ML4425CH Micro Linear, ML4425CH Datasheet
ML4425CH
Related parts for ML4425CH
ML4425CH Summary of contents
Page 1
GENERAL DESCRIPTION The ML4425 PWM motor controller provides all of the functions necessary for starting and controlling the speed of delta or wye wound Brushless DC (BLDC) motors without Hall Effect sensors. Back EMF voltage is sensed from the motor ...
Page 2
ML4425 PIN CONFIGURATION SPEED COMP SPEED SET 2 ML4425 28-Pin Narrow PDIP (P28N) 28-Pin SOIC (S28) I SENSE 1 28 GND REF IOS HC BRAKE 4 25 SPEED COMP ...
Page 3
PIN DESCRIPTION (Pin number in parenthesis is for TQFP package) PIN NAME FUNCTION 1(30) I Motor current sense input. When SENSE I exceeds 0.2 SENSE output drivers LA, LB, and LC are shut off for a fixed time determined by ...
Page 4
ML4425 ABSOLUTE MAXIMUM RATINGS Absolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum ratings are stress ratings only and functional device operation is not implied. V .......................................................................... 14V DD Logic Inputs (, SPEED ...
Page 5
ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER LOGIC INPUTS ( BRAKE ) (Note 3) V Input High Voltage IH V Input Low Voltage IL I Input High Current IH I Input Low Current IL LOGIC OUTPUTS (VCO/TACH, UV FAULT ) (Note 3) VCO/TACH ...
Page 6
ML4425 FUNCTIONAL DESCRIPTION GENERAL The ML4425 provides all the circuitry for sensorless speed control of 3-phase Brushless DC (BLDC) motors. Controller functions include start-up circuitry, back-EMF commutation control, Pulse Width Modulation (PWM) speed control, fixed OFF-time current limiting, braking, and ...
Page 7
FUNCTIONAL DESCRIPTION CURRENT LIMITING IN THE POWER STAGE The current sense resistor (R ) shown in Figure 1 SENSE regulates the maximum current in the power stage and the BLDC motor. Current regulation is accomplished by shutting off the output ...
Page 8
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 ...
Page 9
FUNCTIONAL DESCRIPTION The maximum frequency on the VCO pin is found by: = ™ ™ RPM MAX MAX The voltage at the VCO/TACH pin is equal to the rotor speed. The voltage at SPEED FB ...
Page 10
ML4425 FUNCTIONAL DESCRIPTION BACK EMF SENSING PLL COMMUTATION CONTROL Three blocks form a phase locked loop that locks the commutation clock onto the back EMF signal: the commutation state machine, the voltage controlled oscillator, and the back EMF sampler. The ...
Page 11
750nA – 1. BACK 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 ...
Page 12
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 ...
Page 13
V BUSS 24V–80V C2 330µ 100V 10k 100nF 100V Q4 IRFR9120 Q1 Q2 2N6718 2N6718 12V C3 1µF Q7 IRFR120 R1 470m 2W R12 R13 2k 2k R16 10k C17 C9 100nF R7 100 R5 100 R6 100 ...
Page 14
ML4425 12V IR2118 C16 100nF 25V IN HO COM BUSS 24V–80V C5 R6 330µF 100 400V Q1 IRF720 Q2 IRF720 R12 470m 2W R5 10k C4 C3 1nF 100nF C15 100nF R9 100 ...
Page 15
PHYSICAL DIMENSIONS 0.354 BSC (9.00 BSC) 0.276 BSC (7.00 BSC) 1 PIN 0.032 BSC (0.8 BSC) 28 PIN 0.180 MAX (4.57 MAX) 0.125 - 0.135 (3.18 - 3.43) inches (millimeters Package: H32-7 32-Pin (7 ...
Page 16
... ORDERING INFORMATION PART NUMBER ML4425CP ML4425CS 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; ...