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Electronic Components Datasheet Search |
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TOP254PN Datasheet(PDF) 25 Page - Power Integrations, Inc. |
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TOP254PN Datasheet(HTML) 25 Page - Power Integrations, Inc. |
25 / 48 page ![]() Rev. F 01/09 25 TOP252-262 www.powerint.com Key Application Considerations TOPSwitch-HX vs. TOPSwitch-GX Table 4 compares the features and performance differences between TOPSwitch-HX and TOPSwitch-GX. Many of the new features eliminate the need for additional discrete components. Other features increase the robustness of design, allowing cost savings in the transformer and other power components. TOPSwitch-HX vs. TOPSwitch-GX Function TOPSwitch-GX TOPSwitch-HX TOPSwitch-HX Advantages EcoSmart Linear frequency reduction to 30 kHz (@ 132 kHz) for duty cycles < 10% Multi-mode operation with linear frequency reduction to 30 kHz (@ 132 kHz) and multi-cycle modulation (virtually no audible noise) Improved efficiency over load (e.g. at 25% load point) Improved standby efficiency Improved no-load consumption • • • Output Overvoltage Protection (OVP) Not available User programmable primary or secondary hysteretic or latching OVP Protects power supply output during open loop fault Maximum design flexibility • • Line Feed-Forward with Duty Cycle Reduction Linear reduction Dual slope reduction with lower, more accurate onset point Improved line ripple rejection Smaller DC bus capacitor • • Switching Frequency DIP-8 Package 132 kHz 66 kHz Increased output power for given MOSFET size due to higher efficiency • Lowest MOSFET On Resistance in DIP-8 Package 3.0 Ω (TOP246P) 1.8 Ω (TOP258P) Increased output power in designs without external heatsink • I2f Trimming Not available -10% / +20% Increased output power for given core size Reduced over-load power • • Auto-restart Duty Cycle 5.6% 2% Reduced delivered average output power during open loop faults • Frequency Jitter ±4 kHz @ 132 kHz ±2 kHz @ 66 kHz ±5 kHz @ 132 kHz ±2.5 kHz @ 66 kHz Reduced EMI filter cost • Thermal Shutdown 130 °C to 150 °C 135 °C to 150 °C Increased design margin • External Current Limit 30%-100% of I LIMIT 30%-100% of I LIMIT, additional trim at 0.7 × I LIMIT Reduced tolerances when current limit is set externally • Line UV Detection Threshold 50 μA (2 MΩ sense impedance) 25 μA (4 MΩ sense impedance) Reduced dissipation for lower no-load consumption • Soft-Start 10 ms duty cycle and current limit ramp 17 ms sweep through multi- mode characteristic Reduced peak current and voltage component stress at startup Smooth output voltage rise • • Table 4. Comparison Between TOPSwitch-GX and TOPSwitch-HX. |
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