DPA422-426 DPA-Switch Family Highly Integrated DC-DC Converter ICs for Power over Ethernet & Telecom Applications Product Highlights V O Highly Integrated Solution Eliminates up to 50 external componentssaves space, cost SENSE Integrates 220 V high frequency MOSFET, PWM control CIRCUIT Lower cost plastic DIP surface mount (G package) and DPA-Switch through-hole (P package) options for designs 35 W V IN D L Thermally efficient TO-263-7C (R package) option for high CONTROL power applications RESET/ C CLAMP CIRCUIT Superior Performance and Flexibility S X F Eliminates all external current sensing circuitry Built-in auto-restart for output overload/open loop protection Pin selectable 300/400 kHz fixed frequency PI-2770-032002 Wide input (line) voltage range: 16-75 VDC Figure 1. Typical Forward Converter Application. Externally programmable current limit Source connected tab reduces EMI Output Power Table Line undervoltage (UV) detection: meets ETSI standards Line overvoltage (OV) shutdown protection 2 36-75 VDC Input Range (Forward) UV/OV limits gate drive voltage for synchronous rectification Total Device Max Fully integrated soft-start for minimum stress/overshoot 3 Dissipation 0.5 W 1 W 2.5 W 4 W 6 W Power Supports forward or flyback topology 1 4 Output Product Cycle skipping: regulation to zero load without pre-load Hysteretic thermal shutdown for automatic fault recovery 7,8 DPA422 7.5 W 10 W - - - 10 W RoHS compliant P and G package options DPA423 12 W 16 W - - - 18 W DPA424 16 W 23 W 35 W - - 35 W EcoSmart Energy Efficient Extremely low consumption at no-load DPA425 23 W 32 W 50 W 62 W - 70 W Cycle skipping at light load for high standby efficiency 5 DPA426 25 W 35 W 55 W 70 W 83 W 100 W 2 36-75 VDC Input Range (Flyback) Applications PoE applications, VoIP phones, WLAN, security cameras Total Device Max 3 Dissipation Telco central office equipment: xDSL, ISDN, PABX 0.5 W 0.75 W 1 W 1.5 W Power 1 Distributed power architectures (24 V/48 V bus) 4 Output Product Industrial controls 7,8 DPA422 6.5 W 9.0 W - - 9.0 W Description DPA423 9 W 13 W - - 13 W The DPA-Switch IC family is a highly integrated solution for DPA424 10 W 14.5 W 18 W 24 W 26 W DC-DC conversion applications with 16-75 VDC input. 6 6 6 DPA425 - - - 25.5 W 52 W Table 1. Output Power Table. DPA-Switch uses the same proven topology as TOPSwitch , Notes: cost effectively integrating a power MOSFET, PWM control, fault 1. Maximum output power is limited by device internal current limit. protection and other control circuitry onto a single CMOS chip. 2. See Applications Considerations section for complete description of assumptions High performance features are enabled with three user 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 configurable pins. Hysteretic thermal shutdown is also provided. dissipation In addition, all critical parameters (i.e. current limit, frequency, above 1.5 W is possible with R package. PWM gain) have tight temperature and absolute tolerance, to 4. Packages: P: DIP-8, G: SMD-8, R: TO-263-7C. For lead-free package options, see Part Ordering Information. simplify design and reduce system cost. 5. Available in R package only. 6. Due to higher switching losses, the DPA425 may not deliver additional power compared to a smaller device. 7. Available in P and G package only. 8. DPA422 not recommended for new designs, use DPA423 instead. www.powerint.com December 2012DPA422-426 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 DC Reduction ................................................................................................................ 6 MAX 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 .......................................................................................................................................................... 20 Product Specifications and Test Conditions .......................................................................................................... 21 Typical Performance Characteristics .................................................................................................................. 27 Part Ordering Information ....................................................................................................................................... 30 Package Outlines .................................................................................................................................................... 31 2 Rev. T 12/12 www.powerint.com