The LM1577/LM2577 are monolithic integrated circuits that provide all of the power and control functions for step-up (boost), flyback, and forward converter switching regulators. The device is available in three different output voltage versions: 12V, 15V, and adjustable.

Requiring a minimum number of external components, these regulators are cost effective, and simple to use. Listed in this data sheet are a family of standard inductors and flyback transformers designed to work with these switching regulators.

Included on the chip is a 3.0A NPN switch and its associated protection circuitry, consisting of current and thermal limiting, and undervoltage lockout. Other features include a 52 kHz fixed-frequency oscillator that requires no external components, a soft start mode to reduce in-rush current during start-up, and current mode control for improved rejection of input voltage and output load transients.

• Requires Few External Components
• NPN Output Switches 3.0A, can Stand off 65V
• Wide Input Voltage Range: 3.5V to 40V
• Current-mode Operation for Improved Transient Response, Line Regulation, and Current Limit
• 52 kHz Internal Oscillator
• Soft-start Function Reduces In-rush Current During Start-up
• Output Switch Protected by Current Limit, Under-voltage Lockout, and Thermal Shutdown

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• Vin (Min) (V)
• 3.5
• Vin (Max) (V)
• 40
• Vout (Min) (V)
• 1.23
• Vout (Max) (V)
• 15
• Switch current limit (Typ) (A)
• 3
• Regulated outputs (#)
• 1
• Switching frequency (Min) (kHz)
• 52
• Switching frequency (Max) (kHz)
• 52
• Iq (Typ) (mA)
• 10
• Features
• UVLO Fixed
• Duty cycle (Max) (%)
• 95
• Rating
• Catalog

LM2577的完整型号有：LM2577S-ADJ/NOPB、LM2577SX-ADJ/NOPB、LM2577T-ADJ/LF03、LM2577T-ADJ/NOPB、LM2577S-ADJ、LM2577T-ADJ、LM2577T-ADJ/LB03，以下是这些产品的关键参数及官网采购报价：

LM2577S-ADJ/NOPB，工作温度：-40 to 125，封装：DDPAK/TO-263 (KTT)-5，包装数量MPQ：45个，MSL 等级/回流焊峰值温度：Level-3-245C-168 HR，引脚镀层/焊球材料：SN，TI官网LM2577S-ADJ/NOPB的批量USD价格：3.793（1000+）

LM2577SX-ADJ/NOPB，工作温度：-40 to 125，封装：DDPAK/TO-263 (KTT)-5，包装数量MPQ：500个，MSL 等级/回流焊峰值温度：Level-3-245C-168 HR，引脚镀层/焊球材料：SN，TI官网LM2577SX-ADJ/NOPB的批量USD价格：3.161（1000+）

LM2577T-ADJ/LF03，工作温度：PropertyValue，封装：TO-220 (NDH)-5，包装数量MPQ：45个，MSL 等级/回流焊峰值温度：Level-1-NA-UNLIM，引脚镀层/焊球材料：SN，TI官网LM2577T-ADJ/LF03的批量USD价格：3.161（1000+）

LM2577T-ADJ/NOPB，工作温度：-40 to 125，封装：TO-220 (KC)-5，包装数量MPQ：45个，MSL 等级/回流焊峰值温度：Level-1-NA-UNLIM，引脚镀层/焊球材料：SN，TI官网LM2577T-ADJ/NOPB的批量USD价格：3.161（1000+）

LM2577S-ADJ，工作温度：-40 to 125，封装：DDPAK/TO-263 (KTT)-5，包装数量MPQ：45个，MSL 等级/回流焊峰值温度：Level-3-235C-168 HR，引脚镀层/焊球材料：SNPB，TI官网LM2577S-ADJ的批量USD价格：4.9（1000+）

LM2577T-ADJ，工作温度：-40 to 125，封装：TO-220 (KC)-5，包装数量MPQ：45个，MSL 等级/回流焊峰值温度：Level-1-NA-UNLIM，引脚镀层/焊球材料：SNPB，TI官网LM2577T-ADJ的批量USD价格：4.267（1000+）

LM2577T-ADJ/LB03，工作温度：PropertyValue，封装：TO-220 (NDH)-5，包装数量MPQ：45个，MSL 等级/回流焊峰值温度：Level-1-NA-UNLIM，引脚镀层/焊球材料：SNPB，TI官网LM2577T-ADJ/LB03的批量USD价格：4.267（1000+）

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