bd9845fv ROHM Co. Ltd., bd9845fv Datasheet
bd9845fv
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bd9845fv Summary of contents
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... High-frequency Step-down Switching Regulator(Controller type) BD9845FV ●Overview BD9845FV containing a circuit of switching regulator controller by pulse width modulation system. This circuit can be used for step-down DC/DC converter operation. In addition, the package is designed compact, and is optimum for compact power supply for many kinds of equipment. ●Feature 1) High voltage resistance input (Vcc=35V) 2) FET driver circuit is contained (step-down circuit 1 output) ...
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VCC=6V unless otherwise specified) Item [VREF output unit] Output voltage Input stability Load stability Current capacity [Triangular wave oscillator] Oscillation frequency Frequency fluctuation [Soft start unit] SS source current SS sink current [Pause period adjusting circuit] DT ...
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STB flow-in current Standby mode setting range Active (master) mode setting range SEL flow-in current mode setting range Master Slave mode setting range [Device overall] Standby current Average power consumption * Radiation resistance design is not applied. ...
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Reference data 3.5 3.4 3.3 3.2 3.1 3 2.9 2.8 2.7 2.6 2.5 -50 - 100 125 Ambient Temperature: Ta(°C) Fig.7 UVLO threshold temperature characteristics 1.01 1.008 1.006 1.004 VCC=6V 1.002 1 0.998 0.996 0.994 ...
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VCC=6.0V 40 Ta=25° 1.4 1.6 1 Input Voltage: VDT(V) Fig.19 Output Duty-VDT characteristics (100kHz) 40 Ta=-40°C 35 Ta=25°C 30 Ta=85° VCC=6.0V 5 ...
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VCC VREF REG VREF (2.5V VREF 1V±10mV 2μ ERR - SSOFF INV OSC 200μ 1.5V 200μA MASTER /SLAVE CT VREF CT GND STB C5V OUT VCC Fig.29 Pin layout ...
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REG (reference voltage unit) As for REG (2.5V), reference voltage (2.5V) stabilized better than supply voltage input to VCC terminal is supplied as an operation voltage of IC internal circuit, as well ...
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Soft start (soft start function possible to provide SS terminal (13pin) with soft start function by connecting C as shown on the right. SS Soft start time TSS is shown by the formula below: Vinv Css : ...
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STB /SEL(Standby/Master/Slave function) Standby mode and normal mode can be switched by STB terminal (4pin). 1. When STB<0.5V, standby mode is set. Out put stop (OUT=H) and REG also stops. Circuit current is also Isc = 0 uA here. ...
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Timing chart ◎Starting characteristics (UVLO cancel) and standby operation VCC (1) UVLO (Vcc) is canceled when Vcc>3.2V. ①Vcc＞3.2VでUVLO(Vcc)解除 STB VREF起動電圧 VREF start voltage 1.8Vtyp. VREF停止電圧 VREF stop voltage 0.9Vtyp. VREF (2) UVLO (VREF) is canceled when VREF>2.2V. ②VREF＞2.2VでUVLO(VREF)解除 SS ...
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VREF VREF CT INV VREF Setting of output unit coil (L) and capacitor (Co) Set the coil and capacitor as follows in step-down application: <Setting of L-value> When load current gets heavy, ...
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Example of overcurrent protection circuit Insert a sense resistor between the source and VIN of output Pch-FET for detecting overcurrent as shown in the figure. Refer to the formula below for determining a sense resistor and select permissible loss ...
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About board layout In order to make full use of IC performance, fully investigate the items below in addition to general precautions. ・ Each output of OCP+/OCP- is such a sensitive circuit. When wiring is routed around ...
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Precaution for use 1) About maximum absolute rating When the maximum absolute rating of application voltage or operation voltage range is exceeded, it may lead to deterioration or rupture impossible to forecast rupture in short mode or ...
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Outer dimension view D9845 1pin Lot No. SSOP-B14 [単位:mm] ●Order model name BD 9845 ROHM model name ? ? ? ? ? Part number Package type ? ? ? ?? ? ? ? ? ? FV=SSOP-B14 15/15 FV Taping ...
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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 ...