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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| Part number | Order | 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) | Features | Duty cycle (Max) (%) | Operating temperature range (C) | Type | Rating | Package Group |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| LM2577 |
|
3.5 | 40 | 1.23 | 15 | 3 | 1 | 52 | 52 | 10 | 95 | -40 to 125 | Converter | Catalog |
DDPAK/TO-263 | 5
TO-220 | 5 |
|
| LM2585 |
|
4 | 40 | 1.23 | 60 | 4 | 1 | 85 | 115 | 11 | 98 | -40 to 125 | Converter | Catalog |
DDPAK/TO-263 | 5
TO-220 | 5 |
|
| LM2586 |
|
4 | 40 | 1.23 | 60 | 4 | 1 | 75 | 125 | 11 |
Enable
Frequency Synchronization |
98 | -40 to 125 | Converter | Catalog |
DDPAK/TO-263 | 7
TO-220 | 7 |
| LM2587 |
|
4 | 40 | 1.23 | 60 | 6.5 | 1 | 85 | 115 | 11 | 98 | -40 to 125 | Converter | Catalog |
DDPAK/TO-263 | 5
TO-220 | 5 |
