Ordering number : ENN7257A Monolithic Digital IC LB11872H Three-Phase Brushless Motor Driver for Polygonal Mirror Motors Overview Package Dimensions The LB11872H is a three-phase brushless motor driver developed for driving the motors used for the polygonal mirror in laser printers and similar applications. It can implement, with a single IC chip, all the circuits required for polygonal mirror drive, including speed control and driver functions. The LB11872H can implement motor drive within minimal drive noise due to its use of current linear drive. unit: mm 3233A-HSOP28H [LB11872H] 0.65 15.2 (6.2) 7.9 Functions and Features 1 14 0.8 2.0 0.25 0.3 2.45max (2.25) (0.8) 0.1 • Three-phase bipolar current linear drive + midpoint control circuit • PLL speed control circuit • Speed is controlled by an external clock signal. • Supports Hall FG operation. • Built-in output saturation prevention circuit • Phase lock detection output (with masking function) • Includes current limiter, thermal protection, rotor constraint protection, and low-voltage protection circuits on chip. • On-chip output diodes. 10.5 15 4.9 28 2.7 SANYO: HSOP28H Specifications Absolute Maximum Ratings at Ta = 25°C Parameter Symbol Supply voltage VCC max Output current IO max Conditions Ratings 30 Unit V T ≤ 500 ms 1.2 A 0.8 W Allowable power dissipation 1 Pd max1 Independent IC Allowable power dissipation 2 Pd max2 Mounted on a PCB (114.3 × 76.1 × 1.6 mm, glass epoxy) 2.0 W Operating temperature Topr –20 to +80 °C Storage temperature Tstg –55 to +150 °C Any and all SANYO products described or contained herein do not have specifications that can handle applications that require extremely high levels of reliability, such as life-support systems, aircraft’s control systems, or other applications whose failure can be reasonably expected to result in serious physical and/or material damage. Consult with your SANYO representative nearest you before using any SANYO products described or contained herein in such applications. SANYO assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all SANYO products described or contained herein. SANYO Electric Co.,Ltd. Semiconductor Company TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN 91002AS (OT) No. 7257 -1/13 LB11872H Allowable Operating Ranges at Ta = 25°C Parameter Symbol Supply voltage range Conditions Ratings Unit VCC 10 to 28 V 6.3 V regulator-voltage output current IREG 0 to –20 mA LD pin applied voltage VLD 0 to 28 V LD pin output current ILD 0 to 15 mA FGS pin applied voltage VFG 0 to 28 V FGS pin output current IFG 0 to 10 mA Electrical Characteristics at Ta = 25°C, VCC = VM = 24 V Parameter Symbol Conditions Ratings min typ Unit max Supply current 1 ICC1 Stop mode 5 7 mA Supply curren 2 ICC2 Start mode 17 22 mA [Output Saturation Voltages VAGC = 3.5 V] SOURCE (1) VSAT1-1 IO = 0.5 A, RF = 0 Ω 1.7 2.2 V SOURCE (2) VSAT1-2 IO = 1.0 A, RF = 0 Ω 2.0 2.7 V SINK (1) VSAT2-1 IO = 0.5 A, RF = 0 Ω 0.4 0.9 V SINK (2) VSAT2-2 IO = 1.0 A, RF = 0 Ω 1.0 1.7 V Output leakage current IO (LEAK) VCC = 28 V 100 µA [6.3 V Regulator-Voltage Output] Output voltage Voltage regulation VREG ∆VREG1 6.25 6.60 V VCC = 9.5 to 28 V 5.90 50 100 mV 10 60 Load regulation ∆VREG2 Iload = –5 to –20 mA Temperature coefficient ∆VREG3 Design target value 0 mV mV/°C [Hall Amplifier Block] Input bias current IB (HA) Differential input voltage range VHIN Common-phase input voltage range VICM Input offset voltage VIOH Differential input: 50 mVp-p SIN wave input 2 10 50 *600 Differential input: 50 mVp-p 2.0 VCC – 2.5 Design target value –20 20 µA mVp-p V mV [FG Amplifier and Schmitt Block (IN1)] Input amplifier gain GFG 5 Input hysteresis (high to low) VSHL 0 mV Input hysteresis (low to high) VSLH –10 mV Hysteresis width VFGL Input conversion 4 7 deg 12 mV [Low-Voltage Protection Circuit] Operating voltage Hysteresis width VSD 8.4 8.8 9.2 V ∆VSD 0.2 0.4 0.6 V 150 180 °C 40 °C [Thermal Protection Circuit] Thermal shutdown operating temperature Hysteresis width TSD Design target value (junction temperature) ∆TSD Design target value (junction temperature) [Current Limiter Operation] Acceleration limit voltage VRF1 0.53 0.59 0.65 V Deceleration limit voltage VRF2 0.32 0.37 0.42 V [Error Amplifier] Input offset voltage Input bias current VIO (ER) Design target value IB (ER) High-level output voltage VOH (ER) IOH = –500 µA Low-level output voltage VOL (ER) DC bias level VB (ER) –10 10 mV –1 1 µA VREG – 1.2 IOL = 500 µA VREG – 0.9 V 0.9 1.2 V –5% 1/2VREG 5% V VREG – 0.2 VREG – 0.1 [Phase Comparator Output] High-level output voltage VPDH IOH = –100 µA Low-level output voltage VPDL IOL = 100 µA Output source current IPD+ VPD = VREG/2 Output sink current IPD– VPD = VREG/2 Note*: Since kickback can occur in the output waveform if the Hall input amplitude is too large, the Hall input amplitudes should be held to under 350 mVp-p. 0.2 1.5 V 0.3 V –500 µA mA Continued on next page. No. 7257 -2/13 LB11872H Continued from preceding page. Parameter Symbol Conditions Ratings min typ Unit max [Lock Detection Output] Output saturation voltage VLD (SAT) ILD = 10 mA Output leakage current ILD (LEAK) VLD = 28 V 0.15 0.5 V 10 µA [FG Output] Output saturation voltage VFG (SAT) IFG = 5 mA Output leakage current IFG (LEAK) VFG = 28 V 0.15 0.5 V 10 µA 300 mV [Drive Block] Dead zone width VDZ Output idling voltage VID Forward gain 1 GDF+1 With the phase is locked With phase locked 50 0.4 100 0.5 6 mV 0.6 deg Forward gain 2 GDF+2 With phase unlocked 0.8 1.0 1.2 deg Reverse gain 1 GDF–1 With phase locked –0.6 –0.5 –0.4 deg Reverse gain 2 GDF–2 With phase unlocked –0.8 –1.0 –1.2 deg 5.0 5.6 Acceleration command voltage VSTA Deceleration command voltage VSTO V 0.8 1.5 V Forward limiter voltage VL1 Rf = 22 Ω 0.53 0.59 0.65 V Reverse limiter voltage VL2 Rf = 22 Ω 0.32 0.37 0.42 V Oscillation frequency fOSC C = 0.022 µF High-level pin voltage VCSDH 4.3 4.8 5.3 V Low-level pin voltage VCSDL 0.75 1.15 1.55 V 3 5 7 µA 0.80 V Hz [CSD Oscillator Circuit] External capacitor charge and discharge current ICHG 31 Lock detection delay count CSDCT1 Clock cutoff protection operating count CSDCT2 2 Lock protection count CSDCT3 31 Initial reset voltage Hz 7 VRES 0.60 [Clock Input Block] External input frequency fCLK 400 10000 High-level input voltage VIH (CLK) Design target value 2.0 VREG V Low-level input voltage VIL (CLK) Design target value 0 1.0 V Input open voltage VIO (CLK) 2.7 3.0 3.3 V Hysteresis width VIS (CLK) Design target value 0.1 0.2 0.3 V High-level input current IIH (CLK) V (CLK) = VREG 140 185 Low-level input current IIL (CLK) V (CLK) = 0 V –185 –140 µA µA [S/S Pin] High-level input voltage VIH (S/S) 2.0 VREG V Low-level input voltage VIL (S/S) 0 1.0 V Input open voltage VIO (S/S) 2.7 3.0 3.3 V Hysteresis width VIS (S/S) 0.1 0.2 0.3 V High-level input current IIH (S/S) V (S/S) = VREG 140 185 Low-level input current IIL (S/S) V (S/S) = 0 V –185 –140 µA µA Three-Phase Logic OUT1 to OUT3 (H: Source, L: Sink) IN1 IN2 IN3 OUT1 OUT2 OUT3 H L H L H M H L L L M H H H L M L H L H L H L M L H H H M L L L H M H L For IN1 to IN3, “H” means that IN+ is greater than IN–, and “L” means IN– is greater than IN+. For OUT1 to OUT3, “H” means the output is a source, and “L” means that it is a sink. No. 7257 -3/13 LB11872H LD CLK S/S 21 20 19 18 17 16 15 8 9 10 11 12 13 14 CSD NC FG HSOP28H PD 22 NC VREG 23 EI VCC 24 EO SUB 25 MN RF 26 FC OUT1 27 AGC OUT2 28 GND OUT3 Pin Arrangement 7 NC 6 GND IN2– 5 IN3– IN2+ 4 IN3+ 3 IN1– 2 IN1+ 1 NC LB11872H Pd max – Ta Allowable Power Dissipation, Pdmax – W 2.4 Mounted on a specified board. (114mm × 71.1mm × 1.6mmt, glass epoxy) 2 1.6 1.2 1.12 Independent IC 0.8 0.45 0.4 0 –20 0 20 40 60 80 100 Ambient temprature, Ta – °C No. 7257 -4/13 LB11872H Pin Functions Pin No. Symbol FRAME GND 1 NC 2 to 7 IN1+ to IN3+ IN1– to IN3– 8 AGC 9 MN 10 NC 11 NC 12 CSD 13 NC 14 FG Pin GND pin NC (No connection) pin Hall sensor input pins These pins input the Hall effect sensor signal for each phase. The logic of these inputs is that the input is “high” when VIN+ is greater than VIN–. Frequency characteristics correction pin Insert a capacitor between pin 8 and ground. Test pin This pin must be left open. Phase lock detection chattering prevention pin Insert a capacitor between pin 12 and ground. FG output pin This is an open-collector output Low: start mode 15 S/S Start/stop switching pin 16 CLK Clock signal input pin 17 LD Phase lock detection output pin 18 PD Phase comparator output pin 19 EI Error amplifier input pin 20 EO Error amplifier output pin 21 FC Frequency characteristics correction pin Insert a capacitor between pin 21 and ground. 22 VREG Stabilized power supply output pin Insert a capacitor between pin 22 and ground. This pin goes to the on state when the phase is locked. It is an open-collector output. 23 VCC Power supply pin 24 SUB SUBGND pin Connect this pin to ground. Output current detection pin Insert a resistor between pin 25 and ground. 25 Rf 26 to 28 OUT1 to 3 Output pins No. 7257 -5/13 FG LD 12 CSD MN 9 FG 14 LD 17 22 Vreg ×5 RESET OSC 6.3VREG LD FILTER FG 4 5 IN1 2 3 IN2 6 7 IN3 HALL AMP & MATRIX RESTRICT DET LOCK DET PD PLL 18 16 CLOCK DET PD CLK CLK EI 19 8 AGC AGC V - AMP EO 20 24 SUB OUTPUT OCL LVSD TSD FREAM GND OUT1 OUT2 OUT3 26 27 28 25 RF 21 FC 15 S/S 23 Vcc S/S Vcc LB11872H LB11872H Equivalent Circuit Block Diagram No. 7257 -6/13 LB11872H Pin Circuits and Functions Pin No. Pin Function Equivalent circuit Vcc Hall effect sensor signal inputs 2 IN2+ 3 IN2– 4 IN1+ 5 IN1– 6 IN3+ 7 IN3– These inputs are high when IN+ is greater than IN- and low when IN- is greater than IN+. Insert capacitors between the IN+ and IN– pins to reduce noise. An amplitude of over 50 mA p-p and under 350 mVp-p is desirable for the Hall input signals. 3 5 300Ω 7 300Ω 2 4 6 Kickback can occur in the output waveform if the Hall input amplitude is over 350 mVp-p. VREG AGC amplifier frequency characteristics correction. 8 AGC 9 MN 300Ω Insert a capacitor (about 0.022 µF) between this pin and ground. 8 Monitor pin This pin should be left open in normal operation. VREG 12 CSD Used for both initial reset pulse generation and as the reference time for constraint protection circuits. 300Ω 12 Insert a capacitor between this pin and ground. VREG 14 14 FG FG pulse output. This is an open-collector output. VREG 33kΩ Start/stop control. 15 S/S Low: Start 0 to 1.0 V 5kΩ 15 High: Stop 2.0 V to VREG This pin goes to the high level when open. 30kΩ Continued on next page. No. 7257 -7/13 LB11872H Continued from preceding page. Pin No. Pin Function Equivalent circuit VREG 33kΩ Clock input. 16 CLK Low: 0 to 1.0 V 5kΩ 16 High: 2.0 V to VREG This pin goes to the high level when open. 30kΩ VREG Phase locked state detection output 17 LD 17 This output goes to the on state when the PLL locked state is detected. This is an open-collector output. VREG Phase comparator output (PLL output) 18 PD 18 This pin output the phase error as a pulse signal with varying duty.The output current increases as the duty becomes smaller. VREG 19 EI Error amplifier in put pin. 300Ω 19 VREG 20 EO Error amplifier output pin. 300Ω 20 The output current increases when this output is high. 40kΩ Continued on next page. No. 7257 -8/13 LB11872H Continued from preceding page. Pin No. Pin Function Equivalent circuit VREG Control amplifier frequency correction. 21 FC 21 Inserting a capacitor (about 5600 pF) between this pin and ground will stop closed loop oscillation in the current control system. The output current response characteristics will be degraded if the capacitor is too large. Vcc Stabilized power supply (6.3 V) 22 VREG 23 VCC 24 SUB 22 Insert a capacitor (about 0.1 µF) between this pin and ground for stabilization. Power supply SUB pin. Connect this pin to ground. Output current detection. 25 RF Vcc Insert low-valued resistors (Rf) between these pins and ground. The output current will be limited to the value set by the equation IOUT = VL/RF. VREG 26 27 28 26 OUT1 Motor drive outputs. 27 OUT2 28 OUT3 If the output oscillates, insert a capacitor (about 0.1 µF) between this pin and ground. 300Ω 25 1 10 11 NC No connection (NC) pins. These pins may be used for wiring connections. 13 FRAME GND Ground No. 7257 -9/13 LB11872H Overview of the LB11872H 1. Speed Control Circuit This IC adopts a PLL speed control technique and provides stable motor operation with high precision and low jitter. This PLL circuit compares the phase error at the edges of the CLK signal (falling edges) and FG signal (rising edges (low to high transitions) on the IN1 input), and the IC uses the detected error to control the motor speed. During this control operation, the FG servo frequency will be the same as the CLK frequency. fFG (servo) = fCLK 2. Output Drive Circuit To minimize motor noise, this IC adopts three-phase full-wave current linear drive. This IC also adopts a midpoint control technique to prevent ASO destruction of the output transistors. Reverse torque braking is used during motor deceleration during speed switching and lock pull-in. In stop mode, the drive is cut and the motor is left in the free-running state. Since the output block may oscillate depending on the motor actually used, capacitors (about 0.1 µF) must be inserted between the OUT pins and ground. 3. Hall Input Signals This IC includes an AGC circuit that minimizes the influence on the output of changes in the Hall signal input amplitudes due to the motor used. However, note that if there are discrepancies in the input amplitudes between the individual phases, discrepancies in the output phase switching timing may occur. An amplitude (differential) of at least 50 mVp-p is required in the Hall input signals. However, if the input amplitude exceeds 350 mVp-p, the AGC circuit control range will be exceeded and kickback may occur in the output. If Hall signal input frequencies in excess of 1 kHz (the frequency in a single Hall input phase) are used, internal IC heating during startup and certain other times (that is, when the output transistors are saturated) may increase. Reducing the number of magnetic poles can be effective in dealing with problem. The IN1 Hall signal is used as the FG signal for speed control internally to the IC. Since noise can easily become a problem, a capacitor must be inserted across this input. However, since this could result in differences between the signal amplitudes of the three phases, capacitors must be inserted across all of the three input phases. Although VCC can be used as the Hall element bias power supply, using VREG can reduce the chances of problems occurring during noise testing and at other times. If VREG is used, since there is no longer any need to be concerned with the upper limit of the Hall amplifier common-mode input voltage range, bias setting resistors may be used only on the low side. 4. Power Saving Circuit This IC goes into a power saving state that reduces the current drain in the stop state. The power saving state is implemented by removing the bias current from most of the circuits in the IC. However, the 6.3 V regulator output is provided in the power saving state. 5. Reference Clock Care must be taken to assure that no chattering or other noise is present on the externally input clock signal. Although the input circuit does have hysteresis, if problems do occur, the noise must be excluded with a capacitor. This IC includes an internal clock cutoff protection circuit. If a signal with a frequency below that given by the formula below is input, the IC will not perform normal control, but rather will operate in intermittent drive mode. f (Hz) .=. 0.64 ÷ CCSD CCSD (µF): The capacitor inserted between the CSD pin and ground. When a capacitor of 0.022 µF is used, the frequency will be about 29 Hz. If the IC is set to the start state when the reference clock signal is completely absent, the motor will turn somewhat and then motor drive will be shut off. After the motor stops and the rotor constraint protection time elapses, drive will not be restarted, even if the clock signal is then reapplied. However, drive will restart if the clock signal is reapplied before the rotor constraint protection time elapses. No. 7257 -10/13 LB11872H 6. Rotor Constraint Protection Circuit This IC provides a rotor constraint protection circuit to protect the IC itself and the motor when the motor is constrained physically, i.e. prevented from turning. If the FG signal (edges of one type (rising or falling edges) on the IN1 signal) does not switch within a fixed time, output drive will be turned off. The time constant is determined by the capacitor connected to the CSD pin. <time constant (in seconds)> .=. 30.5 × 1.57 × CCSD (µF) If a 0.02 µF capacitor is used, the protection time will be about 1.05 seconds. To clear the rotor constraint protection state, the IC must be set to the stopped state or the power must be turned off and reapplied. If there is noise present on the FG signal during the constraint time, the rotor constraint protection circuit may not operate normally. 7. Phase Lock Signal (1) Phase lock range Since this IC does not include a counter or similar functionality in the speed control system, the speed error range in the phase locked state cannot be determined solely by IC characteristics. (This is because the acceleration of the changes in the FG frequency influences the range.) When it is necessary to stipulate this characteristic for the motor, the designer must determine this by measuring the actual motor state. Since speed errors occur easily in states where the FG acceleration is large, it is thought that the speed errors will be the largest during lock pull-in at startup and when unlocked due to switching clock frequencies. (2) Masking function for the phase lock state signal A stable lock signal can be provided by masking the short-term low-level signals due to hunting during lock pullin. However, this results in the lock state signal output being delayed by the masking time. The masking time is determined by the capacitor inserted between the CSD pin and ground. <masking time (seconds)> .=. 6.5 × 1.57 × CCSD (µF) When a 0.022 µF capacitor is used, the masking time will be about 225 ms. In cases where complete masking is required, a masking time with fully adequate margin must be used. 8. Initial Reset To initially reset the logic circuits in start mode, the IC goes to the reset state when the CSD pin voltage goes to zero until it reaches 0.63 V. Drive output starts after the reset state is cleared. The reset time can be calculated to a good approximation using the following formula. <reset time (seconds)> .=. 0.13 × CCSD (µF) A reset time of over 100 µs is required. 9. Current Limiter Circuit The current limit value is determined by the resistor Rf inserted between the RF pin and ground. ILIM = VL/Rf VL = 0.59 V (typical) (during acceleration) and 0.37 V (typical) (during deceleration) 10. Power Supply Stabilization An adequately large capacitor must be inserted between the VCC pin and ground for power supply stabilization. If diodes are inserted in the power supply lines to prevent destruction of the device if the power supply is connected with reverse polarity, the power supply line levels will be even more easily disrupted, and even larger capacitors must be used. If high-frequency noise is a problem, a ceramic capacitor of about 0.1 µF must also be inserted in parallel. No. 7257 -11/13 LB11872H 11. VREG Stabilization A capacitor of at least 0.1 µF must be used to stabilize the VREG voltage, which is the control circuit power supply. The capacitor must be connected as close as possible to the pins. 12. Error Amplifier External Component Values To prevent adverse influence from noise, the error amplifier external components must be located as close to the IC as possible. 13. FRAME Pin and Heat sink Area The FRAME pin and the heat sink area function as the control circuit ground terminal. It is desirable that this ground line and the Rf resistor ground line be grounded at a single point at the ground for the electrolytic capacitor. Thermal dissipation can be improved significantly by tightly bonding the metallic surface of the back of the IC package to the PCB with, for example, a solder with good thermal conductivity. 14. CSD Pin The capacitor connected to the CSD pin influences several operational aspects of this IC, including the rotor constraint protection time and the phase lock signal mask time. The following are possible ways of determining the value of this capacitor. (1) If removing chattering from the phase lock state signal is most important: Select a capacitance that can assure an adequate mask time. (2) If startup time is more important than chattering: Select a capacitance such that the rotor constraint protection circuit does not operate at startup time and verify that there are no problems with the clock cutoff protection circuit and initial reset time. Operation of the rotor constraint protection circuit may hinder the study of motor characteristics in the uncontrolled state. It is possible to only operate the initial reset function and not operate the rotor constraint protection circuit by inserting a resistor (about 390 kΩ) in parallel with the capacitor between the CSD pin and ground. 15. FC Pin The capacitor connected to the FC pin is required for current limiter loop phase compensation. If the value is too low, the output will oscillate. If the value is too large, it will be easier for currents in excess of the limit value to flow during the current limit time (time before the circuit operates) in states where the output is saturated. (This is because the control response characteristics become worse.) 16. AGC Pin A capacitance that allows a certain amount of smoothing of the AGC pin voltage in the motor speed range used must be selected for the capacitor connected to the AGC pin. It is also desirable to use a capacitance that allows the AGC voltage to reach an essentially stabilized voltage before the initial reset is cleared. (If the capacitance is too large, the rate of change of the AGC voltage will become slower.) No. 7257 -12/13 LB11872H Specifications of any and all SANYO products described or contained herein stipulate the performance, characteristics, and functions of the described products in the independent state, and are not guarantees of the performance, characteristics, and functions of the described products as mounted in the customer’s products or equipment. To verify symptoms and states that cannot be evaluated in an independent device, the customer should always evaluate and test devices mounted in the customer’s products or equipment. SANYO Electric Co., Ltd. strives to supply high-quality high-reliability products. However, any and all semiconductor products fail with some probability. It is possible that these probabilistic failures could give rise to accidents or events that could endanger human lives, that could give rise to smoke or fire, or that could cause damage to other property. When designing equipment, adopt safety measures so that these kinds of accidents or events cannot occur. Such measures include but are not limited to protective circuits and error prevention circuits for safe design, redundant design, and structural design. In the event that any or all SANYO products (including technical data, services) described or contained herein are controlled under any of applicable local export control laws and regulations, such products must not be exported without obtaining the export license from the authorities concerned in accordance with the above law. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording, or any information storage or retrieval system, or otherwise, without the prior written permission of SANYO Electric Co., Ltd. Any and all information described or contained herein are subject to change without notice due to product/technology improvement, etc. When designing equipment, refer to the “Delivery Specification” for the SANYO product that you intend to use. 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 September 2002. Specifications and information herein are subject to change without notice. PS No. 7257 -13/13