nju7343/44/45 -1- ver.5.2 single-phase dc brushless motor driver ic general description the nju7343/ 44/ 45 are single-phase dc brushless motor driver ic. that features mos-fet driver circuit for better output characteristics. the drivers includes lock detect and thermal shutdown circuit. each of the drivers includes fg output (nju7343), half fg output (NJU7344), and rd output (nju7345). maximum output current is 500ma and input offset voltage is 7mv. it is suitable for 5v high current small fan-motor applications. package outline nju7343r/44r/45r features ? operating voltage 2.2 to 5.5v ? lock detect / auto release ? control output terminal nju7343:fg(frequency generator) NJU7344:half fg nju7345:rd(rotation detect) ? thermal shutdown circuit ? low operating current ? low saturation output voltage ? vsat= 0.25v @io= 500ma ? input offset voltage 5mv ? cmos technology ? package outline vsp10 block diaglam nju7343(fg), NJU7344(half fg) nju7345(rd) pin function 1: ct 2: fg(nju7343),half fg(NJU7344), rd(nju7345) 3: v dd 4: out b 5: vss 6: vss 7: out a 8: v dd 9: in- 10: in+ (note) all v dd and v ss pins should be connected th e power supply and the ground respectively. otherwise, the electrical characteristic may no t satisfy specifications ld 7 8 9 10 6 4 5 3 2 1 ts d
nju7343/44/45 - 2 - absolute maximum ratings (ta=25 c) parameter ratings symbol (unit) note supply voltage +7.0 v dd (v) input voltage -0.3 v dd +0.3 v id (v) output current (peak) 1000 i o peak (ma) operating temperature range -40 +85 topr ( c) storage temperature range -50 +150 tstg ( c) power dissipation 400 p d (mw) device itself recommended operating conditions (v dd =5v, ta=25c) parameter symbol condition min. typ. max. unit supply voltage v dd ct=0 2.2 5.0 5.5 v junction temperature range tj - -40 - 125 c input common mode voltage range v icm - 0.4 - 4.0 v output current i o - - - 500 ma
nju7343/44/45 - 3 - electrical characteristics (v dd =5v, ta=25c) parameter symbol condition min. typ. max. unit general operating current i dd - - 3.0 4.0 ma thermal shutdown temperature t tsd - - 180 - c thermal shutdown hysteresis t hys - - 50 - c hall amplifier input offset voltage v io - -5 - 5 mv feedback resistance r f - 22.0 27.5 33.0 k ? open loop gain a v - - 80 - db input common mode voltage range v icm - 0.4 4.0 - - v output v oh io=+350ma 4.65 4.80 - maximum output voltage range v ol io=-350ma - 0.20 0.35 v r onh io=+500ma - 0.5 - output resistance r onl io=-500ma - 0.5 - ? fg(rd) l output voltage v fg 9pin=0v, 10pin=5v, r 3 =10k ? - - 0.3 v fg(rd) h leak current i fg-leak 9pin=5v, 10pin=0v, r 3 =10k ? - - 1.0 a lock detect circuit* lock protect operation voltage v lop - 4.0 - - v lock detect charge current i chg - - 0.6 - a lock detect discharge current i dchg - - 0.1 - a clamp voltage v cl - - 2.8 - v detect voltage v id - - 0.8 - v
nju7343/44/45 - 4 - application note the nju7343/44/45 are single-phase dc brushless motor driver ic in small vsp-10 package. with minimal external components, that can drive up to 500ma of motor current for small fan application. [application circuit example] in+ in- vdd ct vss outb out a fg,1/2fg,rd moto r hall element c2 r1 r3 r2 fg,half-fg,rd out nju7343/44/45 v+ gnd c1 d1 [design notes] above application example is designed for 5v operation with motor current of 500ma. it uses the following components: hall elements: hw101a (ake) 1. selection of c1 and d1: c1 is used for a noise reduction purpose. a typical value is 0.1uf. optimize the value in actual operating conditions if necessary. d1 is a diode for protection against reverse voltage supply. silicon rectifier diode (wo3c, 10d1 and equivalent) is appropriate. 2. lock protection function (design of c2 value): lock protection function, consists of motor lock detection and auto resume function, is a safety feature to protect a motor and a driver circuit from fatal destruction in case of motor halt. motor lock detection detects motor halt due to irregular load conditions and then cuts motor driving current f or safety operation. a value of c2 determines lock detection time (ton) and auto resume time (toff). lock detection time (ton) is given by: [] sec 2 ich v v c t id cl on ? =
nju7343/44/45 - 5 - where c2 is 0.15uf: auto resume time (toff) is given by: where c2 is 0.15uf: in actual application, lock detection time (ton) is affected by the mechanical time constant of a motor. therefore, constant start up must be confirmed in actual evaluation taking operating variations (i.e. temperature, voltage change and so on) in consideration. a typical value of c2 is either from 0.1uf to 0.47uf depending on a motor. *remarks : when v dd becomes lower than 4v,the clamp voltage( v cl ) becomes lower accordingly. this makes ton and toff shorter and may cause issues associated with the restarting of the motor from the lock protection state.therefore, careful evaluation is necessary with actual motors. 3. design of hall element bias resistance ( r1 and r2 ) hall amplifier is a differential amplifier. the common-mode input voltage is between 0.4v and vdd-1v and the input signal must be within the range. non-excitation hall bias voltage is to be set at a half of vdd for effective use of common-mode input voltage range. therefore the same value of hall bias resistors is selected for r1 and r2. given that the bias current is set to be 5ma by hw101a datasheet, r1 and r2 can be determined as follows: ? = = ? = = = + + ? 300 2 1 0 . 1 10 5 5 2 1 3 r r k ihbias vdd rin r r [] sec 49 . 0 10 6 . 0 8 . 0 8 . 2 10 15 . 0 6 6 = ? = ? ? on t [] sec 2 idis v v c t id cl off ? = [] sec 00 . 3 10 1 . 0 8 . 0 8 . 2 10 15 . 0 6 6 = ? = ? ? off t motor lock protection period returns to normal operation hall input motor output ct terminal voltage motor loxked ton toff v cl
nju7343/44/45 - 6 - the output voltage of hall elements is influenced by the bias current and magnetic flux density of hall elements. the optimum input voltage of nju7343/44/45 are 100mvp-p and higher. with such input voltage, the highest efficiency can be obtained. 4. design of fg output resistance ( r3 ) fg out (fg: pin8) is an open drain output and r3 is a pull up register. a typical value of r3 is 10k ? . the timing chart of fg out (half-fg,rd) is as follows. note that the pull up resistance shall be connected to below supply voltage. the specifications on this data book are only given fo r information, without any guarantee as regards eithe r mistakes or omissions. the application circuit in this dat a book are described only to show representative usages o f the product and not intended for the guarantee o r permission of any right including the industrial rights. hall input in+ fg terminal volta g e
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