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Details, datasheet, quote on part number:A3972SB
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| Part: | A3972SB |
| Category: | Power Management => Motor Controller/Drivers => DC Motor drivers/Controllers => DC Specific |
| Description: | Dual Dmos Full-bridge Driver |
| Company: | Allegro Micro Systems, Inc. |
| Datasheet: | Download A3972SB datasheet File size : 195 kB |
| Request For quote: | Find where to buy A3972SB
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Datasheet text preview:
3972
CHARGE PUMP
DUAL DMOS FULL-BRIDGE MICROSTEPPING PWM MOTOR DRIVER
VCP CP1 CP2 OUT1B LOAD SUPPLY 1 GROUND GROUND SENSE1 OUT1A STROBE CLOCK DATA 1 2 3 4 5 6 7 8 9 9 10 11 12 24 23 22 21 20 19 18 17 16 OSC SLEEP VREG OUT2B LOAD SUPPLY 2 GROUND GROUND SENSE 2 OUT2A LOGIC SUPPLY MUX REF
6-BIT DAC & LOGIC
6-BIT DAC & LOGIC
V BB1
V BB2
SERIAL PORT
VDD
15 14 13
Dwg. PP-069-3
ABSOLUTE MAXIMUM RATINGS at TA = +25°C
Load Supply Voltage, VBB ....... 50 V Output Current, IOUT .... ±1.5 A Logic Supply Voltage, VDD ..... 7.0 V Logic Input Voltage Range, VIN ....... -0.3 V to VDD + 0.3 V Reference Voltage, VREF ............ 3 V Sense Voltage (dc), VS ....... 500 mV Package Power Dissipation, PD ......... 3.1 W Operating Temperature Range, TA .. -20°C to +85°C Junction Temperature, TJ .... +150°C Storage Temperature Range, TS ....... -55°C to +150°C
Output current rating may be limited by duty cycle, ambient temperature, and heat sinking. Under any set of conditions, do not exceed the specified current rating or a junction temperature of 150°C.
Designed for pulse-width modulated (PWM) current control of bipolar microstepping stepper motors, the A3972SB is capable of continuous output currents to ±1.5 A and operating voltages to 50 V. Internal fixed off-time PWM current-control timing circuitry can be programmed via a serial interface to operate in slow, fast, and mixed current-decay modes. The desired load-current level is set via the serial port with two 6-bit linear DACs in conjunction with a reference voltage. The six bits of control allow maximum flexibility in torque control for a variety of step methods, from microstepping to full-step drive. Load current is set in 1.56% increments of the maximum value. Synchronous rectification circuitry allows the load current to flow through the low rDS(on) of the DMOS output driver during the current decay. This feature will eliminate the need for external clamp diodes in most applications, saving cost and external component count, while minimizing power dissipation. Internal circuit protection includes thermal shutdown with hysteresis, transient-suppression diodes, and crossover-current protection. Special power-up sequencing is not required. The A3972SB is supplied in a 24-lead plastic DIP with a copper batwing power tab (suffix `B'). The power tab is at ground potential and needs no electrical isolation.
Data Sheet 29319.33
FEATURES
I ±1.5 A, 50 V Continuous Output Rating I Low rDS(on) DMOS Output Drivers I Optimized Microstepping via 6-Bit Linear DACs I Programmable Mixed, Fast, and Slow Current-Decay Modes I 4 MHz Internal Oscillator for Digital Timing I Serial-Interface Controls Chip Functions I Synchronous Rectification for Low Power Dissipation I Internal UVLO and Thermal Shutdown Circuitry I Crossover-Current Protection I Precision 2 V Reference I Inputs Compatible with 3.3 V or 5 V Control Signals I Sleep and Idle Modes Always order by complete part number: A3972SB .
3972 DUAL DMOS FULL-BRIDGE MICROSTEPPING PWM MOTOR DRIVER
FUNCTIONAL BLOCK DIAGRAM
0.22 µF 0.22 µF
22
VREG
3
CP2
2
CP1
LOGIC SUPPLY
2V
15
VDD
UVLO AND FAULT DETECT
REGULATOR BANDGAP
VCP
LOAD SUPPLY
CHARGE PUMP
1
VBB1 MUX 14
5
0.22 µF
6-BIT LINEAR DAC +
6
DMOS H-BRIDGE
SENSE1 VCP
OUT1A
9
OSCILATOR
OSC
24
PROGRAMMABLE PWM TIMER
FIXED-OFF BLANK MIXED DECAY
OUT1B
4
OSC SELECT/ DIVIDER
SENSE1
8
CLOCK 11 DATA 12 STROBE 10
SERIAL PORT
CONTROL LOGIC
PHASE 1/2 SYNC. RECT. MODE SYNC. RECT. DISABLE MODE 1/2
GATE DRIVE
DMOS H-BRIDGE
0.1 µF
20
VBB2
SLEEP 23 OUT2A
16
PROGRAMMABLE PWM TIMER
2V 6 FIXED-OFF BLANK MIXED DECAY
OUT2B
21
REF 13
BUFFER
+ 6-BIT LINEAR DAC
SENSE2
17
0.1 µF 6 GROUND 7 18 19
Dwg. FP-050-1
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115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 Copyright © 2000, Allegro MicroSystems, Inc.
3972 DUAL DMOS FULL-BRIDGE MICROSTEPPING PWM MOTOR DRIVER
ELECTRICAL CHARACTERISTICS at TA = +25°C, VBB = 50 V, VDD = 5.0 V, VS = 0.5 V, fPWM < 50 kHz (unless otherwise noted).
Limits Characteristic Load Supply Voltage Range Symbol V BB VDD I BB Test Conditions Operating During sleep mode Logic Supply Voltage Range Load Supply Current Operating fPWM < 50 kHz Operating, outputs disabled Sleep or idle mode Logic Supply Current I DD fPWM < 50 kHz Outputs off Idle mode (D0 = 1, D18 = 0) Sleep mode Output Drivers Output Leakage Current I DSS rD S ( o n ) VF V OUT = V BB V OUT = 0 V Output On Resistance Source driver, IOUT = 1.5 A Sink driver, IOUT = 1.5 A Body Diode Forward Voltage Source diode, IF = 1.5 A Sink diode, IF = 1.5 A Control Logic Logic Input Voltage V IN(1) V IN(0) Logic Input Current OSC Input Frequency Range IIN(1) IIN(0) fOSC -- VIN VIN = 2.0 V VIN = 0.8 V Divide by one (D0 =1, D13 = 0, D14 = 1) OSC Input Duty Cycle Input Hysterisis 40 0.20 -- -- 60 0.40 % V 2.0 -- -- -- 2.5 -- -- <1.0 <-2.0 -- -- 0.8 20 -20 6.0 V V µA µA MHz -- -- -- -- -- -- <1.0 <-1.0 0.5 0.315 -- -- 50 -50 0.55 0.35 1.2 1.2 µA µA V V Min. 15 0 4.5 -- -- -- -- -- -- -- Typ. -- -- 5.0 -- -- -- -- -- -- -- Max. 50 50 5.5 8.0 6.0 20 12 10 1.5 100 Units V V V mA mA µA mA mA mA µA
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3972 DUAL DMOS FULL-BRIDGE MICROSTEPPING PWM MOTOR DRIVER
ELECTRICAL CHARACTERISTICS at TA = +25°C, VBB = 50 V, VDD = 5.0 V, VS = 0.5 V, fPWM < 50 kHz (unless otherwise noted).
Limits Characteristics Control Logic (continued) Internal Oscillator fOSC ET V REF(EXT) VOS VREF/VS IR E F V REF(INT) EG D0 = 0, D17 = 0, D18 = 0, DAC = 63 D18 = 0, DAC = 31 D18 = 1, DAC = 63 D18 = 1, DAC = 15 Comparator Input Offset Voltage Propagation Delay Times V IO t pd V REF = 0 V 50% to 90%: PWM change to source on PWM change to source off PWM change to sink on PWM change to sink off Crossover Dead Time Thermal Shutdown Temperature Thermal Shutdown Hysteresis UVLO Enable Threshold UVLO Hysteresis t dt TJ TJ V UVLO VUVLO I n c r e a s i n g VD D 500 50 500 50 300 -- -- 3.9 0.05 800 150 800 150 700 165 15 4.2 0.10 1200 350 1200 350 900 -- -- 4.45 -- ns ns ns ns ns °C °C V V -- -- -- -- -- 0 0 0 0 ± 5.0 ±6 ±9 ±6 ± 10 -- % % % % mV D0 = 0, D18 = 0 D0 = 0, D18 = 1 Reference Input Current Internal Reference Voltage Gain (Gm) Error (note 3) VREF = 2.0 V OSC shorted to ground ROSC = 51 k DAC Accuracy (total error) Relative to DAC reference buffer output, D0 = 0, D17 = 0 Reference Input Voltage Range Reference Buffer Offset Reference Divider Ratio 0.5 -- -- -- -- 1.94 -- ± 10 8.0 4.0 -- 2.0 2.6 -- -- -- ± 0.5 2.06 V mV -- -- µA V 3.0 3.4 -- 4.0 4.0 ± 1/2 5.0 4.6 -- MHz MHz LSB Symbol Test Conditions Min. Typ. Max. Units
NOTES: 1. Typical Data is for design information only. 2. Negative current is defined as coming out of (sourcing) the specified device terminal. 3. EG = [(VREF/Range) VS]/(VREF/Range).
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115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
3972 DUAL DMOS FULL-BRIDGE MICROSTEPPING PWM MOTOR DRIVER
FUNCTIONAL DESCRIPTION
Serial Interface. The A3972SB is controlled via a 3-wire (clock, data, strobe) serial port. The programmable functions allow maximum flexibility in configuring the PWM to the motor drive requirements. The serial data is written as two 19-bit words: 1 bit to select the word and 18 bits of data. The serial data is clocked in starting with D18. Word 0 Bit Assignments Bit D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 D10 D11 D12 D13 D14 D15 D16 D17 D18 Function Word select = 0 Bridge 1, DAC, LSB Bridge 1, DAC, bit 2 Bridge 1, DAC, bit 3 Bridge 1, DAC, bit 4 Bridge 1, DAC, bit 5 Bridge 1, DAC, MSB Bridge 2, DAC, LSB Bridge 2, DAC, bit 2 Bridge 2, DAC, bit 3 Bridge 2, DAC, bit 4 Bridge 2, DAC, bit 5 Bridge 2, DAC, MSB Bridge 1 phase Bridge 2 phase Bridge 1 mode Bridge 2 mode REF select Range select
D13 Bridge 1 Phase. This bit controls the direction of output current for Load 1. D13 O U T1A O U T1B 0 1 L H H L
D14 Bridge 2 Phase. This bit controls the direction of output current for Load 2. O U T2B D14 O U T2A 0 1 D15 Bridge 1 Mode. D15 0 1 D16 Bridge 2 Mode. D16 0 1 Mode Mixed-decay Slow-decay Mode Mixed-decay Slow-decay L H H L
D17 REF Select. This bit determines the reference input for the 6-bit linear DACs. D17 0 1 Reference Voltage Internal 2 V External (3 V max)
D1 D6 Bridge 1 Linear DAC. Six-bit word sets desired current level for Bridge 1. Setting all six bits to zero disables Bridge 1, with all drivers off (See current regulation section of functional description). D7 D12 Bridge 2 Linear DAC. Six-bit word sets desired current level for Bridge 2. Setting all six bits to zero disables Bridge 2, with all drivers off (See current regulation section of functional description).
D18 Gm Range Select. This bit determines the scaling factor (4 or 8) used. D18 0 1 Divider 1/8 1/4 Load Current I TRIP = V DAC/ 8 R S I TRIP = V DAC/ 4 R S
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