6356

Maximum Supply Voltage
                                                                                          45V
ON/OFF Pin Input Voltage
                                                                                          -0.3V Output Voltage to Ground
   (Steady State)                                                                -1V
Power Dissipation
(Note 2, 3)
                                                                                          Internally Limited
Storage Temperature Range
                                                                                          -65 C to +150 C
Minimum ESD Rating
   (C = 100pF, R = 1.5K Ohms)                                           3KV
Lead Temperature
(Soldering, 10 seconds)
   CERDIP                                                                           260 C
   TO3                                                                                 300 C
Maximum Junction Temperature
                                                                                           150 C
Thermal Resistance
ThetaJA
   Metal Can (Still Air)                                                           45 C/W
   Metal Can (500LF/Min Air flow)                                         10 C/W
   CERDIP    (Still Air)                                                            70 C/W
   CERDIP    (500LF/Min Air flow)                                           33 C/W
ThetaJC
   Metal Can                                                                          3.3 C/W
   CERDIP (Note 3 applicable to this Pkg only)                      2.0 C/W
                                                                                             (Note 3)
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur.Operating Ratings indicate conditions for which the device is functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. The guaranteed specifications apply only for the test conditions listed. Some performance characteristics may degrade when the device is not operated under the listed test conditions. 

Note 2: The maximum power dissipation must be derated at elevated temperatures and is dictated by Tjmax (maximum junction temperature), ThetaJA (package junction to ambient thermal resistance), and TA (ambient temperature). The maximum allowable power dissipation at any temperature is Pdmax = (Tjmax - TA)/ThetaJA or the number given in the Absolute Maximum Ratings, whichever is lower. 

Note 3: The package material for these devices allows much improved heat transfer over our standard ceramic packages. In order to take full advantage of this improved heat transfer, heat sinking must be provided between the package base (directly beneath the die), and either metal traces on, or thermal vias through, the printed circuit board. Without this additional heat sinking, device power dissipation must be calculated using junction-to-ambient, rather than junction-to-case, thermal resistance. It must not be assumed that the device leads will provide substantial heat transfer out of the package, since the thermal resistance of the leadframe material is very poor, relative to the material of the package base. The stated junction-to-case thermal resistance is for the package material only, and does not account for the additional thermal resistance between the package base and the printed circuit board. The user must determine the value of the additional thermal resistance and must combine this with the stated value for the package, to calculate the total allowed power dissipation for the device.

The LM1575 regulator is a monolithic integrated circuit that provides all the active functions from a step-down (buck) switching regulator, capable of driving a 1A load with excellent line and load regulation.

Requiring a minimum number of external components, this regulator LM1575 is simple to use and includes internal frequency compensation and a fixed-frequency oscillator.  The LM1575 offers a high-efficiency replacement for popular three-terminal linear regulators. It substantially reduces the size of the heat sink, and in many cases no heat sink is required.

A standard series of inductors optimized for use with the LM1575 are available from several different manufacturers. This feature greatly simplifies the design of switch-mode power supplies.

Other features of LM1575 include a guaranteed +4% tolerance on output voltage within specified input voltage and output load conditions, and +10% on the oscillator frequency. External shutdown of LM1575 is included, featuring 50uA (typical) standby current. The output switch includes cycle-by-cycle current limiting, as well as thermal shutdown for full protection under fault conditions.