2.5V to 12V Output MD1322F DESCRIPTION Company Name TAB2 28 The MD1322F is a high-efficiency step down DC-DC converter 15 Type No. Barrier Diode. The MD1322F can deliver 7.5 watts maximum 12.23 +– 0.3 8.8 +– 0.1 SHINDENGEN MD1322F 5030N power integrated circuit with main MOSFET switch and Schottky (5V, 3.0A) with high efficiency over a wide input voltage range. This device has output voltage digitally selectable from 2.5V to 12V. With the MD1322F you can construct a complete DC-DC converter using only a few external components. Featuring an HSOP 28-pin 14 TAB1 1 Lot No. surface mount package, the MD1322F allows you to incorporate a very small and thin power supply on your circuit board. BLOCK DIAGRAM FEATURES Vref Vcc Vboot VB VG VDD 26 5 6 23 22 TAB2 START UP START=7.2V STOP=6.7V BOOT Reference Vref=6.5V Driver Vref=Vout+5.8V ■ High efficiency ■ Wide input voltage load range 8VDC to 30VDC Up to 3ADC Reference Vref=5V±5% ■ Output voltage selectable function Main Switch MOS OFF TSD driver 2.5V to 12V 150˚C 100˚C ■ Internal Switching power device Error amp TAB1 PWM comp - VOUT + + Main MOSFET for switch SBD for rectification + Q 3V 2.45V R S ■ Fixed 250kHz PWM frequency - 1V Without external resistor and capacitor OSC f=250kHz CLM Vth= 0.1~0.2V ■ Overcurrent protection 28 27 1 2 amp- ampOUT S/S OCL- 3 4.24 8-11 OCL+ GND P.GND ■ Thermal shutdown function PIN ASSIGNMENT S/S: 1 28: amp- OCL-: 2 27: ampOUT OCL+: 3 26: Vref: GND: 4 25: VTS Vcc: 5 24: GND Vboot: 6 23: VB N/C: 7 22: VG VOUT:TAB1 TAB2:VDD P.GND: 8 P.GND: 9 P.GND: 10 P.GND: 11 21: N/C N/C: 12 17: N/C N/C: 13 N/C: 14 16: N/C 20: N/C Pin# 15: N/C ■ Vref - Temperature compensated internal voltage. You can pull 1mA maximum for external circuit. ■ OSC - Uses internal oscillator without external component. Frequency (Saw tooth wave form) is trimmed to 250kHz on chip. Function description 1 S/S 2 OCL- Overcurrent protection (OCL) (-) 3 OCL+ Overcurrent protection (OCL) (+) 4 GND Signal GND 5 Vcc Input voltage 6 Vboot 7 N/C Capacitor for softstart High side drive supply for main MOS Non-connection 8 ~ 11 P.GND 12 ~ 21 N/C Non-connection 22 VG Gate terminal of main MOS 23 VB Bootstrap capacitor between VB and VOUT 24 GND Signal GND 25 VTS Output voltage selectable terminal 26 Vref Internal voltage reference 27 AmpOUT 19: N/C 18: N/C Symbol Power GND Error Amp out ■ Error Amp - Error Amp detects output voltage of DC-DC converter 28 amp- Error Amp (-) input and controls PWM signal. You can adjust the loop gain when you TAB1 VOUT Power stage output connect feedback resistor and capacitor between AmpOUT and TAB2 VDD Drain of main MOS Switch Amp (-). It will provide stable phase compensation. ■ Overcurrent protection - 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 MD1322F ABSOLUTE MAXIMUM RATINGS Parameter (Ta=25°C) RECOMMENDED OPERATION CONDITIONS Parameter Recommendation Units Input voltage 8 ~ 30 V Output voltage setting range 2.5 ~ 12 V -10 ~ 80 °C Symbol Rating Units Line voltage VIN 32 V Output MOS input voltage VDD 32 V Operation temperature Output current (AVE) IOUT ave 3 A Output Current (PEAK) IOUT peak 4 A OCL-,OCL+terminal voltage VOCL 5.5 V Storage temperature Tstg -40 ~ 150 °C Junction temperature Tj 150 °C OUTPUT CURRENT DERATING FOR 5.3V OR HIGHER OUTPUT Output setting voltage Output current 2.5V ~5.3V =< 6V 2.5V =< 8V < = 12V 1.5A 3A 2A ELECTRICAL CHARACTERISTICS Parameter Symbol (Ta=25°C) Conditions MIN TYP MAX Units High side MOS D - S voltage Vdss ID=1mA, VGS=0V 32 - - V High side MOS Drain interruption current Idss VDS=30V, VGS=0V - - 10 uA High side MOS Drain-source ON resistance Ron ID=1.2A, VGS=4V - 140 250 mΩ High side MOS Source-drain Di forward voltage VSD IS=1.2A, VDS=0V - - 1.5 V Low side SBD Peak reverse voltage VRM - 40 - - V Low side SBD Forward voltage VF IF=1.2A - - 0.55 V Low side SBD Reverse current IR VR=VRM - - 2 mA 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 ~ 30V - 8 10 mA BOOT terminal voltage Vboot Vcc=8V ~ 30V 5.4 6.5 7.6 V 5 5.25 V Internal reference voltage Vref Vcc=8V ~ 30V 4.75 Initial 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 Vcc=8V ~30V 2.4 2.45 2.5 V Overcurrent protection operating temperature T_TSD - - 150 - °C 1 - 8 0 0 - 6 3 4 - 3 6 5 4