typical application (fixed output voltage versions) connection diagrams and ordering information applications simple high-efficiency step-down (buck) regulator on-card switching regulators positive to negative converter features 3.3v, 5v, 12v, and adjustable output versions adjustable version output voltage range, 1.2v to 37v 3% max over line and load conditions available in to-220 guaranteed 3a output load current input voltage range up to 40v requires only 4 external components excellent line and load regulation specifications 150 khz fixed frequency internal oscillator ttl shutdown capability low power standby mode, i q typically 100 a high efficiency thermal shutdown and cu rrent limit protection description the LM7596 series of regulators are monolithic integrated circuits that provide all the active functions for a step-down switching regulator, capable of driving a 3a load with excellent line and load regulation. these devices ar e vailable in fixed output voltages of 3.3v, 5v, 12v and an adjustable output version. requiring a minimum number of external components, these regulators are simple to use. the LM7596 series operates at a switching frequency of 150khz. available in standard 5-lead to-220 package. other features include a guaranteed 3% tolerance on output voltage under specified input voltage and output load conditions, and 15% on the oscillator frequency. external shutdown is included, featuring typically 100a standby current. self protection features include a two stage frequency reducing current limit for output switch and an over temperature shutdown for complete protection under fault conditions. the over temperature shutdown level is about 145c with 5c hysteresis. LM7596 simple switcher power converter 150khz 3a step-down voltage regulator
absolute maximum ratings operating conditions ma ximum supply voltage 45v temperature range -40c ? t j ? +125c on /off pin input voltage -0.3 ? v ? +25v supply voltage 4.5v to 40v feedback pin voltage -0.3 ? v ? +25v output voltage to ground -1v storage temperature range -65c to +150c power dissipation internally limited maximum junction temperature +150c electrical characteristics unless otherwise specified, tj=25c. v in = 12v for the 3.3v, 5v and adjustable version and v in = 24v for the 12v version. i load = 500ma. characteristic symbol test condition min typ max unit LM7596-3.0 4.75v LM7596-5.0 7v LM7596-12 15v LM7596-3.0 i load = 3a 73 LM7596-5.0 i load = 3a 80 LM7596-12 v in =24v,i load = 3a 90 efficiency LM7596-adj v in =12v, v out = 3v, i load = 3a 73 % feedback voltage v fb LM7596-adj 4.5v LM7596-adj v fb = 1.3v 15 50 na oscillator frequency f o 127 1 50 173 khz saturation voltage v sat i out = 3a (note 1,2) 1.16 1.4 v max duty cycle (on) (note 2) 100 min duty cycle (off) dc (note 3) 0 % current limit i cl peak current (note 1,2) 3.4 4.5 6.0 a output = 0v (note 1,3) 50 a output leaked current i l output = -1v, v in = 40v 2 30 ma quiescent current i q (note 3) 5 10 ma standby quiescent current i stby on/off pin = 5v (off), v in = 40v 100 200 a 1.3 v ih low (regulator on) 0.6 on/off pin logic input threshold voltage v il high (regulator off) 2.0 v i h v logic = 2.5v (regulator off) 5 15 on/off pin input current i l v logic = 0.5v (regulator on) 0.02 5 a note 1: no elements connected to output pin. note 2: feedback pin removed from output and connected to 0v to force the output transistor switch on. note 3: feedback pin removed from output and connected to 12v for the 3.3v, 5v, and the a version, and 15v for the 12v version. to force the output transistor switch off. LM7596 simple switcher power converter 150khz 3a step-down voltage regulator
physical characteristics LM7596 pad layout x wafer diameter??100 r 0.5 mm x wafer thickness??350 r 20 p m x scribe width?????.. 100 p m x passivation??????.psg x metallization bottom........ ti-ni-ag ti-ni ? 0.5-0.7 p m ag ? 0.6-0.1 p m pad location coordinates note: i the chip substrate is electrically connected to gnd (pad 3) i pads 1 and 1a are internally connected i pads 2 and 2a are internally connected bonding diagram note: wire diameter > 60 micron pad 1 and pad 1a (v in ) are connected to the pin1. pad 2 and pad 2a (output) are connected to the pin 2. pad 3 (ground) is connected to the pin 3. pad 4 (fe edback) is connected to the pin 4. pad 5 (on/off) is connected to the pin 5. pad no pad name x ( p m) y ( p m) 1 v in 463 1252 1a v in 225 -95 2 output -445 547 2a output -245 615 3 ground -875 -120 4 feedback -875 -1355 5 on/off 875 -1355 LM7596 simple switcher power converter 150khz 3a step-down voltage regulator
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