www. b elling .com .cn 1 0.9 v s tartup, 1 mhz , 300ma io ut, low iq, synchronous boost c onverter b l8536 description the BL8536 is a step - up converter that provides a boosted output voltage from a low voltage source. because of its proprietary design, it starts up at a very low input voltage down to 0.9 v, and only consume s 15ua at standby, making it an ideal choice for single cell alkaline/nimh battery operations. a switching frequency of 1mhz minimizes solution footprint by allowing the use of tiny, low profile inductors and ceramic capacitors. the current mode pwm design is internally compensated, reducing external parts count. BL8536 is available in sot23 - 3 sot23 - 5 and sot 89 - 3 package s . features ? efficiency u p to 9 5 % @vin= 2.7 v, vout= 3.3 v ? typical 15ua standby current ? 1mhz switching frequency allows small inductor and output cap ? input boost - strapping allows using small or no input cap ? low vin start - up voltage down to 0.9 v ideal for single alkaline cell operations ? maximum output current up to 300m a ? low noise pwm control ? internally compensated current mode control ? internal synchronous rectifier ? available in sot23 - 3 sot23 - 5 and sot89 - 3 applications ? one to three cell battery operated devices ? medical instruments ? bluetooth headsets ? flash - based mp3 players ? noise canceling headphones typical app licat ion pin out & marking sot23 - 3 sot23 - 5 sot89 - 3 s : product code x: output voltage yw: date code output voltage code x vout code vout code 1. 8 v 8 2.8v 2.2 v 3.0v 2.5v 3.3v 2.7v 3.6v s : product code x x : output voltage ll: lot no. h: fab code yw: date code BL8536 g n d s w o u t 1 0 u f l c 3 5 0 0 1 0 u f 2 . 2 u h v i n v o u t 1 2 3 s w g n d o u t s x y w 0 3 6 1 2 3 s w g n d o u t s x x l l h y w o u t n c s w g n d n c 2 3 5 4 1 s x y w
www. b elling .com .cn 2 b l8536 ordering information part no. package tape&reel BL8536 cb 3 tr sot23 - 3 3000/reel BL8536 cb 5 tr sot23 - 5 3000/reel BL8536 c c3 tr sot 89 - 3 1 000/reel note : stands for output voltage . absolute maximum rating parameter value sw voltage - 0.3 ~ 6v out voltage - 0.3 ~ 6v max operating junction temperature(tj) 1 25 ? c maximum power dissipation sot23 - 3 450m w sot23 - 5 450m w sot 89 - 3 500m w ambient temperature(ta) - 4 0 ? c C 85 ? c storage temperature(ts) - 55 ? c - 150 ? c lead temperature & time 260 ? c , 10s note : exceed these limits to damage to the device. exposure to absolute maximum rating conditions may affect device reliability. electrical characteristics ( t a =25 ? c ) symbol parameter conditions min typ max unit v in input voltage range 0.9 5 v vstart startup voltage iout = 1m a 0.9 v vhold hold voltage iout = 50ma 0.5 0.7 v vout output voltage range 1.8 3.6 v output voltage accuracy iout = 0ma 2 % line regulation iout = 50ma 0.1 0.2 % /v load regulation iout = 0~300ma 1 2 % fsoc switching frequency vout=0.95vo, no inductor 0.7 1 1. 4 mhz max duty cycle vout=0.95vo, no inductor 85 90 95 % i q quiescent current at vout vout=1.05*vo 5 8 15 ua s upply current at vin iout = 0ma 20 ua efficiency iout = 100ma 85 % rdsonp pmos rdson i sw =100ma 400 600 mohm rdsonn nmos rdson i sw =100ma 200 300 mohm isw lk sw leakage current vout= 3.6 v, vsw = 0 or 5 .2 v 1 ua pin description pin # name description sot23 - 3 sot23 - 5 sot89 - 3 1 2 1 gnd ground 2 4 3 sw to connect inductor to vin 3 5 2 out o u tput voltage pin, with 10 uf ceramic capacitor closely connected to gnd - 1, 3 - nc no connection
www. b elling .com .cn 3 b l8536 electrical performance tested under cin=cout=10uf, l=2.2uh, t a =25 ? c , unless otherwise specified 0% 20% 40% 60% 80% 100% 0.001 0.01 0.1 1 efficiency iout (a) efficiency vs. output current (vout=3.3v) vin=1.0v vin=1.5v vin=2.0v vin=2.7v 0% 20% 40% 60% 80% 100% 0.001 0.01 0.1 1 efficiency iout (a) efficiency vs. output current (vout=3.0v) vin=1.0v vin=1.5v vin=2.0v vin=2.7v 0% 20% 40% 60% 80% 100% 0.001 0.01 0.1 1 efficiency iout (a) efficiency vs. output current (vout=2.2v) vin=1.0v vin=1.2v vin=1.5v vin=2.0v 0% 20% 40% 60% 80% 100% 0.001 0.01 0.1 1 efficiency iout (a) efficiency vs. output current (vout=1.8v) vin=1.0v vin=1.2v vin=1.5v 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 0 0.2 0.4 0.6 0.8 1 vout (v) iout (a) output voltage vs. output current (vout=3.3v) vin=1.0v vin=1.5v vin=2.0v vin=2.7v 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 0 0.2 0.4 0.6 0.8 1 1.2 vout (v) iout (a) output voltage vs. output current (vout=3.0v) vin=1.0v vin=1.5v vin=2.0v vin=2.7v 0.0 0.5 1.0 1.5 2.0 2.5 3.0 0 0.2 0.4 0.6 0.8 1 vout (v) iout (a) output voltage vs. output current (vout=2.2v) vin=1.0v vin=1.2v vin=1.5v vin=2.0v 0.0 0.5 1.0 1.5 2.0 0 0.1 0.2 0.3 0.4 0.5 0.6 vout (v) iout (a) output voltage vs. output current (vout=1.8v) vin=1.0v vin=1.2v vin=1.5v
www. b elling .com .cn 4 b l8536 block diagram detailed description BL8536 is a low input voltage start up, current mode dc - dc step up converter. it s operation can be best understood by referring to the block diagram. upon starting up, the low voltage startup circuitry drives sw with on - off cycles, transferring energy from input to out by storing energy in the inductor during on - time and releasing it to the output during off - time. when out reaches 2v, the startup circuit turns off and the main controller takes over. the main control loop consists of a reference, a gm error amplifier, a pwm controller, a current sense amplifier, an oscillator, a pwm logic control, and it is power stage i ncluding its driver. the main control loop is a classic current mode control loop. the gm stage integrates the error between fb and ref, and its output is used to compare with a triangular wave which the summing result of the current sense amplifier output and a slope compensation voltage. the output of the comparator is used to drive the power stage to reach regulation. a pplication information inductor selection with switching frequency up to 1mhz, small surface mount inductors can be used with values fr om 2.2uh to 4.7uh. for a given chosen inductor value and application conditions make sure the peak - 5 0 5 10 15 20 25 30 - 50 0 50 100 iq(ua) temperature( ) iq vs. temperature supply current at vin quiescent current at vout 3.0 3.1 3.2 3.3 3.4 3.5 - 40 0 40 80 120 vout(v) temperature( ) output voltage vs. temperature vin=1.0v vin=2.6v
www. b elling .com .cn 5 b l8536 inductor current does not exceed the maximum current rating of the selected vendor's inductor. input and output capacitor selection the BL8536 's bootstrap architecture allows the use of very small input capacitor. for applications that only need to drive small output load current, the input capacitor is optional, because once output is started up, the ic's is powered by out, a quiet power supply. the output capacitor is used to stabilize the loop and provide ac current to the load. a low esr ceramic cap with values from 2.2uf to 22uf can be used. smaller value capacitors are generally cheaper with small footprints, while larger capacitor provides lower ripple s and better transient load responses. also, when extreme low startup voltage is needed, larger output capacitors are needed for the part to startup under heavy load condition. package out line package sot - 23 - 3 devices per re el 3000pcs unit mm package dimension
www. b elling .com .cn 6 b l8536 package sot23 - 5 devices per reel 3000 unit mm package specification package sot - 89 - 3 devices per reel 1 000 pcs unit mm package dimension
|
