LP2980 Datasheet, PDF (5/18 Pages) National Semiconductor (TI) – Micropower 50 mA Ultra Low-Dropout Regulator

Electrical Characteristics (Continued)
Note 3: The maximum allowable power dissipation is a function of the maximum junction temperature, T_J(MAX), the junction-to-ambient thermal resistance, θ_JA, and
the ambient temperature, T_A. The maximum allowable power dissipation at any ambient temperature is calculated using:
The value of θ_JA for the SOT-23 package is 220˚C/W and the micro SMD package is 320˚C/W. Exceeding the maximum allowable power dissipation will cause ex-
cessive die temperature, and the regulator will go into thermal shutdown.
Note 4: If used in a dual-supply system where the regulator load is returned to a negative supply, the LP2980 output must be diode-clamped to ground.
Note 5: The output PNP structure contains a diode between the V_IN and V_OUT terminals that is normally reverse-biased. Reversing the polarity from V_IN to V_OUT
will turn on this diode (see Application Hints).
Note 6: Limits are 100% production tested at 25˚C. Limits over the operating temperature range are guaranteed through correlation using Statistical Quality Control
(SQC) methods. The limits are used to calculate National’s Average Outgoing Quality Level (AOQL).
Note 7: Dropout voltage is defined as the input to output differential at which the output voltage drops 100 mV below the value measured with a 1V differential.
Note 8: The ON/OFF inputs must be properly driven to prevent misoperation. For details, refer to Application Hints.
Note 9: See Typical Performance Characteristics curves.
Basic Application Circuit
DS012078-2
*ON/OFF input must be actively terminated. Tie to V_IN if this function is not to be used.
**Minimum Output Capacitance is 1 µF to insure stability over full load current range. More capacitance provides superior dynamic performance and additional
stability margin (see Application Hints).
***Do not make connections to this pin.
5
www.national.com