2.5V-12V Output MD1422N 14.1MAX 13.6 DESCRIPTION Dimensions = mm + – 0.1 32 The MD1422N is a high-efficiency step down DC-DC converter 17 Company Name power integrated circuit with main MOSFET switch and synchronous + 7.5 – SHINDENGEN MD1422N 5038N rectification MOSFET. The MD1422N can deliver high efficiency over 9.95 – 0.3 + 0.1 Type No. a wide input voltage range. This device has output voltage digitally selectable from 2.5V to 12V. With the MD1422N you can construct a complete DC-DC converter using only a few external components. 1 16 (0.8) 0.35 + – 0.1 Featuring an SSOP 32-pin surface mount package, the MD1422N Lot No. allows you to incorporate a very small and thin power supply on your 0.16 M circuit board. 0.8 BLOCK DIAGRAM R/C 5 FEATURES Vref Vcc Vboot VB VG VDD 28 6 8 25 23 18~21 UVLO START = 7.2V STOP = 6.7V BOOT Reference Vref=6.5V High side Vref=Vout+5.8V ON/OFF circuit " High efficiency " Wide input voltage load range 8VDC to 40VDC Up to 3ADC 100˚C Reference Vref=5V+ –5% 150˚C High side Driver TSD Error amp " Output voltage selectable function High-Low MOS synchro-OFF 11~14 + + synchro-ON Prevention Main MOSFET for switch and Low side Vref=6.5V 3V 1V OSC f=250kHz " Internal Switching power device High-Low MOS – 2.45V R synchronous rectification MOSFET Low side Driver + Q S " Fixed 250kHz PWM frequency – P.GND CLM Vth= 0.1~0.2V 30 32 ampOUT amp– 2.5V to 12V VOUT PWM Comp – 1 S/S (Without external resistor and capacitor) 16 2 3 OCL– OCL+ 4,26 9 GND VGL " Overcurrent protection " Thermal shutdown function " Remote control ON/OFF PIN ASSIGNMENT Pin# Symbol 1 2 3 4 5 6 7 8 9 10 11 ~ 14 15 16 17 18 ~ 21 22 23 24 25 26 27 28 29 S/S OCLOCL+ GND R/C Vcc N/C Vboot VGL N/C VOUT N/C P.GND N/C VDD N/C VGH N/C VB GND VTS Vref N/C Function description Capacitor for softstart Overcurrent protection (OCL) (-) Overcurrent protection (OCL) (+) Signal GND Remote ON/OFF control terminal Input voltage Non-connection High side drive supply for main MOS Low side MOSFET gate terminal Non-connection Power stage output Non-connection Power GND Non-connection Drain of main MOS Switch Non-connection Main switch high side MOSFET gate terminal Non-connection Bootstrap capacitor between VB and VOUT Signal GND Output voltage selectable terminal Internal voltage reference Non-connection 30 31 32 AmpOUT N/C amp- Error Amp out Non-connection Error Amp (-) input S/S : 1 OCL– : 2 OCL+ : 3 GND : 4 R/C : 5 VCC : 6 N/C : 7 Vboot : 8 VGL : 9 N/C : 10 VOUT: 11 VOUT: 12 VOUT: 13 VOUT: 14 N/C : 15 P.GND : 16 32 : amp31 : N/C 30 : ampOUT 29 : N/C 28 : Vref 27 : VTS 26 : GND 25 : VB 24 : N/C 23 : VGH 22: N/C 21: VDD 20: VDD 19: VDD 18 : VDD 17 : N/C " Vref - Temperature compensated internal voltage. You can pull 1mA maximum for external circuit. " OSC - MCD1422N uses internal oscillator without external component. Frequency (Saw tooth wave form) is trimmed to 250kHz on chip. " Error Amp - Error Amp detects output voltage of DC-DC converter and controls PWM signal. You can adjust the loop gain when you connect feedback resistor and capacitor between AmpOUT and Amp (-). It will provide stable phase compensation. " Overcurrent protection - MD1422N uses pulse-by-pulse current protection. Current will be sensed voltage drop of external current sensing resistor. Threshold of OCL is 0.19V. 1 - 8 0 0 - 6 3 4 - 3 6 5 4 2.5V-12V Output MD1422N ABSOLUTE MAXIMUM RATINGS Parameter Symbol Input voltage (Ta=25°C) Rating Units RECOMMENDED OPERATION CONDITIONS Parameter Input voltage Recommendation 8 ~ 40 Units V VIN 42 V Output voltage setting range 2.5~12 V Operation temperature -10 ~ 80 °C Main MOS voltage VDD 42 V Output current (ave) IOUT ave 3 A Output current (peak) IOUT peak 4 A OCL-, OCL+ terminal voltage VOCL 5.5 V Remote control voltage VRC 5.5 V Storage temperature Tstg -40 ~ 150 °C Junction temperature Tj 150 °C OUTPUT CURRENT DERATING FOR 8V OR HIGHER OUTPUT Output setting voltage 2.5V ~8V =< 12V Output current 3A 2.5A ELECTRIC CHARACTERISTICS (Ta=25°C) Parameter Symbol Conditions MIN TYP MAX Units High side MOS Drain-source breakdown voltage Vdss ID=1mA, VGS=0V 42 - - V High side MOS Drain interruption current Idss VDS=40V, VGS=0V - - 10 uA High side MOS Drain-source ON resistance Ron ID=1.2A, VGS=4.5V - 33 70 mΩ High side MOS Source-drain Di forward voltage VSD IS=1.2A, VDS=0V - - 1.5 V Low side MOS Drain-source breakdown voltage Vdss ID=1mA, VGS=0V 42 - - V Low side MOS Drain interruption current Idss VDS=40V, VGS=0V - - 10 uA Low side MOS Drain-source ON resistance Ron ID=1.2A, VGS=4.5V - 33 70 mΩ Low side MOS Source-drain Di forward voltage VSD IS=1.2A, VDS=0V - - 1.5 V Start voltage Vcc_start - 6.5 7.2 7.9 V Stop voltage Vcc_stop - 6.0 6.7 7.4 V Stop-start voltage hysteresis Vcc_hys - - 0.5 - V Current consumption Icc Vcc=8V ~ 40V - 10 13 mA Current consumption with remote control OFF Icc_off Vcc=8V ~ 40V - 1.2 1.5 mA Remote control terminal ON voltage VRC_ON Vcc=8V ~ 40V -0.2 - 0.5 V Remote control terminal OFF voltage VRC_OFF Vcc=8V ~ 40V 2.5 - 5.3 V uA Remote control terminal shorted voltage IRC Vcc=8V ~ 40V - - 250 BOOT terminal voltage Vboot Vcc=24V 5.4 6.5 7.6 V Internal reference voltage Vref Vcc=8V ~ 40V 4.75 5 5.25 V Internal oscillation frequency fosc Vcc=24V 212.5 250 287.5 kHz Overcurrent threshold voltage Vth_OCL Vcc=24V 0.162 0.19 0.218 V Softstart terminal current IS/S Vcc=24V -20 -12.5 -5 uA Error amplifier reference voltage Vamp 2.4 2.45 2.5 V Overcurrent protection operating temperature T_TSD Vcc=8V~ 40V - - 150 - °C 1 - 8 0 0 - 6 3 4 - 3 6 5 4