description 5v, 12v, 15v and a versatile adjustable output a minimum number of external components. frequency oscillator. replacement for popular three-terminal linear regulators, and is requiring a smaller heat sink or even no heat sink. performs well with standard inductors from several manufacturers, and simplifying the design of switch-mode power supplies. tolerance on output voltage within specified input voltages protection under fault conditions. g m 4 3 1 typical applica tion features 3.3v, 5v , 12v, 15v and adjustable version output voltage range 1a output current requires only 4 external components high efficiency ttl shutdown capability and low power standby mode thermal shutdown, current limit protection uses standard inductors 52 khz fixed frequency internal oscillator 7 v - 4 0 v u n r e g u la te d d c i n p u t + c in 1 0 0 f + v in 1 5 3 4 2 g n d d 1 1 n 5 8 1 9 o u tp u t 3 3 0 h l 1 f e e d b a c k c o u t 3 3 0 f 5 .0 v , 1 a r e g u la te d o u tp u t + o n / o f f application pre-regulator for linear regulators high-efficiency step-down buck regulator on-card/ board switching regulators positive to negative converter (buck-boost ) of regulators provides all the active functions for a step- down (buck) switching regulator, and drives 1a load with excellent line and load regulation. is available in fixed output volt ages of 3.3v, version. these regulators are simple to use and require features include internal frequency compensation and a fixed- and output load conditions, and 10% on the oscillator frequency. external shutdown is included with 50 ua(typical) standby current. the output switch has cycle-by-cycle current limiting as well as thermal shutdown for full 1.23v to 37v 4% max over line and load conditions adjustable output versions LM2575 LM2575 LM2575 LM2575 guarantee +/-4% LM2575 high-efficiency LM2575 -5.0 LM2575 1.0a step - down voltage switching regulators
-5.0tc5t -5.0tc5r to-252-5 to-252-5 marking information & pin configura tions 80 units/ tube 2,500 units/ t ape & reel 5.0 5.0 on/off feedback ground output v in to-220- 5 v v, vvv = output v oltage (33=3.3v , 120=12v,a=adj) a = assem bly location y = y ear w w = weekly 2 to-263-5(d pak) on/off feedback ground output v in to-252-5 (dpak) on/off feedback ground output v in -ata5t -3.3ta5t -5.0ta5t -12ta5t -15ta5t -atb5t -3.3tb5t -5.0tb5t -12tb5t -15tb5t -atb5bt -3.3tb5bt -5.0tb5bt -12tb5bt -15tb5bt -ata5r -3.3ta5r -5.0ta5r -12ta5r -15ta5r to-220-5 to-220-5 to-220-5 to-220-5 to-220-5 to-220-5b to-220-5b to-220-5b to-220-5b to-220-5b 50 units / t ube 50 units / t ube 50 units / t ube 50 units / t ube 50 units / t ube 50 units / t ube 50 units / t ube 50 units / t ube 50 units / t ube 50 units / t ube 800 units/ t ape & reel 800 units/ t ape & reel 800 units/ t ape & reel 800 units/ t ape & reel 800 units/ t ape & reel a d j 3.3 5.0 12 15 5.0 12 15 5.0 12 15 5.0 12 15 3.3 3.3 3.3 a d j a d j 50 units / t ube 50 units / t ube 50 units / t ube 50 units / t ube 50 units / t ube output voltage package shipping ordering number ordering information a d j to-263-5 to-263-5 to-263-5 to-263-5 to-263-5 to-263-5 to-263-5 to-263-5 to-263-5 to-263-5 * tb5b: bent and staggered leads of to-220 package ** for detail ordering number identification, please see last page. on/off feedback ground output v in to-220- 5b 1 2 3 4 5 LM2575 LM2575 LM2575 LM2575 LM2575 LM2575 LM2575 LM2575 LM2575 LM2575 LM2575 LM2575 LM2575 LM2575 LM2575 LM2575 LM2575 LM2575 LM2575 LM2575 LM2575 LM2575 l m 2 5 75 1. 0 a s t e p - d o w n v oltage s w i tc hing r e g u lat o r s
absolute maximum ratings 1 + 5 3 4 2 1.23v band-gap reference 52khz oscillator reset thermal shutdown current limit feed- back v in + - + - fixed gain error amp comparator driver 1 amp switch internal regulator on/off on/off output l1 d1 gnd c out + l o a d block diagram unregulated dc input c in v outp ut v oltag e to g roun d (st eady stat e) powe r dis sipat ion stora ge t empe ratur e ra nge maxi mum junc tion t empe ratur e lead t empe ratur e (so lderin g, 10 sec. ) c c c maxi mum sup ply v oltag e value unit on/o ff p in inp ut v oltag e 45 -0.3 v v in internally limited -65 to + 150 +150 +260 -1.0 v v - r2 1.0k r1 v out v out 3.3v, r2 = 1.7k 5v, r2 = 3.1k 12v, r2 = 8.84k 15v, r2 = 1 1.3k for adj. version r1 = open, r2 = 0 w recommended operating conditions t empe ratur e ra nge value unit supp ly v oltag e 40 v -40 t j 125 c p ara met er p ara met er l m 2 5 75 1. 0 a s t e p - d o w n v oltage s w i tc hing r e g u lat o r s
4 electrical characteristics: (specifications with standard type face are for t = 25c, and those with boldface type apply over full operating temperature range) j parameter conditions symbol min typ max unit output voltage output voltage efficiency v = 12v, i = 0.2a in load v = 12v, i = 1a in load v out v out h 3.234 3.168/ 3.135 - 3.3 3.3 75 3.366 3.432/ 3.465 - v % v 4.75v v 40v, 0.2a i 1a in load parameter conditions symbol min typ max unit output voltage output voltage efficiency v = 12v, i = 0.2a l in oad v = 12v, i = 1a in load v out v out h 4.900 4.800/ 4.750 - 5.0 5.0 77 5.100 5.200/ 5.250 - v % v electrical characteristics: (specifications with standard type face are for t = 25c, and those with boldface type apply over full operating temperature range) j 8v v 40v, 0.2a i 1a in load parameter conditions symbol min typ max unit output voltage output voltage efficiency v = 25v, i = 0.2a in load v = 15v, i = 1a in load v out v out h 11.76 11.52/ 11.40 - 12.0 12.0 88 12.24 12.48/ 12.60 - v % v electrical characteristics: (specifications with standard type face are for t = 25c, and those with boldface type apply over full operating temperature range) j 15v v 40v, 0.2a i 1a in load parameter conditions symbol min typ max unit feedback voltage feedback voltage efficiency v = 30v, i = 0.2a in load v = 18v, i = 1a in load v out v out h 14.70 14.40/ 14.25 - 15.0 15.0 88 15.30 15.60/ 15.75 - v % v electrical characteristics: (specifications with standard type face are for t = 25c, and those with boldface type apply over full operating temperature range) j 18v v 40v, 0.2a i 1a in load electrical characteristics: (specifications with standard type face are for t = 25c, and those with boldface type apply over full operating temperature range) j conditions symbol min typ max unit v = 12v, i = 0.2a, v = 5v in load out v = 12v, i = 1.0a, =5v in load v out v out v out h 1.217 1.193/ 1.180 - 1.230 1.230 77 1.243 1.267/ 1.280 - v % v parameter feedback voltage feedback voltage efficiency 8v v 40v, 0.2a i 1a in load v = 5v out LM2575-3.3 LM2575-5.0 LM2575-12 LM2575-15 LM2575-adj l m 2 5 75 1. 0 a s t e p - d o w n v oltage s w i tc hing r e g u lat o r s
5 electrical characteristics: all output v oltage versions (specifications with standard type face are for t = 25c, and those with boldface type apply over full operating temperature range. unless otherwise j specified, v = 12v for the 3.3v, 5.0v and adj version, v = 25v for 12v version. and v = 30v for 15v version. i = 500 ma) in in in load parameter conditions symbol min typ max unit oscillator frequency saturation voltage max duty cycle (on) output leakage current quiescent current standby quiescent current thermal resistance feedback bias current current limit logic input level on/off pin on/off pin input current v = 5v (adjustable version only) out (note 11) i = 1a (notes 4) out (note 5) (note 4, 11) (notes 6, 7) output = 0 v output = -1v (note 6) on/off pin = 5v (off) to-220 package, junction to ambient (note 8) to-220 package, junction to ambient (note 8) to-220,to-263, package, junction to case to-252 package, junction to case to-263 package, junction to ambient (note 10) v =0v out v = nominal output voltage out i fb f o v sat t dc i ol i q i stby v ih v il v ih i il - 47 / 42 - - - - - - - - - - - - 50 52 0.9 98 2.2 - 7.5 5 50 1.4 1.2 12 0 65 45 2 6 37 - - - - 100 / 500 58 / 63 1.2 / 1.4 - 2 30 10 200 30 10 khz v % a ma ma m a c/w v v m a m a na 93 i cl 1.7 / 1.3 3.0 / 3.2 on/off pin = 5v (off) on/off pin = 0v (on) 2.2 / 2.4 - - 1.0 / 0.8 note 1: absolute maximum ratings indicate limits beyond which damage to the device may occur . operating ratings indic ate conditions for which the device is intended to be functional, but do not guarantee specific performance limits. guaranteed specifications and t est conditions are shown in electrical characteristics. note 2: all limits guaranteed at 25c (standard type face) and over full operating temperature range (bold type face). all 25c limits are 100% production tested. all limits over full operating temperature range are guaranteed via correlation using standard statistics quality control methods. note 3: external components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance. when the as shown in system parameters section of electrical characteristics. note 4: output pin sourcing current. no diode, inductor or capacitor connected to output. note 5: feedback pin removed from output and connected to 0v. note 6: feedback pin removed from output and connected to +12v for the adjustable, 3.3v , and 5v versions, and +25v for the 12v and 15v versions, to force the output transistor off. note 7: v = 40v in note 8: junction to ambient thermal resistance (no external heat sink) for the 5 lead to-220 package mounted vertically , with ? inch leads in a socket, or on a pc board with minimum copper area. note 9: junction to ambient thermal resistance (no external heat sink) for the 5 lead to-220 package mounted vertically , with ? inch leads soldered to a pc board containing approximately 4 square inches of copper area surrounding the leads. note 10: if the to-263 package is used, the thermal resistance can be reduced by increasing the pc board copper area thermally connected to the package. using 0.5 square inches of copper area, q is 50c//w, with 1 square inch ja of copper area, q is 37c/w, and with 1.6 or more square inches of copper area, q is 32c/w. ja ja note 11: the oscillator frequency reduces to approximately 11 khz in the event of an output short or an overload which causes the regulated output voltage to drop approximately 40% from the nominal output voltage. this self- protection feature lowers the average power dissipation of 5% down to approximately 2%. q ja q ja q jc q jc q ja LM2575 by lowering the minimum duty cycle from LM2575 is used as show in the figure 2 test circuit, system performance will be l m 2 5 75 1. 0 a s t e p - d o w n v oltage s w i tc hing r e g u lat o r s
6 test circuit and la yout guidelines careful layout is important with any switching regulator. rapidly switching currents associated with wiring inductance generate voltage transients, which can cause problems. t o minimize inductance and ground loops, the lengths of the leads indicated by heavy lines in figure 1 below should be kept as short as possible. single- point grounding (as indicated in figure 1) or ground plane construction should be used for best results. when using the adjustable version, place the programming resistors as close as possible to sensitive feedback wiring short. v in unregulated dc input +v in 1 + c in gnd 3 5 2 output 4 feedback l1 d1 mbr360 c out v out fixed output + on/off l o a d figure 1(a). fixed output voltage v ersions c - 100 f , 75v, aluminum electrolytic in c - 330 f , 25v, aluminum electrolytic out d1 - schottky, mbr360 l1 - 330 h, r1 - 2k, 0.1% r2 - 6.12k, 0.1% 3l electronic corp. tc-331m-1.0a- 5026 330 h 330 f 100 f LM2575, to keep the LM2575 l m 2 5 75 1. 0 a s t e p - d o w n v oltage s w i tc hing r e g u lat o r s
7v - 40v unregulated dc input +v in 1 c in gnd 3 5 2 4 d1 mbr360 l1 r2 r1 output feedback v =5.0v out c out + + l o a d figure 1(b). adjustable output voltage v ersions v = v ( 1 + ) out ref r2 = r1 ( -1) where v = 1.23v, r1 between 1k and 5k. ref r2 r1 v out v ref 330 f 100 f 330 h on/ off figure 2. switch saturation voltage 1.2 1.0 0.8 0.6 0.4 0 0.2 0.4 0.6 0.8 1.0 switch current (a) s a t u r a t i o n v o l t a g e ( v ) t = - 5 5c j 2.0 1.5 1.0 0.5 0 -75 -50 -25 0 25 50 75 100 125 150 junction temperature (c) i n p u t - o u t p u t d i f f e r e n t i a l ( v ) figure 3. dropout voltage d v out = 5% r = 0.2 w ind i = 1a load i = 200ma load typical performance characteristics t = - 2 5c j t = 150 c j LM2575-adj l m 2 5 75 1. 0 a s t e p - d o w n v oltage s w i tc hing r e g u lat o r s
8 typical performance characteristics 0 10 20 30 40 50 60 70 80 90 100 q = 32 ja c/ w ambient temperature (c) figure 5. maximum power dissipation(to-263) 4 3 2 1 0 q = 37 ja c/ w q = 50 ja c/ w q = 73 ja c/ w 20 18 16 14 12 10 8 6 4 0 10 20 30 40 50 60 input volt age (v) q u i e s c e n t c u r r e n t ( m a ) figure 4. quiescent current v = 5v out measured at ground pin t = 25c j i = 1a load i = 200ma load 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 -50 -25 0 25 50 75 100 125 junction temperature (c) i n p u t v o l t a g e ( v ) figure 6. minimum operating voltage v = 1.23v out i = 120 ma load 8 7 6 5 4 3 2 1 0 0 5 10 15 20 25 on / off pin volt age (v) c u r r e n t ( a ) figure 7. on / off pin current (sinking) v = 40v in -40c t 125 j c p o w e r d i s s i p a t i o n ( w ) adjustable version only l m 2 5 75 1. 0 a s t e p - d o w n v oltage s w i tc hing r e g u lat o r s
9 to-220-5 package outline dimensions to-263-5 p ackage outline dimensions pad layout 1 1 . 5 9 3.8 1.07 units: mm 17.5 1.7 9.90 15 0.40 1.50 dp0.20 9.20 4.90 15.3 0.80 1.70 typ (1.70 0.20) 3 4.50 1.30 0.10 2.40 2.00 r0.30 r0.30 2.54 0.50 4.40 7.0 10.0 0.40 r 0.45 7.2 9.20 4.90 unit: mm 10.00 3 3 4.60 1.20 0.75 3 8.0 1.75 15.30 r 0.3 1.20 0.90 9.90 0.20 1.50 dp0.20 1 3 . 0 8 0 . 2 0 9 . 2 0 0 . 2 0 3.70 0.20 1.30 2.80 0.10 1 5 . 9 0 0 . 2 0 2 8 . 7 8 m a x 0.50 2.40 0.20 unit: mm 1.30 0.10 4.50 0.20 8.70 1.70 4.60 +0.1 -0.05 3 3 3 +0.1 -0.05 8.0 0.20 7.0 7.0 0.20 3-r0.2 10.00 0.20 3 3 8.40 2 - r 0.3 3.60 0.20 1.2 1.7(typ) 5-0.8 0.10 9.97 0.20 9.20 0.20 l m 2 5 75 1. 0 a s t e p - d o w n v oltage s w i tc hing r e g u lat o r s
10 to-252-5 p ackage outline dimensions 29 0.5 0.256 0.004 6.5 0.1 0.212 0.003 5.375 0.075 0.024 ref 0.600 ref 0.24 0.004 6.10 0.1 0.2835 0.0035 7.20 0.1 0.0235 0.0015 0.60 0.025 0.050bsc 1.270bsc 0.025 0.002 0.64 0.05 0.039 0.002 1.0 0.05 0.02 0.001 0.51 0.02 0.06 0.004 1.525 0.1 0.39 0.008 9.9 0.2 0.003 0.002 0.07 0.05 0.091 0.002 2.3 0.05 inches mm ( ) to-220-5b p ackage outline dimensions 0.4 10.16 0.006 0.15 inches mm ( ) 0.151 0.002 3.84 0.05 0.108 .74 0.006 2 0.15 0.4985 0.0075 12.66 0.2 0.268 0.68 0.004 0.1 0.032 0.81 0.004 0.1 0.213 0.004 5.4 0.1 0.138 0.004 3.5 0.1 0.1535 0.0035 3.9 0.1 0.220 typ 1.700 typ 0.18 0.004 4.57 0.1 0.05 0.004 1.27 0.1 0.05 0.004 1.27 0.1 0.358 0.008 9.1 0.2 0.9645 0.0075 24.5 0.2 0.996 0.008 25.3 0.2 0.105 0.006 2.76 0.15 0.173 0.006 4.4 0.15 0.331 0.006 8.4 0.15 0.0165 0.0045 0.42 0.11 pad layo ut 7 units: mm 7 3 0.9 1.27 6.25 l m 2 5 75 1. 0 a s t e p - d o w n v oltage s w i tc hing r e g u lat o r s
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