LM34910 Datasheet, PDF (5/11 Pages) National Semiconductor (TI) – High Voltage (40V, 1.25A) Step Down Switching Regulator

Electrical Characteristics Specifications with standard typeface are for T_J = 25˚C, and those with boldface
type apply over full Operating Junction Temperature range. V_IN = 24V, R_ON = 200k unless otherwise stated (Note
5). (Continued)
Symbol
Parameter
Thermal Shutdown
T_SD
Thermal shutdown
temperature
Thermal shutdown hysteresis
Conditions
Min
Typ
Max
Units
175
˚C
20
˚C
Note 1: Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which operation of the device
is intended to be functional. For guaranteed specifications and test conditions, see the Electrical Characteristics.
Note 2: The human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin.
Note 3: V_CC provides self bias for the internal gate drive and control circuits. Device thermal limitations limit external loading
Note 4: For detailed information on soldering plastic LLP packages, refer to the Packaging Data Book available from National Semiconductor Corporation.
Note 5: Typical specifications represent the most likely parametric norm at 25˚C operation.
Typical Performance Characteristics
FIGURE 2. V_CC vs V_IN
20110904
20110905
FIGURE 3. ON-Time vs V_IN and R_ON
5
www.national.com