AM2170 AMTEK | Alldatasheet
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AAMMtteekk sseemmiiccoonndduuccttoorrss OOCCTT.. 22000088 VV11..22 - 1 - Dual Full-Bridge PWM Motor Driver AM2170 The AM2170 motor driver is designed to drive both windings of a bipolar stepper motor or to control bi-directionally two DC motors. Both bridges are capab le of sustaining 45V and include internal pulse-width modulation (PWM) control of the output current to 750mA. The outputs have been optimized for a low output saturation voltage drop (less than 1.8V total source plus sink at 500mA). For PWM current control, the maximum output current is de termined by the user’s selection of a reference voltage and sensing resistor. Two logic-level inputs select output cu rrent limits of 0, 33%, 67%, or 100% of the maximum level. A PHASE input to each bridge determines load current direction. The bridges include both ground clamp and fly-back diodes for protection against inductive transients. Internally generated delays prevent cross-over currents when switchi ng current direction. Special power-up sequencing is not required. A thermal protection circuitry disables the outputs if the chip temperature exceeds safe operating limits. The IC is supplied in HSOP28 Package. Its thermal wing construction provides for maximum package power dissipation in the smallest possible construction. Pack age material is Pb-Free for purpose of environmental protection. z Applications Scanner, Printer, MFP z Features 1) 750mA continuous output current 2) 45V output sustaining voltage 3) Internal clamp diodes 4) Internal PWM current control 5) Low output saturation voltage 6) Internal thermal shutdown circuitry z Absolute Maximum Ratings at TJ ≤ 150℃ Parameter Symbol Limits Unit Motor supply voltage V BB 45 V Peak +1.0 A Output current Continuous IOUT +750 mA Logic supply voltage V CC 7.0 V Logic input voltage range V IN -0.3 ~ +7.0 V Output emitter voltage V SENSE 1.5 V Operating temperature range T A -20 ~ +85 ℃ Storage temperature range T S -55 ~ +150 ℃ *Output current rating may be limited by duty cycle, ambient temperature, and heat sinking. Under any set of conditions, do not exceed the specified peak current rating or a junction temperature of +150℃.
AAMMtteekk sseemmiiccoonndduuccttoorrss OOCCTT.. 22000088 VV11..22 - 2 - VCC OUT 1A OUT 2A SENSE 2 COMP IN 2 OUT 2B GROUND I 02 I 12 PHASE 2 VREF 2 RC 2 LOAD SUPPLY SENSE 1 COMP IN 1 OUT 1B I 01 GROUND I 11 PHASE 1 VREF 1 RC 1 LOGIC SUPPLY 1 28 NC NC NC GND NC NC NC GND VBB PWM 2 PWM 1 z Thermal Data Description Symbol Value Unit Thermal Resistance Junction-case Rthjc 6.7 ℃/W Thermal Resistance Junction-ambient R thja 56.8 ℃/W *With minimized copper area z Block Diagram
AAMMtteekk sseemmiiccoonndduuccttoorrss OOCCTT.. 22000088 VV11..22 - 3 - OUT A +10 20KΩ 40KΩ 10KΩ VBB OUT B SENSE -COMP IN RC RS CC ONE SHOT SOURCE DISABLE RCI0 V REF RT CT 1 22 z PWM Current-Control Circuitry Channel 1 terminal numbers shown TRUTH TABLE PHASE OUT A OUT B H H L L L H
AAMMtteekk sseemmiiccoonndduuccttoorrss OOCCTT.. 22000088 VV11..22 - 4 - z Electrical Characteristics ( Unless otherwise specified, Ta = 25℃, Tj ≤ 150℃, VBB = 45V , VCC = 4.75V to 5.25V , VREF = 5.0V ) Limit Unit Parameter Symbol Conditions Min Typ Max ＜Output Drivers (OUTA or OUTB)＞ Motor supply range V BB 10 - 45 V VOUT = VBB - < 1.0 50 μA Output leakage current ICEX VOUT = 0 - < -1.0 -50 μA Output sustaining voltage V CE(sus) IOUT = ±750mA, L = 3.0mH 45 - - V Sink driver, IOUT = +500mA - 0.4 0.6 V Sink driver, IOUT = +750mA - 1.0 1.2 V Source driver, IOUT = -500mA - 1.0 1.2 V Output saturation voltage V CE(SAT) Source driver, IOUT = -750mA - 1.3 1.5 V Clamp diode leakage current I R V R = 45V - < 1.0 50 μA Clamp diode forward voltage V F I F = 750mA - 1.6 2.0 V IBB(ON) Both bridges ON, no load - 20 25 mA Driver supply current IBB(OFF) Both bridges OFF - 5.0 10 mA ＜Control Logic ＞ VIN(1) All inputs 2.4 - - V Input voltage VIN(0) All inputs - - 0.8 V VIN = 2.4V - < 1.0 20 μA Input current I IN(1) VIN = 0.8V - -3.0 -200 μA Reference voltage range V REF Operating 1.5 - 7.5 V I0 = I1 = 0.8V 9.5 10 10.5 - I0 = 2.4V , I1 = 0.8V 13.5 15 16.5 - Current limit threshold (at trip point) VREF/ VCOMPIN I0 = 0.8V , I1 = 2.4V 25.5 30 34.5 - Thermal shutdown temperature T J - 170 - ℃ ICC(ON) I 0 = I1 = 0.8V , No load - 40 50 mA Total logic supply current ICC(OFF) I 0 = I1 = 2.4V , No load - 10 12 mA
AAMMtteekk sseemmiiccoonndduuccttoorrss OOCCTT.. 22000088 VV11..22 - 5 - z Power dissipation curve: *70mm×70mm×1.6mm glass epoxy board. *De-rating is done at 17.6mW/℃ for operating above T a=25℃ Power dissipation: Pd (W) Ambient temperature : Ta (℃) 2.0 1.5 1.0 25 50 75 100 125 150 Pd(W) Ta(℃) 2.5
AAMMtteekk sseemmiiccoonndduuccttoorrss OOCCTT.. 22000088 VV11..22 - 6 - z Application Information ‧PWM Current control The AM2170 dual bridge is designed to drive both windings of a bipolar stepper motor or to control bidirectionally two DC motors. The output current of each part is sensed and controlled independently in each bridge by external sense resistors (RS), internal comparator, and monostable multivibrator. When the bridge is turned ON, current increases in the motor winding and it is sensed by the external sense resistor until the sense voltage (VCOMPIN) reaches the level set at the comparator’s input: ITRIP = VREF / 10RS The comparator then triggers the monostabel that turns O FF the source driver of the bridge. The actual load current peak will be slightly higher than the trip point (especially for low-inductance loads) becau se of the internal logic and switching delays. This delay (t d) is typically 2 μs. After turn-off, the motor current decays, circulating through the ground-clamp diode and sink transistor. The source driver’s OFF time (and therefore the magnitude of the current decrease) is determined by the monostable’ s external RC timing components, where t off = R TCT within the range of 20kΩ to 100kΩ and 100pF to 1000pF. When the source driver is re-enabled , the winding current (the sense voltage ) is again allowed to rise to the comparator’s threshold. This cycle repeats itself, maintaining the average motor winding current at the desired level. Loads with highly distributed capacitances may result in high turn-ON current peaks. This peak (appearing across RS) will attempt to trip the comparator, resulting in erroneous current control or high-frequency oscillations. An external RCCC time delay should be used to further delay the action of the comparator. Depending on load type, many applications will not require these external components (SENSE connected to COMP IN). Load Current Paths VBB RS BRIDGE ON SOURCE OFF ALL OFF PWM Output Current Wave Form V PHASE I TRIP t offt d I OUT
AAMMtteekk sseemmiiccoonndduuccttoorrss OOCCTT.. 22000088 VV11..22 - 7 - ‧Logic Control Of Output Current Two logic level inputs (I 0 and I1) allow digital selection of the motor winding current at 100%, 67%, 33%, or 0% of the maximum level (see table). The 0% output current condition turns OFF all drivers in the bridge and can be used as an OUTPUT DISABLE function. Current – Control Truth Table I0 I 1 Output Current L L V REF / 10RS = ITRIP H L V REF / 15RS = 2/3 ITRIP L H V REF / 30RS = 1/3 ITRIP H H 0 These logic level inputs greatly enhance the implementation of μP-controlled drive formats. During half-step operations, the I 0 and I1 allow the μP to control the motor at a cons tant torque between all positions in an eight-step sequence. This is a accomplished by dig itally selecting 100% drive cu rrent when only one phase is ON and 67% drive current when two phases are ON. Logic highs on both I 0 and I1 turn OFF all drivers to allow rapid current decay when switching phases. This helps to ensure proper motor operation at high step rates. The logic control inputs can also be used to select a redu ced current level (and reduced power dissipation) for ‘hold’ conditions and/or increased current (and available torque) for start-up conditions. ‧General The PHASE input to each bridge determines the direction of current flow in the motor winding. An internally generated deadtime (approximately 2μs) prevents crossover currents that can occur when switching the PHASE input. All four drivers in the bridge output can be turned OFF between steps (I 0 = I 1 ≧ 2.4V) resulting in a fast current decay through the internal out put clamp and flyback diodes. The fast curre nt decay is desirable in half-step and high-speed applications. All inputs float high. Varying the reference voltage (V REF) provides continuous control of the peak load current for microstepping applications and DC motor control. Thermal protection circuitry turns OFF all driv ers when the junction temperature reaches +170 ℃. It is only intended to protect the device from failures due to excessive junc tion temperature and should not imply that output short circuits are permitted. The output drivers are re-enabled when the junction temperature cools to +145℃. The AM2170 output drivers are optimized for low output satur ation voltages – less than 1.8V total (source plus sink) at 500mA. Under normal operating conditions, when combined with the excellent thermal properties of the batwing packing design, this allows continuous operation of both bridges simultaneously at 500mA.
AAMMtteekk sseemmiiccoonndduuccttoorrss OOCCTT.. 22000088 VV11..22 - 8 - θ 1 V BB V CC PW M 1 R C R S C C R C R S C C V BB μ P θ 2 PW M 2 V REF FROM C T R T 13 16 1514 + 5V C T R T V REF μ P FROM z Typical Application
AAMMtteekk sseemmiiccoonndduuccttoorrss OOCCTT.. 22000088 VV11..22 - 9 - D E1E B b1e 1528 1 14 0.15 C AA2 C L z Package Outline HSOP28 MILLIMETERS INCHES SYMBOL Min. Max. Min. Max. A - 2.75 - 0.108 A1 - 0.3 - 0.012 A2 - 2.45 - 0.096 B 4.95 5.35 0.195 0.211 b1 0.23 0.47 0.009 0.019 C 0.2 0.36 0.008 0.014 D 17.89 18.8 0.704 0.740 E 7.3 7.9 0.287 0.311 E1 9.6 10.65 0.378 0.419 e 0.8 (TYP) 0.031(TYP) L 0.3 1.27 0.012 0.05
AAMMtteekk sseemmiiccoonndduuccttoorrss OOCCTT.. 22000088 VV11..22 - 10 - AMtek Row II Row III Row I z Marking Identification Row I AMtek Row II AM2170 Row III Lot number