MCP1501 1.1.6 LOAD REGULATION An ideal voltage reference will maintain the specified output voltage regardless of the load's current demand. However, real devices experience a small error voltage that deviates from the specified output voltage when a load is present. Load regulation is defined as the voltage difference when under no load (VOUT @ IOUT|0) and under maximum load (VOUT @ IOUT|MAX), and is expressed as a percentage, as shown in Equation 1-10. EQUATION 1-10: V OUT @ I OUT|0 – V OUT @ I OUT|MAX ---------------------------- 100% = % Load Regulation V OUT @ I OUT|0 Similar to line regulation, load regulation may also be expressed as %/mA or in ppm/mA as shown in Equation 1-11 and Equation 1-12, respectively. EQUATION 1-11: V OUT --------- V OUT NOM % ----------- 100% = --Load Regulation I OUT mA EQUATION 1-16: V OUT 10 V- --------- ---- V OUT NOM 2.048V 6 6 ----------- 10 = ------ 10 = 2.441 ppm --- I OUT mA 2 mA EQUATION 1-12: V OUT --------- V OUT NOM 6 ppm ----------- 10 = ---Load Regulation I OUT mA As an example, if the MCP1501-20 is implemented in a design and a 10 µV change in output voltage is measured from a 2 mA change on the input, then the error in percent, ppm, percent/volt, ppm/volt, as shown in Equation 1-13 – Equation 1-16. EQUATION 1-13: 2.048V – 2.04799V------------ 100% = . 0004882% 2.04799V EQUATION 1-14: 6 6 2.048V – 2.04799V2.048V – 2.04799V ------------ 10 = ------------ 10 = 4.882 ppm 2.04799V 2.04799V EQUATION 1-15: V OUT 10 V --------- ---- V OUT NOM 2.048V %----------- 100% = ------ 100% = 0.2441 --2 mA I OUT mA DS20005474E-page 6 2015-2017 Microchip Technology Inc.