mitsubishi M62291gp 5-pin sot-23 5.0v system fixed output voltage dc-dc converter description M62291gp is an integrated circuit designed as 5v fixed output voltage general purpose dc-dc converter. integrating peripheral components in ultrasmall 5-pin sot23 package allows for simplified external circuit and compact low cost design. this ic is applicable to portable equipments due to low circuit current 570ua(typ.) especially this is most suitable for localized power source such as audio equipments, and so on as converter from 12 to 5v system. features wide operation power supply voltage range -- 6v to 15v(vcc=12v typ.) low power consumption -- 570? max.(vcc=12v typ., at no load) built-in oscillator without peripheral components (110khz typ.) built-in overcurrent protection circuit ultrasmall 5-pin sot23 package applications localized power supply for audio, portable equipments, and general electric products ( 1 / ) block diagram op amp current limit circuit pwm comp v cc in gnd osc. 1.25v collector 1 2 3 4 5 clm (120khz) jan. 2000 pin configuration (top view) outline 5p2x-a (sot-23)
M62291gp ( 2 / ) absolute maximum ratings (ta=25c, unless otherwise noted) supply voltage output current symbol parameter conditions ratings unit vcc io 16 v 100 ma pd power dissipation 200 mw k theta thermal derating ratio 2.0 mw/c topr tstg operating ambient temperature storage temperature -20 to +85 -40 to +125 c c ta=25c ta>25c electrical characteristics (ta=25c, vcc=12v, unless otherwise noted) block symbol parameter conditions units limits min typ max vcc supply voltage icc supply current 6.0 15 v ? vo vreg-l output voltage ref line regulation iin in input current v mv ? 5.0 4.75 5.25 5 30 160 fosc oscillator frequency 120 khz v thclm current limit voltage 140 mv output leakage current i cl output saturation voltage vsat -1 1 1.2 2.0 vcc - clm ? v maximum on duty t duty 90 % 800 - no load - 300 70 175 110 170 - - vcc= 4 to 12v vcc = 15v, vc = 15v error amp. oscillator clm output io = 100ma 570 jan. 2000 mitsubishi 5-pin sot-23 5.0v system fixed output voltage dc-dc converter 3
( 3 / ) 1. application circuit (5.0v output dc-dc converter; M62291gp) current limit detction: when the voltage drop between 4pin and 5pin becomes 140mv or more, current limit detection circuit starts to operate. in the example of application (fig.1), the current is limited to 1.5a. 2 1 3 4 5 in vcc clm collector gnd + + M62291 v in (12v) v out (5.0v,1a) 100? 100? 0.09ohm r clm 1kohm 1kohm 150? fig.1 example of application circuit of m62270gp 2. the expression of circuit constants vf : forward voltage drop of an external diode. vsat : output saturation voltage of an external switching transistor. d io :set to 1/3 to 1/5 of maximum output current choose an external transistor, diode and inductor with peak current rating greater than "ipk". constants t on t off (t on +t off ) max t off(min) t on(max) l (min) v o +v f v in - v ce(sat) - v o 1 fosc - t off d i o ( v in - v ce(sat) - v o ) t on(max) 1 fosc fosc:110khz(vcc=5v) expressions ipk r clm ( t on + t off ) / t on t off 1 + ( ) io + 1 2 d io 0.15 ipk d v clm :150mv(vcc=5v) M62291gp mitsubishi 5-pin sot-23 5.0v system fixed output voltage dc-dc converter jan. 2000 3
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