DRV8818

www.ti.com

SLVSAX9A

– SEPTEMBER 2011 – REVISED FEBRUARY 2012

TERMINAL FUNCTIONS

NAME

NO.

DESCRIPTION

EXTERNAL COMPONENTS OR CONNECTIONS

POWER AND GROUND

GND

7, 21

-

Device ground

VMA

28

-

Bridge A power supply

Connect to motor supply (8 V to 35 V). Both pins must be connected

to same supply.

VMB

15

-

Bridge B power supply

Connect to motor supply (8 V to 35 V). Both pins must be connected

to same supply.

VCC

10

-

Logic supply voltage

Connect to 3-V to 5-V logic supply. Bypass to GND with a 0.1-

μF

ceramic capacitor.

CP1

23

IO

Charge pump flying capacitor

Connect a 0.22-

μF capacitor between CP1 and CP2.

CP2

24

IO

Charge pump flying capacitor

Connect a 0.22-

μF capacitor between CP1 and CP2.

VCP

22

IO

High-side gate drive voltage

Connect a 0.22-

VGD

20

IO

Low-side gate drive voltage

Bypass to GND with a 0.22-

μF ceramic capacitor.

CONTROL

ENABLEn

26

I

Enable input

Logic high to disable device outputs, logic low to enable outputs.

Weak internal pullup to VCC.

SLEEPn

27

I

Sleep mode input

Logic high to enable device, logic low to enter low-power sleep mode.

Weak internal pulldown.

DECAY

5

I

Decay mode select

Voltage applied sets decay mode - see motor driver description for

details. Bypass to GND with a 0.1-

μF ceramic capacitor. Weak

internal pulldown.

STEP

19

I

Step input

Rising edge causes the indexer to move one step. Weak internal

pulldown.

DIR

3

I

Direction input

Level sets the direction of stepping. Weak internal pulldown.

USM0

13

I

Microstep mode 0

USM0 and USM1 set the step mode - full step, half step, quarter

step, or eight microsteps/step. Weak internal pulldown.

USM1

12

I

Microstep mode 1

USM0 and USM1 set the step mode - full step, half step, quarter

step, or eight microsteps/step. Weak internal pulldown.

RESETn

17

I

Reset input

Active-low reset input initializes the indexer logic and disables the

H-bridge outputs. Weak internal pullup to VCC.

SRn

16

I

Sync. Rect. enable input

When active low, synchronous rectification is enabled. Weak internal

pulldown.

VREF

8

I

Current set reference input

Reference voltage for winding current set

RCA

6

I

Bridge A blanking and off time adjust

Connect a parallel resistor and capacitor to GND - see motor driver

description for details.

RCB

9

I

Bridge B blanking and off time adjust

Connect a parallel resistor and capacitor to GND - see motor driver

description for details.

ISENA

1

-

Bridge A ground / Isense

Connect to current sense resistor for bridge A

ISENB

14

-

Bridge B ground / Isense

Connect to current sense resistor for bridge B

OUTPUTS

AOUT1

4

O

Bridge A output 1

Connect to bipolar stepper motor winding

AOUT2

25

O

Bridge A output 2

Positive current is AOUT1

→ AOUT2

BOUT1

11

O

Bridge B output 1

Connect to bipolar stepper motor winding

BOUT2

18

O

Bridge B output 2

Positive current is BOUT1

→ BOUT2

HOMEn

2

O

Home position

Logic low when at home state of step table, logic high at other states

(1)

Directions: I = input, O = output, OZ = 3-state output, OD = open-drain output, IO = input/output

Copyright

© 2011–2012, Texas Instruments Incorporated

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