BD8158FVM ROHM Co. Ltd., BD8158FVM Datasheet

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... TFT-LCD panel is suppressed. Features 1) Current mode PWM system 2) Input voltage is 2 5.5 V (BD8152FVM), 2 5.5 V (BD8158FVM, providing the low power input) 3) Switching frequency is variable as 600 kHz/1,200 kHz. 4) Built-in 0.25 Ω power switch 5) Feedback voltage 1.245 ± 1% ...

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... Recommended Operating Ranges (Ta = 25°C) Parameter Power supply voltage (BD8152FVM) Power supply voltage (BD8158FVM) Switch current Switch pin voltage *Specified at 600kHz switching operating. Electrical Characteristics BD8152FVM (Unless otherwise specified 25°C; Vcc = 3.3 V; ENB = 3.3 V) Parameter [triangular waveform oscillator] Oscillating frequency 1 Oscillating frequency 2 ...

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... Electrical Characteristics BD8158FVM (Unless otherwise specified 25°C; Vcc = 2.5 V; ENB = 2.5 V) Parameter [triangular waveform oscillator] Oscillating frequency 1 Oscillating frequency 2 [Overcurrent protection circuit] Overcurrent limit [Soft start circuit] SS source current [Under-voltage lockout protection circuit] Off threshold voltage On threshold voltage [Error amp] Input bias current ...

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... FCLK VOLTAGE:VFCLK[V] Fig. 7 FCLK Pin Current 2.000 1.500 1.000 125°C 0.500 0.000 -0.500 25°C -40°C -1.000 -1.500 -2.000 SUPPLY VOLTAGE:Vcc [V] Fig. 2 Standby Current 2.0 BD8158FVM 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 SUPPLY VOLTAGE:VCC[V] Fig. 5 Reference Voltage vs Power Supply Voltage 20 15 125°C 10 25°C 5 -40° ...

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... OUTPUT CURRENT:Io[A] Fig. 11 Vcc = 2.5V Power Efficiency 0.8 BD8158FVM 0.6 0 600 kHz 0 1200 kHz 0 2.0 2.4 2.8 3.2 3.6 4.0 SUPPLY VOLTAGE:Vcc[V] Fig. 14 Max. Load Current vs Power Supply Voltage 9 Vcc = 2.5 V 8.8 8.6 8.4 8.2 BD8158FVM 8 0.0 0.1 1.0 LOAD CURRENT:Io[A] Fig. 17 Output Voltage Load Regulation 1 5/ BD8152FVM 50 0.05 0.15 0.25 0.35 0.45 OUTPUT CURRENT:Io[A] Fig. 12 Vcc = 5V Power Efficiency Io = 100 ...

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Block Diagram Pin Assignment Diagram and Function Pin No. Pin name 1 COMP Error amp output pin 2 FB Error amp inversion input pin 3 ENB Control input pin 4 GND Ground pin 5 SW N-channel power FET drain output ...

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... Protection circuit (UVLO/TSD) UVLO (under-voltage lockout protection circuit) shuts down the circuits when the voltage is 2.2 V (TYP.BD8152FVM),1.8 V (TYP.BD8158FVM) or lower. Thermal shutdown circuit shuts down IC at 175°C (Typ.) and recovers at 160°C (Typ.). • Overcurrent protection circuit (OCP) Current flowing to the power FET is detected by voltage at the CURRENT SENSE and the overcurrent protection operates (Typ.). When the overcurrent protection operates, switching is turned off and the SS pin capacity is discharged. • ...

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Timing Chart Startup sequence VCC ENB Overcurrent protection operating 2.5V VCC,ENB Fig. 21 Startup Sequence Waveform Fig. 22 Overcurrent Protection Operating Waveform 8/16 ...

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... Set with sufficient margin because the coil L value may have the dispersion of approx. ±30%. If the coil current exceeds the rating current I BD8152FVM / BD8158FVM use the current mode DC/DC converter control and has the optimized design at the coil value. The following coil values are recommended from the aspects of power efficiency, response and safety. When the coil out of this range is selected, the stable continual operation is not guaranteed such as the switching waveform becomes irregular ...

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Selecting the output rectification diode Schottky barrier diode is recommended as the rectification diode to use at the DC/DC converter output stage. Select the diode paying attention to the max. inductor current and max. output voltage. Max. Inductor current ...

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Setting the phase compensation circuit the current mode control, since the coil current is controlled, a pole (phase lag) made by the CR filter composed of the output capacitor and load resistor ...

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Application Examples * Although ROHM is sure that the application examples are recommendable ones, further check the characteristics of components that require high precision before using them. When a circuit is used modifying the externally connected circuit constant, be sure ...

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... Application Examples (3) When the circuit is intended to operate at the lower voltage than the IC operating range: Although the recommended operating range of IC starts from 2 2.1 V (BD8152FVM / BD8158FVM possible to continue operating by composing the self-energizing type step-up DC/DC converter application even if the input voltage lowered than 2.1 V. This example is recommended for the application with battery input. ...

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... Application Examples (5) When the Supply Voltage is over 4.0 V (BD8158FVM only) The Capacitor C4 is inserted to COMP pin, and it operates when the Supply Voltage is over 4 this case, Switching Frequency is limited to 600kHz. C1 10uF C2 0.01uF SOFT COMP C4 R3 100pF C3 I/O Equivalent Circuit Diagrams 1.COMP Vcc 2. 3.ENB 7.FCLK Vcc 130kΩ ...

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... P/N junctions are formed at the intersection of these P layers with the N layers of other elements to create a variety of parasitic elements. For example, when the resistors and transistors are connected to the pins as shown in Fig. 35, a parasitic diode or a transistor operates by inversing the pin voltage and GND voltage. ...

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... MSOP8 <Dimension> 2.9 ± 0 +0.05 0.145 0.475 −0.03 +0.05 0.22 −0.04 0.08 M 0.65 0. 70×70×1.6mm Board BD8158FVM BD8152FVM 100 AMBIENT TEMPERATURE[ ℃ ] Fig. 36 Power Dissipation Reduction Package MSOP8 Package MSOP8 <Tape and Reel information> Tape Embossed carrier tape ...

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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 ...