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march 1994 2 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 features bandgap reference generator slow-start circuitry low-loss peak current sensing over-voltage protection hysteresis controlled stand-by function error amplifier with gain setting programmable transfer character generator protection against open- and short-circuited feedback loop over-load current fold back characteristic led driver demagnetization protection programmable determination of switch-on moment of switching transistor for low-switching losses feed-forward input regulation-indicator output programmable minimum on-time of switching transistor accurate peak-current setting. general description the TDA8385 is intended to be used in combination with the opto-coupler (cnr50) as a control unit for a self-oscillating power supply. ordering information extended type number package pins pin position material code TDA8385 16 dil plastic sot38wbe
march 1994 3 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 block diagrams handbook, full pagewidth mcd417 29 v ts differential amplifier control part regulation indicator (2.5 v) 27 reset (28) quick discharge clamp 50 m a 50 m a charge 19 2.5 v tcg 4 3 v tcg v diff v ss + minimum voltage clamp 6 x iii vii fo v v mv fb v 13 1 rio 11 v diff 9 4 7 v ss 7 16 14 3 reference block stabilized supply detector v p (min) 28 1 2 supply references (28, 27, 23) reset latch i ref i ref v stab v ref v ref i current reference setting feed forward input regulation indicator output differential amplifier output slow start voltage input feedback voltage input transistor-on setting input v p gnd slow start v ts 5 t on(min) t on (min) fig.1 block diagram; part a (continued in fig.2; part b).
march 1994 4 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 handbook, full pagewidth stand-by voltage input over-voltage protection latch 22 24 11 mcd418 100 m a slow discharge 21 (17) (28) viii q r s ff 23 over voltage q 115 mv 2.5 v over-voltage protection delay 12 115 mv 100 mv sawtooth generator dem 12 15 5 6 8 q 13 r s v r v sb v sim 8 pwm iv 14 16 demagnetization led control demagnetization (28) 18 v 9 i 12 12 0.2 i i sim i peak 25 2.5 v 2 v stand-by ix 2.5 v latch q (23) 17 output stage 15 led led driver vi 10 TDA8385 2 led driver output delay setting demagnetization input peak-current setting input current simulation input 26 comparator ii v c 10 ff fig.2 block diagram; part b (continued from fig.1; part a).
march 1994 5 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 pinning symbol pin description rio 1 regulation indicator output led 2 led driver output i ref 3 current reference setting t on(min) 4 transistor-on setting input i peak 5 peak current setting input delay 6 delay setting v ss 7 slow start voltage input ovp 8 over-voltage protection v fb 9 feedback voltage input v sb 10 stand-by voltage input v diff 11 differential ampli?er output i sim 12 current simulation input v fo 13 feed forward input gnd 14 ground (0 v) dem 15 demagnetization input v p 16 positive supply voltage fig.3 pinning diagram. handbook, 2 columns 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 rio led delay ovp i ref t on(min) i peak v ss dem gnd v p v fo i sim v diff sb v fb v TDA8385 mcd402 functional description the TDA8385 can be divided into 10 functional blocks as shown in fig.1 and fig.2. block for figs 1 and 2 these 10 functional blocks of fig.1 and fig.2 contain sub-sections numbered 1 to 28 which are block no. description i supply references ii sawtooth generator iii control part iv pulse width modulator (pwm) v led control vi led driver vii slow-start circuitry viii over-voltage protection ix stand-by circuit x regulation-indicator output cross-referenced in the following description. supply references (block i) the TDA8385 is intended to be used on the secondary side of the self-oscillating power supply. it can be supplied either by an auxiliary winding of the transformer or an external supply e.g. 50 hz transformer. charging of the capacitor c p (see fig.16) takes place during transistor on-time (t on ; see fig.17). during stand-by the ic is supplied by the stand-by voltage v sb (pin 10). the operating voltage range is from 7.5 to 20 v. the supply current, inclusive drive current for the led, is less than 20 ma. a bandgap based reference (2.5 v) generates a stabilized voltage v stab of 3.9 v to supply all internal circuits of the ic except the led driver. the led driver is directly supplied by v p . the reference block generates all the reference voltages in the circuit. by means of a resistor connected to pin 3, a reference current (i ref ) is defined. this current is reflected several times and is used to obtain ic-independent settings e.g. t on(min) setting, delay setting, charging and discharging of slow-start capacitor c ss on pin 7 (see fig.16). the power supply is released by the opto-coupler ic at an input voltage level, which is high enough to guarantee correct operation of the TDA8385 e.g. v p = 10 v by sensing the mains voltage v i . as soon as the sops switching transistor (t1, see fig.16) is conductive the capacitor c p is charged. as long as the ic supply voltage is below 7.5 v the led driver is blocked (see latch output; sub-section 28) in order to guarantee start-up of sops. during the initialization phase the quick-discharge-switch (sub-section 27), set input of flip-flop (13) and reset input of flip-flop (23) are also activated. as soon as the voltage of 7.5 v is reached the control functions of the ic are operative. hysteresis on the initialization level is 2.3 v.
march 1994 6 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 fig.4 latch initialization as a function of supply voltage v p . 5.2 7.5 20 latch initialization operation v p (v) mcd403 sawtooth generator (block ii) c urrent simulation ( see figs 5 and 16) the current of the power supply switching transistor is detected on the secondary side by an indirect method of current sensing. information of the collector current (i c ) is obtained by integrating the voltage of an auxiliary winding of the transformer during transistor on-time (t on ). an external capacitor c on pin 5 is charged during t on by the current source i sim . the current i sim is the reflection of the current which flows into pin 12. this current is obtained by connecting an external resistor r12 to the auxiliary transformer winding. during transistor on-time this current is related to the input voltage v i . during transistor off time (t off ) the capacitor c is discharged by switch sw1. this switch is active during the total t off time. in this way a sawtooth voltage v c is formed across c. this sawtooth is a measure for the collector current of the switching transistor t1. for the voltage v c yields: (1) (2) where: p = reflection factor; (2) ? (1) gives: (3) v c i sim t on c ------------------------ - = i sim p n h n p ----- - v i r1 2 ---------- - = p i sim i 12 --------- 0. 2 = = v c p c --- - n h n p ----- - v i r12 ---------- - t on = fig.5 determination of the peak current i c . handbook, full pagewidth v i c r12 i 12 12 5 i sim l t1 n p i c n h v c t mcd404 v c t on t off sw1
march 1994 7 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 for t on yields: (4) for the primary current i c yields: (5) substitution (4) into (5): (6) equation (6) shows that by limiting the voltage v c the collector peak current can be limited. the peak current is limited by means of the clamping circuit in the transfer character generator (tcg); see fig.1 sub-section 4. the clamping level can be externally influenced by means of a resistor on pin 7. the collector peak current can be influenced in several ways: resistor r12 on pin 12 capacitor c on pin 5 capacitor on pin 7 transfer ratio n h /n p inductance l before comparing the sawtooth voltage v c with the control voltage v r in the pulse width modulator, a voltage of 100 mv is added to v c . in this way it will be possible for v r to become smaller than v sim , which is important for a stabilized no-load operation (see fig.6 area 3). d emagnetization input ( pin 15) this input prevents the switching transistor from conducting during demagnetization of the transformer in order to prevent the transformer from going into saturation. the output of comparator (11) is high as soon as the voltage of the transformer winding exceeds 115 mv. t on v c c n p r12 p n h v i ---------------------------------------------- - = i c v i l ---- - t on = i c c l --- - 1 p -- - n p n h ----- - r12 v c = d elay setting ( pin 6) the output of sub-section 11 is extended by the delay circuit of sub-section 12. the starting (reference) point of the delay circuit is the falling edge of the output of demagnetizing comparator (11) the delay can be determined externally by capacitor (c delay ) on pin 6. the switch-on moment of the switching transistor can be determined by capacitor c delay . a minimum delay time is required to prevent transistor t1 from switching during demagnetization of the transformer because of oscillations caused by the leakage inductance. control part (block iii) the differential amplifier, sub-section 3, compares the feedback voltage (v fb ) with the reference voltage v ref . the output of the differential amplifier is available on pin 11 to allow gain setting. the differential amplifier is internally compensated for 0 db feedback stability. the feedback input (pin 9) is also used as the input for the tcg (see fig.6) with which a current foldback characteristic can be obtained as shown in fig.7. fig.6 reference voltage (v mv ) as a function of feedback voltage (v fb ). (1), (2), (3) = v tcg . (4), (5) = v diff . (5) (4) (3) (2) (1) mcd405 fb v v mv v ton(min) v clamp
march 1994 8 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 fig.7 current foldback characteristic; stabilized output voltage (v o ) as function of load current (i o ). (5) v o i o (4) (3) (2) (1) mcd406 (1), (2), (3) = v tcg . (4), (5) = v diff . the voltage v ton(min) determines the minimum on-time of the switching transistor. this voltage can be determined externally with a resistor on pin 4. with this resistor the current foldback characteristic can be influenced (see dotted line in figs 6 and 7). the minimum on-time is of importance for the following. stand-by operation starting-up of power supply overload and short-circuit conditions. the output of the differential amplifier (v diff ), the output of the tcg (v tcg ) and the voltage v ss + v ton(min) are compared in a minimum voltage clamping circuit (see fig.1 sub-section 6). the output voltage is equal to the lowest input voltage. some relevant characteristics of the control part are depicted in fig.8. fig.8 characteristics of the control part. the voltage v mv determines the collector peak current i c of transistor t1. the right-hand curve is passed through at start-up. when the feedback voltage slowly increases from zero, the peak current starts at i c(min) and rises along the straight line until i c(max) is reached. at a slightly higher feedback voltage the regulation slope is reached, which is approximately v ref . the plateau of the top between the points x and y has to be kept as small as possible. the voltage v diff decreases with the decreasing load. for good no-load operation the peak current has to be made zero with v diff . due to the characteristic of the tcg open- and short-circuit feedback loop will result in low peak current. an additional signal on pin 13 can be supplied which is subtracted from the signal v mv . this input can be used for feed forward information. if no feed forward information is used, pin 13 should be connected to ground. handbook, full pagewidth mcd407 v ss + fb v i c (max) i c (min) i c v mv x y v ref v tcg external peak-current setting (pin 7) diff v mv v v ton(min)
march 1994 9 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 pulse width modulator (block iv) the pulse width modulator compares the control voltage v r with the sawtooth voltage v sim . if v sim > v r output sub-section 8 is high the led is switched on and then the switching transistor is switched off. in this way the output voltage is controlled. e xample if the load decreases, v o increases and therefore v r decreases. this causes the led to start conducting prematurely, which implies that the switching transistor is turned off sooner. the consequence is that the collector peak current decreases and hence less energy is stored in the transformer and v o will decrease. led control (block v) if either output of sub-section 8 or output of sub-section 16 are high the led is conductive. in order to improve the start-up behaviour of the power supply, the demagnetization signal of sub-section 12 will only activate the led driver if flip-flop (13) has previously been set. the set signal is generated in the following three ways. 1. pulse width modulator (sub-section 8) 2. comparator (18) 3. v p(min) detector set signal (2.) and (3.) are added as extra security to guarantee a demagnetization pulse in the event of the switching transistor not having enough base current. in that situation e.g. at start-up, no comparator signal, set signal (3.) is generated by sub-section 8. led driver (block vi) the led driver (pin 2) is blocked if the supply voltage v p is in the initialization phase (see fig.4). the output stage is a push-pull stage, which can sink 5 ma and source 10 ma. slow-start circuit (block vii) the slow-start circuit is active at start-up, over voltage protection or after an overload (short-circuited), and stand-by mode. the voltage v ss and therefore the voltage v mv and the peak current i c slowly increase at start-up. by means of sub-section 27 the slow start voltage v ss is clamped to the voltage v fb . if the feedback voltage is reduced, e.g. as overload, the slow-start capacitor is discharged to the level of v fb . in this way a slow start-up is also guaranteed after an overload, short-circuit situation or after a stand-by mode. the circuit of sub-section 27 is not active during an over voltage protection. when the supply voltage v p is below the reset-level of 5.2 v (sub-section 28) the slow-start capacitor is quickly discharged. the slow-start input (pin 7) can also be used for i c(max) setting by connecting a resistor to this pin. over voltage protection (block viii) the operation of the over voltage protection circuit is, in the event of the ic being sops-supplied, quite different from when the ic is externally supplied. o peration when the ic is externally supplied when the voltage on pin 8 exceeds 2.5 v the slow-start capacitor is slowly discharged. during discharge the led is permanently conducting. discharge is stopped when v ss is below 115 mv. flip-flop (23) will then be reset and the circuit is ready again for a new slow-start procedure. during an over voltage sub-section 27 is not active so that the output voltage v o cannot influence the slow-start discharge procedure. o peration when ic is sops- supplied ( see figs 9 and 10) when the voltage on pin 8 exceeds 2.5 v the slow-start capacitor is slowly discharged. during discharge of c ss the supply capacitor c p is also discharged. because the capacitors c p and c ss have almost the same value and the supply current i p ( ? 15 ma) is much larger than the slow discharge current ( ? 50 m a), the led will be switched off by means of the v p(min) detection circuit (5.2 v). at that moment the switching transistor will be switched on again until the 7.5 v level is reached. during this hysteresis interval the slow-charge capacitor is quickly discharged. at the 7.5 v level the led will be switched on again because flip-flop (23) output is still high. the same procedure will be repeated several times until the slow-start capacitor reaches the 115 mv reset level. at that moment the slow-start procedure is started again. if there is still an over voltage the procedure will be repeated. figure 10 is a detailed exposure of fig.11.
march 1994 10 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 handbook, full pagewidth mcd408 i c t v ss t (1) fig.9 over voltage protection. (1) for detail see fig.10. fig.10 detailed over voltage protection of fig.9. 0 v p (v) t 7.5 v 5.2 v mcd409 t q ff23 t delay 0 v ss (v) t slow discharge quick discharge i c t
march 1994 11 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 stand-by circuit (block ix) during stand-by operation the voltage v sb is supplied from the sops via thyristor th1 (see fig.16). in the stand-by state, sops operates in a burst mode. when the voltage on pin 10 exceeds 2.5 v the led driver is permanently activated. the led driver is released again if the voltage is below 2 v (see fig.11). fig.11 stand-by operation; burst mode. handbook, full pagewidth mcd410 t 0 output sub-section 25 t 0 t 0 v sb (v) i led (ma) 5 ma 2.5 v 2 v
march 1994 12 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 regulation indicator output (block x) pin 1 can be used to reset the logic circuit in the tv receiver at power on and off. sub-section 29 has an open-collector output. the output of this block is low during the regulation mode (v diff < v ts ; see fig.12). handbook, full pagewidth v 2.5 0 t 0 t v rio 0 t v fb v ts v diff v p v rio : open-collector output mcd411 fig.12 regulation indicator output; pin 1. a desired delay at power-on reset can be made externally.
march 1994 13 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 limiting values in accordance with the absolute maximum rating system (iec 134). all voltages are measured with respect to ground; positive current ?ow into the ic; all pins not mentioned in the voltage list are not allowed to be voltage driven. the voltage ratings are valid provided other ratings are not violated; current ratings are valid provided the power rating is not violated. thermal resistance symbol parameter conditions min. max. unit voltages v p supply voltage pin 2 connected - 0.5 20 v pin 2 open-circuit - 0.5 18 v v n voltage on pins 1, 2, 4, 7, 9 and 13 - 0.5 +18 v v 3 voltage on pin 3 - 0.5 +6 v v 8,10 voltage on pins 8 and 10 - 0.5 +3.9 v v 12 voltage on pin 12 - 0.1 +0.5 v v 15 voltage on pin 15 - 0.5 +0.5 v currents i 1 current on pin 1 0 2 ma i n current on pins 2, 12 and 15 - 10 +10 ma i 3 current on pin 3 - 1 0 ma i 5, 6 current on pins 5 and 6 - 1 +1 ma i 7 current on pin 7 - 1 +25 ma i 11 current on pin 11 - 10 +0.5 ma i 16 current on pin 16 0 20 ma temperatures t amb operating ambient temperature - 25 +70 c t stg storage temperature - 55 +150 c power dissipation p tot total power dissipation - 500 mw symbol parameter thermal resistance r th j-a from junction to ambient in free air 55 k/w
march 1994 14 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 characteristics v p = 15 v; i 3 = 200 m a; t amb = 25 c; unless otherwise speci?ed. symbol parameter conditions min. typ. max. unit supply v p supply voltage (pin 16) 7.9 - 20 v v 16 supply initialization level 7.1 7.5 7.9 v v 16(hys) internal ?xed hysteresis 2.5 - 2.55 v i 16 supply current active led output - - 20 ma v 11 supply voltage ripple rejection see figs 13 and 14 - 60 - mv reference voltage v 3 reference voltage at pin 3 0.52 0.55 0.58 v error ampli?er v 9 threshold voltage error amplitude 2.4 2.5 2.6 v i 9 input current feedback input - - 0.5 m a i 11 sink current output v 11 = 80 mv 400 - - m a i 11 source current output v 11 = 2.5 v 500 - - m a g o open loop gain - 100 - db b unity gain bandwidth - 600 - khz d v 9 / d t temperature coef?cient - 300 10 - 6 - k - 1 v 5 threshold for switching output v diff = 1.25 v; v 4 = 2 v; v 13 = 0 v; v 7 > v 9 ; i 2 = 2 ma - v diff - v os (1) - v transfer characteristic generator i 4 /i 3 current ratio v 4 = 0.5 v 0.23 0.25 0.27 v 5 threshold for switching output v 4 = 0.5 v; v 13 = 0 v; v 7 > v 9 ; i 2 = 2 ma t on(min) v 9 = 0 v 0.4 - v os 0.5 - v os 0.6 - v os v v fb = 20% v 9 = 0.4 v - 0.9 - v os - v v fb = 50% v 9 = 1 v 1.4 - v os 1.5 - v os 1.6 - v os v v fb = 80% v 9 = 1.6 v - 2.1 - v os - v clamp v 9 = 2.25 v 2.4 - v os - 2.6 - v os v t plh response time pulse width modulation pin 5 to pin 2 low-to-high note 2 - - 700 ns t phl response time pulse width modulation pin 5 to pin 2 high-to-low note 2 - - 1 m s feed forward v 5 threshold for switching output (v fo ) v 4 = 0.5 v; v 13 = 0 v; v 7 = v 9 = 3 v; i 2 = 2 ma; v 11 = 1 v 0.6 - v os 0.7 - v os 0.8 - v os v i 13 input bias current v 13 = 0 v - - 1 m a
march 1994 15 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 slow-start i 7 /i 3 charge current ratio v 7 = 0.5 v 0.22 0.24 0.26 i 7 quick discharge current v 7 = 1 v 20 - - ma v 7 = 100 mv 50 - - m a v 7 clamping level i 7 = 100 m a 2.8 3.0 3.2 v v 5 threshold for switching output (v ss ) v 4 = 0.5 v; v 13 = 0 v; v 7 = 1 v; i 2 = 2 ma; v 9 = 2 v 1.4 - v os 1.5 - v os 1.6 - v os v output stage v 2(sat) saturation voltage i 2 = 2 ma - - 300 mv i 2 source current v 2 = 2 v operating 4.8 5.3 6.3 ma initialization phase - - 50 m a v 2 open output voltage high i 2 = 5 ma 12 - - v current simulation i 5 /i 12 current ratio v 5 = 1 v; i 12 = 0.5 ma 0.19 0.2 0.21 v 12 simulation input voltage i 12 = 0.5 ma - - 1.1 v v 5(sat) saturation voltage v 15 = v 6 = 0 v; i 5 = 1 ma - - 300 mv v 15 = v 6 = 0 v; i 5 = 200 m a - - 200 mv d v threshold for switching output; voltage dif ference between pins 5 and 11; offset simulation voltage (v os ) v 4 = 0.5 v; v 13 = 0 v; v 7 = v 9 = 3 v; i 2 = 2 ma; v 11 = 0.5 v 60 100 140 mv demagnetization input t demlh delay from pin 15 to pin 5 low-to-high see fig.15; pin 6 not connected - - 500 ns t demhl delay from pin 15 to pin 5 high-to-low see fig.15 - - 1 m s v 15 clamping level i 15 = 10 ma positive - - 1.2 v negative - - - 1 v v 15 demagnetization threshold voltage 90 115 140 mv c 15 input capacitance - - 10 pf i 15 input bias current v 15 = 60 mv - - 0.5 m a symbol parameter conditions min. typ. max. unit
march 1994 16 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 notes 1. v os = v offset. 2. v 5 pulse = 1 v; v 4 = 0.5 v; v 9 = v 7 = 3 v; v 11 = 0.5 v; v 13 = 0 v; i 2 = 2 ma. delay setting i 6 /i 3 charge current ratio v 6 = 1 v 1.1 1.2 1.3 i 6 charge current initialization phase v 6 = 1 v; v 16 = 5 v 2 - - ma v 6 clamping level 2.8 - 3.2 v v 6(sat) saturation voltage v 15 = 140 mv - 50 100 mv t dlh delay from pin 6 to pin 2; v 6 crossing the 2.5 v level; low-to-high c 6 = 470 pf; v 5 = 0 v; i 2 = 2 ma; v 15 see fig.15; excluding capacitive tolerances - - 1.2 m s t/c delay setting (t = c 6 v/i) v 6 = 2.5 v; i 3 = 250 m a - 10 - ns/pf stand-by v 10h threshold level high 2.4 2.5 2.6 v v 10(hys) hysteresis 450 500 550 mv t dlh delay to output pin 10 to pin 2 low-to-high - - 1 m s t dhl delay to output pin 10 to pin 2 high-to-low - - 1 m s i 10 input current v 10 = 2.3 v - - 5 m a over voltage protection v 8 threshold level 2.4 2.5 2.6 v t dlh delay to output pin 8 to pin 2 low-to-high - - 1 m s t dhl delay to output pin 8 to pin 2 high-to-low - - 1 m s v 7 reset level 90 - 140 mv i 7 /i 3 slow discharge current ratio v 7 = 1 v 0.12 0.23 0.31 i 8 input current v 8 = 3 v - - 1 m a regulation indicator output v 1 saturation voltage i 1 = 1 ma - - 300 mv i 1 leakage current v 1 = v 16 - - 1 m a symbol parameter conditions min. typ. max. unit
march 1994 17 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 frequency = 50 khz. slew rate = 0.2 m s. fig.13 supply voltage ripple rejection; v p as a function of time. 2 v 15 v t v p mcd412 fig.14 supply voltage ripple rejection; v diff as a function of time. t v diff mcd413 3 v ~ ~ (pin 11) frequency = 50 khz. slew rate = 0.2 m s. table 1 condition of test circuit used for figs 13 and 14. pins status 1, 2, 4 to 6, 12, 13 not connected 8 to 10, 14, 15 ground 3 r ref = 2.7 k w 7 c ss = 4.7 m f 16 v p ; see fig.13 11 v diff ; see fig.14
march 1994 18 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 fig.15 timing diagram; demagnetization delay time. handbook, full pagewidth mcd414 115 mv 90% 10% t demlh demhl t ~ ~ + 0.8 v 0 v ~ ~ ?0.8 v 1 v 0 v peak-current setting input (pin 5) demagnetization input (pin 15)
march 1994 19 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 application information handbook, full pagewidth v o n s v stab v p c p v f n h 1/2 cnr50 n p i c c o v (mains) i 1/2 cnr50 TDA8385 9 11 8 14 5 6 4 7 3 15 10 16 12 2 1 13 c ss r ref r ton(min) c delay c r15 r12 rc th1 t1 mcd415 a a fig.16 application circuit of sops with stand-by facility.
march 1994 20 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 fig.17 application timing diagram. handbook, full pagewidth output sub-section 11 output sub-section 12 demagnetization output sub-section 8 comparator output sub-section 13 q output sub-section 16 demagnetization output sub-section 14 led driver set (sub-section 13) reset (sub-section 13) t off t on storage time and delay (sops) delay v f v o i c v sim v c v r (output sub-section 7) (output sub-section 10) v sim comparator (18) level = 1 v v i n s n p mcd416 t
march 1994 21 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 package outline fig.18 16-lead dual in-line; plastic with internal heat spreader; opposite bent leads (sot38wbe). dimensions in mm. 8.25 7.80 0.32 max 7.62 9.5 8.3 msa349 16 1 9 8 1.4 max 6.48 6.14 22.00 21.35 5.1 max 1.2 min 3.9 3.4 seating plane 0.254 m 0.53 max 2.54 (14x) 2.2 max
march 1994 22 philips semiconductors preliminary speci?cation control circuit for a self-oscillating power supply (sops) TDA8385 soldering plastic dual in-line packages b y dip or wave the maximum permissible temperature of the solder is 260 c; this temperature must not be in contact with the joint for more than 5 s. the total contact time of successive solder waves must not exceed 5 s. the device may be mounted up to the seating plane, but the temperature of the plastic body must not exceed the specified storage maximum. if the printed-circuit board has been pre-heated, forced cooling may be necessary immediately after soldering to keep the temperature within the permissible limit. r epairing soldered joints apply a low voltage soldering iron below the seating plane (or not more than 2 mm above it). if its temperature is below 300 c, it must not be in contact for more than 10 s; if between 300 and 400 c, for not more than 5 s. definitions life support applications these products are not designed for use in life support appliances, devices, or systems where malfunction of these products can reasonably be expected to result in personal injury. philips customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify philips for any damages resulting from such improper use or sale. data sheet status objective speci?cation this data sheet contains target or goal speci?cations for product development. preliminary speci?cation this data sheet contains preliminary data; supplementary data may be published later. product speci?cation this data sheet contains ?nal product speci?cations. limiting values limiting values given are in accordance with the absolute maximum rating system (iec 134). stress above one or more of the limiting values may cause permanent damage to the device. these are stress ratings only and operation of the device at these or at any other conditions above those given in the characteristics sections of the speci?cation is not implied. exposure to limiting values for extended periods may affect device reliability. application information where application information is given, it is advisory and does not form part of the speci?cation.

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