1/8 n constant voltage and constant current control n low voltage operation n low external component count n current sink output stage n easy compensation voltage reference n fixed output voltage reference 2.5v n 0.5% and 1% voltage precision description TSM1011 is a highly integrated solution for smps applications requiring cv (constant voltage) and cc (constant current) mode. TSM1011 integrates one voltage reference and two operational amplifiers (with ored outputs - common collectors). the voltage reference combined with one opera- tional amplifier makes it an ideal voltage control- ler. the other operational, combined with few ex- ternal resistors and the voltage reference, can be used as a current limiter. applications n adapters n battery chargers order code d = small outline package (so) - also available in tape & reel (dt s = small outline package (miniso8) - also available in tape & reel (st) pin connections (top view) part number temperature range package marking sd TSM1011i 0 to 105c m1011 TSM1011ai 0 to 105c m1011a TSM1011i 0 to 105c m802 TSM1011ai 0 to 105c m803 d so8 (plastic package) d miniso8 (plastic micropackage) 1 2 3 45 6 ve- gnd vcc vref out 7 8 ve+ ve+ ve- this is a preliminary information on a new product now in development. details are subject to change without notice. february 2003 TSM1011 constant voltage and constant current controller for battery chargers and adaptors advance data
TSM1011 2/8 pin description so8 & miniso8 pinout absolute maximum ratings operating conditions name pin # type function vref 1 analog output voltage reference ve- 2 analog input input pin of the operationnal amplifier ve+ 3 analog input input pin of the operationnal amplifier ve- 4 analog input input pin of the operationnal amplifier ve+ 5 analog input input pin of the operationnal amplifier gnd 6 power supply ground line. 0v reference for all voltages out 7 analog output output of the two operational amplifier vcc 8 power supply power supply line. symbol dc supply voltage value unit vcc dc supply voltage (50ma =< icc) -0.3v to vz v vi input voltage -0.3 to vcc v pt power dissipation w toper operational temperature 0 to 105 c tstg storage temperature -55 to 150 c tj junction temperature 150 c iref voltage reference output current 10 ma esd electrostatic discharge 2 kv rthja thermal resistance junction to ambient mini so8 package c/w rthja thermal resistance junction to ambient dip8 package c/w symbol parameter value unit vcc dc supply conditions 4.5 to vz v
TSM1011 3/8 electrical characteristics tamb = 25c and vcc = +18v (unless otherwise specified) symbol parameter test condition min typ max unit total current consumption icc total supply current, excluding current in voltage reference. vcc = 18v, no load tmin. < tamb < tmax. 1ma vz vcc clamp voltage icc = 50ma 28 v operators v io input offset voltage TSM1011 TSM1011a t amb = 25c t min. t amb t max. t amb = 25c t min. t amb t max. 1 0.5 4 5 2 3 mv dv io input offset voltage drift 7 m v/c i io input offset current t amb = 25c t min. t amb t max. 230 50 na i ib input bias current t amb = 25c t min. t amb t max. 20 50 150 200 na svr supply voltage rejection ration v cc = 4.5v to 28v 65 100 db vicm input common mode voltage range 0 vcc-1.5 v cmr common mode rejection ratio t amb = 25c t min. t amb t max. 70 60 85 db output stage gm transconduction gain. sink current only 1) 1. 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. t amb = 25c t min. t amb t max. 1 3.5 2.5 ma/mv vol low level output voltage at 10 ma sinking current 200 mv ios output short circuit current. output to vcc. sink current only t amb = 25c t min. t amb t max. 27 50 ma voltage reference v ref reference input voltage, iload=1ma TSM1011 1% precision TSM1011a 0.5% precision t amb = 25c t min. t amb t max. t amb = 25c t min. t amb t max. 2.5 tbd 2.5 v d v ref reference input voltage deviation over temperature range t min. t amb t max. 20 30 mv regline reference input voltage deviation over vcc range. iload = 5ma 20 mv regload reference input voltage deviation over output current. vcc = 18v, 0 < iload < 10ma 10 mv
TSM1011 4/8 in the above application schematic, the TSM1011 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. figure 1 : internal schematic figure 2 : typical adapter or battery charger application using TSM1011 + - + - 28v vcc ve- out gnd ve- ve+ ve+ vref 1 4 5 6 3 2 7 8 cv cc d + r2 r1 rsense rvc1 22k cvc1 2.2nf ric1 22k to primary out+ out- + cic1 2.2nf load il ric2 1k r5 1k r4 10k r3 100 il vsense + - + - 28v vcc ve- out gnd ve- ve+ ve+ vref 1 4 5 6 3 2 7 8 cv cc TSM1011
5/8 1. voltage and current control 1.1. voltage control the voltage loop is controlled via a first transcon- ductance operational amplifier, the resistor bridge r1, r2, and the optocoupler which is directly con- nected 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) eq1 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 100k w (or more) would be appropriate for the resistors r1 and r2. as an example, with r2 = 100k w , vout = 4.10v, vref = 2.5v, then r1 = 41.9k w . note that if the low drop diode should be inserted between the load and the voltage regulation resis- tor bridge to avoid current flowing from the load through the resistor bridge, this drop should be taken into account in the above calculations by re- placing vout by (vout + vdrop). 1.2. current control 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 re- sistor bridge tied to the vref voltage reference. its middle point is tied to the positive input of the cur- rent 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 re- sistors of this bridge are matched to provide the best precision possible the control equation verifies: rsense x ilim = vsense eq2 vsense = r5*vref/(r4+r5) ilim = r5*vref/(r4+r5)*rsense eq2' 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. eq3 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 trans-con- nuctance operational amplifiers are common (to the output of the ic). this makes an oring func- tion which ensures that whenever the current or the voltage reaches too high values, the optocou- pler is activated. the relation between the controlled current and the controlled output voltage can be described with a square characteristic as shown in the fol- lowing v/i output-power graph. figure 3 : output voltage versus output current 2. compensation the voltage-control trans-conductance operation- al 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=22k w in series. vout iout voltage regulation current regulation TSM1011 vcc : independent power supply 0 secondary current regulation TSM1011 vcc : on power output primary current regulation TSM1011 principle of operation and application hints
TSM1011 6/8 the current-control trans-conductance operation- al 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=22k w in series. 3. start up and short circuit conditions under start-up or short-circuit conditions the TSM1011 is not provided with a high enough sup- ply 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. therefore, the current limitation can only be en- sured by the primary pwm module, which should be chosen accordingly. if the primary current limitation is considered not to be precise enough for the application, then a suffi- cient supply for the TSM1011 has to be ensured under any condition. it would then be necessary to add some circuitry to supply the chip with a sep- arate power line. this can be achieved in numer- ous ways, including an additional winding on the transformer. 4. voltage clamp the following schematic shows how to realise a low-cost power supply for the TSM1011 (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 TSM1011 supply voltage is 28v. in the aim to protect he TSM1011 against such how voltage values a in- ternal zener clamp is integrated. rlimit = (vcc-vz)ivz figure 4 : clamp voltage figure 5 : vz 28v vcc rlimit vcc ivz TSM1011 + cs ds d r2 r1 rsense rvc1 22k cvc1 2.2nf ric1 22k to primary out+ out- + cic1 2.2nf load il ric2 1k r5 1k r4 10k r3 100 il vsense + rlimit vcc + - + - 28v vcc ve- out gnd ve- ve+ ve+ vref 1 4 5 6 3 2 7 8 cv cc TSM1011
TSM1011 7/8 package mechanical data 8 pins - plastic micropackage (miniso8) dimensions millimeters inches min. typ. max. min. typ. max. a 1.100 0.043 a1 0.050 0.100 0.150 0.002 0.004 0.006 a2 0.780 0.860 0.940 0.031 0.034 0.037 b 0.250 0.330 0.400 0.010 0.013 0.016 c 0.130 0.180 0.230 0.005 0.007 0.009 d 2.900 3.000 3.100 0.114 0.118 0.122 e 4.750 4.900 5.050 0.187 0.193 0.199 e1 2.900 3.000 3.100 0.114 0.118 0.122 e 0.650 0.026 l 0.400 0.550 0.700 0.016 0.022 0.028 l1 0.950 0.037 k 0d3d6d0d3d6d aaa 0.100 0.004 0,25 mm .010 inch gage plane c ccc c plane seating e a a2 a1 d b e e1 l k c 1 4 8 5 pin 1 identification l1
TSM1011 8/8 package mechanical data 8 pins - plastic micropackage (so8) dimensions millimeters inches min. typ. max. min. typ. max. a 1.75 0.069 a1 0.1 0.25 0.004 0.010 a2 1.65 0.065 a3 0.65 0.85 0.026 0.033 b 0.35 0.48 0.014 0.019 b1 0.19 0.25 0.007 0.010 c 0.25 0.5 0.010 0.020 c1 45 (typ.) d 4.8 5.0 0.189 0.197 e 5.8 6.2 0.228 0.244 e 1.27 0.050 e3 3.81 0.150 f 3.8 4.0 0.150 0.157 l 0.4 1.27 0.016 0.050 m 0.6 0.024 s 8 (max.) 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 f rom its use. no license is granted by implication or otherwise under any patent or patent rights of stmicroelectronics. specificati ons 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 ? 2003 stmicroelectronics - all rights reserved stmicroelectronics group of companies australia - brazil - china - finland - france - germany - hong kong - india - italy - japan - malaysia - malta - morocco singapore - spain - sweden - switzerland - united kingdom http://www.st.com
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