NJU7333 Single-phaseDC Brushless Motor Driver IC ■ GENERAL DESCRIPTION ■ PACKAGE OUTLINE The NJU7333 is a single-phase DC brushless motor driver IC for small fan-motor and high power applications. It features MOS-FET driver circuit for better saturation characteristics. Slew late of amplifiers and feedback resistors are optimized to achieve low-noise motor operation. Maximum output current is 500mA. The NJU7333 includes. frequency generator (FG) output, lock detect (with auto recovery circuit) ,and a thermal shutdown circuit . NJU7333R ■ FEATURES • Operating Voltage VDD=2.4 ∼ 5.5V • FG Output • Internal Lock Detect / Auto Recovery Circuit • Internal Thermal Shutdown Circuit • Low Operating Current IDD=3mA (Typ.) • Low Saturation Output Voltage Vsat=±0.35V @Io=±500mA • C-MOS Technology • Package Outline VSP10 ■ BLOCK DIAGLAM ■ PIN FUNCTION 1:Ct 2: FG 3: Vdd 4: OUT B 5: Vss 6: Vss 7: OUT A 8: Vdd 9: IN10: IN+ -1- NJU7333 Preliminary ■ ABSOLUTE MAXIMUM RATINGS PARAMETER RATINGS Supply Voltage Input Voltage Output Current (Peak) Operating Temperature Range Storage Temperature Range Power Dissipation SYMBOL (unit) +7.0 -0.3 ∼ VDD+0.3 1.0 -40 ∼ +85 -50 ∼ +150 400 ■ RECOMMENDED OPERATING CONDITIONS PARAMETER SYMBOL (Ta=25°C) NOTE VDD (V) VID(V) IO PEAK (A) Topr (°C) Tstg (°C) PD (mW) Device itself (VDD=5V, Ta=25°C) TYP. MAX. UNIT 5.0 5.5 V VDD CONDITION - MIN. 2.4 Tj - -40 - 85 °C Input Common Mode Voltage Range VICM - 0.4 - 4.0 V Output Current Io - - - 0.5 A Supply Voltage Operating Temperature Range -2- NJU7333 Preliminary ■ ELECTRICAL CHARACTERISTICS PARAMETER SYMBOL (VDD=5V, Ta=25°C) TYP. MAX. UNIT CONDITION MIN. IDD - - 3.0 4.0 mA TTSD - - 180 - °C THYS - - 50 - °C Input Offset Voltage VIO - -7 - 7 mV Feedback Resistance RF - 22.0 27.5 33.0 kΩ Open loop gain AV - - 80 - dB Input Common Mode Voltage Range VICM - 0.4∼4.0 - - V VOH Io=+350mA 4.65 4.75 - VOL Io= -350mA - 0.25 0.35 RONH Io=+500mA - 0.5 - RONL Io= -500mA - 0.5 - FG L Output Voltage VFG 4pin=5V,3pin=0V, RP=10kΩ - - 0.3 V FG H Leak Current IFG - LEAK 4pin=0V,3pin=5V, RP=10kΩ - - 1.0 µA VLOP - 4.0 - - V IDCHG - - 1.5 - µA IDCHG - - 0.5 - µA Clamp Voltage VCL - - 2.6 - V Detect Voltage VID - - 0.6 - V General Operating Current Thermal Shutdown Temperature Thermal Shutdown Hysteresis Hall Amplifier Outputs Maximum Output Voltage Range Output Resistance Lock Detect Circuits Lock Protect Operating Voltage Lock Detect Discharge Current Lock Detect Discharge Current V Ω -3- NJU7333 Preliminary ■ APPLICATION NOTE The NJU7333 is a single-phase DC brushless motor driver IC featuring CMOS process. It is suitable for fan motor drivers for a small equipment such as the note personal computers. [Application Circuit Example] V+ D1 C1 GND R3 R1 VDD Hall element OUTA IN+ Motor INR2 Ct OUTB NJU7333 C2 VSS FG FG out [Design Notes] Above application example is designed for 5V operation with motor current of 500mA. It uses the following components: Hall Elements: HW101A (AKE) 1. Selection of C1 and D1: C1 is used for a noise reduction purpose. A typical value is 0.1uF. Optimize the value in actual operating conditions if necessary. D1 is a diode for protection against reverse voltage supply. Silicon rectifier diode (WO3C, 10D1 and equivalent) is appropriate. 2. Lock Protection Function (Design of C2 value): Lock Protection Function, consists of Motor Lock Detection and Auto Resume Function, is a safety feature to protect a motor and a driver circuit from fatal destruction in case of motor halt. Motor Lock Detection detects motor halt due to irregular load conditions and then cuts motor driving current f or safety operation. A value of C2 determines Lock detection time (Ton) and Auto Resume Time (Toff). -4- NJU7333 Preliminary Lock detection time (Ton) is given by: TON = C 2 VCL − VID [sec] ICHG Where C2 is 0.47uF: TON = 0.47 × 10 − 6 × 2 .6 − 0 . 6 = 0.62[sec ] 1.5 × 10 − 6 Auto Resume Time (Toff) is given by: TOFF = C 2 VCL − VID [sec] IDCHG Where C2 is 0.47uF: TOFF = 0.47 × 10 − 6 × 2.6 − 0.6 = 1.88[sec ] 0.5 × 10 − 6 In actual application, Lock detection time (Ton) is affected by the mechanical time constant of a motor. Therefore, constant start up must be confirmed in actual evaluation taking operating variations (i.e.Temperature, Voltage change and so on) in consideration. A typical value of C2 is either 0.47uF or 1uF depending on a motor. Hall input Motor output Ct Terminal voltage Toff Ton Motor Lock protection period Motor Locked Returns to normal operation 3. Design of hall element bias resistance (R1 and R2) Hall amplifier is a differential amplifier with hysteresis characteristics (24mV typical). The common-mode input voltage is between 0.4V and VDD-1V and the input signal must be within the range.Non-excitation hall bias voltage is to be set at a half of VDD for effective use of common-mode input voltage range. Therefore the same value of hall bias resistors is selected for R1 and R2. -5- NJU7333 Preliminary Given that the bias current is set to be 5mA by HW101A datasheet, R1 and R2 can be determined as follows: R1 + R 2 + Rin = R1 = R 2 = 300 Ω VDD 5 = = 1kΩ Ihbias 5 × 10 −3 The output voltage of hall elements is influenced by the bias current and magnetic flux density of hall elements. The optimum input voltage of NJU7333 is 100mVp-p and higher. With such input voltage, the highest efficiency can be obtained. 4. Design of FG output resistsnce (R3) FG Out(FG:Pin2) is a open drain output and R3 is a pull up register. A typical value of R3 is 10kΩ. The timing chart of FG Out is as follows. Hall input IN+ FG Terminal voltage The specifications on this data book are only given for information, without any guarantee as regards either mistakes or omissions. The application circuit in this data book are described only to show representative usages of the product and not intended for the guarantee or permission of any right including the industrial rights. -6-