MCP1701 vs MCP1701A vs MCP1702 Technical Brief

TB3006 MCP1701 vs MCP1701A vs MCP1702 OPERATION Author: Matthew Williams Microchip Technology Inc. Thermal Protection The MCP1702 thermal protection circuitry will shut- INTRODUCTION down the LDO if the internal junction temperature of the LDO rises above the typical threshold temperature of Since the initial release of the MCP1701 2 µA Low 150°C. The LDO will remain shutdown until the junction Dropout Positive Voltage Regulator, Microchip temperature has cooled to the typical turn-on junction Technology Inc. has been addressing customer temperature of 130°C. At that point, the LDO will turn requests for device enhancements. The customer back on. If the power dissipation is low enough, the requests for the MCP1701 enhancements were higher device will continue to cool and operate normally. If the output currents, higher input operating voltage, and a power dissipation remains high, the thermal shutdown reduction in output voltage overshoot at startup. These protection circuitry will turn off the LDO again. requests have been implemented in the newly released MCP1702 250 mA Low Quiescent Current LDO The MCP1701 and MCP1701A do not incorporate an Regulator. active thermal protection circuit. Thus, the designer should limit the power dissipation of the device through The original MCP1701 provided the designer with an good design practices. LDO that was capable of 250 mA of output current at 5.0V with an input voltage of up to 10V. The 10V input Wider Input Operating Voltage - operating voltage maximum gave designers a solution 2.7V to 13.2V for voltages in the range of 6 to 10 volts, with the MCP1700 LDO being used for voltages up to 6.0 volts. The MCP1702 device has an input operating voltage range of 2.7V to 13.2V over the entire operating The MCP1701 was replaced by the MCP1701A. The temperature range. The MCP1701 and MCP1701A MCP1701A device added another package option, the devices specify an upper operating voltage of 10V. The TO-92. Enhancements incorporated into the additional 3.2V of operating voltage headroom allow MCP1701A were improved transient response to load the MCP1702 device to be used with standard 12V variations and lower dropout voltages. supply voltages. The higher junction temperature The MCP1702 was developed to extend the range and ratings of the MCP1702 allows the device to supply performance of the MCP1701 line of regulators. The more current at the higher input voltages. As an MCP1702 has several key enhancements, which make example, the MCP1702 5.0V regulator in a SOT-89 the device favorable compared to the MCP1701 and package can provide the full rated 250 mA of current MCP1701A devices. The MCP1702 provides the with an input voltage of 12 volts at an ambient following major enhancements over its predecessors: temperature of 34°C. * Thermal Protection Output Current Rated Overtemperature Wider Input Operating Voltage 2.7V to 13.2V -40°C to +125°C Output Current Rated Over Temperature: - -40°C to +125°C The MCP1702 now rates many of the device parameters over the extended temperature range of Stable with Ceramic, Tantalum, and Aluminum -40°C to +125°C. The following parameters are now Electrolytic Capacitors