View ACE701430AMH_5361868.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

ace 7 01 pfm step - up dc/dc converter with high efficiency and low noise ver 1. 5 1 d escription the ace701 series are cmos - based pfm step - up dc - dc converter. the converter can start up by supply voltage as low as 0.8v, and capable of delivering max imum 200ma output current at 3.3v output with 1.8v input voltage. quiescent current drawn f rom power source is as low as 7 ua. all of these features make ace701 series be suitable for the portable devices, which are supplied by a single battery to four - cell batteries. to reduce the noise caused by the switch regulator, ace701 is well considerated in circuit design and manufacture. so that the interferer to other circuits by the device is reduced greatly. ace701 integrates stable reference circuits and trimming technology , so it can afford high precision and low temperature - drift coefficient of the output voltage. features ? deliver 200ma at 3.3v output voltage with 1.8v input voltage ? low start - up voltage (when the output current is 1ma) 0.8v ? the converter output voltage can be adjusted from 2.5v 6.0v(in 0.1v step) ? output voltage accuracy ? 2 ? low temperature - drift coefficient of the output voltage ? 100ppm/ ? only three external components are necessary: an inductor, a schottky diode and an outpu t filter capacitor ? high power conversion efficiency 85 ? low quiescent current drawn from power source < 5.5 ua application ? power source for pda. dsc. mp3 player. electronic toy and wireless mouse ? power source for a single or dual - cell battery - powered equip ments ? power source for led absolute maximum ratings p arameter s ymbol m ax u nit input supply voltage v in - 0.3~12 v input voltage v i(lx) - 0.3~vout+0.3 v ce pin voltage - 0.3~vout+0.3 lx pin output current 0.7 a power dissipation sot - 89 - 3 sot - 23 - 5 50 0 250 mw operating j unction temperature t j 125 o c storage temperature t s - 4 0 to 150 o c ambient temperature t a - 40 to 85 o c
ace 701 pfm step - up dc/dc converter with high efficiency and low noise ver 1. 5 2 packaging type sot - 8 9 - 3 sot - 23 - 5 5 4 1 2 3 1 2 3 sot - 89 - 3 sot - 23 - 5 description function 1 4 v ss (gnd) ground pin 2 2 v out output pin, power supply for internal circuits 3 5 l x (ext) switching pin 3 nc no connection 1 ce chip enable pin (active high) ordering information ace 7 01 x xx xx + h output voltage : 2.5v / 3.0v
ace 701 pfm step - up dc/dc converter with high efficiency and low noise ver 1. 5 3 block diagram ace701 re commended work conditions item min nom max unit input voltage range 0.8 vout v inductor 10 27 100 h input capacitor 0 R 10 f output capacitor 47 100 220 f operating junction temperature - 20 85 *suggestion: use tantalum capacitor to reduce the ripple of the output voltage.
ace 701 pfm step - up dc/dc converter with high efficiency and low noise ver 1. 5 4 electrical characteristics parameter symbol test cond itions min typ m ax unit output voltage vout 2.45 2.5 2.55 v 2.646 2.7 2.754 2.94 3.0 3.06 3.234 3.3 3.366 3.528 3.6 3.672 3.92 4.0 4.08 4.9 5.0 5.1 5.88 6.0 6.12 input voltage vin 12 v input current lin iout=0ma, v in=vout*0.6 12 15 ua start - up voltage vstart iout=1ma, vin:0 ? 2v 0.8 0.9 v hold - on voltage vhold iout=1ma, vin:2 ? 0v 0.6 0.7 v quiescent current drawn from power source i dd without external components, vout=vout x 1.05 4 7 ua switch on resistance rsw on 0.4 0.5 lx leakage current i lxleak vout=vlx=6v 0.5 5 ua ce h threshold voltage v ceh v ce : 0 ? 2v 0.6 0.9 v ce l threshold voltage v cel v ce : 2 ? 0v 0.3 0.6 v oscillator frequency f osc lx on l side vout=vout * 0.96 300 350 400 khz oscillator duty cycle maxdty on (vlx l) si de 70 75 80 % effi c iency 85 % note : 1. diode: schottky type, such as: 1n5817, 1n5819, 1n5822 2. inductor: 27uh(r<0.5) 3. capacitor: 100uf (tantalum type) typical application circuit d 1n5819 vin vout l 27uh lx lx out iout cin 47uf ace701 gnd cout rload 100uf tan
ace 701 pfm step - up dc/dc converter with high efficiency and low noise ver 1. 5 5 detailed description the ace701 series are boost structure, voltage - type pulse - frequency mo dulation(pfm) step - up dc - dc converter. only three external components are necessary: an inductor, a n output filter capacitor and a schottky diode. and the converter s low noise and low ripple output voltage can be adjusted from 2.5v to 5.0v, 0.1v step. by using the depletion technics, the quiescent current drawn from power source is lower than 7ua. the high efficiency device consists of resistors for output voltage detection and trimming, a start - up voltage circuit, an oscillator, a reference circuit, a pfm control circuit, a switch protection circuit and a driver transistor. the pfm control circuit is the core of the ace701 ic. this block controls power switch on duty cycle to stabilize output voltage by calculating results of other blocks which sense inpu t voltage, output voltage, output current and load conditions. in pfm modulation system, the frequency and pulse width is fixed. the duty cycle is adjusted by skipping pulses, so that switch on - time is changed based on the conditions such as input voltage, output current and load. the oscillate block inside ace701 provides fixed frequency and pulse width wave. the reference circuit provides stable reference voltage to output stable output voltage. because internal trimming technology is used, the chip outpu t change less than 2%. at the same time the problem of temperature - drift coefficient of output voltage is considered in design, so temperature - drift coefficient of output voltage is less than 100ppm/ high - gain differential error amplifier guarantees stable output voltage at difference input voltage and load. in order to reduce ripple and noise, the error amplifier is designed with high band - with. though at very low load condition, the quiescent current of chip do effect efficiency certainly. the four main energy loss of boost structure dc - dc converter in full load are the esr of inductor, the voltage of schottky diode, on resistor of internal n - channel mosfet and its driver. in order to improve the efficiency, ace701 integrates low on - resistor n - channel mosfet and well design driver circuits. the switch energy loss is limited at very low level. selection of the external components thus it can be seen, the inductor and s c hottky diode affect the conversion efficiency greatly. the inductor and the capacitor also have great influence on the output voltage ripple of the converter. so it is necessary to choose a suitable inductor, a capacitor and a right schottky diode, to obtain high efficiency, low ripple and low noise. before discussion we define d vout - vin / vout (1) inductor selection above all, we should define the minimum value of the inductor that can ensure the boost dc - dc to operate in the continuous current - mode condition. lmin R d(1 - d) 2 r l / 2f
ace 701 pfm step - up dc/dc converter with high efficiency and low noise ver 1. 5 6 the above expression is got un der conditions of continuous current mode, neglect schottky diode s voltage, esr of both inductor and capacitor. the actual value is greater that it. if inductor s value is less than lmin the efficiency of dc - dc converter will drop greatly, and the dc - dc c ircuit will not be stable. secondly, consider the ripple of the output voltage, i=d ? vin / lf im ax=vin / (1 - d) 2 r l + dvin / 2lf if inductor value is too small, the current ripple through it will be great. then the current through diode and power switc h will be great. because the power switch on chip is not ideal switch, the energy of switch will improve. the efficiency will fall. thirdly in general, smaller inductor values supply more output current while larger values start up with lower input voltage and acquire high efficiency. an inductor value of 3uh to 1mh works well in most applications. if dc - dc converter delivers large output current (for example: output current is great than 50ma), large inductor value is recommended in order to improve effici ency. if dc - dc must output very large current at low input supply voltage, small inductor value is recommended. the esr of inductor will effect efficiency greatly. suppose esr value of inductor is r l r load is load resistor then the energy can be cal culated by following expression: ?? r l / r load (1 - d) 2 for example: input 1.5v, output is 3.0v, r load =20 , r l =0.5 , the energy loss is 10%. consider all above inductor value of 47uh esr<0.5 is recommend ed in most applications . large value is recommended in high efficiency applications and smaller value is recommended (2) capacitor selection ignore esr of capacitor the ripple of output voltage is: r = vout / vout=d / r load cf so large value capacitor is needed to reduce ripple. but too large capacitor value will slow down system reaction and cost will improve. so 100uf capacitor is recommended. larger capacitor value will be used in large output current system. if output current is small (<10ma), small value is needed. consider esr of capacitor ripple will increase r'=r+imax ? r esr / vout when current is large, ripple caused by esr will be main factor. it may be greater than 100mv the esr will affects efficiency and increase energy loss. so low - esr capacitor (for examp le: tantalum capacitor) is recommend or connect two or more filter capacitors in parallel.
ace 701 pfm step - up dc/dc converter with high efficiency and low noise ver 1. 5 7 (3) diode selection rectifier diode will affects efficiency greatly though a common diode (such as 1n4148) will work well for light load it will reduce about 5%~10% efficiency for heavy load for optimum performance, a schottky diode (such as 1n5817 1n5819 1n5822) is recommend ed. (4) input capacitor if supply voltage is stable, the dc - dc circuit can output low ripple, low noise and stable voltage without input capacitor. if voltage source is far away from dc - dc circuit, input capacitor value greater than 10uf is recommended. t est circuits (1) output voltage test circuit (i load =1ma) ace701 (2) start - up voltage test circuit (i load =1ma) ace701
ace 701 pfm step - up dc/dc converter with high efficiency and low noise ver 1. 5 8 (3) hold - on voltage test circuit (i load =1ma) ace701 (4) quiescent current test circuit ace701 note: vout=vout _nom * 1.05, r=1k , c=0.1 uf (5) oscillator frequency and duty cycle test circuit ace701 oscillograph note: v in =vout* 0.95 , r=1k
ace 701 pfm step - up dc/dc converter with high efficiency and low noise ver 1. 5 9 typical characteristic (r ecommended operating conditions: cin=47uf, cout=47uf, topt=25 , unless otherwise noted) 1. output voltage vs. output current 2. output voltage vs. output current ace701125am+ output voltage v s. output current ace 701133 am+ output voltage vs. output current output current (ma) output current (ma) 3.output voltage vs. output current 4.efficiency vs. output current ace7011 40 am+ output voltage vs. output current ace 701125 am+ efficiency vs. output current output current (ma) output current (ma) 5. efficiency vs. output current 6.efficiency vs. output curr ent ace7011 33 a m+ efficiency vs. output current ace 701140 am+ efficiency vs. output current output current (ma) output current (ma)
ace 701 pfm step - up dc/dc converter with high efficiency and low noise ver 1. 5 10 7. ripple vs. output current 8.ripple vs . output current ace7011 25a m+ ripple voltage vs. output current ace 701133 am+ ripple voltage vs. output current output current (ma) output current (ma) 9 . ripple vs. output current 1 0 . ino load vs. input voltage ace7011 40 a m+ ripple voltage vs. output current ace 701 quie scent current (ino load) vs. input voltage output current (ma) in put voltage ( v )
ace 701 pfm step - up dc/dc converter with high efficiency and low noise ver 1. 5 11 packing i nformation sot - 89 - 3
ace 701 pfm step - up dc/dc converter with high efficiency and low noise ver 1. 5 12 packing information sot - 23 - 5
ace 701 pfm step - up dc/dc converter with high efficiency and low noise ver 1. 5 13 notes ace does not a ssume 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 systems 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 significant 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 effectivenes s. ace technology co., ltd. http://www.ace - ele.com/

▲Up To Search▲

Price & Availability of ACE701430AMH

	To Download ACE701430AMH Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .