ld7577gs Leadtrend Technology, ld7577gs Datasheet
ld7577gs
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ld7577gs Summary of contents
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... Typical Application EMI AC input Filter *See Application Information Leadtrend Technology Corporation LD7577-DS-01 January 2009 Brown-Out Protection Features High-Voltage (500V) Startup Circuit Current Mode Control Non-Audible-Noise Green Mode Control UVLO (Under Voltage Lockout) ...
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... LD7577-DS-01 January 2009 SOP-8 & DIP-8 (TOP VIEW YY: Year code TOP MARK WW: Week code PP: Production code YYWWPP Package Top Mark Green package LD7577GS Green package LD7577GN FUNCTION 2 www.leadtrend.com.tw LD7577 Shipping 2500 /tape & reel 3600 /tube /Carton ...
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... Block Diagram 32V 16.0V/ 10.0V 65 KHz OSC Green Mode Control Vbias COMP Leading CS Edge Blanking 5.0V BNO 1. 05V/0. 95V Leadtrend Technology Corporation LD7577-DS-01 January 2009 UVLO Comparator internal bias & Vref VCC OK PG Vref OK OLP Protection PWM Comparator Slope Compensation + OCP Comparator ...
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... Stresses beyond the ratings specified in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Leadtrend Technology Corporation LD7577-DS-01 January 2009 4 www ...
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... Current Sensing (CS Pin) Maximum Input Voltage Leading Edge Blanking Time Input impedance Delay to Output Oscillator for Switching Frequency Frequency Green Mode Frequency Temp. Stability Voltage Stability Leadtrend Technology Corporation LD7577-DS-01 January 2009 =15.0V) CC CONDITIONS Vcc< UVLO(on), HV=500V Vcc> UVLO(off), HV=500V Vcc< UVLO(on) V =0V ...
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... Gate Drive Output (OUT Pin) Output Low Level Output High Level Rising Time Falling Time OLP (Over Load Protection) OLP Trip Level OLP Delay Time De_Latch VCC Level Leadtrend Technology Corporation LD7577-DS-01 January 2009 =15.0V =1.5μA BNO VCC=15V, Io=20mA VCC=15V, Io=20mA ...
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... Fig Current Source vs. Temperature (HV=500V, Vcc=0V) 18.0 17.2 16.4 15.6 14.8 14.0 - Temperature (°C) Fig. 3 UVLO (on) vs. Temperature -40 - Temperature (°C) Fig Switching Frequency Leadtrend Technology Corporation LD7577-DS-01 January 2009 0.90 0.89 0.88 0.87 0.86 0.85 120 125 80 -40 12 11.2 10.4 9.6 8 120 125 - ...
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... Vcc (V) Fig. 7 Frequency vs. Vcc - Temperature (°C) Fig. 9 Max Duty vs. Temperature 7.0 6.5 6.0 5.5 5.0 4.5 - Temperature (°C) Fig open loop voltage vs. Temperature COMP Leadtrend Technology Corporation LD7577-DS-01 January 2009 120 125 -40 6.0 5.5 5.0 4.5 4 ...
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... LD7577 is built in with high voltage startup circuit to optimize the power saving. During the startup sequence, a high-voltage current source sinks current from C Leadtrend Technology Corporation LD7577-DS-01 January 2009 capacitor to provide the startup current as well as to charge the Vcc capacitor C1. During the initialization of the startup, Vcc voltage is lower than the UVLO(off) threshold thus the current source supply a current of 1mA ...
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... CS pin is not as low as -0.3V, the R-C filter (as shown in Fig.15) can be eliminated. Nevertheless strongly recommended to remain a small R-C filter (as Leadtrend Technology Corporation LD7577-DS-01 January 2009 shown in Fig. 16) for higher power applications to avoid the CS pin being damaged by negative turn-on spikes. ...
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... What the LD7577 uses to implement the power-saving operation is Leadtrend Technology’s own IP. By using this dual-oscillator control, the burst -mode frequency can be well controlled and further to avoid the generation of audible noise ...
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... On the other hand, the removal of the OVP condition should render the Vcc level back to normal level, causing the output automatically returning to the normal operation. Leadtrend Technology Corporation LD7577-DS-01 January 2009 Brownout Protection & Line voltage OVP (Over voltage protection) The LD7577 is programmable to set the brownout protection point and the line voltage OVP point though BNO pin ...
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... UVLO- OFF OUT Non- Switching Switching Fig.20 Leadtrend Technology Corporation LD7577-DS-01 January 2009 In order to protect BNO pin from being damaged during the dividing resistors floating, an internal zener diode is implemented in BNO pin. Fig. 19 shows the sinking capability of the zener diode. To protect BNO pin, the current flowing in BNO pin must be below 1.5μ ...
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... Protection Resistor on the Hi-V Path In some other Hi-V processes and designs, there is probably some parasitic SCR caused around HV pin, V Leadtrend Technology Corporation LD7577-DS-01 January 2009 and GND. As shown in figure 24, a small negative spike in the HV pin may trigger this parasitic SCR and cause the ...
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... Reference Application Circuit Schematic Leadtrend Technology Corporation LD7577-DS-01 January 2009 15 www.leadtrend.com.tw LD7577 ...
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... Package Information SOP-8 Symbols θ Leadtrend Technology Corporation LD7577-DS-01 January 2009 Dimensions in Millimeters MIN MAX 4.801 5.004 0.189 3.810 3.988 0.150 1.346 1.753 0.053 0.330 0.508 0.013 1.194 1.346 0.047 0.178 0.229 0.007 0.102 0.254 0.004 5.791 6 ...
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... Important Notice Leadtrend Technology Corp. reserves the right to make changes or corrections to its products at any time without notice. Customers should verify the datasheets are current and complete before placing order. Leadtrend Technology Corporation LD7577-DS-01 January 2009 Dimension in Millimeters Dimensions in Inches ...
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... Revision History Rev. Date 00 9/26/2008 01 1/9/2009 Leadtrend Technology Corporation LD7577-DS-01 January 2009 Change Notice Original specification BNO function implementation. 18 www.leadtrend.com.tw LD7577 ...