e up3466 d s3466 ver0.1 sep. 2013 1 cc/cv mode step-down converter d escription t he EUP3466 is a step-down converter capable of driving 3a continuous load with excellent line and load regulation. the EUP3466 operates in either cc (constant current) mode or cv (constant voltage) mode with an input voltage range from 8v to 36v. the EUP3466 provides programmable cable compensation by adjusting external resistor divider. the EUP3466 stops switching when the output reaches over voltage threshold which is programmed by external resistor divider. fault protection includes secondary cycle-by-cycle current limit, short circuit protection and thermal shutdown. in shutdown mode the regulator draws 3 a of supply current. internal soft-start minimizes the inrush supply current and the output overshoot at initial startup. the EUP3466 is available in sop-8 package. t ypical application circuit features 8 v to 36v wide input operating range 40v input voltage surge fixed 80khz switching frequency cc/cv mode control up to 3a output current +/- 1% voltage reference accuracy +/- 4% constant current accuracy programmable cable compensation internal soft start output over voltage protection foldback short circuit protection secondary cycle-by-cycle current limit thermal shutdown available sop-8 package rohs compliant and 100% lead(pb)-free halogen-free a pplications c ar charger portable charger applications dc/dc converters with current limited f igure 1. application circuit v?mw`r?y?b? w w w . g o f o t e c h . c o m
EUP3466 ds3466 ver0.1 sep. 2013 2 pin configurations package type pin configurations sop-8 pin description pin name sop-8 description gnd 1 ground. fb 2 output feedback input. isen- 3 current sense negative input pin. isen+ 4 current sense positive input pin. sw 5 power switcher output. vin 6 input supply pin. oven 7 ov (output over voltage) threshold setting pin and enable input. drive oven voltage logic high to turn off the converter. comp 8 loop compensation pin. v?mw`r?y?b? w w w . g o f o t e c h . c o m
EUP3466 ds3466 ver0.1 sep. 2013 3 ordering information order number package type marking operating temperature range EUP3466dir1 sop-8 xxxxx p3466 -40c to +85c EUP3466 lead free code 1: lead free, halogen free packing r: tape & reel operating temperature range i: industry standard package type d: sop block diagram figure 2. functional block diagram v?mw`r?y?b? w w w . g o f o t e c h . c o m
EUP3466 ds3466 ver0.1 sep. 2013 4 absolute maximum ratings (1) input voltage (v in ) ----------------------------------------------------------------- -0.3v to 40v switch voltage (v sw ) -------------------------------------------------------------- -1v to vin +0.3v isen+, isen- --------------------------------------------------------------------- -0.3v to 7v all other pins --------------------------------------------------------------------- -0.3v to 6v junction temperature -------------------------------------------------------------- 150c storage temperature --------------------------------------------------------------- -65c to +150c lead temp(soldering, 10sec) ---------------------------------------------------- 260c thermal resistance ja (sop-8) ------------------------------------------------- 125c /w recommend operating conditions (2) supply voltage (v in ) ------------------------------------------------------------ 8v to 36v operating temperature range ----------------------------------------------- -40c to +85c note (1): stress beyond those listed under absolute maximum ratings may damage the device. note (2): the device is not guaranteed to function outside the recommended operating conditions. electrical characteristics (v in =12v, t a =+25c, i out =2.0a, unless otherwise specified) EUP3466 parameter conditions min. typ. max. unit input voltage 8 36 v input no load current i out =0a 10 ma quiescent current v oven =0v,v fb =1.5v 0.5 1 ma shutdown current v oven =5v 2.5 a input under voltage lockout threshold rising 6.2 6.7 7.2 v input under voltage lockout threshold hysteresis 1 v current limit 4.5 a 72 80 88 khz operating frequency t j = -25c to 125c 68 92 khz maximum duty cycle 100 % minimum on-time 400 ns 1.168 1.18 1.192 v reference voltage of the voltage error amplifier t j = -25c to 125c 1.155 1.205 v 113 118 123 mv reference voltage of the current error amplifier t j = -25c to 125c 111 125 mv transconductance of error amplifier 75 a /v 1.145 1.18 1.215 v reference voltage of the over voltage comparator t j = -25c to 125c 1.133 1.227 v reference voltage of the short circuit foldback comparator 0.46 v oven enable threshold voltage 0.4 v oven shutdown threshold voltage 2.5 v temperature rising 150 c thermal shut-down temperature temperature falling 100 c pmos drain-source on-state resistance v in =24v, i out =1a 90 m v?mw`r?y?b? w w w . g o f o t e c h . c o m
EUP3466 ds3466 ver0.1 sep. 2013 5 typical operating characteristics v in =12v, v out =5v, t a =25c, unless otherwise noted. v?mw`r?y?b? w w w . g o f o t e c h . c o m
EUP3466 ds3466 ver0.1 sep. 2013 6 typical operating characteristics (continued) v in =12v, v out =5v, t a =25c, unless otherwise noted. v?mw`r?y?b? w w w . g o f o t e c h . c o m
EUP3466 ds3466 ver0.1 sep. 2013 7 typical operating characteristics (continued) v in =12v, v out =5v, t a =25c, unless otherwise noted. v?mw`r?y?b? w w w . g o f o t e c h . c o m
EUP3466 ds3466 ver0.1 sep. 2013 8 typical operating characteristics (continued) v in =12v, v out =5v, t a =25c, unless otherwise noted. v?mw`r?y?b? w w w . g o f o t e c h . c o m
EUP3466 ds3466 ver0.1 sep. 2013 9 functional description the EUP3466 is a current-mode step-down converter with 8v to 36v input power supply. the device can provide up to 3a continuous current to the output. the EUP3466 uses current-mode architecture to control the regulator loop. the output voltage is measured at fb through a resistive voltage divider and amplified through the internal error amplifier. the output current of the transconductance error amplifier is presented at comp pin where a rc network compensates the regulator loop. slope compensation is internally added to eliminate subharmonic oscillation at high duty cycle. the slope compensation adds voltage ramp to the inductor current signal which reduces maximum inductor peak current at high duty cycles. cc/cv mode control the EUP3466 operates in either cc mode or cv mode. the cv mode regulates the output voltage. when output current reaches the cc threshold, the device enters cc mode to limit the output current. programmable cable compensation the EUP3466 provides programmable cable compensation by adjusting the external resistor divider to compensate resistive voltage drop across the charger's output cable. internal soft-start internal soft-start minimizes the inrush supply current and the output overshoot at initial startup. over voltage protection ovp (over voltage protection) function with programmable ov (over voltage) threshold set by the external resistor divider is provided. when output over voltage occurs, the device shuts down and returns to normal operation automatically when the output over voltage is released. short circuit protection the EUP3466 provides the output short circuit protection function to prevent large output short circuit from damaging the device. when output short happens, the device shuts down and returns to normal operation automatically when the short circuit condition is released. thermal shutdown the EUP3466 stops switching when its junction temperature exceeds 150c and resumes when the temperature has dropped by 50c to protect the device. application information the output voltage is set through a resistive voltage divider and can be expressed by the equation as follows 4r/)4r3r(*v18.1v out + = setting the cc current EUP3466 constant current value is set by the resistor r2 connected between the isen- and isen+ pins. the cc current is determined by the equation as follows 2r/v118.0i cc = setting the output over voltage threshold the oven pin voltage is set by a resistor divider connected between vout and gnd. when oven pin voltage is higher than 1.18v, the regulator stops switching until oven pin voltage falls below 1.18v. thus the output over voltage threshold is 6r/)6r5r(*v18.1v ov + = setting the cable compensation the EUP3466 provides programmable cable voltage drop compensation using the impedance at the fb pin to compensate voltage drop across the charger's output cable. the cable compensation voltage can be expressed as 3r*2r*i*27.5v out out m = d by adjust the value of r3, the cable compensation voltage can be programmed. v?mw`r?y?b? w w w . g o f o t e c h . c o m
EUP3466 ds3466 ver0.1 sep. 2013 10 packaging information sop-8 millimeters inches symbols min. normal max. min. normal max. a 1.35 - 1.75 0.053 - 0.069 a1 0.05 - 0.25 0.002 - 0.010 d 4.80 4.90 5.00 0.189 0.193 0.197 e1 3.70 3.90 4.00 0.146 0.154 0.157 e 5.80 6.00 6.20 0.228 0.236 0.244 l 0.40 - 1.27 0.016 - 0.050 b 0.31 - 0.51 0.012 - 0.020 e 1.27 ref 0.050 ref v?mw`r?y?b? w w w . g o f o t e c h . c o m
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