MITSUBISHI(Standard Linear ICs) M62294FP 3.3V, 2.0V FIXED 2-OUTPUT VOLTAGE DC-DC CONVERTER DESCRIPTION M62293FP is 3.3V and 2.5V f ixed stable 2-output step-down DC-DC conv erter. It is possible to simplif y peripheral circuit and to design compact and low cost sets because this dev ice includes peripheral dev ices in small size 8pin package. The IC also has Reset circuit with time delay that monitors power supply (Vcc=5V) and one regulator output(Vout1=3.3V;IN1 terminal), theref ore an application sy s t em is protected system errors. Especially this is most suitable f or application sy s y t em with microprocessor and ASIC. PIN CONFIGURATION(TOP VIEW) 1 8 IN1 GND 2 7 RESET Cout2 3 6 Cd Vcc 4 5 IN2 Cout1 FEATURES Outline 8P2S-A *3.3V and 2.0V step-down conv erter *4 to 15V wide input supply v oltage (Vcc=5V ty p.) *Reset circuit with time delay monitors supply v oltage(Vcc=5V)and regulator output (3.3V) *110kHz f ixed f requency oscillator without peripheral dev ices *8pin SOP package APPLICATION application sy s t em with microprocessor and ASIC BLOCK DIAGRAM Vcc Cd IN1;3.3V 25A RESET Vref 1.25V 0.6A comparator (3.3V detect) comparator (Vcc detect) Vcc oscillator (110kHz) Cout2 Cout1 PWM comp. op amp op amp IN1(3.3V) IN2(2.0V) ( 1 / 4) PWM comp. GND 000131 MITSUBISHI(Standard Linear ICs) M62294FP 3.3V, 2.0V FIXED 2-OUTPUT VOLTAGE DC-DC CONVERTER ABSOLUTE MAXIMUM RATINGS(Ta=25C,unless otherwise noted) Symbol Vcc Io IoRESET Parameter Conditions Ratings Unit 16 V 30 mA 6 mA Supply v oltage Output current(DC-DC conv erter block) ch1,ch2 Output current(Reset block) Pd Power dissipation Ta=25C 440 mW K Thermal derating Ta>25C 4.4 mW/C Topr Operating temperature -20~+85 C Tstg Storage temperature -40~+125 C ELECTRICAL CHARACTERISTICS(Ta=25C,Vcc=5V,unless otherwise noted) Limits Block All Blocks Symbol Parameter Test condition Unit Min. Ty p. Max. 4.0 5.0 15 V 1.5 2.8 mA ch1 output 3.15 3.30 3.45 1.90 2.00 2.10 Line regulation ch2 output Vcc=4~12V 5 15 mV Iin Input current 1 ch1 150 450 A Iin Input current 2 ch2 300 A Oscillator f requency 65 100 110 160 KHz Maximum ON duty 90 % 1 2.0 V Vcc Supply v oltage Icc Supply c urrent Without load DC-DC Conv erter Block Vo1 Vo2 Error Amp. Oscillator Vreg-L f osc TDUTY Output Output v oltage V Output leakage current Vcc=12V, Vc=12V -1 Output saturation v oltage Io=10mA,Darlington connection 1.2 Vs1 Detecting v oltage 1 Vcc=5V detection 3.6 3.8 4.0 V Vs1 Vs2 hysterisy s v oltage 1 30 50 80 mV 2.46 2.58 2.70 V Vs2 Hysterisy s v oltage 2 30 50 80 mV ICL Vsat V Reset circuit Block Reset Circuit Detecting v oltage 2 ch1output (3.3V)detection IPD Cd output current tpd Delay t ime Cd=4700pF -1.1 5 -0.6 10 -0.3 20 msec IOC RESET output current Vcc=5V, Vo=1/2 X Vcc -40 -25 -17 A VOL RESET LOW v oltage IoRESET=4mA VOH RESET High v oltage 0.8Vo1 ( 2 / 4) A 0.2Vo1 V V 000131 MITSUBISHI(Standard Linear ICs) M62294FP 3.3V, 2.0V FIXED 2-OUTPUT VOLTAGE DC-DC CONVERTER RESET BLOCK timing chart 5V 3.85V 3.80V 0V t 3.3V 2.63V 2.58V 0V t Vo1 td td td 0V t td : RESET Delay Time *** . -3 td(msec) =. 2.13 X 10 X Cd(pF) ( 3 / 4) 000131 MITSUBISHI(Standard Linear ICs) M62294FP 3.3V, 2.0V FIXED 2-OUTPUT VOLTAGE DC-DC CONVERTER APPLICATION CIRCUIT (3.3V and 2.0V 2-output voltage DC-DC converter VIN(5V) + Cin Vcc VOUT1(3.3V) R2 Q1 IN1 + Co1 Cout1 L1 M62294FP VOUT2(2.0V) Co2 R4 Q2 Cout2 IN2 RESET Cd + D1 R1 R3 GND L2 D2 3.3V LINE 2.0V LINE MCU etc. THE EXPRESSION OF CIRCUIT CONSTANTS Constants T ON T OFF (T ON +T OFF )MAX T OFF(MIN) T ON(MAX) L (MIN) Ipk Expressions V O+V F V IN - V CE(sat) - V O 1 fosc fosc:110KHz(Vcc=5V) ( T ON + T OFF ) / ( 1 + T ON ) T OFF 1 fosc - T OFF ( VIN - V CE(sat) - V O ) X T ON(MAX) I o 1 Io Io + 2 note: *VF : Forward voltage drop of an external diode *Vsat : Output saturation voltage of an external switching transistor. *I O : Set to 1/3 to 1/5 of maximum output current. *Choose an external transistor, diode and inductor with peak current rating approximately greater than "Ipk". ( 4 /4 ) 000131