2919

2919_06 ALLEGRO

Document overview

• Manufacturer or author: Provided By www.digicamel.com(FREE DATASHEET DOWNLOAD SITE)
• PDF pages: 9

Technical content

Data Sheet29319.21E ABSOLUTE MAXIMUM RATINGS Output Current, IOUT Logic Input Voltage Range, Package Power Dissipation, Operating Temperature Range, Storage Temperature Range, 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°C. The A2919SB and A2919SLB motor drivers are designed to drive both windings of a bipolar stepper motor or bidirectionally control two dc motors. Both bridges are capable of sustaining 45 V and include internal pulse width modulation (PWM) control of the output current to 750 mA. The outputs have been optimized for a low output-saturation voltage drop (less than 1.8 V total source plus sink at 500 mA). For PWM current control, the maximum output current is deter- mined by the user’s selection of a reference voltage and sensing resistor. Two logic-level inputs select output current limits of 0%, 41%, 67%, or 100% of the maximum level. A PHASE input to each bridge determines load current direction. The bridges include both ground clamp and flyback diodes for protection against inductive transients. Internally generated delays prevent crossover currents when switching current direction. Special power-up sequencing is not required. Thermal protection circuitry disables the outputs if the chip temperature exceeds safe operating limits. The A2919SB is supplied in a 24-pin dual in-line plastic batwing package with a copper lead-frame and heat sinkable tabs for improved power dissipation capabilities. The A2919SLB is supplied in a 24-lead surface-mountable SOIC. Their batwing construction provides for maximum package power dissipation in the smallest possible construc- tion. The A2919SB/SLB are available for operation from -40°C to +85°C. To order, change the suffix from 'S–' to 'E–'. These devices are also available on special order for operation to +125°C. For applica- tions not requiring quarter-step operation, but desire lower detent or running current, the similar UDN2916B/EB/LB may be preferred.

FEATURES

■ 750 mA Continuous Output Current ■ 45 V Output Sustaining Voltage ■ Internal Clamp Diodes ■ Internal PWM Current Control ■ Low Output Saturation Voltage ■ Internal Thermal Shutdown Circuitry ■ Half- or Quarter-Step Operation of Bipolar Stepper Motors 2919 1312 θ 2 θ 1 V CC V BB GROUND GROUND GROUND GROUND 02 I 12 I PHASE 2 V REF 2 2RC 1RC V REF 1 PHASE 1 11 I 2BOUT SEN SE 2 2AOUT 1AOUT SEN SE 1 1BOUT 01 I LOAD SUPPLY LOGIC SUPPLY Dw g . PP- 005 PWM 1 PWM 2

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-5000 1Pb-based variants are being phased out of the product line. The variants cited in this footnote are in production but have been determined to be LAST TIME BUY. This classification indicates that sale of this device is currently restricted to existing cust omer applications. The variants should not be purchased for new design applications because obsolescence in the near future is probable. Samples are no longer available. Status change : October 31, 2006. Deadline for receipt of LAST TIME BUY orders: April 27, 2007. These variants include: A2919SB, A2919SLB and A2919SLBTR. Selection Guide Part Number Pb-free 1 RθJA (°C/W) RθJT (°C/W) Package Packing Ambient Temperature (°C) A2919SLB-T Yes 40 6.0 24-Lead SOIC 31 per tube –20 to 85 A2919SLBTR-T Yes 55 6.0 24-Lead SOIC 1000 per reel –20 to 85

Worcester, Massachusetts 01615-0036 (508) 853-5000 A2919SLB PWM CURRENT-CONTROL CIRCUITRY VBB 1312 GROUND GROUND GROUND GROUND 02 I 12 I PHASE 2 V REF 2 2RC V CC 1RC V REF 1 PHASE 1 11 I 2BOUT SENSE 2 2AOUT 1AOUT SENSE 1 1BOUT 01 I LOAD SUPPLY LOGIC SUPPLY PWM 2PWM 1 q 1 q 2 Dwg. PP-047 1 50 75 100 125 150 ALLOWABLE PACKAGE POWER DISSIPATION IN WATTSTEMPERATURE IN °C Dwg. GP-049A R = 6.0°C/WqJT SUFFIX 'B', R = 40°C/WqJA SUFFIX 'LB', R = 55°C/WqJA TRUTH TABLE PHASE OUT A OUT B HHL LLH V REF Dwg. EP-007-3 VBB SENSE ONE SHOT SOURCE DISABLE RC ‚10 E OUT A OUT B 'B' PACKAGE, CHANNEL 1 PIN NUMBERS SHOWN. R C R S R T C C C T 60 kW 120 kW 42 kW 211 W Copyright © 1994 Allegro MicroSystems, Inc.

Characteristic Symbol Test Conditions Min. Typ. Max. Units Output Drivers (OUTA or OUTB) Motor Supply Range V BB Operating 10 — 45 V Output Leakage Current I CEX VOUT = VBB — < 1.0 50 µA VOUT = 0 — <-1.0 -50 µA Output Sustaining Voltage V CE(sus) IOUT = ±750 mA, L = 3.0 mH 45 + V F —— V Output Saturation Voltage V CE(SAT) Sink Driver, IOUT = +500 mA — 0.4 0.6 V Sink Driver, IOUT = +750 mA — 1.0 1.2 V Source Driver, IOUT = -500 mA — 1.0 1.2 V Source Driver, IOUT = -750 mA — 1.3 1.5 V Clamp Diode Leakage Current I R VR = 45 V — < 1.0 50 µA Clamp Diode Forward Voltage V F IF = 750 mA — 1.6 2.0 V Driver Supply Current I BB(ON) Both Bridges ON, No Load — 20 25 mA IBB(OFF) Both Bridges OFF — 5.0 10 mA Control Logic Input Voltage V IN(1) All inputs 2.4 — — V VIN(0) All inputs — — 0.8 V Input Current I IN(1) VIN = 2.4 V — <1.0 20 µA VIN = 0.8 V — - 3.0 -200 µA Reference Voltage Range V REF 1.0 — 7.5 V I0 = 2.4 V, I1 = 0.8 V, 13.5 15 16.5 — VREF = 1.5 V to 7.5 V VREF = 1.5 V to 7.5 V Thermal Shutdown Temperature T J — 170 — °C Total Logic Supply Current I CC(ON) I0 = I1 = 0.8 V, No Load — 40 50 mA ICC(OFF) I0 = I1 = 2.4 V, No Load — 10 12 mA Total Reference Current I REF1 + IREF2 VREF1 = VREF2 = 7.5 V, I0 = I1 = 2.4 V 140 185 250 µA Fixed Off-Time t off RT = 56 kΩ , CT = 820 pF — 46 — µs ELECTRICAL CHARACTERISTICS at TA = +25°C, TJ ≤ 150°C, VBB = 45 V, VCC = 4.75 V to 5.25 V, VREF = 5.0 V (unless otherwise noted). (at trip point)

Worcester, Massachusetts 01615-0036 (508) 853-5000 APPLICATIONS INFORMATION PWM CURRENT CONTROL The A2919SB/SLB dual bridges are designed to drive both windings of a bipolar stepper motor. Output current is sensed and controlled independently in each bridge by an external sense resistor (R S), internal comparator, and monostable multivibrator. When the bridge is turned ON, current increases in the motor winding and flows through the external sense resistor until the sense voltage (V S) reaches the level set at the comparator’s input: ITRIP = VREF/10 RS The comparator then triggers the monostable, which turns OFF the source driver of the bridge. The actual load current peak will be slightly higher than the trip point (especially for low-inductance loads) because 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 = RTCT within the range of 20 kΩ to 100 kΩ and 100 pF to 1000 pF. The fixed-off time should be short enough to keep the current chopping above the audible range (< 46 µs) and long enough to properly regulate the current. Be- cause only slow-decay current control is available, short off times (< 10 µs) require additional efforts to ensure proper current regulation. Factors that can negatively affect the ability to properly regulate the current when using short off times include: higher motor-supply voltage, light load, and longer than necessary blank time. 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, main- taining the average motor winding current at the desired level. Loads with high distributed capacitances may cause current spikes capable of tripping the comparator, resulting in erroneous current control. An external R CCC time delay should be used to delay the action of the comparator. Depending on load type, many applications will not require these external components (SENSE connected to E). PWM OUTPUT CURRENT WAVE FORM LOAD CURRENT PATHS Dwg. E P-006-1 R S BBV BRIDGE ON SOURCE OFF ALL OFF Dwg. WM-003-1A V PHASE I OUT td toff I TRIP

LOGIC CONTROL OF OUTPUT CURRENT Two logic level inputs (l0 and I1) allow digital selection of the motor winding current at 100%, 67%, 41%, or 0% of the maximum level per the table. The 0% output current condition turns OFF all drivers in the bridge and can be used as an OUTPUT ENABLE function. CURRENT-CONTROL TRUTH TABLE l0 I1 Output Current LL V REF /10 RS = 100% ITRIP HL V REF /15 RS = 67% ITRIP LH V REF /24.4 RS = 41% ITRIP HH 0 These logic level inputs greatly enhance the implem- entation of µP-controlled drive formats. During half-step operations, l0 and l1 allow the µP to control the motor at a constant torque between all posi- tions in an eight-step sequence. This is accomplished by digitally selecting 100% drive current when only one phase is ON and 67% drive current when two phases are ON. Logic highs on both l 0 and l1 turn OFF all drivers to allow rapid current decay. During quarter-step operation, I0 and I1 allow the µP to control the motor position in a sixteen-step sequence. This is accomplished by digitally selecting drive current as shown in the table (for one quadrant of operation). Logic highs on both I 0 and I1 turn OFF all drivers to allow rapid current decay. The logic control inputs can also be used to select a reduced current level (and reduced power dissipation) for ‘hold’ conditions and/or increased current (and available torque) for start-up conditions. QUARTER-STEPPING CURRENT CONTROL Phase 1 Phase 2 Current Level Current Level 100% 0% 100% 41% 67% 67% 41% 100% 0% 100% GENERAL The PHASE input to each bridge determines the direction motor winding current flows. An internally generated deadtime (approximately 2 µs) prevents cross- over currents that can occur when switching the PHASE input. All four drivers in the bridge output can be turned OFF between steps (l 0 = l1 ≥ 2.4 V) resulting in a fast current decay through the internal output clamp and flyback diodes. The fast current decay is desirable in half-step and high-speed applications. The PHASE, l 0, and I1 inputs float high. Varying the reference voltage (VREF ) provides continu- ous control of the peak load current for micro-stepping applications. Thermal protection circuitry turns OFF all drivers when the junction temperature reaches +170°C. It is only intended to protect the device from failures due to exces- sive junction temperature and should not imply that output short circuits are permitted. The output drivers are re- enabled when the junction temperature cools to +145°C. The A2919SB/SLB output drivers are optimized for low output saturation voltages—less than 1.8 V total (source plus sink) at 500 mA. Under normal operating conditions, when combined with the excellent thermal properties of the batwing package design, this allows continuous operation of both bridges simultaneously at 500 mA.

Worcester, Massachusetts 01615-0036 (508) 853-5000 TYPICAL APPLICATION FROM µP VREF Dwg. EP-008B1 VBB FROM µP 1312 θ 2 VCC VBB VREF +5 V STEPPER MOTOR RS RS RC RC RTCT CC CC PWM 1 PWM 2 θ 1 820 pF 56 k Ω CT 820 pF56 kΩ RT

0.014 0.008 0.300 BSC Dwg. MA-001-25A in 0.430 MAX 16 12 0.280 0.240 0.210 MAX 0.070 0.045 0.015 MIN 0.022 0.014 0.100 BSC 0.005 MIN 0.150 0.115 1.280 1.230 NOTE 1 0.355 0.204 7.62 BSC Dwg. MA-001-25A mm 10.92 MAX 1 12 7.11 6.10 5.33 MAX 1.77 1.15 0.39 MIN 0.558 0.356 2.54 BSC 0.13 MIN 3.81 2.93 32.51 31.24 NOTE 1 A2919SB Dimensions in Inches (controlling dimensions) Dimensions in Millimeters (for reference only) NOTES: 1. Webbed lead frame. Leads 6, 7, 18, and 19 are internally one piece. 2. Lead thickness is measured at seating plane or below. 3. Lead spacing tolerance is non-cumulative. 4. Exact body and lead configuration at vendor’s option within limits shown.

Worcester, Massachusetts 01615-0036 (508) 853-5000 A2919SLB Dimensions in Inches (for reference only) Dimensions in Millimeters (controlling dimensions) NOTES: 1. Webbed lead frame. Leads 6, 7, 18, and 19 are internally one piece. 2. Lead spacing tolerance is non-cumulative. 3. Exact body and lead configuration at vendor’s option within limits shown. 0° TO 8° 1 2 3 0.2992 0.2914 0.6141 0.5985 0.491 0.394 0.020 0.013 0.0926 0.1043 0.0040 MIN. 0.0125 0.0091 Dwg. MA-008-25 in 0.050 BSC 24 13 NOTE 1 NOTE 3 0.050 0.016 0° TO 8° 1 2 3 7.60 7.40 15.60 15.20 10.65 10.00 0.51 0.33 2.65 2.35 0.10 MIN. 0.32 0.23 Dwg. MA-008-25A mm 1.27 BSC 24 13 NOTE 1 NOTE 3 1.27 0.40 Allegro MicroSystems, Inc. reserves the right to make, from time to time, such departures from the detail specifications as may be required to permit improvements in the design of its products. The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, Inc. assumes no responsibility for its use; nor for any infringements of patents or other rights of third parties which may result from its use.