LB1976

LB1976 ONSEMI | Alldatasheet

Document overview

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• PDF pages: 10

Technical content

Features

• Withstand voltage 60V, output current 2.5A
• Direct PWM drive output
• 3 built-in output top-side diodes
• Built-in current limiter
• Built-in FG output circuit Specifications Absolute Maximum Ratings at Ta = 25°C Parameter Symbol Conditions Ratings Unit VCC max 7V Supply voltage VM max 60 V Output current I O max 2.5 A Maximum input current I REG max V REG pin 10 mA Pd max1 Independent IC 3 W Allowable power dissipation Pd max2 With infinite hear sink 20 W Operating temperature Topr -20 to +100 °C Storage temperature Tstg -55 to +150 °C Monolithic Digital IC For Fan Motor 3-phase Brushless Motor Driver

No.6088-2/10 Allowable Operating Ranges at Ta = 25°C Parameter Symbol Conditions Ratings Unit VCC 4.5 to 6.7 V Supply voltage range VM 20 to 56 V Input current range I REG V REG pin 1 to 5 mA FG pin applied voltage V FG 0 to VCC V FG pin output current I FG 0 to 10 mA Electrical Characteristics at Ta = 25°C, VCC = 5V, VM = 45V Ratings Parameter Symbol Conditions min typ max Unit Supply current I CC 10 14 18 mA Output Block VOsat1(L) I O = 1.0A, VO(sink) 1.1 1.4 V VOsat1(H) I O = 1.0A, VO(source) 0.9 1.3 V VOsat1 I O = 1.0A, VO(sink) + VO(source) 2.0 2.6 V VOsat2(L) I O = 2.0A, VO(sink) 1.4 1.8 V VOsat2(H) I O = 2.0A, VO(source) 1.2 1.7 V Output saturation voltage VOsat2 I O = 2.0A, VO(sink) + VO(source) 2.6 3.4 V IOLeak(L) 100 μA Output leak current IOLeak(H) -100 μA VFH1 I O = 1.0A 1.2 1.6 V Upper side diode forward voltage VFH2 I O = 2.0A 2.1 2.6 V Hall Amplifier Input bias current I HB -4 -1 μA Common-mode input voltage range V ICM 1.5 V CC-1.5 V Hall input sensitivity VH IN 60 mVp-p Hysteresis width ΔVIN(HA) 23 32 39 mV Input voltage (low to high) V SLH 6 16 25 mV Input voltage (high to low) V SHL -25 -16 -6 mV FG Pin (speed pulse output) Output low-level voltage V FGL I FG = 5mA 0.5 V Pull-up resistor value R FG 7.5 10 12.5 k Ω Current Limiter Limiter V RF 0.45 0.50 0.55 V Thermal Shutdown Thermal shutdown operating temperature TSD Design target Value (junction temperature) 150 180 °C Hysteresis width ΔTSD Design target Value (junction temperature) 40 °C Low-Voltage Protection Operating voltage V LVSD 3.5 3.8 4.1 V Non-operating voltage V LVSD(OFF) 4.3 4.5 V Hysteresis width ΔVLVSD 0.4 0.5 0.6 V PWM Oscillator Output high-level voltage V OH(OSC) 2.95 3.10 3.25 V Output low-level voltage V OL(OSC) 1.38 1.45 1.59 V Amplitude V OSC 1.50 1.65 1.71 Vp-p Oscillator frequency f OSC C = 2200pF 19.6 23.0 27.6 kHz Charge current I CHG -110 -94 -83 μA Discharge resistance R DCHG 1.6 2.1 2.6 k Ω VREG Pin Pin voltage V REG I REG = 1.5mA 6.6 7.0 7.2 V Continued on next page.

No.6088-3/10 Continued from preceding page. Ratings Parameter Symbol Conditions min typ max Unit VCTL Pin VCTL1 Output duty 0% 1.1 1.4 1.7 V Input voltage VCTL2 Output duty 100% 3.2 3.5 3.8 V IB1(CTL) V CTL = 0V -82 μA Input bias current IB2(CTL) V CTL = 5V 92 μA VCTL Amplifier Reference voltage V CREF 2.23 2.35 2.46 V VCOUT1 V CTL = 0V 3.90 4.20 4.40 V Output voltage VCOUT2 V CTL = 5V 0.60 0.80 1.10 V Start/Stop Pin High-level input voltage range V IH(S/S) V CC-1.5 V CC V Low-level input voltage range V IL(S/S) 0 1.5 V Input open voltage V IO(S/S) V CC-0.5 V CC V Hysteresis width ΔVIN(S/S) 0.35 0.50 0.65 V High-level input current I IH(S/S) V(S/S) = V CC -10 0 +10 μA Low-level input current I IL(S/S) V(S/S) = 0V -280 -210 μA Forward/Reverse Pin High-level input voltage range V IH(F/R) V CC-1.5 V CC V Low-level input voltage range V IL(F/R) 0 1.5 V Input open voltage V IO(F/R) V CC-0.5 V CC V Hysteresis width ΔVIN(F/R) 0.35 0.50 0.65 V High-level input current I IH(F/R) V(F/R) = V CC -10 0 +10 μA Low-level input current I IL(F/R) V(F/R) = 0V -280 -210 μA Package Dimensions unit : mm (typ) 3147C SANYO : DIP28H(500mil) 1 14 28 15 0.4 0.6 4.04.0 26.75 20.0 R1.7 8.4 (1.81) 1.78 1.0 12.7 11.2 -20 0 20 40 60 80 1200 Pd max -- Ta 100 Ambient temperature, Ta -- °C Allowable power dissipation, Pd max -- W Independent IC With infinite heat sink

No.6088-4/10 FG1 FG2 Pin Assignment LB1976 VCOUT VCC VREG S/S F/R (NC) OUT1 OUT2 OUT3 (NC) (NC) GND3 GND2 RF V M VCTL OSC (NC) V CREF IN1− IN1+ IN2− IN2+ IN3− IN3+ FG1 FG2 GND1 Top view 28 27 26 25 24 23 22 21 20 19 18 17 16 15 1 2 3 5 5 6 7 8 9 10 11 12 13 14 Truth Table Input Forward/reverse control Output FG output IN1 IN2 IN3 F/R Source → Sink FG1 FG2 L OUT2 → OUT1

1 H L H

H OUT1 → OUT2 L L L OUT3 → OUT1

2 H L L

H OUT1 → OUT3 L H L OUT3 → OUT2

3 H H L

H OUT2 → OUT3 L L L OUT1 → OUT2

4 L H L

H OUT2 → OUT1 H H L OUT1 → OUT3

5 L H H

H OUT3 → OUT1 H L L OUT2 → OUT3

6 L L H

H OUT3 → OUT2 H H F / R F G o u t p u t Forward rotation Low 0V to 1.5V Reverse rotation High V CC − 1.5V to VCC 100 VCTL1V CTL2 Duty -- VCTL characteristics Duty -- % Control voltage, VCTL -- V

No.6088-5/10 Block Diagram and Peripheral Circuit VCOUT VCC VREG OUT1 OUT2 OUT3 GND3GND2 RF VM VCTL OSCVCREF GND1 Reg IN1 IN2 IN3 Hys.Amp 31kΩ 40kΩ VCTL Amp PWM OSC FG1 FG2 LVDS TSD Current Limiter 0.5V VM S/S F/R VCC H H H VCTL Logic 2.35V Pin Functions Pin No. Pin name Pin voltage Function Equivalent circuit 1 V CC 4.5V to 6.7V Power supply for blocks other than the output block. 2 V REG 0.0V to 7.3V Shunt regulator output pin (7V). 3 S/S 0.0V to V CC Start/stop control pin. Low: start High or Open: stop Typical threshold voltage for VCC = 5V: approx. 2.8V (low to high) approx. 2.3V (high to low) 3.8kΩ 20kΩ VCC Continued on next page.

No.6088-6/10 Continued from preceding page. Pin No. Pin name Pin voltage Function Equivalent circuit 4 F/R 0.0V to V CC Forward/reverse pin. Low: forward High or Open: reverse Typical threshold voltage for VCC = 5V: approx. 2.8V (low to high) approx. 2.3V (high to low) 3.8kΩ 20kΩ VCC OUT1 OUT2 OUT3 Output pin 1. Output pin 2. Output pin 3. 13 RF 0.0V to V CC Output current detect pin. Connect resistor Rf between this pin and ground. Output current is limited to value set with VRF/Rf. (Current limiter operation) 14 V M Output block power supply. 200Ω VCC 0.5V 11 GND3 Output block ground. GND1 GND2 Ground for blocks other than the output block. 17 FG1 0.0V to V CC Speed pulse output pin 1 with built-in pull-up resistor. 16 FG2 0.0V to V CC Speed pulse output pin 2 with built-in pull-up resistor. 10kΩ VCC 16 17 IN1+ IN1- IN2+ IN2- IN3+ IN3- 1.5V to VCC − 1.5V Hall input pin. IN+ > IN- : High input IN+ < IN- : Low input 300Ω VCC 300Ω 26 OSC 1.0V to V CC This pin sets the PWM oscillation frequency. Connect a capacitor between this pin and ground. 2.1kΩ VCC 200Ω 94μA Continued on next page.

No.6088-7/10 Continued from preceding page. Pin No. Pin name Pin voltage Function Equivalent circuit 27 V CTL 0.0V to 6.7V Output duty cycle control pin.

• VCTL ≤ VCTL1 Duty cycle 0%
• VCTL1 < VCTL < VCTL2 Duty cycle is controlled by VCTL
• VCTL ≥ VCTL2 Duty cycle 100% 40kΩ VCC 272.35V 31kΩ 24 V CREF 0.0V to VCC − 2.0V VCTL amplifier internal reference voltage pin (2.35V). 23.5kΩ VCC 200Ω 100μA 28 V COUT 0.7V to VCC − 0.7V VCTL amplifier output pin. VCC 28 31kΩ 200Ω

No.6088-8/10 IC Description 1. Direct PWM Drive The LB1976 employs the direct PWM drive principle. Motor rotation speed is controlled by varying the output duty cycle according to an analog voltage input (VCTL). This eliminates the need to alter the motor power supply voltage. Compared to previous ICs using the PAM principle (such as the LB1690), this allows simplification of the power supply circuitry. The VCTL input can be directly supplied by a microcontroller, motor speed can, therefore, be controlled directly from the microcontroller. For PWM, the source-side output transistors are switched on and off so that the ON duty tracks the VCTL input. The output duty cycle can be controlled over the range of 0% to 100% by the VCTL input. 2. PWM Frequency The PWM oscillator frequency fPWM [Hz] is set by the capacitance C [pF] connected between the OSC pin and GND. The following equation applies: Because output transistor on/off switching is subject to a delay, setting the PWM frequency to a very high value will cause the delay to become noticeable. The PWM frequency therefore should normally be kept below 40kHz (typ.), which is achieved with a capacitance C of 1300pF or higher. For reference, the source-side output transistor switching delay time is about 2μs for ON and about 4μs for OFF. 3. Output Diodes Because the PWM switching operation is carried out by the source-side output transistors, Schottky barrier diodes must be connected between the OUT pins and GND (OUT1 to OUT3). Use diodes with an average forward current rating in the range of 1.0 to 2.0A, in accordance with the motor type and current limiting requirements. If no Schottky barrier diodes are connected externally, or if Schottky barrier diodes with high forward voltage (VF) are used, the internal parasitic diode between OUT and GND becomes active. When this happens, the output logic circuit may malfunction, resulting in feed-through current in the output which can destroy the output transistors. To prevent this possibility, Schottky barrier diodes must be used and dimensioned properly. The larger the VF of the externally connected Schottky barrier diodes, or the hotter the IC is, the more likely are the parasitic diodes between OUT and GND to become active and the more likely is malfunction to occur. The VF of the Schottky barrier diodes must be determined so that output malfunction does not occur also when the IC becomes hot. If malfunction occurs, choose a Schottky barrier diode with lower VF. 4. Protection circuits 4-1. Low voltage protection circuit When the VCC voltage falls below a stipulated level (VLVSD), the low voltage protection circuit cuts off the source-side output transistors to prevent VCC related malfunction. 4-2. Thermal shutdown circuit (overheat protection circuit) When the junction temperature rises above a stipulated value (TSD), the thermal shutdown circuit cuts off the sourceside output transistors to prevent IC damage due to overheating. Design the application heat characteristics so that the protection circuit will not be triggered under normal circumstances. 4-3. Current limiter The current limiter cuts off the source-side output transistors when the output current reaches a preset value (limiter value). This interrupts the source current and thereby limits the output current peak value. By connecting the resistance Rf between the RF pin and ground, the output current can be detected as a voltage. When the RF pin voltage reaches 0.5V (typ.), the current limiter is activated. It performs on/off control of the source-side output transistors, thereby limiting the output current to the value determined by 0.5/Rf. 5. Hall Input Circuit The Hall input circuit is a differential amplifier with a hysteresis of 32mV (typ.). The operation DC level must be within the common-mode input voltage range (1.5V to VCC − 1.5V). To prevent noise and other adverse influences, the input level should be at least 3 times the hysteresis (120 to 16mVp-p). If noise at the Hall input is a problem, a noise-canceling capacitor (about 0.01μF) should be connected across the Hall input IN+ and IN− pins. 6. FG Output Circuit The Hall input signal at IN1, IN2, and IN3 is combined and subject to waveform shaping before being output. The signal at FG1 has the same frequency as the FG1 Hall input, and the signal at FG2 has a frequency that is three times higher.

No.6088-9/10 7. Start/Stop Control Circuit The start/stop control circuit turns the source-side output transistors OFF (motor stop) when a High signal is input at the S/S pin or when the pin is Open. When a Low signal is input at the S/S pin, the source-side output transistors are turned ON, and the normal operation state is established (motor start). 8. Forward/Reverse Switching The LB1976 is designed under the assumption that forward/reverse switching is not carried out while the motor is running. If switching is carried out while the motor is running, reverse torque braking occurs, leading to a high current flow. If the current limiter is triggered, the source-side output transistors are switched off, and the sink-side output transistors go into the short brake condition. However, because the current limiter of this IC cannot control the current flowing in the sink-side output transistors, these may be destroyed by the short brake current. Therefore F/R switching while the motor is running is permissible only if the output current (IO) is limited to a maximum of 2.5A using the motor coil resistance or other suitable means. F/R switching should be carried out only while a High signal is input to the S/S pin or the pin is Open (stop condition), or while the VCTL pin conforms to the following condition: VCTL≤ VCTL1 (duty cycle 0%). In any other condition, F/R switching will result in feed-through current. The F/R pin should therefore be fixed to Low (forward) or High or Open (reverse) during use. 9. VCC, VM Power Supplies When the power supply voltage (VCC, VM) rises very quickly when a power is first applied, a feed-through current may occur at the output. If the current remains below about 0.2A to 0.3A, it does not pose a problem, but such a possibility should still be prevented by slowing down the voltage rise at power-on. Especially if the F/R pin is set to High or Open (reverse), a quick rise in VCC is likely to cause feed-through current. This should be prevented by ensuring that ΔVCC / Δt = 0.2V/µs or less. Feed-through current can also be prevented by first switching on VCC and then VM during power-on. The sequence at power-down should be as follows. Provide a stop input to the S/S pin or a duty ratio 0% input to the VCTL pin. When the motor has come to a full stop, switch off VM and then VCC. If power is switched off while the motor is still rotating or a current is flowing in the motor coil (including motor restraint or inertia rotation), a counter electromotive current or kickback current may flow on the VM side, depending on the motor type and power-off procedure. If this current cannot be absorbed by the VM power supply or a capacitor, VM voltage may rise and exceed the absolute maximum VM rating for the IC. Ensure that this does not happen through proper design of the VM power supply or through use of a capacitor. Because the LB1976 incorporates a shunt regulator, it can be used on a single power supply. In this case, supply VCC (6.3V typ.) to the VREG pin via an external NPN transistor and resistor. When not using the regulator, leave the VREG pin open. 10. Power Supply Stabilizing Capacitors If the VCC line fluctuates drastically, the low-voltage protection circuit may be activated by mistake, or other malfunctions may occur. The VCC line must therefore be stabilized by connecting a capacitor of at least several μF between VCC and GND. Because a large switching current flows in the VM line, wiring inductance and other factors can lead to VM voltage fluctuations. As the GND line also fluctuates, the VM line must be stabilized by connecting a capacitor of at least several µF between VM and GND, to prevent exceeding VM max or other problems. Especially when long wiring runs (VM, VCC, GND) are used, sufficient capacitance should be provided to ensure power supply stability. 11. VCREF Pin, VCOUT Pin These pins are always used in the Open condition. If chattering occurs in the PWM switching output, connect a capacitor (about 0.1μF) between VCREF and ground or between VCOUT and GND. 12. IC Heat Dissipation Fins A heat sink may be mounted to the heat dissipation fins of this IC, but it may not be connected to GND. The sink should be electrically open.

PS No.6088-10/10 13. Sample calculation for internal power dissipation (approximate) The calculation assumes the following parameters: VCC = 5V VM = 30V Source-side output transistor ON duty cycle 80% (PWM control) Output current IO = 1A (RF pin average current) (1) ICC power dissipation P1 P1 = VCC × ICC = 5V × 14mA = 0.07W (2) Output drive current power dissipation P2 P2 = VM × 11mA = 30V × 11mA = 0.33W (3) Source-side output transistor power dissipation P3 P3 = VO(source) × IO × Duty(on) = 0.9V × 1A × 0.8 = 0.72W (4) Sink-side output transistor power dissipation P4 P4 = VO(sink) × IO = 1.1V × 1A = 1.10W (5) Total internal power dissipation P P = P1 + P2 + P3 + P4 = 2.22W 14. IC temperature Rise Measurement Because the chip temperature of the IC cannot be measured directly, measurement according to one of the following procedures should always be carried out. 14-1. Thermocouple measurement A thermocouple element is mounted to the IC heat dissipation fin. This measurement method is easy to implement, but it will be subject to measurement errors if the temperature is not stable. 14-2. Measurement using internal diode characteristics of IC This is the recommended measurement method. It makes use of the parasitic diode incorporated in the IC between FG1 and GND. Set FG1 to High and measure the voltage VF of the parasitic diode to calculate the temperature. (Our company data: for IF = −1mA, VF temperature characteristics are about −2mV/°C) 15. NC Pins Because NC pins are electrically open, they may be used for wiring purpose etc. ON Semiconductor and the ON logo are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC owns the rights to a number of patents, trademarks, copyrights, trade secrets, and other intellectual property. A listing of SCILLC’s product/patent coverage may be accessed at warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequentia l or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by customer’s techn ical experts. SCILLC does not convey any license under its patent rights nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should Buyer purchase or use SCILLC productsfor any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates, anddistributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture oft h e part. SCILLC is an Equal Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner.