Synchronous Rectification
DC-DC Converter Power
I
C
MD3221N
Application Manual
CAT. No. U100 -1
SHINDENGEN ELECTRIC MFG. CO., LTD.
查询MD3221N供应商
捷多邦，专业PCB打样工厂，24小时加急出货
Page 1: ...Synchronous Rectification DC DC Converter Power IC MD3221N Application Manual CAT No U100 1 SHINDENGEN ELECTRIC MFG CO LTD MD3221N PCB 24...
Page 2: ...t in the appearance of smoke and flames If a breakdown or other abnormal condition occurs during equipment use immediately stop power to the equipment Contact our company at your earliest possible con...
Page 3: ...Current Limiting Function The Overheat Protection Function Error Amp Gain Adjustment Bootstrap The L Cut cut off detect Function Cautions for Pattern Design 16 Primary Circuit Pattern Design Control...
Page 4: ...tating flexible design in applications A surface mount S SOP32 package is used to ensure a small and thin power supply circuit Features Input voltage range of 4 5V to 20V Adjustable output voltage ran...
Page 5: ...on frequency select Control circuit GND Control circuit power supply Low side MOSFET drive circuit GND Vboot 7 Low side MOSFET drive circuit power supply Cut off detect select Low side MOSFET sources...
Page 6: ...p voltage hysteresis Current consumption at f 100kHz BOOT pin voltage Power supply voltage variation Voltage load variation Power supply voltage variation Voltage load variation Internal reference vol...
Page 7: ...3 3 2 5 33 2 9 3 45 100 2 85 Typ 0 800 0 784 2 425 3 200 2 500 3 300 Max 0 816 115 26 3 05 3 6 0 816 2 575 3 400 Unit A V mV A V V V A V V Output voltage detect accuracy set at 0 8V 140 Output voltag...
Page 8: ...hat I is approximately 30 of the maximum output current when the input voltage is at its maximum Current Waveform in Output Choke Coil L1 Vi max Maximum input voltage V VO Output voltage V I 30 of max...
Page 9: ...the output condenser must also have a reasonable capacitance Control will readily become unstable and amp gain adjustment will prove difficult if capacitance is low Aluminum electrolytic condensers a...
Page 10: ...tive MOSFET and requires a diode to bypass the regenerative current during the dead time interval If this diode is not present regenerative current flows in the MOSFET body diode during the dead time...
Page 11: ...cy of the reference voltages and the accuracy of the resistor Wiring for Variable Output Selecting the Oscillation Frequency The MD3221N incorporates an internal oscillator and an external C R is ther...
Page 12: ...s not follow the increase at the S S pin thus preventing start up in some cases Relationship Between Soft Start Voltage and Input Output Voltage It is necessary to monitor output voltage VO is always...
Page 13: ...al MOSFET an external detection resistance is not required When the over current condition is detected the condenser C2 connected to the S S pin is charged again and when a level of 3 45V is reached t...
Page 14: ...the load side approaches zero current increases and the timer latch operates to protect the circuit The OCL and OCL should be shorted if this function is not used Circuit for Current Limiting Functio...
Page 15: ...is the output current when the output current is less than 1 2 at low load the current becomes discontinuous cut off The MD3221N allows selection of two operating modes in the cut off region 1 Power S...
Page 16: ...er to 13 Error Amp Gain Adjustment for details For the graph above two 1200 F aluminum electrolytic condensers C5 were used for the output condenser a 100pF condenser for C6 and a 1M resistor for R3 L...
Page 17: ...the VDD and VOUT pins are allocated each to four pins and connected directly to the internal lead frame All of these pins may therefore be used to ensure a large pattern area and thus provide for eff...
Page 18: ...4 26 18 21 Application Circuit Example Component code Type C1 High polymer organic semiconductor electrolytic condenser C2 Ceramic condenser C3 Ceramic condenser C4 Ceramic condenser C5 Ceramic conden...
Page 19: ...5 9 95 0 1 0 3 32 17 0 1 13 6 14 1MAX 1 16 0 1 0 35 0 16 M 0 8 0 8 Lot No 0 1 0 0 2 0 2 0 1 0 0 5 0 4 A Portion Detail of A Portion S 15 1 0 10 2 2 0 1 0 1 0 1 2 3 0 2 MD3221N Company Name Type No Di...
Page 20: ...ing Example Cautions for Mounting Both flow and reflow is applicable when mounting As this pattern does not incorporate an over current protection circuit or input fuse they must be added separately i...
Page 21: ...ppear unchanged at the output despite operation being halted if the IC is damaged for any reason Such damage to the load may result in smoke and fire and an over voltage protection circuit should ther...
Page 22: ...ut voltage Vo V Temperature Characteristics at Vi 5V IO 3A 0 5 10 15 20 3 2 3 24 3 28 3 32 3 36 3 4 Input voltage Vi V Output voltage Vo V Line Regulation at IO 3A X axis 10ms div Y axis CH1 5V div CH...
Page 23: ...H Ta 25 Output voltage 3 3V Efficiency Output current Io A 3 2 5 2 1 5 1 0 5 0 60 50 40 70 80 90 100 Vo 3 3V Vo 2 5V Vo 1 8V Vo 1 2V Vo 0 8V Efficiency by Output Voltage at Vi 5V Efficiency Circuit lo...
Page 24: ...1 5 0 1 0 3 0 1 10 4 12 0 0 1 1 75 0 1 11 5 0 1 24 0 0 9 2 0 0 1 0 0 2 0 4 0 6 0 8 P S Label 25 5 0 5 330 2 80 1 13 0 2 29 4 0 1 JEITA RRM 24 D Reel Material Polystyrene Dimensions Comply with JEITA...
Page 25: ...date ordering quantities at basic ordering quantity unit 2000 Package Code No SSOP32 4072 2000 pcs Carton Weight kg D W 6000 7 6 363 363 160 H Quantities per Outer Carton Minimum Ordering Quantities Q...
Page 26: ...Germany Phone 49 211 491968 0 Fax 49 211 4986499 Asia Shindengen Singapore PTE Ltd 159 Sin Ming Road 04 07 Amtech Building Singapore 575625 Phone 65 6552 3635 Fax 65 6552 4210 Shindengen H K Co Ltd H...
