CONSTANT VOLTAGE AND CONSTANT CURRENT CONTROLLER FOR ADATPTORS AND BATTERY CHARGERS FEATURES SOT-23-6LD ● CONSTANT VOLTAGE AND CONSTANT CURRENT CONTROL ● LOW VOLTAGE OPERATION ● PRECISION INTERNAL COMPONENT COUNT ● CURRENT SINK OUTPUT STAGE ● EASY COMPENSATION ● LOW AC MAINS VOLTAGE REJECTION DESCRIPTION TJ1051 is a highly integrated solution for SMPS applications requiring constant voltage and constant current mode. TJ1051 integrates one voltage reference, two operational amplifiers (with ORed ouputs - common collectors), and a current sensing circuit. The voltage reference combined with one operational amplifiers makes it an ideal voltage controller, and the TJ1051 SOP-8 ORDERING INFORMATION Device Marking Package TJ1051CL 1051 SOT-23-6LD TJ1051CD TJ1051 SOP-8 PIN CONNECTIONS (TOP VIEW) SOP-8 SOT-23-6 1 Vctrl Vcc 6 2 Gnd Vsense 5 other low voltage reference combined with the other Ictrl 3 Out operational amplifier makes it an ideal current limiter for output low side current sensing. The current threshold is fixed and precise. The only external components are : ● A resistor brideg to be connected to the output Block Diagram of the power supply (adaptor, battery charger) to set the voltage regulation by dividing the 1.210V desired output voltage to match the internal voltage reference value. ● A sense resistor having a value and allowable dissipation power which need to be chosen according to the internal vlotage threshold. ● Optional compensation components (R and C). 200mV 4 1 Vctrl Gnd 8 2 Vcc Out 7 3 Vsense Ictrl 6 4 Nc Nc 5 Vcc Out Vctrl APPLICATIONS Gnd Ictrl ● BATTERY CHARGERS ● ADAPTERS Vsense TJ1051, is ideal for smallest package available, is ideal for space shrinked applications such as battery chargers and adaptors. HTC Jan. 2007-Rev 1.0 1 CONSTANT VOLTAGE AND CONSTANT CURRENT CONTROLLER FOR ADATPTORS AND BATTERY CHARGERS TJ1051 PIN DESCRIPTION SOT23-6 Pinout Name Vcc GND Vctrl Ictrl Out Vsense Pin# 6 2 1 4 3 5 Type Power Supply Power Supply Analog Input Analog Input Current Shink Output Analog Input Function Positive Power Supply Line Ground Line. 0V Reference For All Voltages Input Pin of the Voltge Control Loop Input Pin of the Current Control Loop Output Pin. Sinking Current Only Input Pin of the Current Control Loop Pin# 2 8 1 6 7 3 5 4 Type Power Supply Power Supply Analog Input Analog Input Current Shink Output Analog Input Function Positive Power Supply Line Ground Line. 0V Reference For All Voltages Input Pin of the Voltge Control Loop Input Pin of the Current Control Loop Output Pin. Sinking Current Only Input Pin of the Current Control Loop SOP-8 Pinout Name Vcc GND Vctrl Ictrl Out Vsense Nc Nc ABSOLUTE MAXIMUM RATINGS Symbol Vcc Vi Top Tj Parameter DC Supply Voltage Input Voltage Operating Free Air Temperature Range Maximum Junction Temperature Value 14 -0.3 to Vcc 0 to 85 150 Unit V V ℃ ℃ Value 2.5 to 12 Unit V OPERATION CONDITIONS Symbol Parameter Vcc DC Supply Conditions HTC Jan. 2007-Rev 1.0 2 CONSTANT VOLTAGE AND CONSTANT CURRENT CONTROLLER FOR ADATPTORS AND BATTERY CHARGERS TJ1051 ELECTRICAL CHARACTERISTICS Tamb = 25℃ and Vcc = +5V (unless otherwise specified) Symbol Parameter Test Condition Min Typ Max Unit 2 mA Total Current Consumption Icc Total Supply Current - not taking the Tamb 1.1 output sinking current into account 0 < Tamb < 85 ℃ 1.2 Voltage Control Loop Gmv Transconduction Gain (Vctrl). Sink Current Only 1) Vref Voltage Control Loop Referenc Iibv Tamb 0 < Tamb < 85 ℃ 2) Input Bias Current (Vctrl) 1 Tamb 1.198 0 < Tamb < 85 ℃ 1.186 3.5 mA/mV 2.5 1.21 Tamb 50 0 < Tamb < 85 ℃ 100 1.222 V 1.234 nA Current Control Loop Gmi Transconduction Gain (Ictrl). Sink Current Only 3) Tamb 0 < Tamb < 85 ℃ 4) Vsense Current Control Loop Reference Iibi Current out of pin Ictrl at - 200mV 1.5 Iout =2.5mA Tamb 196 0 < Tamb < 85 ℃ 192 7 200 Tamb 25 0 < Tamb < 85 ℃ 50 mA/mV 204 mV 208 ㎂ Output Stage Vol Ios Low output voltage at 10 mA sinking Current Output Short Circuit Current. Output to Vcc. Sink Current Only Tamb 0 < Tamb < 85 ℃ 200 Tamb 27 0 < Tamb < 85 ℃ 35 mV 50 mA 1) If the voltage on Vctrl (the negative input of the amplifier) is higher than the positive amplifier input (Vref=1.210V), and it is increased by 1mV, the sinking current at the output OUT will be increased by 3.5mA. 2) The internal Voltage Reference is set at 1.210V (bandgap reference). The voltage control loop precision takes into account the cumulative effects of the internal voltage reference deviation as well as the input offset voltage of the trans conductance operational amplifier. The internal Voltage Reference is fixed by bandgap, and trimmed to 0.5% accuracy room temperature. 3) When the positive input at Ictrl is lower than - 200mV, and the voltage is decreased by 1mV, the sinking current at the output OUT will be increased by 7mA. 4) The internal current sense threshold is set to - 200mV. The current control loop precision takes into account the cumulative effects of the internal voltage reference deviation as well as the input offset voltage of the transconduction operational amplifier. HTC Jan. 2007-Rev 1.0 3 CONSTANT VOLTAGE AND CONSTANT CURRENT CONTROLLER FOR ADATPTORS AND BATTERY CHARGERS TJ1051 Figure 1 : Typical Adaptor or Battery Charger Application Using TJ1051 D OUT Top primary TJ1051 R2 Vcc Rout Rvc Cvc1 2.2n 1 Out Vctrl Cic1 2.2nF 200mV Gnd Ictrl IL Cvc2 22pF Load 1.210V Vsense + Ric1 22K R1 + Ric2 500 Vsense Rsense OUT IL In the avove application schematic, the TJ1051 is used on the secondary side of a flyback adapte (or battary charger) to provide an accurate control of voltage and current. The above feedback loo is made with an optocoupler. HTC Jan. 2007-Rev 1.0 4