GM34063

GM34063 ETC1

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Revision 1, May 2002 www.gammamicro.com 1.5A DC-to-DC CONVERTER CONTROL CIRCUIT GM34063PRELIMINARY „„„„„ Adjustable Output Voltage „„„„„ Output Switch Current to 1.5A „„„„„ Low Standby Current „„„„„ Operating Frequency to 100kHz „„„„„ Precision 2% Reference The GM34063 has all the functions required for DC-to-DC converters: an internal temperature- compensated reference, comparator, controlled duty cycle oscillator with an active current limit circuit, driver, and high-current output switch. The 34063 designed for step-down, step-up and voltage-inverting applications using a minimum number of external components. SCHEMATIC DIAGRAM PIN CONNECTIONS Applications: Switch Collector Driver Collector Switch Emitter Timing Capacitor GND Ipk Sense VCC Comparator Inverting unit (Top View) 5 4 Driver Collector Ipk Sense VCC Comparator Inverting unit GND Timing Capacitor Switch Emitter Switch Collector (Bottom View) S R QQ 2 100 Comparator 1.25V Reference Regulator Ipk Oscillator CT * The GM34063 has 51 active transistors on-chip.

Revision 1, May 2002 www.gammamicro.com 1.5A DC-to-DC CONVERTER CONTROL CIRCUIT GM34063PRELIMINARY Absolute Maximum Ratings gnitaRl obmySe ulaVt inU egatloVylppuSrewoPV CC 04c dV egnaRegatloVtupnIrotarapmoCV RI 04+ot3.0–c dV egatloVrotcelloChctiwSC V )hctiws( 04c dV V(egatloVrettimEhctiwS 1niP )V04=E V )hctiws( 04c V egatloVrettimEotrotcelloChctiwSE CV )hctiws( 04c dV egatloVrotcelloCrevirDC V )revird( 04c dV )1etoN(tnerruCrotcelloCrevirDC I )revird( 001A m tnerruChctiwSI WS 5.1A scitsiretcarahClamrehTdnanoitapissiDrewoP xiffuS1P,P,egakcaPcitsalP TA C°52= ecnatsiseRlamrehT xiffuSD,egakcaPCIOS TA C°52= ecnatsiseRlamrehT PD R2 AJ PD R2 AJ 52.1 001 526 061 W W/C° Wm W/C° erutarepmeTnoitcnuJgnitarepOT J 051+C ° egnaRerutarepmeTtneibmAgnitarepOT A 07+ot0C ° egnaRerutarepmeTegarotST gts 051+ot56–C ° Note 1. Maximum package power dissipation limits must be observed.

Revision 1, May 2002 www.gammamicro.com 1.5A DC-to-DC CONVERTER CONTROL CIRCUIT GM34063PRELIMINARY

ELECTRICAL CHARACTERISTICS

(VCC = 5.0 V, TA = Tlow to Thigh unless otherwise specified) scitsiretcarahCl obmySn iMp yTx aMt inU ROTALLICSO V(ycneuqerF 5niP C,V0= T T,Fn0.1= A )C°52=f cso 423 32 4z Hk V(tnerruCegrahC CC T,V04otV0.5= A )C°52=I ghc 425 32 4 :::::A V(tnerruCegrahcsiD CC T,V04otV0.5= A )C°52=I ghcsid 0410 220 62 :::::A Vot7niP(oitaRtnerruCegrahCotegrahcsiD ,CC TA )C°52=I ghcsid I/ ghc 2.55 .65 .7– I(egatloVesneStimiLtnerruC ghc I= ghcsid T, A )C°52=V )esnes(kpi 0520 030 53V m )2etoN(HCTIWSTUPTUO noitcennoCnotgnilraD,egatloVnoitarutaS I( WS )detcennoc8,1sniP,A0.1= V )tas(EC –0 .13 .1V )3etoN(egatloVnoitarutaS I( WS R,A0.1= 8niP 28= S Vot CC decroF, $ . )02 V )tas(EC –5 4.07 .0V I(niaGtnerruCCD WS V,A0.1= EC T,V0.5= A )C°52=h EF 055 7– – V(tnerruCetatS–ffOrotcelloC EC )V04=I )ffo(C –1 0.00 01 :::::A ROTARAPMOC egatloVdlohserhT TA C°52= TA T= wol Tot hgih V ht 522.1 012.1 52.1 572.1 92.1 V V(noitalugeReniLegatloVdlohserhT CC )V04otV0.3=g eR enil -4 .10 .5V m V(tnerruCsaiBtupnI ni )V0=I BI -0 2-0 04-A n ECIVEDLATOT V(tnerruCylppuS CC C,V04otV0.5= T V=7niP,Fn0.1= CC , V 5niP V> ht )neposnipgniniamer,dnG=2niP, I CC -- 0 .4A m Note 2. Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient as possible. Note 3. If the output switch is driven into hard saturation (non–Darlington configuration) at low switch currents (#300 mA) and high driver currents ($30 mA), it may take up to 2.0 µs for it to come out of saturation. This condition will shorten the off time at frequencies $30 kHz, and is magnified at high temperatures. This condition does not occur with a Darlington configuration, since the output switch cannot saturate. If a non–Darlington configuration is used, the following output drive condition is recommended: Forced β of output switch : I C output $10 IC driver – 7.0 mA * * The 100 Ω resistor in the emitter of the driver device requires about 7.0 mA before the output switch conducts.

Revision 1, May 2002 www.gammamicro.com 1.5A DC-to-DC CONVERTER CONTROL CIRCUIT GM34063PRELIMINARY tseTs noitidnoCs tluseR noitalugeReniLV ni I,V61otV0.8= O Am571=% 50.0±=Vm03 noitalugeRdaoLV ni I,V21= O Am571otAm57=% 710.0±=Vm01 elppiRtuptuOV ni I,V21= O Am571=p pVm004 ycneiciffEV ni I,V21= O Am571=% 7.78 retliFlanoitpOhtiWelppiRtuptuOV ni I,V21= O Am571=p pVm04 Step–Up Converter 170 µH 180 + 3 100 Vin 12 V Rsc 0.22 + + 1N5819 1500 pF 330 100 Vout 1.0 µH 47k 2.2k R1 CO Vout

28 V / 175 mA

L S R Q Q2 + 1.25V Reference Regulator Ipk Osc. CT VCC Optional Filter Comp. CT

saturate. If a non–Darlington configuration is used, the following output drive condition is recommended. Figure 9. External Current Boost Connections for IC Peak Greater than 1.5 A

Revision 1, May 2002 www.gammamicro.com 1.5A DC-to-DC CONVERTER CONTROL CIRCUIT GM34063PRELIMINARY 5 4 100 Vin 25 V Rsc 0.33 1N5819 470 pF 470 1.0 µH 3.6k 1.2k R1 CO Vout

5.0 V / 500 mA

S R Q Q2 + 1.25V Reference Regulator Ipk Osc. CT VCC Optional Filter Comp. CT 220 µH Vout 100 tseTs noitidnoCs tluseR noitalugeReniLV ni I,V52otV51= O Am005=% 21.0±=Vm21 noitalugeRdaoLV ni I,V52= O Am005otAm57=% 30.0±=Vm0.3 elppiRtuptuOV ni I,V52= O Am005=p pVm021 tnerruCtiucriCtrohSV ni R,V52= L 1.0= S A1.1 ycneiciffEV ni I,V52= O Am005=% 7.38 retliFlanoitpOhtiWelppiRtuptuOV ni I,V52= O Am005=p pVm04 Step – Down Converter

Figure 11. External Current Boost Connections for IC Peak Greater than 1.5 A

Revision 1, May 2002 www.gammamicro.com 1.5A DC-to-DC CONVERTER CONTROL CIRCUIT GM34063PRELIMINARY tseTs noitidnoCs tluseR noitalugeReniLV ni I,V0.6otV5.4= O Am001=% 210.0±=Vm0.3 noitalugeRdaoLV ni I,V0.5= O Am001otAm01=% 90.0±=V220.0 elppiRtuptuOV ni I,V0.5= O Am001=p pVm005 tnerruCtiucriCtrohSV ni R,V0.5= L 1.0= S Am019 ycneiciffEV ni I,V0.5= O Am001=% 2.26 retliFlanoitpOhtiWelppiRtuptuOV ni I,V0.5= O Am001=p pVm07 Voltage Inverting Converter 100 Vin

4.5 V to 6V

0.24 1N5819 1500 pF 1.0 µH 953 8.2k R2 CO Vout -12 V / 100 mA S R Q Q2 + 1.25V Reference Regulator Ipk Osc. CT VCC Optional Filter Comp. 88 µH Vout 1001000 µf + L

Figure 13. External Current Boost Connections for IC Peak Greater than 1.5 A

Revision 1, May 2002 www.gammamicro.com 1.5A DC-to-DC CONVERTER CONTROL CIRCUIT GM34063PRELIMINARY noitaluclaCp U-petSn woD-petSg nitrevnI-egatloV t no t/ ffo V )nim(ni V- tas V )nim(ni V- tas -V tuo V ni V- tas t( no t+ ffo ) 1 f f f t ffo t no ___ 1+t ffo t no ___ 1+t ffo t no ___ 1+t ffo t no t( no t+ ffo t-) ffo t( no t+ ffo t-) ffo t( no t+ ffo t-) ffo CT 01x0.4 5- t no 01x0.4 5- t no 01x0.4 5- t no I )hctiws(kp t no ___l2 )xam(tuo ( 1+ )t ffo l2 )xam(tuo t no ___l2 )xam(tuo ( 1+ )t ffo R cs l/3.0 )hctiws(kp l/3.0 )hctiws(kp l/3.0 )hctiws(kp L )nim( V( )nim(ni V- tas )__________() t )xam(noI )hctiws(kp V( )nim(ni V- tas V- tuo )____________ )( t )xam(noI )hctiws(kp V( )nim(ni V- tas )__________() t )xam(noI )hctiws(kp CO I tuo t no V )pp(elppir I )hctiws(kp t( no t+ ffo ) V8 )pp(elppir I tuo t no V )pp(elppir Vsat = Saturation voltage of the output switch. VF = Forward voltage drop of the output rectifier. Vin – Nominal input voltage. Vout – Desired output voltage, Iout – Desired output current. fmin – Minimum desired output switching frequency at the selected values of Vin and IO. Vripple(pp) – Desired peak–to–peak output ripple voltage. In practice, the calculated capacitor value will need to be increased due to its equivalent series resistance and board layout. The ripple voltage should be kept to a low value since it will directly affect the line and load regulation. 36043MG EGAKCAP .oNTRAP 8-POS8 S36043MG 8-PID8 D36043MG „„„„„ ORDERING INFORMATION