Ordering number : EN5678 Monolithic Digital IC LB1695 Three-Phase Brushless Motor Driver Overview The LB1695 is a three-phase brushless motor driver IC that is optimal for DC fan motor drive in home appliances such as on-demand water heaters. Features • Three-phase brushless motor drive • 45-V voltage handling capacity, 2-A output current • • • • • Current limiter circuit Low-voltage protection circuit Thermal shutdown protection circuit Hall amplifiers with hysteresis characteristics FG output function Package Dimensions unit: mm 3196-DIP30SD [LB1695] Allowable power dissipation, Pdmax – W With a 20% wiring density on a glass-epoxy board 114.3 × 76.2 × 1.6 mm3 SANYO: DIP30SD Ambient temperature, Ta – °C Specifications Absolute Maximum Ratings at Ta = 25°C Parameter Supply voltage Output current Allowable power dissipation Symbol Conditions Ratings Unit VCC 10 V VM 45 V IO 2.0 A 2.5 W Pd max Mounted on a printed circuit board (114.3 × 76.2 × 1.6 mm3 glass-epoxy board) Operating temperature Topr –20 to +100 °C Storage temperature Tstg –55 to +150 °C Ratings Unit Allowable Operating Ranges at Ta = 25°C Parameter Power-supply voltage range Maximum power-supply slew rate at power on Symbol Conditions VCC 4.5 to 5.5 V VM 5 to 42 V ∆VCC/∆t At VCC = VLVSD(OFF)* No more than 0.04 V/µs ∆VM/∆t At VM = 0 V* No more than 0.16 V/µs Note: *These items are stipulated because output through currents can occur if the speed with which the power-supply voltage rises is too fast when power is first applied. 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Semiconductor Bussiness Headquarters TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN 63097HA(OT) No. 5678-1/7 LB1695 Electrical Characteristics at Ta = 25°C, VCC = 5 V, VM = 30 V Parameter Current drain Output saturation voltage Output leakage current Symbol ICC Conditions Ratings min typ Unit max Forward rotation 13 19 mA VO(sat)1 IO = 0.5 A, VO (sink) + VO (source) 1.8 2.4 V VO(sat)2 IO = 1.0 A, VO (sink) + VO (source) 2.1 2.8 V 100 µA 4 µA IO leak [Hall Amplifier] Input bias current IHB 1 Common-mode input voltage range VICM 1.5 Hysteresis ∆VIN 21 3.2 V 30 37 mV Input voltage (low → high) VSLH 5 15 25 mV Input voltage (high → low) VSHL –25 –15 –5 mV 0.4 V 7.5 10.0 12.5 kΩ 0 0.8 [FG Pin] (Speed pulse output) Output low-level voltage VFGL Pull-up resistance RFG IFG = 5 mA [Forward/Reverse Operation] Forward VFR1 Reverse VFR2 4.2 5.0 VRF 0.42 0.5 150 180 °C 40 °C V V [Current Limiter Operation] Limiter 0.6 V [Thermal Shutdown Operation] Operating temperature Hysteresis TSD * ∆TSD * [Low-Voltage Protection Operation] Operating voltage Release voltage Hysteresis VLVSD 3.5 VLVSD(OFF) ∆VLVSD 0.4 3.8 4.1 V 4.3 4.5 V 0.5 0.6 V [Pin C] Charge current ICL R = 33 kΩ 30 40 50 µA Discharge current ICH R = 33 kΩ 90 120 150 µA Charge start voltage VCL R = 33 kΩ 0.3 0.4 0.5 V Discharge start voltage VCH R = 33 kΩ 1.5 2.0 2.5 V Output current ignored time tsm R = 33 kΩ, C = 4700 pF 58 68 78 µs Output off time tso R = 33 kΩ, C = 4700 pF 164 193 222 µs Note: *The items marked with an asterisk are design target values and are not tested. Pin Assignment No. 5678-2/7 LB1695 Truth Table Input IN1 IN2 IN3 1 H L H 2 H L L 3 H H L 4 L H L 5 L H H 6 L L H F/R Forward/reverse control Output F/R Source → sink L OUT2 → OUT1 H OUT1 → OUT2 L OUT3 → OUT1 H OUT1 → OUT3 L OUT3 → OUT2 H OUT2 → OUT3 L OUT1 → OUT2 H OUT2 → OUT1 L OUT1 → OUT3 H OUT3 → OUT1 L OUT2 → OUT3 H OUT3 → OUT2 FG output FG1 FG2 L L L H L L H H H L H H FG Output Forward (low): 0.0 to 0.8 V FG1 Reverse (high): 4.2 to 5.0 V FG2 Pin Functions Pin No. Pin 2 30 28 OUT1 OUT2 OUT3 Pin voltage(V) Pin function 25 VM • Power supply pin that provides the output 26 RF • Output current detection Connect the resistor Rf between this pin and ground. • The current limiter limits the output current to the value set by V RF /Rf (current limiter operation). 5 C • The capacitor connected to this pin determines both the time the output is turned off when the current limiter operates and the time the output current is ignored. 6 R • The resistor connected to this pin determines the charge current for the pin C capacitor. Equivalent circuit • Output pin 1 • Output pin 2 • Output pin 3 Continued on next page. No. 5678-3/7 LB1695 Continued from preceding page. Pin No. Pin 7, 8, 9, 22, 23, 24 FRAME Pin voltage(V) • This pin is used for heat dissipation. Electrically, it must be left open. 10 VCC • Power for all circuits other than the output block. 11 FG1 • First speed pulse output. A pull-up resistor is built in. 12 FG2 • Second speed pulse output. A pull-up resistor is built in. 13 14 IN1– IN1+ 16 17 IN2– IN2+ • Hall element input Logic high is defined as IN+ > IN–. 18 19 IN3– IN3+ • Hall element input Logic high is defined as IN+ > IN–. 20 F/R 21 GND 1.5 V min VCC–1.8V max 0.0 V min VCC max Pin function Equivalent circuit • Hall element input Logic high is defined as IN+ > IN–. • Forward/reverse control • Ground for all circuits other than the output block. The lowest potential of the output transistors will be the potential of the Rf pin. No. 5678-4/7 LB1695 Block Diagram and Peripheral Circuits LB1695 Functional Description 1.Hall element input circuits The Hall element input circuits are differential amplifiers with a hysteresis of about 30 mV (typical). The operating DC level must be within the common-mode input voltage range (1.5 V to VCC – 1.8 V). We recommend providing input levels that exceed the hysteresis by at least a factor of three (120 to 160 mVp-p) to assure that circuit operation is not affected by noise. If the ability to withstand noise is determined to be a problem during noise evaluation or other testing, insert capacitors (of about 0.01 µF) between the Hall input IN+ and IN– pins. 2.Protection circuit 2.1 Low-voltage protection circuit The sink side output transistors are turned off if the VCC voltage falls below the stipulated voltage (VLVSD). This circuit prevents incorrect operation when the VCC voltage is reduced. 2.2 Thermal shutdown circuit The sink side output transistors are turned off if the junction temperature exceeds the stipulated temperature (TSD). This circuit prevents the IC from being destroyed by overheating. Applications must be designed so that this circuit does not operate except in unusual situations. 3.FG output circuit The LB1695 combines the IN1, IN2, and IN3 inputs and then wave shapes the combined signal. The FG1 output has the same frequency as the Hall inputs, and the FG2 output has a frequency three times that of the Hall inputs. 4.Forward/reverse control circuit This circuit was designed with the assumption that the direction will not be switched from the F/R pin while the motor is turning. If the direction is switched while the motor is turning, through currents will flow in the output and ASO will become a problem. We recommend only using F/R switching when the VM power supply is in the off state, i.e. with the motor in the stopped state. 5.VCC and VM power supplies If the speed with which the power-supply voltages (VCC and VM) rise when power is first applied is too fast, through currents will flow in the output and ASO will become a problem. Applications must assure that the power supply rise speeds do not exceed 0.04 V/µs (∆VCC/∆t) and 0.16 V/µs (∆VM/∆t). When applying power, it is desirable to apply VCC first and then apply VM. When turning the power off, it is desirable to first turn off VM, then to wait for the motor to stop, and only then turn off VCC. If VCC is turned off after VM is turned off but while the motor is still turning due to No. 5678-5/7 LB1695 inertia, certain motor types may cause the VM voltage at the IC to rise and generate voltages that exceed the voltage handling capacity of the IC. 6.Power supply stabilization capacitor The low-voltage protection circuit may operate or other problems may occur if large fluctuations occur in the VCC line voltage. The VCC line must be stabilized by a capacitor (of a few µF) inserted between VCC and ground. Also, the large switching currents that flow in the VM line can cause fluctuations in the IC VM voltage due to inductive components in the circuit wiring. The VM line must also be stabilized by a capacitor inserted between VM and ground to prevent fluctuations in the ground line potential, incorrect operation, and voltages that exceed the voltage handling capacity of the IC. In particular, applications that have long circuit lines for VM, VCC, and ground must have adequate stabilization capacitors inserted in the power lines. 7.Current limiter circuit The current limiter circuit turns off the sink side output transistors when the output current reaches the set limit value (the limit current). The RF pin is used for current detection, and the output current is detected as a voltage by inserting the resistor Rf between the RF pin and ground. The current limiter circuit operates when the RF pin reaches 0.5 V (typical), and thus the output current is limited to the current limit set by the term 0.5/Rf. 7.1 Output off time After the current limiter circuit operates and turns off the sink side output transistors, it then turns the output on again after a fixed period (the output off time) has elapsed. This current limiter circuit output switching technique adopted in the LB1695 is much less susceptible to problems with ASO than are output limitation techniques in which the output is not operated at the saturated level. The output off time it determined by the charge time for the capacitor connected to the C pin. When the current limiter circuit operates, the C pin capacitor begins to charge, and the time required to charge this capacitor to the C voltage, which is 2 volts (typical), is the output off time. When the capacitor is charged to the C voltage of 2 volts, the sink side output transistors are turned on again. The C pin charge current is a fixed current determined by the resistor R connected to the R pin. The capacitor charge current ICL and the output off time toff are related as follows. ICL ≈ 1.3/R (R must be set to a value in the range 13 to 100 kΩ) toff ≈ C/ICL × 2.0 ≈ 1.53 × R × C 7.2 Output current ignored time While the current limiter circuit is operating and the sink side output is off, a regenerative current flows in the external diode provided to absorb regenerative currents in the upper side of the output circuit that was turned off. When the sink side output is turned off after the output off time has elapsed, a reverse current flows instantaneously in this diode due to the diode’s reverse recovery time. Due to this phenomenon, a current that may reach the current limit value flows instantaneously in the output. If the current limiter operated again due to this current, the output would be turned off and the average current level would fall. This could result in significantly lower torque during, for example, motor startup. Therefore, to prevent this current from being detected, the current limiter circuit also provides a fixed period (the output current ignored time) during which the output current is not detected at the point where the sink side output is turned on again after being turned off. The output current ignored time is determined by the discharge time for the capacitor connected to the C pin. This discharge starts at the point where the capacitor is charged to 2 volts following operation of the current limiter circuit. The output current ignored time is the time for the capacitor to discharge to 0.4 volts (typical). The capacitor discharge current is a fixed current and is set to be a current about three times the charge current. Therefore, the output current ignored time is about 1/3 the output off time. The capacitor discharge current ICH and the output current ignored time tsm are related as follows. ICH ≈ 1.3/R × 3 tsm ≈ C/ICH × 1.6 ≈ 0.41 × R × C Since the current limiter circuit provides a slope to the on time when the sink side output is turned on again, the reverse circuit never becomes significantly large, even if a rectifying diode (i.e. a diode whose reverse recovery time is not particularly short) is used as the regenerative current absorption external diode. 7.3 Output off time setting The output off time must be set to a period optimal for the type of motor used. This time is set by the values of the external resistor attached to the R pin and the external capacitor attached to the C pin. Figure 1 shows the waveforms during current limiter operation. No. 5678-6/7 LB1695 (1) If a shorter output off time is used: Since the output off time and the output current ignored time are set to have a ratio of about 3:1 by IC internal circuits, it is not possible to set these periods independently. Thus the output current ignored period may become insufficient if the output off time is set to an excessively short period. If the output current ignored period is too short, the reverse current in the regenerative current absorption external diode may cause the current limiter circuit to operate. (See Section 7.2.) Also, if the output off time is decreased, the diode reverse current will increase and ASO may become a problem. (2) If a longer output off time is used: If an excessively long output off time is used, the average current will decrease resulting in reduced torque during motor startup. For some motor types, this may make it impossible to switch from the current limiter operating state to steady state operation. C pin voltage RF pin voltage Figure 1. Current Limiter Operating Waveforms 8.IC internal power dissipation calculation Pd = (VCC × ICC) + (VM × IM) – (power dissipated in the motor coils) 9.Techniques for measuring IC internal temperature increases Since it is not possible to measure the IC internal temperature directly, one of the following techniques is normally used for temperature measurement. 9.1 Thermocouple measurement When using a thermocouple for temperature measurement, the thermocouple is attached to a fin on the heat sink. While this measurement technique is simple, it suffers from large measurement errors when the thermal generation process is not at steady state. 9.2 Measurement using IC internal diode properties We recommend using the properties of the parasitic diode that exists between FG1 and ground for measuring the temperature of this IC. Set FG1 to the high (off) state and measure the VF voltage of the parasitic diode. Then calculate the temperature from the temperature characteristics of the VF voltage. ■ 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: ➀ 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: ➁ 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 June, 1997. Specifications and information herein are subject to change without notice. No. 5678-7/7