6368

Supply Voltage
                                                        45V
Output Switch Voltage
                                                        65V
Output Switch Current
   (Note 2)                                        6.0A
Power Dissipation
                                                        Internally Limited
Storage Temperature Range
                                                        -65 C to +150 C
Lead Temperature
   (Soldering, 10 seconds)                260 C
Maximum Junction Temperature
                                                        150 C
Thermal Resistance
ThetaJA
   TO3    (Still Air)                              38 C/W
   TO3    (500LF/Min Air flow)            15.5 C/W
   MD078  (Still Air)                            57 C/W
   MD078  (500LF/Min Air flow)          16 C/W
ThetaJC
   TO3                                                2.0 C/W
   MD078                                           1.6 C/W
Minimum ESD Rating
(Note 3)
                                                         2kV
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur.Operating ratings indicate conditions for which the device is intended to be functional, but device parameter specifications may not be guaranteed under these conditions. For guaranteed specifications and test conditions, see the ELectrical Characteristics.

Note 2: Due to timing considerations of the LM1577 current limit circuit, output current cannot be internally limited when the LM1577 is used as a set-up regulator. To prevent damage to the switch, its current must be externally limited to 6.0A.However, output current is internally limited when the LM1577 is used as a flyback or forward converter regulator in accordance to the Application Hints. 

Note 3: Human body model, 1.5K Ohm in series with 100pF.

The LM1577-12 is a monolithic integrated circuit that provides all of the power and control functions for set-up (boost), flyback, and forward converter switching regulators.Requiring a minimum number of external components, this regulator LM1577-12 is cost effective, and simple to use.

Included on the LM1577-12 is a 3.0A NPN switch and its associated protection circuitry,consisting of current and thermal limiting, and undervoltage lockout. Other features of LM1577-12 include a 52kHz 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.