ml4425 Microsemi Corporation, ml4425 Datasheet
ml4425
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ml4425 Summary of contents
Page 1
... Phase BLDC motors and is insensitive to PWM noise and motor snubbing circuitry. The ML4425 limits the motor current using a constant off- time PWM control loop. The velocity loop is controlled with an onboard amplifier. The ML4425 has circuitry to ensure that there is no shoot-through in directly driven external power MOSFETs ...
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... SPEED FAULT LIMIT VCO/TACH VCO VCO TOP VIEW ML4425 32-Pin TQFP (H32- REF ...
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... SENSE I , LIMIT 25(25) BRAKE 26(26) C IOS 27(27) R REF 28(28) GND ML4425 FUNCTION A capacitor to GND sets the time that the controller stays in the align mode This output goes low when V DD drops below the UVLO threshold, and indicates that all output drivers have been disabled A capacitor to GND sets the time ...
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... Gain SENSE One Shot OFF-Time 4 Thermal Resistance ( 28-Pin Narrow PDIP ......................................... 48ºC/W 28-Pin SOIC ..................................................... 75ºC/W 32-Pin TQFP ..................................................... 80ºC/W OPERATING CONDITIONS + 0.3V DD Temperature Range ML4425CX................................................. 0ºC to 70ºC ML4425IX ............................................... –40ºC to 85ºC V ......................................................... 10.8V to 13. 10nF 100pF, R SENSE VCO IOS CONDITIONS Line, Temp C = 1nF ...
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... PHB DD State 5V, C Suffix Suffix PHB –10µ 1mA LX V Suffix V SENSE I Suffix V C Suffix I Suffix resistor to the internal reference. ML4425 MIN TYP MAX UNITS 2 V 0.8 V 2.4 mA 2.9 mA 2.2 V 0.6 V 3.4 4.5 5.4 V 3.2 5.6 V 0.6 V 125 250 mV 500 720 ...
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... The output drivers LA, LB, LC, HA, HB, and HC provide totem pole output drive signals for a 3 phase bridge power stage. All control functions in the ML4425 translate to outputs at these pins. LA, LB, and LC provide the low-side drive signals for phases A, B, and C of the 3 phase power stage and are 12V active high signals ...
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... I LIMIT The voltage on the I pin sets the current limit LIMIT threshold. The ML4425 has an internal voltage divider from V that sets a default current limit threshold of REF 2.3V (see Figure 2). An external voltage divider referenced to V can be used to override the default ...
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... ML4425 STATE LA R OFF A OFF B OFF OFF F OFF HIGH SIDE HB DRIVE OUTPUTS HC LA LOW SIDE LB DRIVE OUTPUTS LC Figure 4. Output Commutation Sequence Timing Diagram Cycle 1 - Full Commutation, Cycle 2 - Commutation with 50% PWM Duty Cycle FUNCTIONAL DESCRIPTION Voltage Controlled Oscillator (VCO) ...
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... EMF sampler. The back EMF sense pins and FB C inputs to the back EMF sampler require a signal from the motor phase leads that is below the V ML4425. The phase sense input impedance This requires a series resistor RES1 from the motor phase lead as shown in Figure 6 based on the following equation: ...
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... calculated as The rate at which the ML4425 ramps up the motor speed is determined by a fixed 500µA current source on the SPEED FB pin. The current sources charges up the PLL filter components causing the VCO frequency to ramp up. (7) During ramp mode, the back EMF sampler is disabled to allow control of the ramping to be set only by the 500µ ...
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... EMF FB C SAMPLER OF COMMUTATION Figure 8. ML4425 Start-up Circuitry for Controlling the Align and Ramp Times Run Mode (Back EMF Sensing) At the end of ramp mode the controller goes into run mode. In run mode, the back EMF sensing is enabled and commutation is now under the control of the phase locked loop ...
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... ML4425 FUNCTIONAL DESCRIPTION CROSS CONDUCTION COMPARATOR When the ML4425 goes from align mode into ramp mode, there is a possibility of cross conduction in phase 3 of the bridge power stage. This cross conduction can happen when the align mode shown as state R in Table 1, and the controller transitions to state A in ramp mode where HC is turned off and LC is turned on ...
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... SPEED COMP REF 1nF C12 SPEED SET R18 10k LA R21 LB 787 LC I LIMIT VCO/TACH 12V V DD C13 C14 100nF 1µF ML4425 MOTOR R20 GND 137k R REF C16 C IOS 330pF BRAKE R8 (RES1 (RES1 R10 (RES1 C14 C RR SPEED FB R17 C7 ...
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... IRF720 R12 470m 2W R5 10k C4 C3 1nF 100nF C15 100nF R9 100 R10 100 R11 100 (3 1N5819) Figure 12. ML4425 High Voltage Motor Drive Application Circuit 14 IR2118 D1 D2 MUR150 MUR150 C17 100nF 25V IN HO C19 C20 2.2µF 2.2µF COM VS 25V 25V ...
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... MAX) (0.29 - 0.45) 0.037 - 0.041 (0.95 - 1.05) Package: P28N 28-Pin Narrow PDIP 1.355 - 1.365 (34.42 - 34.67) 0.045 - 0.055 0.100 BSC (1.14 - 1.40) (2.54 BSC) SEATING PLANE 0.015 - 0.021 (0.38 - 0.53) ML4425 0º - 8º 0.003 - 0.008 (0.09 - 0.20) 0.018 - 0.030 (0.45 - 0.75) SEATING PLANE 0.280 - 0.296 0.299 - 0.325 (7.11 - 7.52) (7.60 - 8.26) 0.020 MIN (0.51 MIN) 0.008 - 0.012 0º - 15º (0.20 - 0.31) ...
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... ML4425CH (Obsolete) ML4425IP ML4425IS ML4425IH (Obsolete) © Micro Linear 1998 registered trademark of Micro Linear Corporation. All other trademarks are the property of their respective owners. Products described herein may be covered by one or more of the following U.S. patents: 4,897,611; 4,964,026; 5,027,116; 5,281,862; 5,283,483; 5,418,502; ...