Electronic component search and free download site.Transistors,MosFET ,Diode,Integrated circuits English한국어日本語русский简体中文español
Part Name

# TC1263-5.0VOA View Datasheet(PDF) - Microchip Technology

 Part Name TC1263-5.0VOA Microchip Technology Description 500 mA, Fixed-Output, CMOS LDO with Shutdown
TC1263-5.0VOA Datasheet PDF : 18 Pages
 1 2 3 4 5 6 7 8 9 10 Next Last
 TC1263 5.0 THERMAL CONSIDERATIONS 5.1 Thermal Shutdown Integrated thermal protection circuitry shuts the regulator off when the die temperature exceeds 160°C. The regulator remains off until the die temperature drops to approximately 150°C. 5.2 Power Dissipation The amount of power the regulator dissipates is primarily a function of input and output voltage and out- put current. The following equation is used to calculate worst-case actual power dissipation: EQUATION 5-1: PD = VINMAX – VOUTMINILOADMAX Where: PD = Worst-case actual power dissipation VINMAX = Maximum voltage on VIN VOUTMIN = Minimum regulator output voltage ILOADMAX = Maximum output (load) current The maximum allowable power dissipation (Equation 5-2) is a function of the maximum ambient temperature (TAMAX), the maximum allowable die temperature (TJMAX) and the thermal resistance from junction-to-air (JA). EQUATION 5-2: Where: PDMAX = T----J---M----A---X----–-J---A-T---A----M----A---X- PD = Worst-case actual power dissipation VINMAX = Maximum voltage on VIN VOUTMIN = Minimum regulator output voltage ILOADMAX = Maximum output (load) current Table 5-1 and Table 5-2 show various values of JA for the TC1263 package types. TABLE 5-1: THERMAL RESISTANCE GUIDELINES FOR TC1263 IN 8-PIN SOIC PACKAGE Copper Area (Topside)* Copper Area (Backside) Board Area Thermal Resistance JA) 2500 sq mm 2500 sq mm 2500 sq mm 60°C/W 1000 sq mm 2500 sq mm 2500 sq mm 60°C/W 225 sq mm 2500 sq mm 2500 sq mm 68°C/W 100 sq mm 2500 sq mm 2500 sq mm 74°C/W * Pin 2 is ground. Device is mounted on top-side. TABLE 5-2: THERMAL RESISTANCE GUIDELINES FOR TC1263 IN 5-PIN DDPAK/TO-220 PACKAGE Copper Area (Topside)* Copper Area (Backside) Board Area Thermal Resistance JA) 2500 sq mm 2500 sq mm 2500 sq mm 25°C/W 1000 sq mm 2500 sq mm 2500 sq mm 27°C/W 125 sq mm 2500 sq mm 2500 sq mm 35°C/W * Tab of device attached to top-side copper Equation 5-1 can be used in conjunction with Equation 5-2 to ensure regulator thermal operation is within limits. For example: Given: VINMAX = 3.3V ± 10% VOUTMIN = 2.7V ± 0.5% ILOADMAX = 275 mA TJMAX = 125°C TAMAX = 95°C JA = 60° C/W (SOIC) Find: 1. Actual power dissipation 2. Maximum allowable dissipation Actual power dissipation: PD  VINMAX – VOUTMINILOADMAX PD = 3.3  1.1 – 2.7  .995275  10–3 PD = 260 mW Maximum allowable power dissipation: PDMAX = T----J---M----A---X----–-J---A-T---A----M----A---X- PDMAX = ---1---2---5-6----–0----9---5---- PDMAX = 500 mW In this example, the TC1263 dissipates a maximum of 260 mW below the allowable limit of 500 mW. In a similar manner, Equation 5-1 and Equation 5-2 can be used to calculate maximum current and/or input voltage limits. For example, the maximum allowable VIN is found by substituting the maximum allowable power dissipation of 500 mW into Equation 5-1, from which VINMAX = 4.6V. DS21374D-page 8  2002-2012 Microchip Technology Inc.