POWERHALL SENSOR/DRIVERS FOR BRUSHLESS DC MOTORS

3625 AND 3626 POWERHALL® SENSOR/DRIVERS FOR BRUSHLESS DC MOTORS Requiring a minimum of external components, the UDN3625M and UDN3626M are monolithic ICs that provide single-chip control and direct drive solutions for many small, single-phase, unipolar brushless dc motor applications. Integrated into the ICs are a highsensitivity Hall-effect sensor, control and commutating logic, a stable voltage regulator, extensive self and system protective functions, and two high-current saturated npn outputs. Both ICs include thermal shutdown, output over-current limiting, and output transient protection/ flyback diodes. The UDN3625M is nominally for 12 V motor applications while the UDN3626M is better suited to 24 V motors. Output over-current limiting (relating to startup surge or a locked rotor condition) and short-circuit protection are provided by an internal current-sense resistor. The maximum (default) output load current is typically 1.3 A for the UDN3625M or 600 mA for the UDN3626M, but may be decreased by user selection of an external low-wattage resistor. A separate low-level output provides tachometer capability for motor speed control or sensing a locked rotor condition. With appropriate external logic, pulse-width modulated (PWM) speed control can be accomplished at the output current adjust pin. These sensor/drivers are supplied in an 8-pin mini-DlP plastic package with a copper leadframe for increased package power handling capability. Data Sheet 27690A CONTACT FACTORY for availability and latest information ABSOLUTE MAXIMUM RATINGS Supply Voltage, VCC . . . . . . . . . . See Table Output Current, IO . . . . . . . . . . . . See Table PWM Current Control Voltage, VADJ . . . . . . . . . . . . . See Applications Magnetic Flux Density, B . . . . . . Unlimited Package Power Dissipation, PD . . . . . . . . . . . . . . . . . . . . See Graph Operating Temperature Range, TA . . . . . . . . . . . . . . . . . -20°C to +85°C Storage Temperature Range, TS . . . . . . . . . . . . . . . . -65°C to +150°C UDN3625M VCC(MAX) IO(CONT) IO(PEAK) 14 V 1.0 A 1.6 A UDN3626M 26 V 0.45 A 0.75 A FEATURES s 900 mA /12 V or 400 mA /24 V Operation s Speed-Control (PWM) Capability s Locked-Rotor Indication s Minimum External Components s Over-Current Protected s Thermal Protection s Enhanced Reliability s Reduced Cost Output current rating will be limited by ambient temperature, supply voltage, and duty cycle. Under any set of conditions, do not exceed a junction temperature of +150°C. Always order by complete part number, e.g., UDN3625M . See Maximum Ratings at left. 3625 AND 3626 POWERHALL® SENSOR/DRIVERS FOR BRUSHLESS DC MOTORS FUNCTIONAL BLOCK DIAGRAM SUPPLY 5 OUT B 4 6 OUTA +V 8 TACH OUT GROUND VS REG. TSD X 7 PWM/I O 1 ADJUST RADJ Dwg. FP-005-1 ALLOWABLE PACKAGE POWER DISSIPATION IN WATTS 2.0 RθJC = 55°C/W TRUTH TABLE Mag. Field > +BOP > -BOP Any PWM/IOADJ Open Open <0.3 V OUTA Low High High OUTB High Low High 1.5 1.0 0.5 FREE AIR, RθJA = 80°C/W 0 25 50 75 100 TEMPERATURE IN °C 125 150 Dwg. GP-009-1B 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 Copyright © 1988, 1995, Allegro MicroSystems, Inc. 3625 AND 3626 POWERHALL® SENSOR/DRIVERS FOR BRUSHLESS DC MOTORS ELECTRICAL CHARACTERISTICS at TA = +25°C, RADJ = ∞, Over Operating Voltage Range (unless otherwise noted). Limits Characteristic UDN3625M Operating Voltage Range Output Leakage Current Output Breakdown Voltage Output Saturation Voltage VS IO V(BR)CEX VO(SAT) VCC = VO = 24 V VCC = 24 V, lO = 10 mA* IO = 450 mA, VS = 6.5 V IO = 900 mA, VS = 12 V Output Current Limit Output Clamp Voltage (Test Fig. 1) Output Switching Time Supply Current (Test Fig. 2) UDN3626M Operating Voltage Range Output Leakage Current Output Breakdown Voltage Output Saturation Voltage VS lO V(BR)CEX VO(SAT) VCC = VO = 30 V VCC = 30 V, lO = 10 mA* lO = 250 mA, VS = 6.5 V lO = 400 mA, VS = 24 V Output Current Limit Output Clamp Voltage (Test Fig. 1) Output Switching Time Supply Current (Test Fig. 2) lOMAX VCL RADJ = ∞, VO = 2 V ICL = 10 mA, VCC = 0 ICL = 250 mA, VCC = 0 tPLH lCC 50% VADJ to VO = 3.0 V, lO = 250 mA RADJ = ∞, VS = 26 V, One Output ON RADJ = 0 Ω, VS = 26 V, Outputs OFF ‡ — 50 — — 450 17 19 — — — 24 — — 0.15 0.3 600 18 20 — — 8.0 26 100 — 0.3 0.5 750 20 22 5.0 24 10 V µA V V V mA V V µs mA mA IO MAX VCL RADJ = ∞, VO = 2 V ICL = 10 mA, VCC = 0 ICL = 450 mA=, VCC = 0 tPLH lCC 50% VADJ to VO = 3.0 V, lO = 450 mA RADJ = ∞, VS = 14 V, One Output ON RADJ = 0 Ω, VS = 14 V, Outputs OFF 6.5 — 34 — — 1.0 11 13 — — — 12 — — 0.25 0.5 1.3 12 14 — 30 8.0 14 100 — 0.4 0.8 1.6 13 15 5.0 38 10 V µA V V V A V V µs mA mA Symbol Test Conditions Min. Typ. Max. Units * lO is almost entirely Zener clamp current. † Pulse test. ‡ Dependent on value of external series Zener diode (see Applications), 6.5 V without a Zener diode. Continued next page... 3625 AND 3626 POWERHALL® SENSOR/DRIVERS FOR BRUSHLESS DC MOTORS ELECTRICAL CHARACTERISTICS continued Limits Characteristic Both Operate Point§ Hysteresis Output Current Limit Ratio BOP BH lO/lO MAX RADJ = 39 kΩ RADJ = 17 kΩ RADJ = 10 kΩ PWM Control Current Tach Output Leak. Current Tach Output Sat. Voltage Thermal Shutdown Thermal Hysteresis IADJ IT VT(SAT) TJ ∆TJ VADJ = 0 VT = 14 V IT = 750 µA — — — — — — — — –– –– ±100 200 0.75 0.50 0.25 -350 — 0.2 165 10 ±150 — — — — -500 10 0.4 — — G G — — — µA µA V °C °C Symbol Test Conditions Min. Typ. Max. Units § Magnetic flux density is measured at most sensitive area of device, nominally located 0.055" (1.40 mm) below the top of the package. OUTPUT CLAMP VOLTAGE TEST (ONE OUTPUT TESTED AT A TIME) SUPPLY CURRENT TEST Dwg. No. EP-013 TEST FIG. 1 TEST FIG. 2 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 3625 AND 3626 POWERHALL® SENSOR/DRIVERS FOR BRUSHLESS DC MOTORS SENSOR LOCATION APPLICATIONS INFORMATION Power Dissipation. Care should be taken in evaluating the package power dissipation of these devices. Total power dissipated by the device will consist of power due to the internal regulator, logic and drive circuitry (ICC x VCC), power due to the output drivers (IO x VO(SAT)), and power due to the clamp circuitry (ICL x VCL x duty cycle). For example: ICC x VCC = 38 mA (max) x 14 V = 532 mW (max) IO x VO(SAT) = 450 mA x 0.4 V (max) = 180 mW (max) ICL x VCL x duty cycle = 450 mA x 15 V (max) x 1% = 67.5 mW (max) Total package power dissipation = 779.5 mW (max) Some of the power dissipated by the device (ICC x VCC) can be reduced by inserting a Zener diode in the supply line (ZA in the figure). Note that the voltage at the VCC pin under worst-case conditions must be greater than the minimum operating voltage (6.5 V). Transient Protection. A note of caution concerns negative (below ground) excursions of the outputs. In application, the coupling of the two motor windings can provide for just such a case. Reducing the coupling between windings will help, but ground clamp diodes or diodes in series with the motor windings might be required (DC or DS in the figure). Most small brushless motors will not require these diodes. System requirements usually utilize a diode type of reverse-polarity protection. If series diode protection is used with an inductive load (the usual fan application), a Zener clamp between VS and ground (ZB in the figure) is required. The Zener voltage must be greater than the supply voltage but less than the rated maximum allowable supply voltage. With diode reverse-polarity protection, a high-impedance supply, or a switched supply line, high-voltage spikes will be generated (especially with high-current or high-inductance loads) during normal operation, coasting, or immediately after turn-off. In these situations, a Zener clamp (ZB) from VS to ground will be required. Over-Current Adjust Pin. The over-current limit may be reduced from the default value (IO MAX) by selection of an external resistor (RADJ) at the PWM/IO ADJ pin. 3625 AND 3626 POWERHALL® SENSOR/DRIVERS FOR BRUSHLESS DC MOTORS The external overcurrent adjust and the thermal shutdown are commoned at the PWM/lO ADJ pin and tieing it to VCC will disable the thermal shutdown. PWM current/speed control can be performed at the PWM/lO ADJ pin from a standard totem-pole logic output with a series Schottky diode (1N5818,1N5819, or equivalent) or by pulling it low through an opencollector transistor (no pull-up resistor). PWM/lO ADJ input voltages greater than 0.3 V are not recommended and may create an unstable operating condition. TYPICAL FAN APPLICATION MAGNETIC FIELD DEFINITIONS OUTA ON/LOW S +B O P B=0G -B +B +B -B O P N Dwg. AP-001-1 OUTB ON/LOW Dwg. GP-008 By accepted magnetic convention, lines of flux emanate from the north pole of a magnet and enter the south pole. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 3625 AND 3626 POWERHALL® SENSOR/DRIVERS FOR BRUSHLESS DC MOTORS Dimensions in Inches (controlling dimensions) 0.014 0.008 8 5 0.430 0.280 0.240 MAX 0.300 BSC 1 0.070 0.045 4 0.005 0.400 0.355 MIN 0.210 MAX 0.015 MIN 0.150 0.115 0.022 0.014 0.100 BSC Dwg. MA-001-8A in NOTES: 1. Leads 1, 4, 5, and 8 may be half leads at vendor’s option. 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. 3625 AND 3626 POWERHALL® SENSOR/DRIVERS FOR BRUSHLESS DC MOTORS Dimensions in Millimeters (for reference only) 0.355 0.204 8 5 10.92 7.11 6.10 MAX 7.62 BSC 1 1.77 1.15 4 0.13 10.16 9.02 MIN 5.33 MAX 0.39 MIN 3.81 2.93 0.558 0.356 2.54 BSC Dwg. MA-001-8A mm The products described herein are manufactured under one or more of the following U.S. patents: 5,045,920; 5,264,783; 5,442,283; 5,389,889; 5,581,179; 5,517,112; 5,6