The DRV8825 provides an integrated motor driver solution for printers, scanners, and other automated equipment applications. The device has two H-bridge drivers and a microstepping indexer, and is intended to drive a bipolar stepper motor. The output driver block consists of N-channel power MOSFET’s configured as full H-bridges to drive the motor windings. The DRV8825 is capable of driving up to 2.5 A of current from each output (with proper heat sinking, at 24 V and 25°C).
A simple STEP/DIR interface allows easy interfacing to controller circuits. Mode pins allow for configuration of the motor in full-step up to 1/32-step modes. Decay mode is configurable so that slow decay, fast decay, or mixed decay can be used. A low-power sleep mode is provided which shuts down internal circuitry to achieve very low quiescent current draw. This sleep mode can be set using a dedicated nSLEEP pin.
Internal shutdown functions are provided for overcurrent, short circuit, under voltage lockout and over temperature. Fault conditions are indicated via the nFAULT pin.
PART NUMBER | PACKAGE | BODY SIZE (NOM) |
---|---|---|
DRV8825 | HTSSOP (28) | 9.70 mm × 6.40 mm |
Changes from E Revision (August 2013) to F Revision
PIN | I/O(1) | DESCRIPTION | EXTERNAL COMPONENTS OR CONNECTIONS |
|
---|---|---|---|---|
NAME | NO. | |||
POWER AND GROUND | ||||
CP1 | 1 | I/O | Charge pump flying capacitor | Connect a 0.01-μF 50-V capacitor between CP1 and CP2. |
CP2 | 2 | I/O | Charge pump flying capacitor | |
GND | 14, 28 | — | Device ground | |
VCP | 3 | I/O | High-side gate drive voltage | Connect a 0.1-μF 16-V ceramic capacitor and a 1-MΩ resistor to VM. |
VMA | 4 | — | Bridge A power supply | Connect to motor supply (8.2 to 45 V). Both pins must be connected to the same supply, bypassed with a 0.1-µF capacitor to GND, and connected to appropriate bulk capacitance. |
VMB | 11 | — | Bridge B power supply | |
V3P3OUT | 15 | O | 3.3-V regulator output | Bypass to GND with a 0.47-μF 6.3-V ceramic capacitor. Can be used to supply VREF. |
CONTROL | ||||
AVREF | 12 | I | Bridge A current set reference input | Reference voltage for winding current set. Normally AVREF and BVREF are connected to the same voltage. Can be connected to V3P3OUT. |
BVREF | 13 | I | Bridge B current set reference input | |
DECAY | 19 | I | Decay mode | Low = slow decay, open = mixed decay, high = fast decay. Internal pulldown and pullup. |
DIR | 20 | I | Direction input | Level sets the direction of stepping. Internal pulldown. |
MODE0 | 24 | I | Microstep mode 0 | MODE0 through MODE2 set the step mode - full, 1/2, 1/4, 1/8/ 1/16, or 1/32 step. Internal pulldown. |
MODE1 | 25 | I | Microstep mode 1 | |
MODE2 | 26 | I | Microstep mode 2 | |
NC | 23 | — | No connect | Leave this pin unconnected. |
nENBL | 21 | I | Enable input | Logic high to disable device outputs and indexer operation, logic low to enable. Internal pulldown. |
nRESET | 16 | I | Reset input | Active-low reset input initializes the indexer logic and disables the H-bridge outputs. Internal pulldown. |
nSLEEP | 17 | I | Sleep mode input | Logic high to enable device, logic low to enter low-power sleep mode. Internal pulldown. |
STEP | 22 | I | Step input | Rising edge causes the indexer to move one step. Internal pulldown. |
STATUS | ||||
nFAULT | 18 | OD | Fault | Logic low when in fault condition (overtemp, overcurrent) |
nHOME | 27 | OD | Home position | Logic low when at home state of step table |
OUTPUT | ||||
AOUT1 | 5 | O | Bridge A output 1 | Connect to bipolar stepper motor winding A. Positive current is AOUT1 → AOUT2 |
AOUT2 | 7 | O | Bridge A output 2 | |
BOUT1 | 10 | O | Bridge B output 1 | Connect to bipolar stepper motor winding B. Positive current is BOUT1 → BOUT2 |
BOUT2 | 8 | O | Bridge B output 2 | |
ISENA | 6 | I/O | Bridge A ground / Isense | Connect to current sense resistor for bridge A. |
ISENB | 9 | I/O | Bridge B ground / Isense | Connect to current sense resistor for bridge B. |