIMIT (X) LINE-SENSE (L) - ÷8 ON/OFF SAW + OSCILLATOR S Q LEADING EDGE BLANKING R PWM COMPARATOR RE CYCLE SKIPPING SOURCE (S) PI-2760-070501 Figure 2. Functional Block Diagram. Pin Functional Description DRAIN (D) Pin: High-voltage power MOSFET drain output. The internal start-up bias current is drawn from this pin through a switched highvoltage current source. Internal current limit sense point for drain current. CONTROL (C) Pin: Error amplifier and feedback current input pin for duty cycle control. Internal shunt regulator connection to provide internal bias current during normal operation. It is also used as the connection point for the supply bypass and auto-restart/ compensation capacitor. SOURCE (S) Pin: Output MOSFET source connection for the power return. Primary-side control circuit common and reference point. Tab internally connected to SOURCE pin (See layout considerations) R Package (TO-263-7C) LINE-SENSE (L) Pin: Input pin for overvoltage (OV), undervoltage (UV) lock out, line feed-forward with the maximum duty cycle (DCMAX) reduction, remote ON/OFF and synchronization. A connection to SOURCE pin disables all functions on this pin. EXTERNAL CURRENT LIMIT (X) Pin: Input pin for external current limit adjustment and remote ON/OFF. A connection to SOURCE pin disables all functions on this pin. FREQUENCY (F) Pin: Input pin for selecting switching frequency: 400 kHz if connected to SOURCE pin and 300 kHz if connected to CONTROL pin. 123 4 5 CL X S F P Package (DIP-8) G Package (SMD-8) C 1 8 S L 2 7 S X 3 6 D F 4 5 S 7 D PI-4030-110507 Figure 2. Pin Configuration (Top View). 3 www.power.com Rev. V 10/22 DPA423-426 DPA-Switch Family Functional Description In addition to the standard TOPSwitch features, such as the high-voltage start-up, the cycle-by-cycle current limiting, loop compensation circuitry, auto-restart and thermal shutdown, DPA-Switch also offers many advanced features that reduce system cost and increase power supply performance and design flexibility. Following is a summary of the advanced features: 1. A fully integrated 5 ms soft-start limits peak currents and voltages during start-up and reduces or eliminates output overshoot in most applications. 2. A 75% maximum duty cycle (DCMAX) together with the line feed-forward with DCMAX reduction feature makes DPA-Switch well suited for both flyback and forward topologies. 3. High switching frequency (400 kHz/300 kHz, pin selectable) allows the use of smaller size transformers and offers high bandwidth for power supply control loop. 4. Cycle skipping operation at light load minimizes standby power consumption (typically