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Summary of Contents for Shindengen MD3221N
- Page 1 查询MD3221N供应商 捷多邦，专业PCB打样工厂，24小时加急出货 CAT. No. U100 -1 Synchronous Rectification DC-DC Converter Power IC MD3221N Application Manual SHINDENGEN ELECTRIC MFG. CO., LTD.
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Page 2: Cautions For Use
Thank you for purchasing the MD3221N DC to DC Converter Power IC. This manual contains important information on the safe use of the MD3221N. Your safety is most important to our company. Please read these instructions carefully before using this device. -
Page 3: Table Of Contents
MD3221N Synchronous Rectification DC-DC Converter Power IC Contents ↓Click! Cautions for Use ....... 1 Cautions for Pattern Design ..16 Primary Circuit Pattern Design Outline ........3 Control Circuit Pattern Design Features Application Circuit Examples ... 17 Product Code Standard Connection Diagram Component Examples Pin Layout Dimension Drawing ....18 Pin Functions Specifications ......5 Mounting ......... 19 Absolute maximum ratings Substrate Mounting Example Recommended Operating Conditions Cautions for Mounting Electrical Characteristics External Protection Circuits ... 20 Internal Block Diagrams... -
Page 4: Click
ON □ The L Cut ( Cut off derect ) function resistance of the internal MOSFET and thus provide a simple DC-DC converter of high efficiency. The □ Ambient temperature range: −30℃ to 85℃ oscillation frequency is selected from the 100kHz or 300kHz set internally, not only reducing the number ◆Product Code of external components required, but also facilitating MD3221N 4072 flexible design in applications. A surface mount Specification code S/SOP32 package is used to ensure a small and thin power supply circuit. Product name ◆Standard Connection Diagram Basic Circuit ● Wiring for 3.3V output Efficiency and circuit loss characteristics ... -
Page 5: Pin Layout
◆Pin Layout R/C : 1 32 : S/S Vref : 2 31 : 2.5V/3.3V OSC : 3 30 : ampIN GND : 4 29 : amp- 28 : ampOUT LC : 5 27 : OCL - Vcc : 6 □ Vboot : 7 26 : GND 25 : OCL + P.GND1 : 8... -
Page 6: Specifications
↓Click! Specifications ◆Absolute maximum ratings ◆Recommended Operating Conditions Power supply voltage ( voltage at V Input voltage range 4.5〜20V High side MOSFET input voltage Settable output voltage range 0.8〜14V - 30〜85℃ Average output current Ambient temperature range Peak output current Voltage between V and V 5.5V - 30mA Allowable applied output current at Vboot - 3mA Allowable applied current at Vref - 50〜150℃ Storage temperature Temperature at contacts 150℃ ◆Electrical Characteristics Ta = 25℃ unless specified otherwise. Item Condition Min. Typ. Max. Unit High side MOSFET = 1mA, V... -
Page 7: Internal Block Diagrams
Item Condition Min. Typ. Max. Unit Soft start Vcc = 5V - 2.5 Current at soft start pin μA Error amp Vcc = 5V Error amp reference voltage 0.784 0.800 0.816 Over-Current protection detector Vcc = 5V − Threshold current at ON resistance detection − Vcc = 5V Threshold voltage at external resistance detection Timer latch circuit Vcc = 5V - 40 - 33 - 26 Timer current μA... -
Page 8: Selection Of Primary Components And Pin Connections
↓Click! Selection of Primary Components and Pin Connections The characteristics of the DC-DC converter are influenced by the IC itself, and also significantly by the peripheral components of the circuit. A well-designed circuit is necessary to make the most of the potential of the MD3221N. It is therefore necessary to clarify the specifications of the required power supply, and to select components as follows. Standard Connection Diagram ● Vboot + Vi 18 ~ 21 11 ~ 14 MD3221N OCL+ OCL - ampOUT amp- ampIN 2.5V/3.3V Vref P. GND1 P. GND2 4,26 ◆Selecting the Output Choke Coil ( inductor ) ( L1 ) （Ｖi −V ）... -
Page 9: Selecting The Output Condenser
On the other hand, if a lower inductance value is sufficiently high capacitance so that it need not be selected the size of the required inductor is reduced considered when selecting on the basis of the while peak current is increased, thus slightly equation above. The use of such condensers, rather increasing the loss when a load is applied. than ceramic or film condensers, is therefore recommended. On the other hand, concurrent use of While the MD3221N incorporates an over-current ceramic or film condensers is effective in eliminating protection function, the inductor selected must be such high frequency noise. that magnetic saturation does not occur at the over- current detection point. As a magnetic field is generated in the vicinity of the ◆Selecting the Input Condenser ( C1 ) inductor, component layout and pattern design must be ... -
Page 10: Selecting The Regenerative Diode
A Schottky barrier diode with low V is ideal for use in preventing current flowing in the body diode, however it is important that this diode has a low leakage current to prevent thermal runaway. Recommended component : D1FM3 ( Shindengen ) 30V, 3A V =0.4V =0.1mA （max） （max） M1FM3 ( Shindengen ) 30V, 2.1A V... -
Page 11: Functions
300kHz. Switching losses in switching power supplies generally The internal dividing resistor is connected across the increase as the oscillation frequency increases, OCL and GND pins, with the dividing point however the MD3221N is designed to provide connected to the ampIN pin. The ampIN pin should sufficiently high efficiency at 300kHz. Furthermore, the number of peripheral components ( eg the inductor ) therefore be connected to the amp- pin externally. is minimized, and thus a standard circuit using the An external dividing resistor is required if output 300kHz frequency provides benefits in terms of both cost... -
Page 12: The Soft Start Function
Relationship Between Soft Start Voltage and Input/Output Voltage ● frequency. The 300kHz frequency is selected by connecting the OSC pin to the Vref pin, and 100kHz by connecting it to the GND pin. Frequency Switching ● 2.9V Vref 300kHz MD3221N 100kHz It is necessary to monitor output voltage V always started up in advance to the S / S terminal voltage. ( Refer to the chart above ) As shown in the graph below, the capacitance of the condenser connected to the S / S pin determines the ◆The Soft Start Function start-up time. The MD3221N incorporates a soft start function to Relationship Between S/S Condenser and Output Voltage Start-up Time... -
Page 13: The Reference Voltage
In the process of increasing the output voltage at start- up, the converter generally charges the output condenser resulting in the over-current condition. When the over-current protection circuit operates the latch ◆The Over-current Protection Function ( timer latch ) is halted and start-up becomes impossible. The MD3221N timer circuit is locked to prevent its The MD3221N incorporates an over-current protection operation until the voltage at the S / S pin reaches 2.9V, function. As the over-current condition is detected with and when the S / S pin is fully charged the lock is the use of the voltage drop resulting from the ON cleared and the timer circuit is ready for operation. -
Page 14: Short-Circuit Protection
A protection circuit independent of the MD3221N should therefore be provided to accommodate such cases ( refer to '20. External Protection Circuits' ) . ◆Error Amp Gain Adjustment Error amp gain adjustment is effective in ensuring stable operation of the power supply circuit and good ◆The Current Limiting Function transient response. As the appropriate constant (external resistance detection) varies ... -
Page 15: The L Cut ( Cut Off Detect ) Function
/ output voltage of the choke coil. As the average value is the output current, when the （2） Current Regeneration Mode ( L cut OFF ) output current is less than Δ1/2 at low-load the current becomes discontinuous (cut-off). This mode is OFF when the LC and GND pins are connected ( L ) . The current in the choke coil flows in The MD3221N allows selection of two operating the reverse direction, thus regenerating energy and modes in the cut-off region. resulting in a continuous current even at no-load. - Page 16 As the ON range remains constant irrespective of the load applied, a stable response is obtained even under rapid changes in load from the no-load condition. On the other hand, as the actual current value increases, input current at low-load increases slightly in comparison with that at L cut ON. Transient Response with LC ON / OFF ● LC : OFF LC : ON Conditions : Vi = 5V, Vo = 3.3V, output current 0A 3A X axis : 100μs/div. Y axis : 50mV/div.
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Page 17: Cautions For Pattern Design
As this pattern carries a continuous current, voltage drop rather than Wiring Pattern Illustration ● noise is the important consideration. A long pattern in this case will result in a voltage drop due to pattern DC resistance, and reduced efficiency. The MD3221N is designed to radiate heat through the substrate pattern. In particular, both the V and V pins are allocated each to four pins, and connected directly to the internal lead MD3221N frame. All of these pins may therefore be used to ensure ... -
Page 18: Application Circuit Examples
HSU119 C3 : 0.1 μ F Vboot L1 : 4.7 μ H Vi : 5V : 2.5V/3A 18 ~ 21 11 ~ 14 MD3221N OCL + OCL - 1 μ F ampOUT 0.01 μ F 100kΩ D2 : D1FM3 68 μ F... -
Page 19: Dimension Drawing
↓Click! Dimension Drawing Dimension Drawing ( SSOP32 ) ● 14.1MAX + - 0.1 13.6 Company Name MD3221N ■■■■■ Type No. Lot No. + - 0.1 + - 0.2 （0.8） 0.35 0.16 M Detail of A Portion S＝15/ 1 A Portion 0.10 Unit：mm... -
Page 20: Mounting
R3 R3 C1−1 C1−2 C7 C7 C4 C4 R4 R4−2 R4−2 C5 C5−1 C5−1 C5 C5−2 C5−2 MD3221N As this pattern does not incorporate an over-current protection circuit or input fuse they must be added separately if the circuit is to be used in practice. ◆Cautions for Mounting Both flow and reflow is applicable when mounting. The recommended temperature profile for reflow Ensure that the following requirements are met soldering is shown below. when using a soldering iron. Tip temperature : 300℃ maximum Soldering time : 5 sec. maximum Recommended Temperature Profile... -
Page 21: External Protection Circuits
↓Click! External Protection Circuits ◆Connection of Input Protection Devices ◆Connection of Over-voltage Protection Circuit While the MD3221N incorporates both over-current The MD3221N does not incorporate an over-voltage protection and overheat protection functions, these protection circuit. One of the modes supported is such protection circuits may not operate normally if a that the input voltage will appear unchanged at the output fault or a malfunction develops in the IC. A despite operation being halted if the IC is damaged for protective device ( eg a fuse ) should be inserted in any reason. Such damage to the load may result in smoke the ve input line to prevent overheating and and fire, and an over-voltage protection circuit should... -
Page 22: Characteristics
↓Click! Characteristics ◆Output voltage : 3.3V Conditions LC：OFF, f ＝300kHz, L ＝12μH Ta ＝25℃ unless specified otherwise. Efficiency and Loss Characteristics ( f ＝300kHz ) Temperature Characteristics at Vi ＝5V, I ＝3A ● ● 3.36 Vi = 5V 3.32 Vi = 8V Vi = 12V Vi = 20V 3.28 3.24 [ A ] [ ˚C ] Output current Io Ambient temperature Ta Line Regulation at I... -
Page 23: Efficiency By Output Voltage
◆Efficiency by Output Voltage ◆Efficiency at Frequency of 100KHz Conditions LC：OFF, f ＝300kHz, L ＝12μH Conditions LC：OFF, f ＝100kHz, L ＝22μH Ta＝25℃ Ta＝25℃ Output voltage : V ＝0.8V, 1.2V, 1.8V, 2.5V, 3.3V Output voltage : 3.3V Efficiency and Losses ( f ＝100kHz ) Efficiency by Output Voltage at Vi ＝5V ● ● Vin = 5V Vin = 8V Vin = 12V Vin = 20V Vo = 3.3V Vo = 2.5V Vo = 1.8V Vo = 1.2V Vo = 0.8V... -
Page 24: Packaging
↓Click! Packaging ◆Tape & Reel Tape ● Material : PVC + Carbon Dimensions Comply with JIS, C-0806-3 ( 2.8 ) ±0.1 12.0 ±0.1 ±0.1 +0.1 φ1.5 １PIN Side ±0.1 ±0.1 ±0.1 φ 2.1 10.4 ±0.1 Direction of Feed Unit : mm Reel ● Material : Polystyrene Dimensions Comply with JEITA, ET-7200 ・Label Type No. Code No. Date Code Quantity Manufacturer JEITA.RRM.24.D Label ±0.5 25.5 ±0.1... -
Page 25: Packing
◆Packing ・Marking Type No. Code No. Date Code Quantities Label Unit : mm ・Tape & Reel : 6,000pcs ( 3 Reels ) / Outer Carton ◆Ordering and Dimensions Quantities per Outer Carton ( mm ) Quantities Per Outer Carton Minimum Ordering Inner Carton Package Code No. Quantities ( pcs. ) pcs./Carton Weight (kg) 6000 SSOP32 4072... - Page 26 Phone:886-2-2560-3990 Fax:886-2-2560-3991 Shanghai Liaison Office W504, Sun Plaza, No.88 Xianxia Road Shanghai 200336, China Phone:86-21-6270-1173 Fax:86-21-6270-0419 SHINDENGEN Shindengen Electric Mfg. Co., Ltd. Seoul Office ELECTRIC MFG. CO., LTD. Korea City Air-Terminal Bldg. 606, 159-6 Samsung-Dong Kangnam-ku, Seoul, Korea Ikebukuro office:...
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