GS-R400/2 family small size step-down switching regulator family june 1994 1/3 selection chart type ordering number output voltage (v) input voltage (v) output ripple (mvpp) regulation efficiency (%) notes line (mv/v) load (mv/a) GS-R405/2 5.1 2% 9to40 25 2 20 80 fixed output voltage gs-r412/2 12.0 4% 16 to 40 50 5 40 85 o gs-r415/2 15.0 4% 19 to 40 65 6 60 87 o gs-r424/2 24.0 4% 28 to 40 100 6 80 90 o GS-R400v/2 5.1 to 24 vo+4 to 40 25 to 100 2 to 6 20 to 80 80 to 90 progr. output voltage note : line regulation is measured at i out =1a. load regulation is measured at v in =v o +8v and i out =0.5 to 1.5a. case temperature must be kept below 85 c features mtbf in excess of 500,000 hours 4a max output current 40v max input voltage 4v max drop-out voltage soft start non-latching short circuit protection crow-bar output overvoltage protection description the GS-R400/2 series is a family of small sized high current, high voltage step-down switching regulators. the integral heatsink allows a large power handling capability and it provides also an effective shielding to minimize emi. absolute maximum ratings symbol parameter value unit v i dc input voltage 42 v i o output current 4a t stg storage temperature range 40 to +105 c t cop operating case temperature range 20 to +85 c
pin 5 GS-R400v/2 only dimensions in mm bottom view 2/3 electrical characteristics (t a =25 c unless otherwise specified) symbol parameter test conditions min typ max unit d v o / d t temperature stability v i =v o +8v i o =1a 0.2/0.6 mv/ c i o output current v i =v o +8v 0.1 4 a i ol current limit v i =v o +8v 58a i isc average input current v i = 40v output shorted 0.1 0.2 a f s switching frequency i o =1a 100 khz s vr supply voltage rejection f o = 100hz io = 1a 4/12 mv/v v r ripple voltage i o =1a 25/100 mvpp t ss soft start time 10/35 ms t cb crowbar delay time 5 m s v cth crowbar intervention threshold v o ? 1.25 v r th thermal resistance case to ambient 8 c/w connection diagram and mechanical data pin description pin function description 1 + input dc input voltage. recommended maximum voltage is 40v. 2 input gnd return for input voltage source. 3 output gnd return for output current path. internally connected to pin 2. 4 + output regulated dc output voltage. 5 program a resistor (<10k w ) connected between this pin and pin 4 sets the + output voltage of the GS-R400v/2. GS-R400/2 family
3/3 user notes input voltage the recommended operating maximum dc input voltage is 40v inclusive of the ripple voltage. case grounding the module case is internally connected to pin 2 and pin 3. the pcb area below the module can be used as an effective sixth side shield against emi. thermal characteristics the case-to-ambient thermal resistance of all the GS-R400/2 modules is about 8 c/w. this produces a32 c temperature increase of the module surface for 4w of internal power dissipation. depending on the ambient temperature and/or on the power dissipation, an additional heatsink or forced ventilation may be required. input impedance the module has an internal capacitor connected between the input pins in order to assure pwm stability. this capacitor cannot handle large values of high frequency ripple current and it can be per- manently damaged if the primary energy source impedance is not adequate. the use of an external low esr, high ripple current capacitor located as close the module as possible is recommended. suitable capacitors should have a rms current capability of 2.5 a rms with a working voltage of 50 v dc and an esr of 0,1 w at 100khz. when space is a limitation a 22 m f ceramic multilayer capacitor must be connected to the module input pins. output voltage programming the GS-R400v/2 output voltage is programmed by using a resistor. the resistor must be located very close the module and the pcb layout must minimize injected noise. the value of the resistor is calculated by using the following formula: r v = 2.67 ? ? ? v o 5.1 - 1 ? ? ? k w v o can be adjusted between 5.1 and 24v. module protection the modules are protected against occasional and permanent short circuits of the output pins to ground. during short circuit (when the output cur- rent exceeds the maximum value) the output is automatically disabled. after a fixed time the module starts again in a soft mode. the cycle is repeated until the short circuit condition is removed. the module can be permanently damaged if the case temperature exceeds 85 c power derating curve information furnished is believed to be accurate and reliable. however, sgs-thomson microelectronics assumes no responsibility for the consequences 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 sgs-thomson microelectronics. specification mentioned in this publication are subject to change without notice. this publication supersedes and replaces all information previously supplied. sgs-thomson microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of sgs-thomson microelectronics. ? 1994 sgs-thomson microelectronics all rights reserved sgs-thomson microelectronics group of companies australia - brazil - china - france - germany - hong kong - italy - japan - korea - malaysia - malta - morocco - the netherlands - singapore - spain - sweden - switzerland - taiwan - thailand - united kingdom - u.s.a. GS-R400/2 family
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