ace710 c 1a synchronous pwm boost converter ver 1.1 1 d escription the ACE710C is a step - up conv erter that provides a boosted output voltage f rom a low voltage source. because of its proprietary design, it starts up at a very low input voltage down to 0.9v, and only consumes 15ua at standby, making it an ide al 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, reduci ng external parts count. ACE710C is available in sot23 - 5 package. features ? efficiency up to 95%@vin=4.0v, vout=5.0v ? typical 15ua standby curren t ? 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 0.9v ideal for single alkaline cell operations ? maximum output current up to 1a ? low noise pwm control ? internally compensated current mode control ? internal synchronous rectifier ? logic control shutdown (iq<1ua) ? avai lable in sot23 - 5 application s ? one to three cell battery operated devices ? medical instruments ? bluetooth headsets ? flash - based mp3 players ? noise canceling headphones
ace710 c 1a synchronous pwm boost converter ver 1.1 2 absolute maximum ratings parameter value sw voltage - 0.3v~ 6 v en,out voltage - 0.3v~ 6 v max operating junction temperature (tj) 125 maximum power dissipation sot - 23 - 5 450mw ambient temperature(ta) - 40~85 storage temperature(ts) - 55 ~ 150 lead temperature & time 260 ,10s note: exceed these limits to damage to the device. exposure to absolute maximum rating conditions may affect device reliability. packaging type sot - 23 - 5 pin # name description 1 en enable pin for the ic. drive the pin to high to enable the part, and low to disable 2 out output voltage pin, with 10uf ceramic capacitor closely c onnected to gnd 3 nc no connection 4 gnd ground 5 sw to connect inductor to vin
ace710 c 1a synchronous pwm boost converter ver 1.1 3 ordering information ace710 c xx xx + h typical application block diagram pb - free bn : sot - 23 - 5 halogen - free output voltage: 1.8v =18
ace710 c 1a synchronous pwm boost converter ver 1.1 4 electrical character istics t a =25 o c symbol parameter test conditions min typ m ax unit v in i npu t vo lta g e r a n g e 0.9 5 v v s tart s tar t u p vo lta g e i o u t = 1ma 0.9 v v h o ld ho ld vo lta g e i o u t = 50ma 0.5 0.7 v vo u t o u t pu t vo lta g e r a n g e 1.8 5 .5 v o u t pu t v o lta g e a cc u racy i o u t = 0ma 2 % l i n e r e g u lat i o n i o u t = 50ma 0.1 0.2 % /v lo ad r egu lat i o n i o u t = 0 ~ 300ma 1 2 % fs o c s w itc h i n g f r e qu e n c y vo u t = 0.95 vo , n o i ndu c t o r 0.7 1 1. 4 mhz max d u ty cy c le vo u t = 0.95 vo , n o i ndu c t o r 85 90 95 % i q qu i e s c en t c u r r e n t at vo u t vo u t = 1.05 * v o 5 8 15 ua su p p ly c u r r en t at v in i o u t = 0ma 20 ua shu t d ow n s u pp ly c u r r e n t at v in e n=0 0.1 1 ua e ffi c i en c y i o u t = 100ma 85 % r ds o n p pm o s r ds o n i s w = 100ma 200 300 m o h m r ds o n n n mos r ds o n i s w = 100ma 100 150 m o h m i s w lk s w l e aka g e c u r r en t vo u t = 5.2 v , v s w = 0 o r 5. 2 v , e n=0 1 ua v h_e n e n i npu t hi g h vo lta g e 1 v v l _e n e n i npu t lo w vo lta g e 0.3 v
ace710 c 1a synchronous pwm boost converter ver 1.1 5 t ypical p erformance c haracteristics test conditions: cin = cout=10 uf, t a =25 , unless otherwise specified. efficiency vs. output current efficiency vs. output current (vout=5v) (vout=3v) iout (a) iout (a) output voltage vs. output current output voltage vs. output current (vout=5 v) (vout=3 v) iout (a) iout (a)
ace710 c 1a synchronous pwm boost converter ver 1.1 6 detailed description ACE710C is a low input voltage start up, current mode dc - dc step up converter. its operation can be best understood by referring to the block diagram. upon starting up, the low voltage start up 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 is high enough, 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 including its driver. the main control loop is a classic current mode c ontrol 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. t he output of the comparator is use d to drive the power stage to reach regulation . application information inductor selection with switching freq uency up to 1mhz, small surface mount inductors can be used with values from 2.2uh to 4.7uh. for a given chosen inductor value and application conditions make sure the peak inductor current does not exceed the maximum current rating of the selected vendor's inductor. input and output capacitor selection the ACE710C 's bootst rap architecture allows the use of very small input capacitor. for appli cations 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 t he 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 ripples and better transient load responses. also, when ex treme low startup voltage is needed, larger output capacitors are needed for the part to startup under heavy load condition.
ace710 c 1a synchronous pwm boost converter ver 1.1 7 packing information sot - 23 - 5
ace710 c 1a synchronous pwm boost converter ver 1.1 8 notes ace does not ass ume any responsibility for use as critical components in life support devices or systems without the express written approval of the president and general counsel of ace electronics co., ltd. as sued herein: 1. life support devices or systems are devices or s ystems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and shoes failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a s ignificant injury to the user. 2. a critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. ace technology co., ltd. http://www.ace - ele.com/
|
