constant voltage & constant current controller tj 1052 jul. 2010 ? preliminary - 1 - htc sot-23 6l ordering information device package features z constant voltage and constant current control z low voltage operation z precision internal component count z current sink output stage z easy compensation z low ac mains voltage rejection z moisture sensitivity level 3 application z battery chargers z adapters TJ1052sf6 TJ1052gsf6 sot-23 6l description TJ1052 is a highly integrated solution for smps applicatio ns requiring constant voltage and constant current mode. TJ1052 integrates one voltage reference, tw o operational amplifiers (with one output - common collectors), and a current sensing circuit. the voltage reference combined with one operational amplifier makes it an ideal voltage controller, and the other low voltage reference combined with the other operational amplifier makes it an ideal current limiter for output low side current sensing. the cu rrent threshold is fixed and precise. the only external components are : z a resistor bridge to be connected to the output of t he power supply (adaptor, battery charger) to set the voltage regulation by dividing the desired output volta ge to match the internal voltage reference value. z a sense resistor having a value and allowable dissipation power which need to be chosen according to the internal voltage threshold. TJ1052 is ideal for space shrunk applications such as adapters and battery chargers. absolute maximum ratings (t a = 25 , unless otherwise specified) characteristic symbol min. max. unit dc supply voltage v cc - 20 v input voltage v in -0.3 v cc v operating free air temperature range t opr 0 85 maximum junction temperature t j - 150 operating conditions (t a =25 ) characteristic symbol min. max. unit dc supply voltage v cc 2.5 18 v
constant voltage & constant current controller tj 1052 jul. 2010 ? preliminary - 2 - htc ordering information package order no. package marking supplied as status sot-23 6l TJ1052sf6 TJ1052 reel contact us sot-23 6l TJ1052gsf6 TJ1052 reel contact us pin configuration 4 5 13 2 6 vcc vsense ictrl vctrl gnd out sot-23 6l pin description sot-23 6l pin no. name function 1 v ctrl analog input 2 gnd ground 3 out current sink output 4 i ctrl analog input 5 v sense analog input 6 v cc power supply
constant voltage & constant current controller tj 1052 jul. 2010 ? preliminary - 3 - htc electrical characteristics (t a =25 and v cc = +5v, unless otherwise specified) symbol parameters condition min. typ. max. unit total current consumption i cc total supply current - not taking the output sinking current into account t a = 25 0 < t a < 85c 1.1 1.2 2 ma voltage control loop g mv transconduction gain (v ctrl ). sink current only (note 1) t a = 25 0 < t a < 85c 1 3.5 2.5 ma/mv v ref voltage control loop (note 2) t a = 25 0 < t a < 85c 1.198 1.186 1.21 1.222 1.234 v i ibv input bias current (v ctrl ) t a = 25 0 < t a < 85c 200 300 na current control loop g mi transconduction gain (i ctrl ). sink current only (note 3) t a = 25 0 < t a < 85c 1.5 7 ma/mv v sense current control loop (note 4) iout = 2.5 ma 0 < t a < 85c 196 192 200 204 208 mv i ibi current out of pin i ctrl at -200mv t a = 25 0 < t a < 85c 30 40 a output stage v ol low output voltage at 10 ma sinking current t a = 25 0 < t a < 85c 200 500 mv i os output short circuit current. output to v cc . sink current only t a = 25 0 < t a < 85c 45 60 90 ma note 1. if the voltage on v ctrl (the negative input of the amplifier) is higher than the positive amplifier input (v ref =1.210v), and it is increased by 1mv, the sinking current at the output will be increased by 3.5ma. note 2. the internal voltage reference is set at 1.210v (bandg ap reference). the voltage control loop precision takes into acco unt the cumulative effects of the internal voltage reference deviation as well as the input offset voltage of the trans-conductance ope rational amplifier. the internal voltage reference is fixed by bandgap, and trimmed to 0.5% accuracy at room temperature. note 3. when the positive input at i ctrl is lower than -200mv, and the voltage is decreased by 1mv, the sinking current at the output will be increased by 7ma. note 4. the internal current sense threshold is set to -200mv. the current control loop precision takes into account the cumula tive effects of the internal voltage reference deviation as well as the input offset voltage of the trans-conduction operational amplifier.
constant voltage & constant current controller tj 1052 jul. 2010 ? preliminary - 4 - htc typical application circuit + - + - 1.210 v 200mv i ctrl v sense v cc out 1 2 3 45 6 v ctrl gnd r sense r ic 2 r led r ic 1 r vc 1 c vc 1 c ic 1 r2 r1 i out TJ1052 v out + fig 1. typical adaptor or battery charger application using TJ1052 in the above application schematic, the device is used on the secondary side of a flyback adaptor (or battery charger) to provide an accurate control of voltage and current. the above feedback loop is made with an optocoupler.
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