PIN DESCRIPTION (Pin Types: D = Digital, P = Power, A = Analog)

N.

Name

Function

1

FCOM

Output of the Spindle zero cross or Current Sense circuit.

2

CTAP

Spindle Central Tap used for differential BEMF sensing.

3

PWM/SLEW

RC network sets the Spindle Linear Slew Rate and PWM OFF-Tim e.

4

OUT_C

Spindle DMOS Half Bridge Output and Input C for BEMF sensing.

5

I_SENSE

Input to sense the voltage the SPINDLE Sense Resistor.

6

R_SENSE

Output connection for the Motor Current Sense Resistor to ground.

7

OUT_B

Spindle DMOS Half Bridge Output and Input B for BEMF sensing.

8

GND

Spindle Ground (Substrate).

9

R_SENSE

Output connection for the Motor Current Sense Resistor to ground.

10

OUT_A

Spindle DMOS Half Bridge Output and Input A for BEMF sensing.

11

INDEX

Input to allow Spindle to be locked to Index (servo) pulse.

12

BRK_CAP

Storage Capacitor for brake circuit. typically 5.9V.

13

VCC

+12V Power Supply for Spindle Power section.

14

DGND

Digital Ground.

15

SYS_CLK

Clock Frequency for system timers and counters.

16

SDEN

Serial Data Enable. Active high input pin for the serial port enable.

17

SDATA

Serial Port Data. Input/Output pin for serial data, 8bits of instruction/address followed by 8

bits of data. Open pin is at logic low as an input.

18

SCLK

Serial Port Data Clock. Positive edge triggered clock input for the serial data.

19

VDD

Digital/Analog power supply. +5V nominally.

20

V12/2

Reference Output for VCM control loop. Typically, half of the VCC except when parking.

21

FLL_FILTER

Speed loop R/C compensation connection used for FLL mode operation.

22

VCM_CAL

VCM loop offset voltage used for calibration.

23

CP

External Main Charge Pump Capacitor, Typically, Vz+Vcc is about 17.8V

24

CS

External Charge Pump Capacitor.

25

VCC

+12V Power Supply for VCM Power section.

26

VCM_A-

VCM Power Amplifier negative output terminal.

27

SENSE_IN+

Non inverting Input of the Sense Amplifier for VCM block.

28

VCM_GND

Ground for VCM Power section.

29

SENSE_IN-

Inverting Input of the Sense Amplifier for VCM block.

30

VCM_A+

VCM Power Amplifier positive output terminal.

31

VCC

+12V Power Supply for VCM Power section.

32

FLL_RES

Resistor for setting accurate bias current sources for the chip (62K required).

33

SW1

External ISOFET driver.

34

PORB

Power on Reset Output. Low signal indicates the failure of the supplies.

35

TR_5V

Set Point Input for 5V Supply Monitor ( 2V threshold, 100mV Hysteresis)

36

POR_DELAY

Capacitor connection to set the Power on Reset Delay (3V threshold, 2

µA charging)

37

SENSE_OUT

Output of the Sense Amplifier.

38

ERROR_OUT

Output of the Error Amplifier.

39

ERROR_IN

Inverting Input of the Error Amplifier.

40

TR_12V

Set Point Input for 12V Supply Monitor (2V threshold, 100mV Hysteresis)

41

DAC

Output of the VCM DAC.

42

AGND

Analog Ground. For bang gap voltage reference.

43

VCC

+12V Power Supply for Spindle Power section.

44

SPN_COMP

External RC network that defines the compensation of the Spindle Transconductance Loop

in Linear Mode.

L6268

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