BD9673EFJ-E2 ROHM Electronics, BD9673EFJ-E2 Datasheet

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... BD9673EFJ ●Description Output 1.5A and below High Efficiency Rate Step-down Switching Regulator Power MOSFET Internal Type BD9673EFJ mainly used as secondary side Power supply, for example from fixed Power supply of 12V, 24V etc, Step-down Output of 1.2V/1.8V/3.3V/5V, etc, can be produced. This IC has external Coil/Capacitor down-sizing through 300 kHz Frequency operation, inside Nch-FET SW for 45V “ ...

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... BD9673EFJ ●Electrical Characteristics (Unless otherwise specified, Ta=25℃,VCC=24V, Vo=5V, EN=3V) Parameter 【Circuit Current】 Stand-by current of VCC Circuit current of VCC 【Under Voltage Lock Out (UVLO)】 Detect Voltage Hysteresis width 【Oscillator】 Oscillating frequency Max Duty Cycle 【Error Amp】 FB threshold voltage Input bias current ...

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... BD9673EFJ ●Pin Description Thermal Pad Fig.1 Pin Layout Diagram ●Block Diagram ON/OFF EN TSD UVLO shutdown Error FB AMP - + 1.0V + Soft Start VC www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. Pin Pin No. Name 1 Lx Terminal for inductor 2 GND Ground pin ...

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... BD9673EFJ ●Block Description 1. Reference This block generates Error Amp standard voltage. Standard voltage is 1.0V. 2. REG This is a Gate Drive Voltage Generator and 5V Low saturation regulator for internal circuit power supply. 3. OSC This is a precise wave oscillation circuit with operation frequency fixed to 300 kHz fixed (self-running mode). ...

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... BD9673EFJ ●Detailed Description ◇Synchronizes to External Clock The SYNC pin can be used to synchronize the regulator to an external system clock. To implement the synchronization feature connect a square wave to SYNC pin. The square wave amplitude must transition lower than 0.8V and higher than 2.0V on the SYNC pin and have an on time greater than 100 ns and an off time greater than 100 ns. The synchronization frequency range is 200 kHz to 500 kHz ...

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... BD9673EFJ ◇OCP operation The device has the circuit of over current protection for protecting the FET from over current. To detect OCP 2 times sequentially, the device will stop and after 13msec restart voltage rising by output connect to GND Lx VOUT OCP OCP_LATCH www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. ...

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... BD9673EFJ ●Reference Data (Unless otherwise specified, Ta=25℃,VCC=24V, Vo=5V,EN=3V) 1 0.9 0.8 0.7 VCC=42V 0.6 VCC=36V 0.5 VCC=24V 0.4 VCC=12V 0.3 0.2 0.1 0 -60 -40 - 100 120 Temp[℃ ] Fig.6. Standby Current Temperature Characteristics detect voltage 4 reset voltage -60 -40 - 100 120 Temp[℃ ] Fig ...

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... BD9673EFJ VCC=12V 6 VCC=24V 4 VCC=36V 2 VCC=42V 0 -60 -40 - 100 120 Temp[ ℃ ] Fig.15. Soft Start Time Temperature Characteristics VCC=12V 2 VCC=24V VCC=36V VCC=42V 1 0 -60 -40 - 100 120 Temp[℃ ] Fig.18. OCP Detect Current Temperature Characteristics www.rohm.com © ...

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... BD9673EFJ ●Example of Reference Application Circuit (Input 24V, Output 5.0V/ 1A) 15µH CDRH105R (SUMIDA) 5V/1A VOUT 47µF/15 GRM32EB31C476KE15 (murata ●Reference Application Data (Example of Reference Application Circuit) 100 VCC=12V 50 VCC=24V 40 VCC=36V 30 VCC=42V 500 1000 1500 LOAD CURRENT[mA] Fig.22 Electric Power Conversion Rate VOUT： ...

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... BD9673EFJ ●Evaluation Board Layout Layout is a critical portion of good power supply design. There are several signals paths that conduct fast changing currents or voltages that can interact with stray inductance or parasitic capacitance to generate noise or degrade the power supplies performance. To help eliminate these problems, the VCC pin should be bypassed to ground with a low ESR ceramic bypass capacitor with B dielectric ...

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... BD9673EFJ ● Power Dissipation It is shown below reducing characteristics of power dissipation to mount 70mm×70mm×1.6mm Junction temperature must be designed not to exceed 150℃. 4000 ④3760mW 3500 3000 2500 ③2210mW 2000 ②1100mW 1500 1000 ①820mW 500 Fig.30 Power Dissipation ( 70mm×70mm×1.6mm ● ...

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... BD9673EFJ ●Application Components Selection Method (1) Inductor Something of the shield Type that Fulfills the Current Rating (Current value Ipecac below), with low DCR (Direct Current Resistance element) is recommended. Value of Inductor influences Inductor Ripple Current and becomes the cause of Output Ripple. In the same way as the formula below, this Ripple Current can be made small for as big as the L value of Coil or as high as the Switching Frequency. Ipeak =Iout + ⊿ ...

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... BD9673EFJ (5) About Adjustment of DC/DC Comparator Frequency Characteristics Role of Phase compensation element C1,C2,R3 (See P.7 Example of Reference Application Circuit) Stability and Responsiveness of Loop are controlled through VC Pin which is the output of Error Amp. The combination of zero and pole that determines Stability and Responsiveness is adjusted by the combination of resistor and capacitor that are connected in series to the VC Pin ...

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... BD9673EFJ Selection method of Phase Compensation constant is shown below. 1. Phase Compensation Resistor (R3) is selected in order to set to the desired Cross-over Frequency. Calculation done using the formula below.  2 COUT π Here the desired Cross-over Frequency made about 1/20 and below of the Normal Switching Frequency (fs) ...

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... BD9673EFJ ●I/O Equivalent Schematic Pin. Pin. Pin Equivalent Schematic No Name 1 Lx BST VCC 2 GND 7 BST Lx 8 VCC GND VCC GND GND www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved. Pin. Pin. Pin Equivalent Schematic No Name SYNC 5 SYNC GND ...

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... BD9673EFJ ●Notes for use (1) About Absolute Maximum Rating When the absolute maximum ratings of application voltage, operating temperature range, etc. was exceeded, there is possibility of deterioration and destruction. Also, the short Mode or open mode, etc. destruction condition cannot be assumed. When the special mode where absolute maximum rating is exceeded is assumed, please give consideration to the physical safety countermeasure for the fuse, etc ...

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... BD9673EFJ (12) About IC Pin Input This Monolithic IC, and between each element, it has P N layer of each element and this, the P-N junction is formed, and the parasitic element of each type is composed. For example, like the diagram below, when resistor and transistor is connected to Pin, ○When GND＞(PinA) in Resistor, when GND＞(PinA), when GND＞(Pin B) in Transistor (NPN), the P-N junction will operate as a parasitic diode. ○ ...

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... BD9673EFJ ●Ordering part number Part No. Part No. HTSOP-J8 4.9±0.1 (MAX 5.25 include BURR) (3.2) + 6° 4° −4° 1PIN MARK 0.545 S 1.27 +0.05 0.42 -0.04 0.08 0.08 S www.rohm.com © 2012 ROHM Co., Ltd. All rights reserved Package EFJ : HTSOP-J8 <Tape and Reel information> ...

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