US651 / US661 Two-Coil Low Noise Fan Driver Features and Benefits Soft Switching for low noise applications Slope control setting by dedicated pin One-chip solution (Hall + Drivers) Advanced Protection (enhanced locked rotor, reverse voltage, thermal, output clamping) Integrated tachometer (US651) or alarm (US661) signal output Application Examples 5V/12V DC brushless motors Continuous output current up to 350mA Low noise brushless cooling fans PC, server, laptop cooling fan Power supply cooling fan Large and small fan size Ordering Information Part No. US651 US661 Temperature Code E (-40°C to 85°C) E (-40°C to 85°C) 1 Functional Diagram Package Code DC (8-pin narrow SOIC8) DC (8-pin narrow SOIC8) 2 General Description The US651/661 is a one-chip solution for driving two-coil brushless DC fan and motors. It is especially suitable for relatively high-current rated operation as it can drive up to 350mA continuous output current. The use of Melexis Soft Switching concept lowers the acoustic and electrical motor noise and provides smoother operation. This efficient solution is combined with an innovative slope control design controllable via a dedicated pin. The device includes reverse voltage protection, locked rotor protection and thermal protection. Therefore, the IC robustness perfectly suits for consumer and automotive-on-board applications. Tachometer (FG) or Alarm (RD) open-drain output is available. It makes the connectivity with external interface such as hardware monitoring or Super I/O IC easier. The device is delivered in RoHS compliant DC package (SMD) for automatic soldering 390109020902 Rev 002 Page 1 of 12 Preliminary Datasheet Mar/07 US651 / US661 Two-Coil Low Noise Fan Driver 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 Output Behaviour vs Magnetic Pole.............................................................................. 5 9 Detailed General Description ......................................................................................... 5 10 Unique Features............................................................................................................ 6 10.1 Soft Switching & Slope setting.................................................................................................................6 10.2 Enhanced Locked Rotor Protection.........................................................................................................7 11 Performance Graphs .................................................................................................... 7 11.1 RDSON vs TJ ...............................................................................................................................................7 11.2 RDSON vs VDD ............................................................................................................................................7 11.3 IDD vs TJ....................................................................................................................................................7 11.4 IDD vs VDD .................................................................................................................................................7 11.5 Internal Slope Duration vs VDD ................................................................................................................8 11.6 Slope Duration vs VDD..............................................................................................................................8 11.7 VOL vs. TJ .................................................................................................................................................8 11.8 ILEAK vs. TJ ................................................................................................................................................8 11.9 IFGLIM vs. VDD ............................................................................................................................................8 11.10 PDmax vs. TA ............................................................................................................................................8 12 Application Information................................................................................................ 9 13 Application Comments ................................................................................................. 9 14 Standard information regarding manufacturability of Melexis products with different soldering processes......................................................................................... 10 15 ESD Precautions ......................................................................................................... 10 16 DC Package Information (8-pin narrow SOIC) .......................................................... 11 17 Disclaimer.................................................................................................................... 12 390109020902 Rev 002 Page 2 of 12 Preliminary Datasheet Mar/07 US651 / US661 Two-Coil Low Noise Fan Driver 3 Glossary of Terms Two-coil fan MilliTesla (mT), Gauss 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 The current flowing in the coil at start-up, only limited by the coil resistance RCOIL and the output driver resistance RDSON. Average absolute value of the output current when the fan is spinning. 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 Supply Voltage VDD FG / RD voltage VFG (VRD) Voltage on pin SLOPE VSLOPE Peak output current IOUTp Continuous output current IOUTc Operating Temperature Range TA Junction temperature TJ Storage Temperature Range TS Magnetic flux density B Table 1: Absolute maximum ratings Value -12 to 18 -7 to 18 -0.5 to 18 700 350 -40 to 85 125 -55 to 150 Unlimited Units V V V mA mA °C °C °C mT 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 Function FG (RD) Tachometer (Alarm) open-drain output VDD Power Supply pin SLOPE Slope Control pin OUT1 Open Drain Coil Driver 1 GND Ground pin OUT2 Open Drain Coil Driver 2 NC Not connected NC Not connected Table 2: Pin definitions and descriptions Pin number (DC) 1 2 3 4 5 6 7 8 390109020902 Rev 002 Page 3 of 12 Preliminary Datasheet Mar/07 US651 / US661 Two-Coil Low Noise Fan Driver 6 General Electrical Specifications o DC Operating Parameters TJ = 25 C, VDD = 12V (unless otherwise specified) Parameter. Supply Voltage Supply Current OUT1, OUT2 ON Resistance OUT1, OUT2 Clamp Voltage FG / RD Output Low Voltage FG / RD Output Clamp Voltage FG / RD Output Leakage Current FG / RD Output Current Limit Symbol VDD IDD RDSON 1,2 VOUT 1,2 VOL VCLMP ILEAK IFGLIM Test Conditions Operating Min 3 Typ 12 3 3 Max 18 5 5 0.35 0.5 Output Switching Slope Duration (1) TSW VDD = 12V, pin SLOPE left open 40 70 160 µs Output Switching Slope Duration (1) TSW VDD = 12V, RSLOPE =100k 87 120 189 µs Output Switching Slope Duration (1) TSW VDD = 5V, pin SLOPE left open 73 126 250 µs Output Switching Slope Duration (1) TSW Locked Rotor Period Locked Rotor Period Locked Rotor Period 36 IOL = 4mA 18 VFG (VRD) = 5V VFG (VRD) = 12V 10 20 Units V mA Ω V V V µA mA 87 120 189 µs TON TOFF TON VDD = 5V, RSLOPE =100k VDD = 12V VDD = 12V VDD = 5V 0.24 1.44 0.48 0.29 1.5 0.6 0.39 2.34 0.89 s s s Locked Rotor Period TOFF VDD = 5V 2.88 3.65 5.34 s Thermal Protection Shutdown TSD Note 2 160 oC Thermal Protection Release TREL Note 2 130 oC Single layer PCB 150 oC/Watt DC Package Thermal Resistance RTH Table 3: Electrical specifications Note 1: Measured with active load connected to the output, from 10% to 90% of the VDD voltage. Note 2: Guarantied by design 7 Magnetic Specifications o DC Operating Parameters TJ = 25 C, VDD = 12V (unless otherwise specified) Parameter. Symbol Test Conditions Operate point BOP Release point BRP Hysteresis BHYST Table 4: Magnetic specifications 390109020902 Rev 002 Page 4 of 12 Min -6 2 Typ 3 -3 6 Max 6 Units mT mT mT Preliminary Datasheet Mar/07 US651 / US661 Two-Coil Low Noise Fan Driver 8 Output Behaviour vs Magnetic Pole Parameter Test Conditions North pole B < Brp South pole B > Bop Table 5: Driver output vs magnetic pole OUT1 Low High OUT2 High Low FG Low High Note : The magnetic pole is applied facing the branded side of the package 9 Detailed General Description The US651/661 is a one-chip solution for driving two-coil brushless DC fans. Based on CMOS process, the chip contains a Hall-effect sensor with dynamic offset correction, logic control and two low-ohmic open-drain output drivers. The output drivers OUT1 and OUT2 are fully protected against switching transients. So there is no need of external zener diode to cut the high voltage spikes induced by the fan coils. In case the junction temperature TJ exceeds TSD, the thermal protection stops the current flowing through the full bridge by setting the outputs OUT1 and OUT2 low and setting the output FG (RD) high. The IC stays in this state until the junction temperature decreases below TREL. Reverse voltage protection is integrated on the VDD pin. The FG/RD open drain output has an internal current limit which protects the driver in case of accidentally big current flow through the logic driver. It could occur if a low-ohmic pull-up resistor is used or if the FG/RD output is directly short connected to a supply voltage. The US651 has an open-drain tachometer FG output that follows the Hall signal, thus enabling to determine the rotation speed of the fan. In the US661, the open-drain alarm output RD is a safety signal which allows detecting if the fan rotates or not. It is active low during normal spinning of the motor. It goes high when the magnetic flux switching frequency drops below nearly: - 2Hz for 12V application (60RPM for 2 pole-pair fan) - 1Hz for 5V application (30RPM for 2 pole-pair fan) 390109020902 Rev 002 Page 5 of 12 Preliminary Datasheet Mar/07 US651 / US661 Two-Coil Low Noise Fan Driver 10 Unique Features 10.1 Soft Switching & Slope setting The US651/661 provides an efficient solution for low noise application with internal slope control circuit, controllable via a dedicated pin. In Two-coil fan driver, the predominant source of electrical noise is when the output driver is switched off. Due to the electromotive force of the fan coil, the output voltage sharply increases but is internally clamped by the fan driver. This effect lasts until the energy in the coil is dissipated, then the output voltages decreases to a normal value, equal to the sum of the fan supply voltage plus the back EMF of the fan in rotation. The resulting swift change in the coil current increases the overall acoustic noise. (a) – General view (b) – Enlarged view on output switching Figure 1 – Output voltage without slope control (RSLOPE = 0оhm) In the above Fig.1a is observed the US651/661 output voltage with traditional driving technique, also referred as “hard switching”. In this case, the output driver is directly switched on and off which results in large voltage spikes, clamped at the output clamping voltage value (Fig.1b). (a) – General view (b) – Enlarged view on output switching Figure 2 – Output voltage with internal slope control (RSLOPE not connected, SLOPE pin left open) When the SLOPE pin is left open (not connected), the US651/661 provides internally defined output slope duration. In contrast with the “hard switching”, the “soft switching” technique controls the output voltage at the switching event and a rise/fall time is implemented to the driving signal. On Fig.2b, the output clamping voltage is even not reached, result of a smoother recirculation of the fan coil current. (a) – General view (b) – Enlarged view on output switching Figure 3 – Output voltage with long output slope duration (RSLOPE = 500k) When a simple resistor is connected between the SLOPE pin the ground, the US651/661 modifies the output slope duration in relation with the value of the resistor RSLOPE. The output slope duration can be increased so that the output voltages spikes from Fig.1 are totally removed on Fig.3. For most of the application, the internal soft switching mode from the Fig.2 represents the simplest solution and most adequate balance between low fan acoustic noise and IC power dissipation. 390109020902 Rev 002 Page 6 of 12 Preliminary Datasheet Mar/07 US651 / US661 Two-Coil Low Noise Fan Driver It is also possible to run into the 3 different modes as “hard switching”, “internal soft switching” and “external soft switching”, giving the possibility to adapt the fan design to stringent requirements. For example, high speed fan generally requires longer output slope compared to usual middle or low speed fan. Increasing the output slope duration inevitably leads to high power dissipation of the IC itself. However, the device is well protected against over power dissipation thanks to the integrated thermal shutdown. 10.2 Enhanced Locked Rotor Protection Specially designed for driving large fans, the Locked Rotor Protection is optimised for low start-up voltage. At low voltage, fans inevitably starts rotating slower than at higher voltage. Big fans with large inertia 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 US651/661 provides an adequate and simple solution to prevent this by automatically increasing the locked rotor protection period at low voltage. The device internally compares the supply voltage applied on the VDD and automatically double the LRP periods at 5V (0.6s, 3.65s) compared than 12V (0.29s, 1.5s). 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). 11 Performance Graphs 11.2 RDSON vs VDD 11.1 RDSON vs TJ 10 10 VDD = 5V 9 VDD = 12V Tj = -40°C 8 8 7 7 6 6 Ron (ohms) Ron (ohms) 9 5 4 Tj = 25°C Tj = 85°C Tj = 125°C 5 4 3 3 2 2 1 1 0 0 -40 -20 0 20 40 60 80 100 120 3 4 5 6 7 8 9 Tj (°C) 11.3 IDD vs TJ 11 12 13 14 15 16 17 18 11.4 IDD vs VDD 5 5 4 4 3 3 IDD (mA) IDD (mA) 10 VDD (Volts) 2 Tj = -40°C 2 Tj = 25°C Tj = 85°C VDD = 5V 1 Tj = 125°C 1 VDD = 12V 0 0 -40 -20 0 20 40 60 80 100 120 3 Tj (°C) 390109020902 Rev 002 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 VDD (Volts) Page 7 of 12 Preliminary Datasheet Mar/07 US651 / US661 Two-Coil Low Noise Fan Driver 11.5 Internal Slope Duration vs VDD 11.6 Slope Duration vs VDD 200 1200 180 1100 R = 700k R = 500k R = 300k R = 100k R = 50k 1000 160 900 Output Slope (us) Output Slope (us) 140 Tj = 25°C 120 100 80 60 800 700 600 500 400 300 40 200 20 100 0 0 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 3 4 5 6 7 8 9 VDD (Volts) 10 11 12 13 14 15 16 17 18 VDD (Volts) 11.8 ILEAK vs. TJ 11.7 VOL vs. TJ 0.5 100 Tj = -40°C 80 Tj = 25°C 0.3 Leakage Current (uA) FG/RD Output Saturation Voltage (V) 90 0.4 VDD=5V ; Iol=4mA VDD=12V ; Iol=4mA 0.2 70 Tj = 125°C 60 50 40 30 20 0.1 10 0 0 -40 -20 0 20 40 60 80 100 3 120 4 5 6 7 8 9 10 11.9 IFGLIM vs. VDD 12 13 14 15 16 17 18 11.10 PDmax vs. TA 50 0.8 45 Single Layer PCB Pmax = 666mW 0.7 35 Allowable Power Dissipation (W) 40 Current limit (mA) 11 VDD (Volts) Tj (°C) Tj = 25°C Tj = 125°C 30 25 20 15 TA = 25°C 0.6 RTH 1S = 150°C/W 0.5 0.4 TA max = 85°C 0.3 0.2 10 0.1 5 0 TJ max = 125°C 0 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 -40 VDD (Volts) 390109020902 Rev 002 -20 0 20 40 60 80 100 120 140 Ta (°C) Page 8 of 12 Preliminary Datasheet Mar/07 US651 / US661 Two-Coil Low Noise Fan Driver 12 Application Information Typical computer fan application circuit 13 Application Comments During fan rotation, the coils may affect the stability of the VDD voltage. To filter eventual spikes, it is recommended to add a 100nF decoupling capacitor between VDD pin and GND, closer to the chip. If the FG/RD pull-up resistor is connected to VDD, a diode should be connected between the fan supply voltage and the common point of the fan coils to avoid parasitic effects on FG/RD output. The voltage VDD and VPU can be physically the same voltage source. However, the pull-up voltage VPU is generally connected to a different digital power source at 5V as it feeds the FG or RD signal to an IC interface. When the default slope is sufficient, the pin SLOPE may just be left open. For slope adjustment, it is required to connect a resistor RSLOPE between the SLOPE pin to ground. The value of the resistor modifies the output slope as shown in the performance graph. 390109020902 Rev 002 Page 9 of 12 Preliminary Datasheet Mar/07 US651 / US661 Two-Coil Low Noise Fan Driver 14 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 15 ESD Precautions Electronic semiconductor products are sensitive to Electro Static Discharge (ESD). Always observe Electro Static Discharge control procedures whenever handling semiconductor products. 390109020902 Rev 002 Page 10 of 12 Preliminary Datasheet Mar/07 US651 / US661 Two-Coil Low Noise Fan Driver 16 DC Package Information (8-pin narrow SOIC) 8 7 6 5 3.81 3.99 5.80 6.20 Notes: 1. Controlling dimensions in millimeters 2. Detail of pin #1 identifier are optional but must be located within the zone indicated. 3. Lead coplanarity should be to 0.10mm max. 0.41 1.27 1 2 3 4. All dimensions excluding mold flashes and end flash from the package body shall not exceed 0.25mm per side. 4 DETAIL A Pin 1 Mark see note 2 Marking: 4.80 4.98 1.52 1.72 1.37 1.57 h x 45° 0.36 0.46 1.27 BSC Line 1 : US651 (US661) - Name of the Device Line 2 : XXXXXX - Assembly lot number (6 digits) Line 3 : YYWW - Assembly date YY = year WW = calendar week 0.19 0.25 Seating Plane See DETAIL A 0.63 Hall plate location Notes: 1. All dimensions are in millimeters 0.023 2. Hall plate location in X and Y relative to package center 3. Assembly tolerances +/-0.1 390109020902 Rev 002 Page 11 of 12 Preliminary Datasheet Mar/07 US651 / US661 Two-Coil Low Noise Fan Driver 17 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. © 2002 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: [email protected] All other locations: Phone: +1 603 223 2362 E-mail: [email protected] ISO/TS 16949 and ISO14001 Certified 390109020902 Rev 002 Page 12 of 12 Preliminary Datasheet Mar/07