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.
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| Vin (Min) (V) |
| Vin (Max) (V) |
| Vout (Min) (V) |
| Vout (Max) (V) |
| Switch Current Limit (Typ) (A) |
| Regulated Outputs (#) |
| Switching Frequency (Min) (kHz) |
| Switching Frequency (Max) (kHz) |
| Iq (Typ) (mA) |
| Special Features |
| Duty Cycle (Max) (%) |
| Operating Temperature Range (C) |
| Rating |
| Package Group |
| LM2577 | LM2585 | LM2586 | LM2587 |
|---|---|---|---|
| 3.5 | 4 | 4 | 4 |
| 40 | 40 | 40 | 40 |
| 1.23 | 1.23 | 1.23 | 1.23 |
| 15 | 60 | 60 | 60 |
| 3 | 4 | 4 | 6.5 |
| 1 | 1 | 1 | 1 |
| 52 | 85 | 75 | 85 |
| 52 | 115 | 125 | 115 |
| 10 | 11 | 11 | 11 |
| Enable Frequency Synchronization | N/A | ||
| 95 | 98 | 98 | 98 |
| -40 to 125 | -40 to 125 | -40 to 125 | -40 to 125 |
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| DDPAK/TO-263 TO-220 | DDPAK/TO-263 TO-220 | DDPAK/TO-263 TO-220 | DDPAK/TO-263 TO-220 |
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