1/5 gs-r12vxxx1.5 october 2003 this is preliminary information on a new product now in development. details are subject to change without notice. feature n mtbf 1 000 000 hours ( t amb =25 ) c) n 1.5a max output current n 15v max input voltage n 1.5v max drop-out voltage n not-latching overload and short circuit protection n thermal shutdown n no heatsink required description the gs-r12vxxx1.5 series is a family of high effi- ciency step down switching voltage regulator, de- signed to replace linear regulators. the foot print of gs-r12v perfectly fits a standard to220 package. based on stm l5973 device, this non isolated family of regulators are suitable for the full spectrum of ap- plications including telecom, industry, computer and distributed power system applications having a wide- ly ranging input voltage. selection chart typ e ordering number output voltage [v] input voltage [v] output ripple [mvpp] efficiency [%] notes gs-r12v0121.5 1.235 3% 4.5 15 35 68 fixed output voltage gs-r12v0181.5 1.8 4% 4.5 15 35 72 fixed output voltage gs-r12v0251.5 2.5 4% 4.5 15 35 76 fixed output voltage gs-r12v0331.5 3.3 4% 4.5 15 35 82 fixed output voltage gs-r12v0501.5 5.0 4% 6.6 15 35 85 fixed output voltage ordering number: gs-r12vxxx1.5 preliminary 1.8w to 7.5w step down switching regulator family
gs-r12vxxx1.5 2/5 absolute maximum ratings connection diagram and mechanical data symbol parameter value unit v i dc input voltage 16 v i out maximum output current int. limit t stg storage temperature range -40 105 c t op operating ambient temperature -25 70 c
3/5 gs-r12vxxx1.5 pin description electrical characteristics (t amb =25 ) c, unless otherwise specified.) user notes input voltage the recommended operating maximum dc input voltage is 15v inclusive of ripple voltage. current protection the device has two current limit protections, pulse by pulse and frequency fold back. the current is sensed through a resistor and if reaches the threshold, the on time is reduced and consequently the output voltage too. since the minimum switch on time (necessary to avoid false overcurrent signal) is not enough to obtain a suf- ficiently low duty cycle at 250 hz, the output current, in strong overcurrent or short circuit conditions, could in- crease again. for this reason the switching frequency is also reduced, so keeping the inductor current under its maximum threshold. the frequency depends on the feedback voltage. as the feedback voltage decreases (due to the reduced duty cycle), the switching frequency decrease too. thermal shutdown the shutdown block generates a signal that turns off the power stage if the temperature of the internal chip goes higher than a fixed internal threshold (150 oc). the sensing element of the chip is very close to the pdmos area, so ensuring an accurate and fast temperature pin function description 1 + input dc input voltage 2 gnd common gnd 3 + output regulated dc output voltage symbol parameter test condition min. typ. max. unit temperature stability v i =v o + 1.5v i o = 1.5a mv/c i o output current v i =4.5 15v 0 1.5 a i ol current limit v i =4.5 15v 2.5 a i q quiescent current v i =12v i o = 0a 1.8 2.5 ma f s switching frequency v i =12v i o = 1.5a 225 250 275 khz srv supply voltage rejection mv/v v r ripple voltage v i =12v i o = 1a/1.5a 25/35 mvpp r th thermal resistance case to ambient c/w
gs-r12vxxx1.5 4/5 detection. an hysteresis of approximately 20 oc avoids that the devices turns on and off continuously. thermal characteristics additional features and protections feedback disconnection in case of feedback disconnection, the duty cycle increases versus the maximum allowed value, bringing the output voltage close to the input supply. this condition could destroy the load. to avoid this dangerous condition, the device is turned off if the internal feedback pin remains floating. output overvoltage protection the overvoltage protection, ovp, is realized by using an internal comparator, which input is connected to the feedback, that turns off the power stage when the ovp threshold is reached. this threshold is typically 30% higher than the feedback voltage.
information furnished is believed to be accurate and reliable. however, stmicroelectronics assumes no responsibility for the co nsequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. no license is granted by implication or otherwise under any patent or patent rights of stmicroelectronics. specifications mentioned in this publicati on are subject to change without notice. this publication supersedes and replaces all information previously supplied. stmicroelectronics prod ucts are not authorized for use as critical components in life support devices or systems without express written approval of stmicroelectro nics. the st logo is a registered trademark of stmicroelectronics. all other names are the property of their respective owners ? 2003 stmicroelectronics - all rights reserved stmicroelectronics group of companies australia - belgium - brazil - canada -china - czech republic - finland - france - germany - hong kong - india - israel - italy - japan - malaysia - malta - morocco - singapore - spain - sweden - switzerland - united kingdom - u.s.a. http://www.st.com 5/5 gs-r12vxxx1.5
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