LP2957_15 Datasheet, PDF (7/24 Pages) Texas Instruments – 5V Low-Dropout Regulator for μP Applications

LP2957, LP2957A
www.ti.com
SNVS102C – JUNE 1998 – REVISED APRIL 2013
Typical Performance Characteristics (continued)
Unless otherwise specified: V_IN = 6V, I_L = 1 mA, C_L = 2.2 µF, V _SD = 3V, T_A = 25°C
Thermal Regulation
Error Output Sink Current
Figure 22.
Dropout Detection
Threshold Voltages
Figure 23.
Maximum Power Dissipation (DDPAK/TO-263)⁽¹⁾
Figure 24.
Error Output Voltage
Figure 25.
Dropout Voltage
Figure 26.
Figure 27.
(1) 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:
Exceeding the maximum allowable power dissipation will result in excessive die temperature, and the regulator
will go into thermal shutdown. The junction-to-ambient thermal resistance of the TO-220 (without heatsink) is 60°C/W and 73°C/W for
the DDPAK/TO-263. If the DDPAK/TO-263 package is used, the thermal resistance can be reduced by increasing the P.C. board copper
area thermally connected to the package: Using 0.5 Square inches of copper area, θ _JA is 50°C/W, with 1 square inch of copper area,
θ_JA is 37°C/W; and with 1.6 or more square inches of copper area, θ _JA is 32°C/W. The junction-to-case thermal resistance is 3°C/W. If
an external heatsink is used, the effective junction-to-ambient thermal resistance is the sum of the junction-to-case resistance (3°C/W),
the specified thermal resistance of the heatsink selected, and the thermal resistance of the interface between the heatsink and the
LP2957 (see Application Hints).
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