BD9540EFV ROHM Electronics, BD9540EFV Datasheet
BD9540EFV
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BD9540EFV Summary of contents
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... Desktop PC BD9540EFV ●Description BD9540EFV is a 2ch switching regulator synchronous controller that can generate low output voltages (0.75V to 5.5V). High efficiency for the switching regulator can be achieved due to its external N-MOSFET power transistor. The IC also incorporates a new technology called H response against changes in load. For protection and ease of use, the IC also incorporates soft start, and short circuit protection with timer latch functions. This switching regulator is designed for DRAM and power supplies for graphics chips. ● ...
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... BD9540EFV ●Operating Conditions (Ta=25℃) Parameter Input voltage BOOT voltage SW Voltage BOOT-SW voltage Logic Input Voltage 1 Logic Input Voltage 2 Output Voltage MIN ON Time *This product should not be used in a radioactive environment. *The range of the VOUT is limited by the voltage between VIN and VOUT. ...
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... Controller SS2 S OCP Block SW2 REF2 + SS2 + - UVLO ILIM2 SCP TSD LIM TEST NC 2 EN1 FB1 NC 6 BD9540EFV FB2 11 12 EN2 3/17 Technical Note 5VReg V IN BOOT1 1 28 HG1 V 1 OUT 27 SW1 Driver Circuit 5VReg LG1 ...
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... BD9540EFV ●Pin Function PIN No. PIN name 1 BOOT1 EN1 4 VOUT1 5 FB1 GND 8 CTL1 9 CTL2 10 FB2 11 VOUT2 12 EN2 BOOT2 15 HG2 16 SW2 17 LG2 18 PGND2 19 ILIM2 20 TEST 21 VCC 22 5VReg 23 VIN 24 ILIM1 25 PGND1 26 LG1 27 SW1 28 HG1 reverse FIN www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. ...
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... BD9540EFV ●Reference Data V 2 OUT 50[mV/div] SW1 10[V/div] SW2 10[V/div OUT 2[A/div] (2μs/div) Fig.1 Transient Respnse (V =12V V 2=1.05V) IN OUT V 1 OUT 50[mV/div] SW1 10[V/div] SW2 10[V/div OUT 2[A/div] (2μs/div) Fig.4 Transient Respnse (V =12V V 1=3.3V) IN OUT HG, LG 20[V/div] 28μ ...
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... BD9540EFV ●Reference Data 10 VCC=VREG5V 8 EN1=EN2= VIN [V] Fig. IN_STB VEN [V] Fig.16 V ‐I www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 5.2 5.1 5 4.9 4.8 - [℃] Fig.14 Ta-5VREG ...
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... BD9540EFV ●Pin Descriptions ・EN1 (3 pin) / EN2 (12 pin) When the input voltage on the EN pin reaches at least 2.2V, the switching regulator becomes active. At voltages less than 0.3 V, the switching regulator becomes inactive, and the input current drops to 10μA or less. Thus the IC can be controlled from 2.5V, 3. power supplies. ...
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... BD9540EFV ●Explanation of Operation The BD9540EFV is a 2ch switching regulator controller incorporating ROHM’s proprietary H system. When VOUT drops due to a rapid load change, the system quickly restores VOUT by extending the TON time interval Reg control (Normal operation) FB REF HG LG (VOUT drops due to a rapid load change) ...
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... BD9540EFV ●Timing Chart ・Over current protection circuit ・Timer Latch Type Short Circuit Protection REF×0.7 FB 28μ EN/UVLO ・Output Over Voltage Protection OVP threshod voltage V OUT 1.7μ Switching www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. ...
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... BD9540EFV ●External Component Selection 1. Inductor (L) selection ΔIL VIN IL HG VOUT Output Ripple Current ※Passing a current larger than the inductor’s rated current will cause magnetic saturation in the inductor and decrease system efficiency. When selecting an inductor, be sure to allow enough margin to assure that peak current does not exceed the inductor’ ...
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... BD9540EFV 4. MOSFET Selection V IN main switch V OUT L Co synchronous switch 5. Determining Detection Resistance PGND R ILIM www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. Main MOSFET power dissipation is computed as follows: Pmain = RON GATE V OUT 2 +Qg(High)×f×5VReg+ ×R ×I ...
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... BD9540EFV 6. Output Voltage Setting The IC will try to maintain output voltage such that REF≒VFB. However, the actual output voltage will also reflect the average ripple voltage value. The output voltage is set via a resistive voltage divider between the output and the FB pin. The formula for output voltage ...
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... Relationship between output current and frequency BD9540EFV is a fixed-Ton type of switching controller. When the output current increases, the switching loss of the coil and MOSFET also increases and hence the switching frequency speeds up. The loss of the coil and MOSFET is determined as ① ...
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... BD9540EFV ●I/O Equivalent Circuits 1pin, 14pin (BOOT1, BOOT2 5VReg 8pin 9pin (CTL1, CTL2) 26pin, 17pin (LG1, LG2) 5VReg 100KΩ 21pin (VCC) www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved. 3pin, 12pin (EN1, EN2) 1MΩ 2MΩ 28pin, 15pin (HG1, HG2) ...
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... It is not designed to protect the IC from damage or guarantee its operation. ICs should not be used after this function has activated applications where the operation of this circuit is assumed. BD9540EFV (10)Testing on application boards When testing the application board, connecting a capacitor directly to a low-impedance pin may subject the IC to stress. Always discharge capacitors completely after each process or step. The IC’ ...
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... BD9540EFV (11) Regarding input pins of the IC This monolithic IC contains P+ isolation and P substrate layers between adjacent elements in order to keep them isolated. PN junctions are formed at the intersection of these P layers with the N layers of other elements, creating parasitic diodes and/or transistors. For example (refer to the figure below): ...
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... BD9540EFV ●Ordering part number Part No. Part No. HTSSOP-B28 9.7±0.1 (MAX 10.05 include BURR) (5. 1PIN MARK 0.625 S 0.08 S 0.65 +0.05 0.24 -0.04 0.08 M www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved Package EFV : HTSSOP-B28 <Tape and Reel information> Tape Embossed carrier tape (with dry pack) + 6° ...
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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 ...