General Description
The LD7550B is a low cost, low startup current, current mode PWM controller with green-mode power-saving operation. The integrated functions such as the leading-edge blanking of the current sensing, internal slope compensation and the small SOT-26 package provide the users a high efficiency, low external component counts, and low cost solution for AC/DC power applications.
Compared with LD7550, LD7550-B has different parameters or functions on the following characteristics ---
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Enlarger the hysteresis range of UVLO by lower down the UVLO(off) from 11.4V to 10V. |
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Add OVP (Over Voltage Protection) function on Vcc Pin. |
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Shorten the OCP delay time to 100nS to reduce the difference of OCP trip level under high line & low line. |
Features
• High-Voltage CMOS Process with Excellent ESD protection
• Very Low Startup Current (<20uA)
• Under Voltage Lockout (UVLO)
• Current Mode Control with Cycle-by-Cycle Peak Current Limiting
• Leading-Edge Blanking on CS Pin
• Programmable Switching Frequency
• Internal Slope Compensation
• Proprietary Green-Mode Control for Power Saving
• Non-audible-noise Green Mode Control
• 300mA Driving Capability
• OVP (Over Voltage Protection) on Vcc Pin
Applications
• Switching AC/DC Adaptor and Battery Charger
• Open Frame Switching Power Supply
• 384X Replacement
Typical Application
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