BD9781HFP-TR Rohm Semiconductor, BD9781HFP-TR Datasheet
BD9781HFP-TR
Specifications of BD9781HFP-TR
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BD9781HFP-TR Summary of contents
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... Furthermore, an external synchronization input pin (BD9781HFP) enables synchronous operation with external clock. Features 1) Minimal external components 2) Wide input voltage range (BD9778F/HFP and BD9781HFP (BD9001F) 3) Built-in P-ch POWER MOS FET 4) Output voltage setting enabled with external resistor Reference voltage accuracy: ±2% 6) Wide operating temperature range: -40˚ ...
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... OSC V 0.8 1.7 2 μA EN 2/16 Unit ˚C ˚C ˚C BD9781HFP Unit 100 % 50 ~ 500 kHz 39 ~ 800 kΩ BD9781HFP Unit Condition V =0V,Ta=25˚ = =50mA SW * Design assurance V =35V,V = ,Ta=25˚C FB INV INV 35V IN V =1.1V INV V =0.5V INV V =1.5V INV V =1.5V,V =1.5V FB INV V =1 ...
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... Oscillation frequency Frequency input regulation [Enable block] Threshold voltage Sink current * Not designed to be radiation-resistant. BD9781HFP (Unless otherwise specified, Ta=-40˚C ~ +125˚C,V Parameter Standby circuit current Circuit current [SW block] POWER MOS FET ON resistance Operating output current of overcurrent protection ...
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... Fig.9 ON resistance V IN 1.8 1.6 1.4 1.2 Ta=125 1.0 Ta=25 0.8 Ta=125 Ta=-40 0.6 0.4 0.2 0.0 0.0 0.5 1.0 1.5 OUTPUT CURRENT : I Fig.12 ON resistance V (BD9781HFP) IN 125 25 - [V] IN (BD9781HFP) From the top, -40 25 125 [V] IN (BD9781HFP) 4.5 [A] O =5V (BD9781HFP) 2.0 2.5 [A] O =5V (BD9778F/HFP) ...
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... Efficiency(V =12V,f=200kHz (BD9781HFP) 6 Ta=25 Ta=- Ta=125 OUTPUT CURRENT : I [A] O Fig.20 Current capacitance(V =12V,Vo=5V,f=100kHz) IN (BD9781HFP) 5/16 1.8 1.6 1.4 1.2 1.0 Ta=125 0.8 Ta=25 0.6 0.4 Ta=–40 0.2 0.0 0 0.5 1 1.5 2 2.5 OUTPUT CURRENT : I [A] O Fig.15 ON resistance V =7V IN (BD9001F) 100 5V output 3.3V output ...
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... V Power supply input IN (BD9778HFP) EN ON/OFF 5 L:OFF H:ON 33μH DRIVER TSD 330μ CURRENT LIMIT 7 GND V FB INV GND RT No FIN (BD9781HFP) 33 μH DRIVER TSD 330μ CURRENT LIMIT 7 GND EN/SINC IN SW GND INV No. Function FIN 6/ ON/OFF 1 L:OFF H:ON 220μF 1μ ...
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... Setting the EN pin to 0 less makes it possible to shut down the circuit. Standby current is set to 0 μA (Typ.). Furthermore, on the BD9781HFP, applying a pulse having a frequency higher than set oscillation frequency to the EN/SYNC pin allows for external synchronization (up to +50% of the set frequency). ...
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... In order to activate the external synchronizing function, connect the frequency setting resistor to the RT pin and then input a synchronizing signal to the EN/SYNC pin. As the synchronizing signal, input a pulse wave higher than a frequency determined with the setting resistor (RT). On the BD9781HFP, design the frequency difference to be within 50%. Furthermore, set the pulse wave duty between 10% and 90%. ...
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... Select the output capacitor having a value smaller than that obtained by the formula shown below. 3. -Io(Max)) Limit C = Max Vo I imit:2A(BD9778F/HFP,BD9001F), 4A(BD9781HFP this capacitance is not optimum, faulty startup may result. ( 3.5m is soft start time(min.)) INV ...
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Design procedure 4. Selection of diode Set diode rating with an adequate margin to the maximum load current. Also, make setting of the rated inverse voltage with an adequate margin to the maximum input voltage. A diode with a low ...
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... Feedback Since the error amplifier is provided with (1) or (2) phase compensation, the low pass filter is applied. In the case of the DC/DC converter application, the R becomes a parallel resistance of the feedback resistance. C Fig.33 BD9781HFP reference layout pattern 600 700 800 OSCILATING FREQUENCY SETTING RESISTANCE : RT [kΩ] [kΩ ...
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For output capacitors having high ESR, such as electrolyte capacitor For output capacitors that have high ESR (i.e., several Ω), the phase compensation setting procedure becomes comparatively simple. Since the DC/DC converter application has a LC resonant circuit attached ...
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Measurement of open loop of DC/DC converter To measure the open loop of DC/DC converter, use the gain phase analyzer or FRA to measure the frequency characteristics. DC/DC converter controller + Maximum load Load 0 Output voltage Heat loss ...
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... Accordingly, methods by which parasitic diodes operate, such as applying a voltage that is lower than the GND (P substrate) voltage to an input pin, should not be used. Resistor (Pin layer Parasitic element GND Fig.37 Typical simple construction of monolithic IC FB(BD9778F/HFP, BD9781HFP) VREF 50kΩ VIN FB 300kΩ 2kΩ VREF VIN FB 1kΩ 1kΩ Fig.36 Equivalent circuit ...
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Ground wiring pattern It is recommended to separate the large-current GND pattern from the small-signal GND pattern and establish a single ground at the reference point of the set PCB, so that resistance to the wiring pattern and voltage ...
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Selection of order type ROHM model Product No. name 9778 = 36V/2A 9781 = 36V/4A 9001 = 50V/2A SOP8 <Outline dimensions> 5.0±0 0.1 1.27 0.4±0.1 HRP7 <Outline dimensions> 9.395 ± ...
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Appendix No technical content pages of this document may be reproduced in any form or transmitted by any means without prior permission of ROHM CO.,LTD. The contents described herein are subject to change without notice. The specifications for the product ...