TSM1013IST

TSM1013 Constant Voltage and Constant Current Controller for Battery Chargers and Adaptors ■ ■ ■ ■ ■ Constant voltage and constant current control Low voltage operation Low external component count Current sink output stage Easy compensation VOLTAGE REFERENCE ■ ■ D SO-8 Fixed output voltage reference 2.5V 0.5% and 1% Voltage precision DESCRIPTION TSM1013 is a highly integrated solution for SMPS applications requiring CV (constant voltage) and CC (constant current) mode. S Mini SO8 TSM1013 integrates one voltage reference and two operational amplifiers. The voltage reference combined with one operational amplifier makes it an ideal voltage controller. The other operational, combined with few external resistors and the voltage reference, can be used as a current limiter. APPLICATIONS ■ ■ Adapters Battery Chargers ORDER CODE Part Number Temperature Package Range S D TSM1013I TSM1013AI TSM1013I TSM1013AI 0 0 0 0 to 105°C to 105°C to 105°C to 105°C ² ² ² ² Marking PIN CONNECTIONS (top view) 1 Vref Vcc 8 2 Cc- Cc Out 7 3 Cc+ Gnd 6 4 Cv- Cv Out 5 M1013 M1013A M806 M807 Note: S: MiniSO only available in Tape & Reel with T suffix D: SO is available in Tube (D) and in Tape & Reel (DT) February 2004 1/8 TSM1013 1 PIN DESCRIPTION PIN DESCRIPTION SO8 & Mini SO8 Pinout Name Pin # Type Vref CcCc+ CvCv Out Gnd Cc Out Vcc 1 2 3 4 5 6 7 8 Analog Output Analog Input Analog Input Analog Input Analog Output Power Supply Analog Output Power Supply Function Voltage Reference Input pin of the operationnal amplifier Input pin of the operationnal amplifier Input pin of the operationnal amplifier Output of the operational amplifier Ground Line. 0V Reference For All Voltages Output of the operational amplifier Power supply line. ABSOLUTE MAXIMUM RATINGS Symbol Vcc Vi Tstg Tj Iref ESD Rthja Rthja DC Supply Voltage DC Supply Voltage (50mA =< Icc) Input Voltage Storage temperature Junction temperature Voltage reference output current Electrostatic Discharge Thermal Resistance Junction to Ambient Mini SO8 package Thermal Resistance Junction to Ambient SO8 package Value Unit -0.3V to Vz -0.3 to Vcc -55 to 150 150 10 2 180 175 V V °C °C mA KV °C/W °C/W Value Unit 4.5 to Vz 0 to 105 V °C OPERATING CONDITIONS Symbol Vcc Toper 2/8 Parameter DC Supply Conditions Operational temperature ELECTRICAL CHARACTERISTICS 2 TSM1013 ELECTRICAL CHARACTERISTICS Tamb = 25°C and Vcc = +18V (unless otherwise specified) Symbol Parameter Test Condition Min.. Typ. Max. Unit 1 mA Total Current Consumption Icc Vz Total Supply Current, excluding current in Voltage Reference. Vcc clamp voltage Vcc = 18V, no load Tmin. < Tamb < Tmax. Icc = 50mA 28 V Operator 1 : Op-amp with non-inverting input connected to the internal Vref Vref+Vio Input Offset Voltage + Voltage reference TSM1013 TSM1013A DVio Tamb = 25°C Tmin. ≤ Tamb ≤ Tmax. Tamb = 25°C Tmin. ≤ Tamb ≤ Tmax. 2.5446 2.545 Input Offset Voltage Drift 2.574 2.575 2.553 2.560 V µV/°C 7 Operator 2 Vio Input Offset Voltage TSM1013 TSM1013A DVio Tamb = 25°C Tmin. ≤ Tamb ≤ Tmax. Tamb = 25°C Tmin. ≤ Tamb ≤ Tmax. 1 0.5 Input Offset Voltage Drift Tamb = 25°C Tmin. ≤ Tamb ≤ Tmax. Input Bias Current Tamb = 25°C Tmin. ≤ Tamb ≤ Tmax. SVR Supply Voltage Rejection Ratio VCC = 4.5V to 28V 65 Vicm Input Common Mode Voltage Range Common Mode Rejection Ratio Tamb = 25°C Tmin. ≤ Tamb ≤ Tmax. 70 60 Iib CMR Gm Vol Ios Transconduction Gain. Sink Current Only1 Low level output voltage at 10 mA sinking current Output Short Circuit Current. Output to Vcc. Sink Current Only 2 30 50 nA 20 50 150 200 nA 100 0 Output stage Tamb = 25°C Tmin. ≤ Tamb ≤ Tmax. 1 Tamb = 25°C Tmin. ≤ Tamb ≤ Tmax. mV µV/°C 7 Input Offset Current Iio 4 5 2 3 dB Vcc-1.5 85 V dB 3.5 2.5 mA/mV 200 600 mV 27 50 mA 2.545 2.57 2.557 V 20 30 Voltage reference Vref ∆Vref Reference Input Voltage, Iload=1mA TSM1013 1% precision TSM1013A 0.5% precision Reference Input Voltage Deviation Over Temperature Range Reference input voltage deviation over Vcc range. Reference input voltage deviation over RegLoad output current. RegLine 1) Tamb = 25°C Tmin. ≤ Tamb ≤ Tmax. 2.519 2.532 mV Iload = 5mA 20 mV Vcc = 18V, 0 < Iload < 10mA 10 mV The current depends on the difference voltage beween the negative and the positive inputs of the amplifier. If the voltage on the minus input is 1mV higher than the positive amplifier, the sinking current at the output OUT will be increased by 3.5mA. 3/8 TSM1013 ELECTRICAL CHARACTERISTICS Fig. 1: Internal Schematic 1 2 Vref Vcc 8 28V Vref Cc- Cc out 7 CC 3 4 Cc+ Gnd CV Cv- Cv out 6 5 Fig. 2: Typical Adapter Application Using TSM1013 To primary 8 Vcc 1 OUT+ D Vref 28V R2 IL CV R4 100K TSM1013 CV Out 5 Cv- 4 Load R3 100 + 3 Cc+ CC Out CC 7 Rvc1 22K + R5 Vsense 10K Rsense IL 6 Ric2 1K R1 Cic1 2.2nF Gnd 2 Cc- Cvc1 2.2nF Ric1 22K OUT- In the above application schematic, the TSM1013 is used on the secondary side of a flyback adapter (or battery charger) to provide an accurate control of voltage and current. The above feedback loop is made with an optocoupler. 4/8 TSM1013 Principle of Operation and Application Hints 3 VOLTAGE AND CURRENT CONTROL Vsense = R5*Vref/(R4+R5) Ilim = R5*Vref/(R4+R5)*Rsense 3.1 Voltage Control The voltage loop is controlled via a first transconductance operational amplifier, the resistor bridge R1, R2, and the optocoupler which is directly connected to the output. The relation between the values of R1 and R2 should be chosen as writen in Equation 1. R1 = R2 x Vref / (Vout - Vref) Equation 1 Where Vout is the desired output voltage. To avoid the discharge of the load, the resistor bridge R1, R2 should be highly resistive. For this type of application, a total value of 100KΩ (or more) would be appropriate for the resistors R1 and R2. As an example, with R2 = 100KΩ, Vout = 4.10V, Vref = 2.5V, then R1 = 41.9KΩ. Note that if the low drop diode should be inserted between the load and the voltage regulation resistor bridge to avoid current flowing from the load through the resistor bridge, this drop should be taken into account in the above calculations by replacing Vout by (Vout + Vdrop). where Ilim is the desired limited current, and Vsense is the threshold voltage for the current control loop. Note that the Rsense resistor should be chosen taking into account the maximum dissipation (Plim) through it during full load operation. Plim = Vsense x Ilim. Equation 4 Therefore, for most adapter and battery charger applications, a quarter-watt, or half-watt resistor to make the current sensing function is sufficient. The current sinking outputs of the two transconnuctance operational amplifiers are common (to the output of the IC). This makes an ORing function which ensures that whenever the current or the voltage reaches too high values, the optocoupler is activated. The relation between the controlled current and the controlled output voltage can be described with a square characteristic as shown in the following V/I output-power graph. Fig. 3: Output voltage versus output current 3.2 Current Control Vout Voltage regulation Current regulation The current loop is controlled via the second trans-conductance operational amplifier, the sense resistor Rsense, and the optocoupler. Vsense threshold is achieved externally by a resistor bridge tied to the Vref voltage reference. Its middle point is tied to the positive input of the current control operational amplifier, and its foot is to be connected to lower potential point of the sense resistor as shown on the following figure. The resistors of this bridge are matched to provide the best precision possible The control equation verifies: Rsense x Ilim = Vsense Equation 3 0 TSM1013 Vcc : independent power supply Secondary current regulation Iout TSM1013 Vcc : On power output Primary current regulation 4 COMPENSATION Equation 2 5/8 TSM1013 START UP AND SHORT CIRCUIT CONDITIONS sufficient supply for the TSM1013 has to be ensured under any condition. It would then be necessary to add some circuitry to supply the chip with a separate power line. This can be achieved in numerous ways, including an additional winding on the transformer. The voltage-control trans-conductance operational amplifier can be fully compensated. Both of its output and negative input are directly accessible for external compensation components. An example of a suitable compensation network is shown in Fig.2. It consists of a capacitor Cvc1=2.2nF and a resistor Rcv1=22KΩ in series. 6 The following schematic shows how to realise a low-cost power supply for the TSM1013 (with no additional windings).Please pay attention to the fact that in the particular case presented here, this low-cost power supply can reach voltages as high as twice the voltage of the regulated line. Since the Absolute Maximum Rating of the TSM1013 supply voltage is 28V. In the aim to protect he TSM1013 against such how voltage values a internal zener clamp is integrated. The current-control trans-conductance operational amplifier can be fully compensated. Both of its output and negative input are directly accessible for external compensation components. An example of a suitable compensation network is shown in Fig.2. It consists of a capacitor Cic1=2.2nF and a resistor Ric1=22KΩ in series. 5 VOLTAGE CLAMP START UP AND SHORT CIRCUIT CONDITIONS Rlimit = (Vcc-Vz)Ivz Under start-up or short-circuit conditions the TSM1013 is not provided with a high enough supply voltage. This is due to the fact that the chip has its power supply line in common with the power supply line of the system. Fig. 4: Clamp voltage cc Rlimit Therefore, the current limitation can only be ensured by the primary PWM module, which should be chosen accordingly. Vcc Vz Ivz TSM1013 28V If the primary current limitation is considered not to be precise enough for the application, then a Fig. 5: Vcc 1 OUT+ D 8 Rlimit To primary Vcc Vref 28V DS R2 IL CV R4 100K TSM1013 CV Out 5 Cv- 4 Load R3 100 + 3 Cc+ CC Out CC 7 Rvc1 22K + Cc- R5 Vsense 10K Rsense IL 6/8 Ric2 1K R1 Cic1 2.2nF Gnd 6 + 2 CS Cvc1 2.2nF Ric1 22K OUT- PACKAGE MECHANICAL DATA 7 TSM1013 PACKAGE MECHANICAL DATA SO-8 MECHANICAL DATA DIM. mm. MIN. TYP inch MAX. MIN. TYP. MAX. A 1.35 1.75 0.053 0.069 A1 0.10 0.25 0.04 0.010 A2 1.10 1.65 0.043 0.065 B 0.33 0.51 0.013 0.020 C 0.19 0.25 0.007 0.010 D 4.80 5.00 0.189 0.197 E 3.80 4.00 0.150 0.157 e 1.27 0.050 H 5.80 6.20 0.228 0.244 h 0.25 0.50 0.010 0.020 L 0.40 1.27 0.016 0.050 k ddd 8˚ (max.) 0.1 0.04 0016023/C 7/8 TSM1013 PACKAGE MECHANICAL DATA Information furnished is believed to be accurate and reliable. However, STMicroelectronics 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 STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. 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 Repubic - Finland - France - Germany Hong Kong - India - Israel - Italy - Japan - Malaysia - Malta - Morocco - Singapore - Spain Sweden - Switzerland - United Kingdom - United States http://www.st.com 8/8