LP2957ISXSLASHNOPB datasheet(7/24 Pages) TI

7 / 24 page

using:

Exceeding the maximum allowable power dissipation will result in excessive die temperature, and the regulator

LP2957, LP2957A

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SNVS102C – JUNE 1998 – REVISED APRIL 2013

Typical Performance Characteristics (continued)

Unless otherwise specified: VIN = 6V, IL = 1 mA, CL = 2.2 µF, V SD = 3V, TA = 25°C

Thermal Regulation

Error Output Sink Current

Figure 22.

Figure 23.

Dropout Detection

Threshold Voltages

Maximum Power Dissipation (DDPAK/TO-263)(1)

Figure 24.

Figure 25.

Error Output Voltage

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, TA. The maximum allowable power dissipation at any ambient temperature is calculated

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,

θJA 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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