BU6909AGFT-TL ROHM

DC Brushless Fan Motor Driver 5V Single-phase Full-wave Fan Motor Driver BU6909AGFT Description The BU6909AGFT is a 5V single-phase full-wave FAN motor driver with built in HALL element. It is part of the DC brushless FAN motor driver series. BU6909AGFT is built in a compact package and provides Auto Gain Control function (AGC), silent drive by soft switching, and low battery consumption via its standby function. BU6909AGFT is best used for notebook PC cooling FANs. Features Package W(Typ) x D(Typ) x H(Max) Built in HALL element TSSOF6 2.90mm x 3.80mm x 0.8mm Auto Gain Control function (AGC) Soft switching drive (PWM type) Low PWM duty start up Quick start function Stand-by mode Incorporates lock protection and automatic restart circuit Compact package (GFT:TSSOF6 flat lead package) When TSSOF6 is mounted, package thickness is 0.3mm Rotating speed pulse signal (FG) output PWM speed control TSSOF6 Applications For compact 5V FAN such as notebook PC cooling FAN Absolute Maximum Ratings Parameter Symbol Limit Unit Supply Voltage V 7 V CC (Note 1) Power Dissipation Pd 0.54 W Operating Temperature Topr -40 to +85 C Storage Temperature Tstg -55 to +125 C Output Voltage V 7 V OMAX (Note 2) Output Current I 800 mA OMAX FG Signal Output Voltage V 7 V FG FG Signal Output Current I 10 mA FG Junction Temperature Tjmax 125 C (Note 1) Reduce by 5.4mW/ over 25. (On 70.0mm70.0mm1.6mm glass epoxy board) (Note 2) This value is not to exceed Pd. Caution: Operating the IC over the absolute maximum ratings may damage the IC. The damage can either be a short circuit between pins or an open circuit between pins and the internal circuitry. Therefore, it is important to consider circuit protection measures, such as adding a fuse, in case the IC is operated over the absolute maximum ratings. Recommended Operating Condition Parameter Symbol Limit Unit Operating Supply Voltage Range V 1.8 to 5.5 V CC Product structureSilicon monolithic integrated circuit This product has no protection against radioactive rays . www.rohm.com TSZ02201-0H1H0B101190-1-2 2014 ROHM Co., Ltd. All rights reserved. 1/18 TSZ2211114001 28.Oct.2014 Rev.002DatasheetDatasheet BU6909AGFT Block Diagram Consider protection against HALL ELEMENT voltage rise due to reverse This is an open drain output. connection of power supply and Connect a pull-up resistor. FG VCC OFFSET back electromotive force. CANCEL Page 15. 1 6 Page 14. A/D CONVERSION OSCILLATOR CIRCUIT GND PWM 2 5 UVLO Enables speed control by CONTROL PRE applying external PWM signal. H-BRIDGE LOGIC DRIVER TSD Maximum input frequency is 50KHz. Page 10. OUT1 OUT2 3 4 PWM DUTY LOCK SIGNAL OUT PROTECTION M Conventional FAN motor driver IC with HALL element requires adjustment of HALL bias resistor due to several factors that (Heat protection circuit) TSD : Thermal shut down(heat rejection circuit) affect the HALL Amplitude. This IC automatically adjusts HALL UVLO :Under voltage lock outputs (low voltage protection circuit) amplitude through the use of a built in HALL element and unique AGC function. Page 8. Figure 1. Block diagram and Application circuit Pin Description Pin No. Pin Name Function 1 FG FG signal output 2 GND GND 3 OUT1 Motor output 1 4 OUT2 Motor output 2 5 PWM PWM signal input 6 VCC Power supply I/O truth table Supply magnetic direction (positive) Output operation S V V OUT1 OUT2 Marking B B HYS HYS BREV BFWD BREV BFWD N Magnetic flux density Magnetic flux density:B :B Figure 2. Output operation Supply magnetic PWM* OUT1 OUT2 FG direction S H(OPEN) H L L (Output TrON) N H(OPEN) L H H (Output TrOFF) S L L L H (Output TrOFF) N L L L H (Output TrOFF) *When PWM terminal is L, IC state changes to stand-by mode. FG terminal is always H in stand-by mode www.rohm.com TSZ02201-0H1H0B101190-1-2 2014 ROHM Co., Ltd. All rights reserved. 2/18 TSZ2211115001 28.Oct.2014 Rev.002