Introduction to A4988
- The A4988 is a micro-striding driver for governing the stepper motors, it is incorporated with the interpreter for the tranquil process.
- This motor driver offers five, unlike step tenacities which are, 1. Complete Step 2. Half (1/2) Step 3. A quarter (1/4) Step 4. Eight (8th) Step and 5. 16-Step. It also has a potentiometer which regulates the output current, over temperature updraft stoppage and crossover current safety.
- The interpreter of this driver is fundamental to the stress-free employment of the A4988. Only entering one pulse on the stride input drives the motor one micro-step.
- There is no need for phase classification tables, higher frequency outlines, or multifaceted borders to plug-in.
- The interfacing of this module is suitable for such applications where a composite microprocessor is inaccessible or is overloaded.
- During the stepping process, the cutting governer in this module robotically chooses the current falling-off way, sluggish or diversified.
- In diversified decay style, the expedient is set firstly to a fast deterioration for a magnitude of the steady off-time, then to a slow deterioration for the remains of the off-time.
- In this module, interior synchronous modify integrated circuit is connected to mend power indulgence during the PWM process.
- This special integrated circuit consists of thermal cessation with hysteresis, under voltage lockout (UVLO), and crossover-current fortification
- It is available in superficial mounted QFN cascading (ET), with the dimensions of 5mm x 5mm, having a cascading height of .90mm and an uncovered wad for boosted thermal indulgence.
Pinout of A4988
- These are the main pinout A4988 which are described below.
|Pin#4||CP1||It is a charge drive capacitor point.|
|Pin#5||CP2||It is a charge drive capacitor point.|
|Pin#6||VCP||It is a reservoir capacitor point.|
|Pin#8||VREG||It is controller decoupling point.|
|Pin#9||MS1||It is a Logic input pinout.|
|Pin#10||MS2||It is reasoning input pin.|
|Pin#11||MS3||It is reasoning input pin.|
|Pin#12||RESET||It is reasoning input pin.|
|Pin#13||ROSC||It is timing setting pin|
|Pin#14||SLEEP||It is reasoning input pin.|
|Pin#15||VDD||It is the Logic source.|
|Pin#16||STEP||It is reasoning input pin.|
|Pin#17||REF||It is Gm reference voltage input pinout.|
|Pin#3,18||GND||It is ground pinout.|
|Pin#19||DIR||It is a reasoning input pin|
|Pin#21||OUT1B||DMOS Complete Bridge 1 Output B pin.|
|Pin#22||VBB1||It is a supply voltage for load.|
|Pin#23||SENSE1||It is sagacity resistor terminal for Bridge.|
|Pin#24||OUT1A||DMOS Complete Bridge 1 Output A pin.|
|Pin#26||OUT2A||DMOS complete Bridge 2 Output A pin.|
|Pin#7,20,25||NC||It is open pinout.|
|Pin#1||OUT2B||It is DMOS Complete Bridge 2 Output B|
|Pin#27||SENSE2||Sagacity resistor terminal for Bridge 2.|
|Pin#28||VBB2||It is a supply voltage for load.Pin#2ENABLEIt is Logic input pinout.|
|-||PAD||It is unshielded wad for improved thermal indulgence.|
Features of A4988
- These are some features of A4988. Let's discuss them.
- It has a squat RDS (ON) every output pinout.
- It has Instinctive current falling-off type assortment.
- It has Varied and Sluggish current falling-off modes.
- It provides coetaneous rectification for low-slung power indulgence.
- This module has an interior UVLO.
- It provides crossover current fortification.
- It is well accorded with the 3.3 and 5 v logic source.
- It has thermal cessation circuit.
- It also provides fortification from short to ground.
Difference between A4988 and DRV8825
- Now we discuss differences between A4988 and DRv8825.
- The DRV8825 proposals to 1/32 striding, while A4988 only steps to 1/16.
- Both have potentiometer at the dissimilar place.
- There is no coherence between a reference voltage and current limiter.
- DRV8825 needs the smallest step pulse period of 1.9us, while A4988 needs 1us.
- DRV8825 used for high current consuming motors, while A4988 is used for low current consuming motors.
- In the case of A4988, we need special colling to draw high current but in the case of DRV8825, there is no need for any special colling.
Applications of A4988
- These are some applications of A4988.
- As we discussed it is used to control the speed and rotation of stepper motor.
- It is used in robotics to control their motion.
- It is used in different toys.