Ordering number: EN3302A Monolithic Digital IC LB1820 Office Automation-Use 3-Phase Brushless Motor Driver Overview Package Dimensions The LB1820 is a three-phase brushless motor with a digital speed control circuit built in. The LB1820 is ideally suited for use in office automation applications such as laser beam printers and drum motor drivers. unit : mm 3147-DIP28HS [LB1820] Features . Three-phase brushless motor driver with digital speed control . function V withstand voltage and 2.5 A output current . 30Current limiter built in . Low-voltage protection circuit built in . Thermal shutdown circuit built in . Hall amp with hysteresis . Start/stop pin built in . Crystal oscillator and divider built in . Digital speed control circuit built in . Lock detector built in SANYO : DIP28HS Specifications Absolute Maximum Ratings at Ta = 25 °C Parameter Symbol Maximum supply voltage 1 VCC Maximum supply voltage 2 VM Output current IO Conditions t % 100 ms Allowable power dissipation 1 Pd max 1 Independent IC Allowable power dissipation 2 Pd max 2 With arbitrarily large heat sink Ratings Unit 30 V 30 V 2.5 A 3 W 20 W Operating temperature Topr –20 to +80 °C Storage temperature Tstg –55 to +150 °C Ratings Unit 9.5 to 28 V Allowable Operating Ranges at Ta = 25 °C Parameter Supply voltage range 1 Symbol VCC Conditions Supply voltage range 2 VM 5 to 28 V Voltage regulator output current IVH 0 to +20 mA IOSC 0 to +30 mA ILD 0 to +20 mA Comparator output current Lock detector output current SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN 43096HA(II)/3260TA, TS(GTPS) No.3302-1/7 LB1820 Electrical Characteristics at Ta = 25 °C, VCC = VM = 24 V Parameter Supply current 1 Supply current 2 Output saturation voltage Output leak current Voltage regulator Output voltage Voltage variation Load variation Temperature coefficient Hall amp Input bias current Common-mode input voltage Hall input sensitivity Hysteresis width Low-to-high input voltage High-to-low input voltage Oscillator High-level output voltage Low-level output voltage Oscillation amplitude Oscillation frequency Temperature coefficient Comparator output voltage Current limiter Limiter 1 Limiter 2 Thermal shutdown Thermal shutdown temperature Hysteresis width Low-voltage protection voltage Hysteresis width FG amp Input offset voltage Input bias current High-level output voltage Low-level output voltage FG input sensitivity Schmitt width at next stage Operating frequency range Open-loop voltage gain Speed discriminator High-level output voltage Low-level output voltage Maximum clock frequency Number of counts Integrator Input offset voltage Input bias current High-level output voltage Low-level output voltage Open-loop gain Gain-bandwidth product Reference voltage 5 V supply Symbol ICC1 ICC2 VO (sat) 1 VO(sat)2 IO leak VH ∆VH1 ∆VH2 Conditions Stop mode IO = 1 A IO = 2 A IVH = 10 mA VCC = 9.5 to 28 V IVH = 5 to 20 mA IHB VICM VOH(CR) VOL(CR) VOSC 2.9 0.9 1.8 R = 30 kΩ, C = 1500 pF Design target ∆TSD VLVSD ∆VLVSD VIO(FG) IB(FG) VOH(FG) VOL(FG) typ 33 3 2.1 3.0 max 50 5 3.0 4.2 100 Unit mA mA V V µA 4.15 60 60 –2 4.5 150 150 V mV mV mV/ °C 1 4 2.8 33 20 –13 42 32 –1 µA V mVp-p mV mV mV 3.2 1.1 2.1 18.5 0.1 3.5 1.3 2.4 IOSC = 20 mA VRf1 VRf2 TSD 3.8 1.5 100 24 8 –25 ∆VIN VSLH VSHL f ∆f min IFG = –2 mA I(FG) = 2 mA 10 × Gain 1.5 V V V kHz %/ °C V 0.6 0.48 V V 0.42 0.4 0.5 0.44 150 180 7.5 0.45 30 8.1 0.6 8.7 0.75 6.2 1 +10 +1 6.8 1.5 –10 –1 5.6 °C 5 16 5 60 VOH(D) VOL(D) 4.7 0.3 1.0 2044 VIO(INT) IB(INT) VOH(INT) VOL(INT) –10 –0.4 3.7 V5 mV µA V V mV mV kHz dB V V MHz 2046 2048 4.3 0.8 +10 +0.4 4.9 1.2 1.6 V5/2 5 5% 5.4 60 –5% 4.6 °C V V mV µA V V dB MHz V V Continued on next page. No.3302-2/7 LB1820 Continued from preceding page. Parameter Lock detector Low-level output voltage Lock range Start/stop pin Start/stop operating voltage Crystal Oscillator Precision of oscillating frequency Temperature coefficient Drift in rotational speed Symbol VOL(LD) Conditions min ILD=10 mA typ max 0.5 V % 0.6 V ±3.125 0.4 Referenced to indicated frequency 0.5 –500 +500 –3 ±0.01 Unit ppm ppm/ °C % Truth Table Source → Sink Input IN1 IN2 IN3 1 OUT 3 → OUT 2 H H L 2 OUT 3 → OUT 1 H L L 3 OUT 2 → OUT 1 H L H 4 OUT 2 → OUT 3 L L H 5 OUT 1 → OUT 3 L H H 6 OUT 1 → OUT 2 L H L Pin Assignment Allowable power dissipation, Pd max – W Top view With arbitrarily large heat sink Without heat sink Ambient temperature, Ta – °C No.3302-3/7 LB1820 Internal Equivalent Circuit Block Diagram No.3302-4/7 LB1820 Pin Description Pin No. Pin Name 19, 20 17, 18 15, 16 IN+1, IN–1 IN+2, IN–2 IN+3, IN–3 6 8 10 OUT 1 OUT 2 OUT 3 Functions OUT 1: Hall element input pins for Phase 1. ‘‘H’’ logic is the state when IN+ > IN−. OUT 2: Hall element input pins for Phase 2. ‘‘H’’ logic is the state when IN+ > IN−. OUT 3: Hall element input pins for Phase 3. ‘‘H’’ logic is the state when IN+ > IN–. Output pin 1. Output pin 2. Output pin 3. 2 VCC Power supply for other than output blocks. 12 VM Power supply for output blocks. 11 Rf Output current detection pin. Rf is connected across this pin and GND to detect the output current as voltage. 14 GND 3 CR 1 OSC 24 INTOUT Ground for other than output blocks. The lowest potential of output transistor is the voltage at Rf pin. Sets the oscillating frequency of the switching regulator. Outputs duty-controlled pulses. Open-collector output. Integrator output pin (speed control pin). Varies the switching regulator output voltage. 25 INTIN Integrator input pin. 23 DOUT Speed discriminator output pin. Goes LOW when the specified speed is exceeded. 4 C Suppresses ripples in the motor current during operation of current limiter 2. 22 LD Lock detection pin. Goes HIGH when the motor rotation speed is within the locking range. 27 26 FGIN– FGIN+ FG pulse input (Start/Stop control) pin. FG pulse input (4 V supply) pin. 28 FGOUT FG amp output pin. 21 Xtal Crystal oscillator connecting pin. 13 5V 5 V supply pin. No.3302-5/7 LB1820 Operation Notes Speed Control Circuit This IC uses a speed discrimination circuit to perform speed control. The rotation accuracy of the speed discrimination method depends on the counter count. The counter count in this IC is 2046. On the FG1 cycle, a speed error signal with a resolution of 1/2046 is output from the DOUT pin (charge pump method). The DOUT output shifts among three states: high, high impedance, and low: High : Output S (acceleration signal) High impedance : When neither output S nor output F is output Low : Output F (deceleration signal) The relationship between the FG frequency (fFG) and the quartz oscillation frequency (fOSC) can be calculated as follows: fFG = fOSC ÷ (ECL division ratio × count) fOSC ÷ (8 × 2046) fOSC ÷ 16368 PAM Drive System This IC controls motor rotations by configuring an external switching regulator, and controlling the voltage (VM) of the regulator. Select a switching regulator diode with a short reverse recovery time such as an FRD (First Recovery Diode). Because even a smooth coil can become a noise source, attention must be paid to the arrangement of components on the board (especially avoiding the effects of FG signal lines and integrated amplifiers). Select a normal rectifier diode for the upper and lower motor drive pin section (OUT1 to 3). Current Limiter Circuit The current limiter circuit consists of two limiter circuits. 1 Limiter 1 Detection voltage VRf1 = 0.5 V typ. Current is limited by putting the lower output transistor in the nonsaturated state and then dropping the voltage applied to the motor. 2 Limiter 2 Detection voltage VRf2 = 0.44 V typ. The VM voltage is limited by limiting the OSC pin ‘‘on duty’’ ratio. Normally, if an excessive load is put on the motor, limiter 1 operates first, and after a delay in the switching regulator, limiter 2 operates. Sometimes, after startup, the ASO of the output transistor is very severe. In such a case, it is necessary to perform a soft start (in which VM is increased gradually). When using soft starts, connect a capacitor between the pin (VM, 5 V, etc.) on which the voltage is to be increased during startup and the C pin. If soft starts are not to be used, connect a capacitor between the C pin and ground. Speed Lock Range The speed lock signal is output from the LD pin. The speed lock range is within ±3.13%; if the motor rotations fall within the lock range the LD pin goes low (open collector output). Start/stop Operation The FGIN− pin also serves as the start/stop pin. When the FGIN− pin is connected to a transistor, etc., and the voltage is 0.5 V typ. or less, the stop state goes into effect. In the stopped state, in addition to the drive outputs being turned off, the FGIN+, 5 V, and other regulator outputs are also turned off. When it is necessary to drive the motor at high speed, improvement is possible by adding a resistor (of approximately 1 MΩ) between FGOUT and VCC. (The time from when the transistor is turned off until FGIN− goes to 0.5V is reduced.) Initial Reset Operation At startup, it is possible to apply an initial reset to the logic circuits by delaying the increase in voltage on FGIN−. If an initial reset is not applied, the LD pin may go low from start until the FG pulse is input to the logic circuits (until output of approximately 16 mVp-p is generated on FGOUT). When an FG reset is applied, the capacitor between the FGIN+ and GND should be 4.7 µF or more (in order to delay the rise in FGIN−). Caution is required, because if the FG amplifier input capacitor is too small and the feedback capacitor is too large, the reset time will be shorter. At start, a delay of about 5 µs or more from the rising edge of the 5 V regulator output until the FGIN− voltage goes to 1.2 V is desirable. No.3302-6/7 LB1820 PWM Frequency Setting The PWM frequency is determined by the resistor and capacitor connected to the CR pin. When a resistor is connected to the FGIN+ pin, the PWM frequency can be roughly calculated by the following formula: fPWM 6 1 ÷ (1.2 × C × R) The resistor must not be less than 30 kΩ. It is desirable for the PWM frequency to be about 15 kHz. Quartz Oscillator An oscillator, capacitor and resistor are to be connected to the quartz oscillator. When selecting the oscillator and the external capacitor and resistor, always obtain approval from the manufacturer of the oscillator in order to avoid problems. (Circuit with external quartz oscillator) External constants (reference values) Xtal (MHz) C1 (pF) C2 (pF) R (kΩ) 3 to 4 39 82 0.82 4 to 5 39 82 1.0 5 to 7 39 47 1.5 7 to 10 39 27 2.0 However, use a crystal such that the base wave fO impedance : 3fO impedance = 1 : 5 or more When inputting external signals (of several MHz) to the quartz oscillator, connect external components as shown in the diagram below. 5 V pin fIN = 1 to 8 MHz Input signal level High level voltage: 4.0 V min. Low level voltage: 1.5 V max. Ra = 2 kΩ, Rb = 1 kΩ (reference values) Xtal pin Input No products described or contained herein are intended for use in surgical implants, life-support systems, aerospace equipment, nuclear power control systems, vehicles, disaster/crime-prevention equipment and the like, the failure of which may directly or indirectly cause injury, death or property loss. Anyone purchasing any products described or contained herein for an above-mentioned use shall: 1 Accept full responsibility and indemnify and defend SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors and all their officers and employees, jointly and severally, against any and all claims and litigation and all damages, cost and expenses associated with such use: 2 Not impose any responsibility for any fault or negligence which may be cited in any such claim or litigation on SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors or any of their officers and employees jointly or severally. Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed for volume production. SANYO believes information herein is accurate and reliable, but no guarantees are made or implied regarding its use or any infringements of intellectual property rights or other rights of third parties. This catalog provides information as of April, 1996. Specifications and information herein are subject to change without notice. No.3302-7/7