BD8643FV-E2 Rohm Semiconductor, BD8643FV-E2 Datasheet
BD8643FV-E2
Specifications of BD8643FV-E2
Related parts for BD8643FV-E2
BD8643FV-E2 Summary of contents
Page 1
... Switching Regulator with Built-in Power MOSFET BD8643FV ●Description The BD8643FV is a synchronous step-down switching regulator that integrates 2 low resistances N-channel MOSFETs. It achieves 3A continuous output current over a wide input supply range. Current mode operation provides fast transient response and easy phase compensation. ●Feature 1) Synchronous rectification with built-in FET type DC/DC converter 2) 2 ...
Page 2
... BD8643FV ●Electrical characteristic (Unless otherwise noted Ta=25℃, V Parameter V supply current (operating supply current (standby) IN Reference voltage (V ) REF Oscillation frequency High side FET ON resistance Low side FET ON resistance UVLO voltage SW leak current EN terminal H threshold voltage EN terminal L threshold voltage SS/DELAY terminal source current SS/DELAY – ...
Page 3
... BD8643FV ●Reference data 0.810 0.805 VIN=12V 0.800 0.795 0.790 0.785 0.780 0.775 0.770 - [℃] Fig.1 Reference voltage – temperature 340 330 VIN=12V 320 310 300 290 280 270 260 - [℃] Fig.3 Frequency – temperature characteristic 5.6 VIN=12V 5.4 5.2 5.0 4.8 4 ...
Page 4
... BD8643FV ●Block Diagram PSET ●terminal assignment No. Symbol Description 1 PGND Power GND terminal 2 PGND Power GND terminal 3 PGND Power GND terminal 4 SW Switching output terminal 5 SW Switching output terminal 6 SW Switching output terminal 7 BOOT Boot strap terminal 8 NC Soft start adjustment capacity ...
Page 5
... Fig.12 ON/OFF transition wave form in EN controlling 2 Soft start time set function As for BD8643FV, output can do soft start without overshoot by charging soft start capacity (C SS/DELAY (9 pin) and GND (10 pin) terminal. Also, soft start time (tss) can be set by setting soft start capacity (C ...
Page 6
... BD8643FV ●Protection function Protection circuit is effective for destruction prevention due to accident so that avoid using under continuous protection operation. 1 Low voltage protection function (LVP) The voltage of the terminal FB (11pin) is compared with internal reference voltage VREF terminal voltage falls below V state is fixed. Table 1 output low voltage protection function ...
Page 7
... SS terminal 6 Thermal shut down function Thermal shut down circuit (TSD circuit) is built into BD8643FV. When the temperature of the chip exceeds Tjmax=175, the DC/DC converter is fixed in a low voltage. TSD function is aimed to shut down IC from thermal reckless driving under an abnormal state to exceed Tjmax=175. ...
Page 8
... Please select the current that flows to R1 and R2 to become much smaller than output current. 2 Soft start time setting method BD8643FV can soft start without overshoot because of a charge current to the soft start capacitance (CSS). The soft start time can be set by connecting soft start capacity (CSS). ...
Page 9
... Moreover, please similarly have and set the margin enough to a ratings reverse-voltage for the maximum input voltage. 6 OFFLATCH time setting method If it continues abnormal state, BD8643FV output become low voltage and state is fixed. In this case, the OFFLATCH time can be set by connecting capacitor between PSET and GND. Please select the value of OFFLATCH time according to the following expression. Please set OFFLATCH time in 200µ ...
Page 10
... BD8643FV ●Typical application circuit 【Condition】 VOUT = 1.2V fosc = 300kHz OFFLATCH time = 500µsec 220p 10k FB 20k FC 2200p 11k RT 56k PSET 2000p VIN VIN VIN 22µ www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved Softstart/Delay 13 OSC CURRENT 14 Protect time DET 15 EN ...
Page 11
... BD8643FV ●I/O equivalence circuit 4, 5 ,6PIN(SW) VIN SW GND 11PIN(FB) VIN FB 50k Ω 14PIN(PSET) VIN 50k Ω PSET 100k Ω 2k Ω GND GND GND www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 7PIN(BOOT) VREG5 BOOT SW 12PIN(FC) VIN VIN 10kΩ FC 5kΩ ...
Page 12
... BD8643FV ●Note for use 1. About the absolute maximum rating Attention is brushed off enough to the quality control likely to destroy when the absolute maximum rating such as impressed voltages (VCC_IN,DCIN) and ranges (Topr) of the operating temperature exceeded, the mode of breakings of the short or the opening, etc. cannot be specified, and examine it in this IC to give physical measures for safety such as fuses when a special mode that exceeds the absolute maximum rating is assumed ...
Page 13
... BD8643FV ●Ordering part number Part No. Part No. SSOP-B20W 6.5 ± 0 0.1 0.65 0.22 ± 0.1 www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved Package F: SSOP-B20W <Tape and Reel information> Tape Embossed carrier tape Quantity 2000pcs E2 Direction The direction is the 1pin of product is at the upper left when you hold ...
Page 14
No copying or reproduction of this document, in part or in whole, is permitted without the consent of ROHM Co.,Ltd. The content specified herein is subject to change for improvement without notice. The content specified herein is for the purpose ...