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| US890 / US891 Two-Coil Fan Driver - High Output Current Features and Benefits Peak output current up to 1200mA Low start-up voltage Low output resistance High sensitivity integrated Hall Sensor Power-efficient CMOS and power MOSFETs Built-in output protection clamping diode Locked rotor protection and auto-restart Integrated tachometer (US890) or alarm (US891) signal protected output Low cost 2-coil fan driver with FG/RD output in RoHS Compliant 4-pin VK package Application Examples 5V/12V DC brushless motor/fan PC, server, laptop cooling fan Power supply cooling fan Large and small fan size Ordering Information Part No. US890 US891 Temperature Code E (-40 to 85 C C) E (-40 to 85 C C) Package Code VK (4-pin TO-92) VK (4-pin TO-92) 1 Functional Diagram 2 General Description The US890/891 is a one-chip solution for driving two-coil brushless DC motors and fans. Based on the advanced Melexis CMOS process, the IC contains a Hall-effect sensor, dynamic offset correction and powerful output drivers with 1200mA peak output current capability. Specially designed for driving large fans, the device is optimized for low start-up voltage. Frequency Generator or Rotation Detection is available. The open-drain output makes easier the connectivity with any external interface such as hardware monitoring or Super I/O IC. These features are combined with the Melexis patented no-VDD design to fit the IC in a small 4pin VK package. 3901000890 Rev 002 Page 1 of 12 Data Sheet Sep/07 US890 / US891 Two-Coil Fan Driver - High Output Current Table of Contents 1 Functional Diagram ........................................................................................................ 1 2 General Description........................................................................................................ 1 3 Glossary of Terms .......................................................................................................... 3 4 Absolute Maximum Ratings ........................................................................................... 3 5 Pin Definitions and Descriptions................................................................................... 3 6 General Electrical Specifications .................................................................................. 4 7 Magnetic Specifications ................................................................................................. 4 8 Driver Output vs Magnetic Pole..................................................................................... 4 9 Detailed General Description ......................................................................................... 5 10 Unique Features............................................................................................................ 5 11 Performance Graphs .................................................................................................... 7 11.1 RDSON vs TA ............................................................................................................... 7 11.2 RDSON vs VDD ............................................................................................................. 7 11.3 Magnetic parameters vs TA ....................................................................................... 7 11.4 Magnetic parameters vs VDD ..................................................................................... 7 11.5 IDD vs TA .................................................................................................................... 7 11.6 IDD vs VDD .................................................................................................................. 7 12 Test conditions ............................................................................................................. 8 12.1 VDD - operating ......................................................................................................... 8 12.2 RDSON ........................................................................................................................ 8 12.3 IDD ............................................................................................................................. 8 12.4 FG/RD Output Low Voltage ...................................................................................... 8 13 Application Information................................................................................................ 9 13.1 Typical application circuit .......................................................................................... 9 13.2 Recommended circuit for ground disconnection protection....................................... 9 14 Application Comments ................................................................................................. 9 15 Standard information regarding manufacturability of Melexis products with different soldering processes......................................................................................... 10 16 ESD Precautions ......................................................................................................... 10 17 VK Package Information (4-pin TO-92)...................................................................... 11 18 Disclaimer.................................................................................................................... 12 3901000890 Rev 002 Page 2 of 12 Data Sheet Sep/07 US890 / US891 Two-Coil Fan Driver - High Output Current 3 Glossary of Terms Two-coil fan MilliTesla (mT), Gauss VDD IDD Peak output current Continuous output current Locked rotor FG RD A fan with two-coil windings where current alternates from 1 coil to the other depending on the direction of the magnetic field. Units of magnetic flux density : 1mT = 10 Gauss Voltage on the common point of the fan coils. Current supplying the chip which flows through the coil connected to the switched off output driver. The current flowing in the coil at start-up, only limited by the coil resistance RCOIL and the output driver resistance RDSON. The average current flowing in the coil when the fan is spinning normally. The state when the fan stopped spinning due to mechanical blockage. Frequency generator or tachometer output Rotation detection or alarm output 4 Absolute Maximum Ratings Parameter Symbol Fan Supply Voltage VDD Peak Output Current IOUTp Continuous Output Current IOUTc FG/RD Pull-Up Voltage VFG, RD FG/RD Reverse Current IFG_REV, RD_REV Operating Temperature Range TA Junction Temperature TJ Storage Temperature Range TS Magnetic Flux Density B ESD Sensitivity (AEC Q100 002) Table 1: Absolute maximum ratings Value 18 1200 600 18 60 -40 to 85 125 -55 to 150 Unlimited 4 Units V mA mA V mA C C C mT kV Exceeding the absolute maximum ratings may cause permanent damage. Exposure to absolute-maximumrated conditions for extended periods may affect device reliability. 5 Pin Definitions and Descriptions Pin Name Pin number Function FG (RD) 1 Frequency Generator (Rotation Detection) Open Drain Output OUT1 2 Open Drain Coil Driver 1 OUT2 3 Open Drain Coil Driver 2 GND 4 Ground pin Table 2: Pin definitions and descriptions 3901000890 Rev 002 Page 3 of 12 Data Sheet Sep/07 US890 / US891 Two-Coil Fan Driver - High Output Current 6 General Electrical Specifications DC Operating Parameters TA = 25 C, VDD = 12V (unless otherwise specified) Parameter Fan Supply Voltage Supply Current OUT1, OUT2 ON Resistance OUT1, OUT2 ON Resistance OUT1, OUT2 Output Clamp Voltage FG / RD Output Low Voltage FG / RD Output Clamp Voltage FG / RD Output Leakage Current FG / RD Output Current Limit Package Thermal Resistance Locked Rotor Period Locked Rotor Period Locked Rotor Period Locked Rotor Period Output Switching Delay Table 3: Electrical specifications Symbol VDD IDD RDSON 1,2 RDSON 1,2 VOUT1,2 VOL VCLMP ILEAK IFGLIM RTH TON TOFF TON TOFF TDELAY Test Conditions Operating - RCOIL = 100 VDD = 5V, TA = 25C, IOUT = 300mA VDD = 5V, TJ = 125C, IOUT = 300mA 36 IOL = 4mA 18 VFG (VRD) = 5V VFG (VRD) = 12V One-sided PCB, zero LFPM VDD > 7V VDD > 7V VDD < 5.5V VDD < 5.5V "Dead time" when both drivers are off 0.33 25 0.15 23 200 0.25 1.5 0.53(2) 3.2(2) 50 0.5 10 Min 2.6(1) Typ 12 2.5 1 1.8 Max 18 4 1.4 2.5 Units V mA V V V A mA C/Watt s s s s s o 0.37 2.25 0.75 4.51 Note 1: The minimal value of VDD should be determined using the following equation: VDD =2.5V + RCOIL * IDD Note 2: Typical values valid at 5.5V. The values increase at lower voltage to improve fan start-up reliability. 7 Magnetic Specifications DC Operating Parameters TA = 25 C, VDD = 12V (unless otherwise specified) Parameter Symbol Test Conditions Operate point BOP Release point BRP Hysteresis BHYST Table 4: Magnetic specifications Min 0 -6 2 Typ Max 6 0 10 Units mT mT mT o 4.5 8 Driver Output vs Magnetic Pole Parameter North pole South pole Test Conditions B < Brp B > Bop OUT1 High Low OUT2 Low High FG High Low Table 5: Driver output vs magnetic pole Note 1: The magnetic pole is applied facing the branded side of the package 3901000890 Rev 002 Page 4 of 12 Data Sheet Sep/07 US890 / US891 Two-Coil Fan Driver - High Output Current 9 Detailed General Description The US890/891 is a one-chip solution for driving two-coil brushless DC motors and fans. Based on advanced Melexis CMOS process, the chip contains a Hall-effect sensor, dynamic offset correction and powerful output drivers with 1200mA peak output current capability. The low side output coil drivers are fully protected against switching transients. So an external zener diode is not needed to cut the high voltage spikes induced by the motor coils. The US890 has an open-drain integrated tachometer FG output that follows the Hall signal. In the US891, the open-drain rotation detection output RD is active low during normal spinning of the motor. It goes high when the flux switching frequency becomes too low, which means the motor is blocked. 10 Unique Features Specially designed for driving large fans, both ICs have LRP characteristics optimised for low start-up voltage. At low VDD, fans typically take longer to start up than at higher VDD. The motor start-up phase (from zero to maximum rotation speed) is illustrated below. Big fans with large inertia may have slow start-up causing a longer first output pulse after power-on. If this pulse duration is longer than the LRP TON period, the fan may falsely enter locked rotor condition. The US890/891 provides an adequate and simple solution to prevent this by automatically adjusting the LRP period at low voltage. It directly improves the motor start-up reliability. 3901000890 Rev 002 Page 5 of 12 Data Sheet Sep/07 US890 / US891 Two-Coil Fan Driver - High Output Current According to the electrical specification table and the figure above, three behaviours can occur: * VDD < 5.5V, TON/TOFF time periods are longer (from 0.53s / 3.2s typical at 5.5V) The periods increase with operating voltage to improve start-up at very low voltage. * VDD > 7V, TON/TOFF time periods are shorter (0.25s / 1.5s typical) The periods at high voltage are about twice as short as at low voltage * 5.5V < VDD < 7V, the switching event may slightly vary, but is kept within these limits. A small hysteresis is implemented to avoid oscillation around the threshold voltage. The typical mean threshold between the hysteresis is around 6.1V (TA=25 C). This facilitates driving heavier fans and motors with large inertia without any external component (TON/TOFF is increased or decreased depending on the fan supply voltage VDD). The FG/RD output driver provides an over current protection limiting the current flowing in the FG/RD driver while switched ON. It can occur if a too small pull-up resistor is used or if this resistor is short connected. This protection reduces the risk of EOS damage on the FG/RD driver. 3901000890 Rev 002 Page 6 of 12 Data Sheet Sep/07 US890 / US891 Two-Coil Fan Driver - High Output Current 11 Performance Graphs 11.1 RDSON vs TA 2.5 11.2 RDSON vs VDD 2.5 Ta = -40 C Ta = 85 C Ta = 125C Ta = 25C Ta = 105 C 2 VDD = 2.5V VDD = 5V VDD = 18V 2 RDSon (ohms) 1.5 RDSon (ohms) -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 1.5 1 1 0.5 0.5 0 Ta ( C) 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 VDD (Volts) 11.3 Magnetic parameters vs TA 6 11.4 Magnetic parameters vs VDD 6 3 Magnetic field (mT) Magnetic field (mT) 3 Bop, VDD=2.5V Brp, VDD=2.5V 0 Bhyst, VDD=2.5V Bop, VDD=18V Brp, VDD=18V Bhyst, VDD=18V Bop, Ta=25 C Brp, Ta=25C 0 Bhyst, Ta=25 C -3 -3 -6 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 Ta ( C) -6 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 VDD (Volts) 11.5 IDD vs TA 4 VDD = 2.5V VDD = 5V 3 VDD = 12V VDD = 18V IDD (mA) 11.6 IDD vs VDD 4 3 2 IDD (mA) 2 1 1 Ta = -40C Ta = 25C Ta = 85C Ta = 105 C Ta = 125 C 0 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 Ta (C) 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 VDD (Volts) 3901000890 Rev 002 Page 7 of 12 Data Sheet Sep/07 US890 / US891 Two-Coil Fan Driver - High Output Current 12 Test conditions 12.1 VDD - operating 12.2 RDSON 12.3 IDD 12.4 FG/RD Output Low Voltage 3901000890 Rev 002 Page 8 of 12 Data Sheet Sep/07 US890 / US891 Two-Coil Fan Driver - High Output Current 13 Application Information 13.1 Typical application circuit 13.2 Recommended circuit for ground disconnection protection 14 Application Comments The application 13.1 shows the typical application including a diode D1 for additional reverse voltage protection. Without this diode, the reverse current in each coil is equal to the fan peak current, as it is only limited by its coil resistances. In some fan construction where the peak current is not so big, this situation may be acceptable by both IC and coils for short period of time. However, a long exposure may seriously affect the reliability or damage each of them by overheating. The diode D1 connected in series between the supply voltage and the common point of the coils prevents this reverse current to flow. It prevents such reverse voltage damage and best protects both IC and coils. The application 13.2 is given in case the ground connection might be disconnected while the fan operates. At this moment, the current flowing through the coils may circulate from the output (OUT1 or OUT2) to the FG/RD output driver in reverse direction. High reverse current may damage the logic output driver. A bypass capacitor connected between the coil common node and the device ground should prevent such damage occurring by providing a close path to this current. The value of the capacitor needs to be tuned with the motor characteristics. Higher inductance may require higher capacitor value. For 2-wire fan application (tachometer or alarm logical output not required), the FG/RD pin (#1) should be connected to the device ground pin (#4). 3901000890 Rev 002 Page 9 of 12 Data Sheet Sep/07 US890 / US891 Two-Coil Fan Driver - High Output Current 15 Standard information regarding manufacturability of Melexis products with different soldering processes Our products are classified and qualified regarding soldering technology, solderability and moisture sensitivity level according to following test methods: Reflow Soldering SMD's (Surface Mount Devices) * IPC/JEDEC J-STD-020 Moisture/Reflow Sensitivity Classification for Nonhermetic Solid State Surface Mount Devices (classification reflow profiles according to table 5-2) EIA/JEDEC JESD22-A113 Preconditioning of Nonhermetic Surface Mount Devices Prior to Reliability Testing (reflow profiles according to table 2) * Wave Soldering SMD's (Surface Mount Devices) and THD's (Through Hole Devices) * * EN60749-20 Resistance of plastic- encapsulated SMD's to combined effect of moisture and soldering heat EIA/JEDEC JESD22-B106 and EN60749-15 Resistance to soldering temperature for through-hole mounted devices Iron Soldering THD's (Through Hole Devices) * EN60749-15 Resistance to soldering temperature for through-hole mounted devices Solderability SMD's (Surface Mount Devices) and THD's (Through Hole Devices) * EIA/JEDEC JESD22-B102 and EN60749-21 Solderability For all soldering technologies deviating from above mentioned standard conditions (regarding peak temperature, temperature gradient, temperature profile etc) additional classification and qualification tests have to be agreed upon with Melexis. The application of Wave Soldering for SMD's is allowed only after consulting Melexis regarding assurance of adhesive strength between device and board. Melexis is contributing to global environmental conservation by promoting lead free solutions. For more information on qualifications of RoHS compliant products (RoHS = European directive on the Restriction Of the use of certain Hazardous Substances) please visit the quality page on our website: http://www.melexis.com/quality.aspx 16 ESD Precautions Electronic semiconductor products are sensitive to Electro Static Discharge (ESD). Always observe Electro Static Discharge control procedures whenever handling semiconductor products. 3901000890 Rev 002 Page 10 of 12 Data Sheet Sep/07 US890 / US891 Two-Coil Fan Driver - High Output Current 17 VK Package Information (4-pin TO-92) 5.22+/-0.10 4.20+/-0.10 1.55+/-0.10 0.73+/-0.10 3.65+/-0.10 3+2 (2X) 5+2 (2X) -1 Notes: 1. All dimensions are in millimeters 2. Package dimension exclude molding flash. Mold flash shall not exceed 0.127mm. E.D.M Process Surface Ro1.6~2.4um 1.42+/-0.10 0.46 0.00 0.20 2.5 min see note 3 +0.02 - 0.03 3. To preserve reliability, it is recommended to have total lead length equal to 2.5mm minimum, measured from the package line. 4. VK package is a pin though-hole package, hence adapted for wave soldering process. A reflow soldering process is not recommended with VK package as it may seriously affect device reliability. Marking: 1st Line : US890 (US891) - Name of the device 2nd Line : XXYWW XX - lot number (last 2 digits) Y - assembly year (last digit) WW - assembly week number 10.50+/-0.30 1.27+/-0.03 3.81+/-0.03 5 +2 -1 (2X) 0.38+/-0.03 0.38+/-0.03 0.30+/-0.10 (2X) 3+2 (2X) Hall plate location 1.9 0.52 1.3 Notes: 1. All dimensions are in millimeters 3901000890 Rev 002 Page 11 of 12 Data Sheet Sep/07 US890 / US891 Two-Coil Fan Driver - High Output Current 18 Disclaimer Devices sold by Melexis are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. Melexis makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. Melexis reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with Melexis for current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical lifesupport or life-sustaining equipment are specifically not recommended without additional processing by Melexis for each application. The information furnished by Melexis is believed to be correct and accurate. However, Melexis shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interrupt of business or indirect, special incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of Melexis' rendering of technical or other services. (c) 2005 Melexis NV. All rights reserved. For the latest version of this document, go to our website at www.melexis.com Or for additional information contact Melexis Direct: Europe and Japan: Phone: +32 1367 0495 E-mail: sales_europe@melexis.com All other locations: Phone: +1 603 223 2362 E-mail: sales_usa@melexis.com ISO/TS 16949 and ISO14001 Certified 3901000890 Rev 002 Page 12 of 12 Data Sheet Sep/07 |
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