ld7577j Leadtrend Technology, ld7577j Datasheet
ld7577j
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ld7577j Summary of contents
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... It provides functions of low startup current, green-mode power-saving operation, leading-edge blanking of the current sensing and internal slope compensation. Also, the LD7577J features more protections like OLP (Over Load Protection), OVP (Over Voltage Protection), and brownout protection to prevent the circuit being damaged from the abnormal conditions. ...
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... Part number Freq. LD7577J GR 65KHz LD7577J GS 65KHz LD7577J GN 65KHz Note: The LD7577J is ROHS compliant. Pin Descriptions PIN NAME Brownout Protection Pin. Connect a resistor divider between this pin and bulk capacitor voltage to set the brownout level. If the voltage is below threshold voltage, 1 BNO the PWM output will be disabled ...
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... Block Diagram Leadtrend Technology Corporation LD7577J-DS-00b July 2009 3 www.leadtrend.com.tw LD7577J ...
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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 LD7577J-DS-00b July 2009 4 www.leadtrend.com.tw LD7577J 30V -0 ...
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... Leading Edge Blanking Time Input impedance Delay to Output Oscillator for Switching Frequency Frequency Trembling Frequency Green Mode Frequency Modulation Frequency Temp. Stability Voltage Stability Leadtrend Technology Corporation LD7577J-DS-00b July 2009 =15.0V) CC CONDITIONS Vcc< UVLO(on), HV=500V Vcc> UVLO(off), HV=500V V =0V,Fsw=65KHz COMP V =3V,Fsw=65KHz ...
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... 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 LD7577J-DS-00b July 2009 CONDITIONS I =1.5μA BNO VCC=15V, Io=20mA VCC=15V, Io=20mA Load Capacitance=1000pF Load Capacitance=1000pF ...
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... Temperature (°C) 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 - Temperature (°C) Fig. 5 Frequency vs. Temperature Leadtrend Technology Corporation LD7577J-DS-00b July 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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... 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 LD7577J-DS-00b July 2009 120 125 -40 6.0 5.5 5.0 4.5 4 ...
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... Vcc voltage is lower than the UVLO(off) threshold thus the current source supply a current of 1mA. Meanwhile, the Vcc current consumed by the LD7577J is as low as 320μA thus most of the HV current D1 is utilized to charge the Vcc capacitor. By using such configuration, the turn-on delay time will be almost the ...
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... The voltage feedback signal is issued from the TL431 in t the secondary side through the photo-coupler to COMP pin of the LD7577J. The input stage of the LD7577J, like the UC384X, is incorporated with 2 diodes voltage offset circuit and a voltage divider with 1/3 ratio. Therefore, A pull-high resistor is embedded internally, eliminating external corresponding components on a board ...
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... LD7577J, the internal slope compensation circuit has been implemented to simplify the external circuit design. On/Off Control Pulling COMP pin below 1.2V will turn off the LD7577J and disable the gate output pin of the LD7577J. The off-mode will be released when the pull-low signal at COMP pin is removed ...
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... Over Load Protection (OLP) To protect the circuit from being damaged under over load condition or short condition, a smart OLP function is built in with the LD7577J, as shown in Figure 18 shows the waveforms of the OLP operation. If output voltage drops, the feedback system tends to force the voltage loop toward the saturation (5 ...
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... Switching Fig. 19 Brownout Protection & Line voltage OVP (Over voltage protection) The LD7577J is programmable to set the brownout protection point and the line voltage OVP point though BNO pin. The voltage across the BNO pin is proportional to the bulk capacitor voltage, referred as the line voltage. ...
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... MOSFET from being false-triggered by the coupling through the gate-to-drain capacitor C . Therefore, the MOSFET gate should be GD pulled low to maintain in a off-state no matter the gate resistor is disconnected or opened in any case. Leadtrend Technology Corporation LD7577J-DS-00b July 2009 area t Switching t 14 www ...
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... CC damage the chip easily because of the equivalent short-circuit induced. The LD7577J has eliminated the parasitic SCR efficiently. Figure 25 shows the equivalent circuit of the LD7577J’s Hi-V structure. It illustrates the LD7577J is capable to sustain negative voltage and superior than similar products. Even though, a 40KΩ resistor is still recommended to be placed on the Hi-V path ...
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... Reference Application Circuit --- 10W (5V/2A) Adapter Pin < 0.15W when Pout = 0W & Vin = 264Vac Schematic Leadtrend Technology Corporation LD7577J-DS-00b July 2009 16 www.leadtrend.com.tw LD7577J ...
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... Package Information SOP-7 Symbols θ Leadtrend Technology Corporation LD7577J-DS-00b July 2009 Dimensions in Millimeters Dimensions in Inch MIN MAX MIN 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 ...
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... Package Information SOP-8 Symbols θ Leadtrend Technology Corporation LD7577J-DS-00b July 2009 Dimensions in Millimeters Dimensions in Inch MIN MAX MIN 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 ...
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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 LD7577J-DS-00b July 2009 Dimension in Millimeters Dimensions in Inches Min ...
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... Revision History Rev. Date Change Notice 00 12/3/2008 Original Specification 00a 6/10/2009 Package Option: SOP-7 00b 7/27/2009 ESD Voltage Protection, Human Body Model (except HV Pin) Leading Edge Blanking Time update Leadtrend Technology Corporation LD7577J-DS-00b July 2009 20 www.leadtrend.com.tw LD7577J 2.5KV ...