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VBB VDD RDSON VF IBB
Motor Supply Current
Logic Supply Current Control Logic Logic Input Voltage Logic Input Current Microstep Select 2 Input Hysteresis Blank Time Fixed Off-Time Reference Input Voltage Range Reference Input Current Current Trip-Level Error3 Crossover Dead Time Protection Thermal Shutdown Temperature Thermal Shutdown Hysteresis UVLO Enable Threshold UVLO Hysteresis
THERMAL CHARACTERISTICS
Characteristic Package Thermal Resistance Symbol RθJA Test Conditions* 4-layer PCB, based on JEDEC standard) Value Units 28 ºC/W
*In still air. Additional thermal information available on Allegro Web site.
5.5 5.0
Maximum Power Dissipation, PD(max)
Power Dissipation, PD (W)
4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0
Description
The A3983 is a complete microstepping motor driver with built-in translator for easy operation. It is designed to operate bipolar stepper motors in full-, half-, quarter-, and eighth-step modes, with an output drive capacity of up to 35 V and ±2 A. The A3983 includes a fixed off-time current regulator which has the ability to operate in Slow or Mixed decay modes. The translator is the key to the easy implementation of the A3983. Simply inputting one pulse on the STEP input drives the motor one microstep. There are no phase sequence tables, high frequency control lines, or complex interfaces to program. The A3983 interface is an ideal fit for applications where a complex microprocessor is unavailable or is overburdened. The chopping control in the A3983 automatically selects the current decay mode (Slow or Mixed). When a signal occurs at the STEP input pin, the A3983 determines if that step results in a higher or lower current in each of the motor phases. If the change is to a higher current, then the decay mode is set to Slow decay. If the change is to a lower current, then the current decay is set to Mixed (set initially to a fast decay for a period amounting to 31.25% of the fixed off-time, then to a slow decay for the remainder of the off-time). This current decay
DMOS Full Bridge
OUT2A OUT2B
ENABLE SLEEP
SENSE2 RS2
VREF
26184.29D
http://oneic.com/
A3983
DMOS Microstepping Driver with Translator
Description (continued) control scheme results in reduced audible motor noise, increased step accuracy, and reduced power dissipation. Internal synchronous rectification control circuitry is provided to improve power dissipation during PWM operation. Internal circuit protection includes: thermal shutdown with hysteresis, undervoltage Selection Guide
VDD
Current Regulator
OSC
Charge Pump VCP 0.1 μF DMOS Full Bridge
REF DAC
VBB1
OUT1A OUT1B PWM Latch Blanking Mixed Decay
SENSE1 Gate Drive RS1 VBB2
STEP DIR RESET MS1 MS2 PWM Latch Blanking Mixed Decay DAC Translator Control Logic
2
http://oneic.com/
A3983
DMOS Microstepping Driver with Translator
ELECTRICAL CHARACTERISTICS1 at TA = 25°C, VBB = 35 V (unless otherwise noted)
Characteristics Output Drivers Load Supply Voltage Range Logic Supply Voltage Range Output On Resistance Body Diode Forward Voltage Symbolຫໍສະໝຸດ BaiduTest Conditions Operating During Sleep Mode Operating Source Driver, IOUT = –1.5 A Sink Driver, IOUT = 1.5 A Source Diode, IF = –1.5 A Sink Diode, IF = 1.5 A fPWM < 50 kHz Operating, outputs disabled Sleep Mode fPWM < 50 kHz Outputs off Sleep Mode Min. 8 0 3.0 – – – – – – – – – – VDD0.7 VIN = VDD0.7 – –20 –20 – 150 0.7 20 23 0 –3 – – – 100 – – 2.35 0.05 Typ.2 – – – 0.350 0.300 – – – – – – – – – – <1.0 <1.0 100 300 1 30 30 – 0 – – – 475 165 15 2.7 0.10 Max. 35 35 5.5 0.450 0.370 1.2 1.2 4 2 10 8 5 10 – VDD0.3 20 20 – 500 1.3 40 37 4 3 ±15 ±5 ±5 800 – – 3 – Units V V V Ω Ω V V mA mA μA mA mA μA V V μA μA kΩ mV μs μs μs V μA % % % ns °C °C V V
Part Number A3983SLPTR-T Package 24-pin TSSOP with exposed thermal pad Packing 4000 pieces per 13-in. reel
lockout (UVLO), and crossover-current protection. Special poweron sequencing is not required. The A3983 is supplied in a low-profile (1.2 mm maximum height), 24-pin TSSOP with exposed thermal pad (suffix LP). It is lead (Pb) free, with 100% matte tin leadframe plating.
A3983 DMOS Microstepping Driver with Translator
Features and Benefits
▪ ▪ ▪ ▪ ▪ ▪ Low RDS(ON) outputs Automatic current decay mode detection/selection Mixed and Slow current decay modes Synchronous rectification for low power dissipation Internal UVLO and thermal shutdown circuitry Crossover-current protection
Continued on the next page…
Package: 24-pin TSSOP with exposed thermal pad (suffix LP)
Not to scale
Functional Block Diagram
0.22 μF VREG ROSC CP1 0.1 μF CP2
Absolute Maximum Ratings
Characteristic Load Supply Voltage Output Current Logic Input Voltage Sense Voltage Reference Voltage Operating Ambient Temperature Maximum Junction Storage Temperature Symbol VBB IOUT VIN VSENSE VREF TA TJ(max) Tstg Range S 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. Notes Rating 35 ±2 –0.3 to 7 0.5 4 –20 to 85 150 –55 to 150 Units V A V V V ºC ºC ºC
(R
θJ A
=
28
ºC
/W
)
20
40
60
80 100 120 Temperature (°C)
140
160
180
Allegro MicroSystems, Inc. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 www.allegromicro.com