SGS Thomson Microelectronics L6268 Datasheet



L6268

12VDISK DRIVE SPINDLE& VCM, POWER

& CONTROL“COMBO”

PRODUCT PREVIEW

GENERAL

12V (+/- 10%) OPERATION.
REGISTERBASEDARCHITECTURE
MINIMUMEXTERNAL COMPONENTS
BICMOS+ VERTICALDMOS (1.5mm)

VCM DRIVER

1.5ADRIVE CAPABILITY

0.9WTOTALBRIDGE IMPEDANCEAT 25°C
LINEARMODE
PHASESHIFT MODULATION(PWM MODE)
INSTANTANEOUS, (GLICH FREE) SWITCH

BETWEENTHE 2 MODES
CLASS ABOUTPUTDRIVERS
ZEROCROSSOVERDISTORSION
14 BIT DAC DEFINE OUTPUTCURRENT
SELECTABLETRANSCONDUCTANCE
4 PROGRAMMABLEPARKINGVOLTAGE
DYNAMICBRAKE

SPINDLEDRIVER

2.0ADRIVE CAPABILITY

0.8WTOTALBRIDGE IMPEDANCEAT 25°C
BEMF, INTERNAL OR EXTERNAL, PROC-

ESSING
SENSOR-LESSMOTOR COMMUTATION
PROGRAMMABLE COMMUTATION PHASE

DELAY
LINEARMODE AND CONSTANT TOFF PWM

OPERATIONMODE
INTERNAL FREQUENCY LOCKED LOOP

SPEEDCONTROL (FLL)
BEMFRECTIFICATIONDURING RETRACT
BUILT-INALIGNAMENT&GOSTART-UP
INDUCTIVE SENSINGSTART UP OPTION
RESYNCHRONIZATION
DYNAMIC& REVERSEBRAKE
CONTROLLABLEOUTPUTSLEW RATE

OTHER FUNCTIONS

12V AND 5V MONITORINGWITH EXTERNAL
SET TRIP POINTSANDHYSTERESIS

POWERUP/DOWN SEQUENCING

BICMOS TECHNOLOGY

TQFP44 (10x10mm with slug)

ORDERING NUMBER: L6268

LOW VOLTAGESENSE

3.3V INPUT LOGICCOMPATIBILITY
THERMAL SHUTDOWN AND PRETHERMAL

WARNING

DESCRIPTION

The L6268 integrates into a single chip both spin­dle and VCMcontrollers as well as power stages.
The device isdesigned for 12V diskdrive applica­tion requiring up to 2.0A of spindle and 1.5A of
VCM peak currents.

A serialport with up to25 MHz capabilityprovides
easy interface to the microprocessor. A register
controlled Frequency Locked Loop (FLL) allows
flexibility in setting the spindle speed. Integrated
BEMF processing, digital masking, digital delay,
and sequencing minimize the number of external
componentsrequired.

Power On Reset(POR) circuitry is included.Upon
detection of a low voltage condition, POR is as­serted, the internal registers are reset, and spin­dle powercircuitryis tri-stated.The BEMF is recti­fied providing power for actuator retraction
followed by dynamicspindlebraking.

The device is built in BICMOS technology allow­ing dense digital/analog circuitry to be combined
with a highpower DMOS outputstage.

April 1999

This is preliminary information on a new product now in development. Details are subject to change withoutnotice.

1/17

L6268

BLOCK DIAGRAM

CS

SW1

SDATA

SCLK

SDEN

TR_12V

TR_5V

CP

CHARGE

PUMP

ISO

DRIVER

SERIAL

INTERFACE

SUPPLY

FAULT

MONITORS

POR_DELAY

PORB

FLL_RES

FLL_FILTER

INDEX

FREQUENCY

LOCK LOOP

START-UP

REGISTERS

THERMAL

SUPPLY

VDD

GND

SYS_CLK

DGND

FCOM

SPINDLE SEQUENCER

RE_SYNC

DYNAMIC/
REVERSE

BRAKE

VCM

CURRENT

CONTROL PSM/LIN

VCM

CALIBRATION

14 BIT

VCM DAC

REFERENCE
GENERATOR

DAC

SPN_COMP

PROCESSING

ZERO CROSS

VOLTAGE

V12/2

BRK_CAP

PWM/SLEW

BEMF

DETECTION

SPINDLE
CURRENT
CONTROL

PWM/LIN

PARKING

BEMF

RECTIFICATION

VCM_CAL

ERROR_IN

+

-

A

B

C

A+

A-

-

A=4

+

SENSE_OUT

ERROR_OUT

VCC

OUT_A
CTAP

OUT_B
RSENSE

OUT_C
ISENSE

VCM_A+
VCC

VCM_A­VCM_GND

SENSE_IN­SENSE_IN+

D99IN1042

PIN CONNECTION

2/17

FCOM

CTAP

PWM/SLEW

OUT_C

I_SENSE

R_SENSE

OUT_B

GND

R_SENSE

OUT_A

INDEX

SPN_COMP

VCC

AGND

DAC

ERROR_IN

TR-12V

ERROR_OUT

SENSE_OUT

44 43 42 41 3940 38 37 36 35 34

1
2
3
4
5
6
7
8
9

10

12 13 14 15 16

VCC

BRK_CAP

DGND

SDEN

SYS_CLK

171118 19 20 21 22

VDD

SCLK

SDATA

POR_DELAY

TR_5V

PORB

V12/2

VCM_CAL

FLL_FILTER

33
32
31
30
29
28
27
26
25
24
23

D98IN847

SW1
FLL_RES
VCC
VCM_A+
SENSE_IN­VCM_GND
SENSE_IN+
VCM_A­VCC
CS
CP

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

N. Name Function

1 FCOM Output of the Spindle zerocross or Current Sense circuit.
2 CTAP Spindle Central Tap used for differential BEMF sensing.
3 PWM/SLEW RC network sets the Spindle LinearSlew Rateand PWM OFF-Time.
4 OUT_C Spindle DMOS Half BridgeOutput 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 BridgeOutput 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 DataEnable. Active high input pin for the serialport 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 forcalibration.
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 ( 2Vthreshold, 100mV Hysteresis)
36 POR_DELAY Capacitor connection to set thePower on Reset Delay (3V threshold, 2µA 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 PointInput 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 theSpindle Transconductance Loop

in Linear Mode.

L6268

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L6268

ABSOLUTEMAXIMUM RATINGS

Symbol Parameter Value Unit

V

CC

V

dd

V

in max

V

in min

SPINDLE I

VCM I

peak

P

(*) Maximum Total Power Dissipation ≈ 2.5

tot

T

stg,Tj

THERMAL DATA

Symbol Parameter Value Unit

R

th j-case

R

th j-amb

Maximum Supply voltage -0.5 to 14 V
Maximum Logic supply -0.5 to 6 V
Maximum digital input voltage Vdd+0.3V V
Minimum digital input voltage GND - 0.3V V
Spindle peak sink/source output current 2.1 A

peak

VCM peak sink/source output current 1.6 A

3 with soldered slug

≈

Maximum Storage/Junction Temperature -40 to 150 °C

Thermal Resistance Junction to Case

(*) Thermal Resistance to Junction to ambient

25 with soldered slug

≈

11 °C/W

≈

32

≈

W
W

°C/W
°C/W

(*) In typical application with multilayer 120mmx120mm Printead Circuit Board.

RECOMMENDED OPERATINGCONDITIONS

Symbol Parameter Value Unit

V

CC

V

dd

T

amb

T

j

ELECTRICAL CHARACTERISTICS

Supply voltage 10.8 to 13.2 V
Maximum Logic supply 4.5 to 5.5 V
Operating Ambient Temperature 0 to 70 °C
Junction Temperature 0 to 125 °C

(All specificationsare for 0 < T

<70°C, VCC= 12V; VDD= 5V,

amb

FLL_RES= 62kΩ, unless otherwisespecified.)

Symbol Parameter Test Condition Min. Typ. Max. Unit

POWER SUPPLIES

V

I

VCC

V

rectified

V

I

CC

dd

Vdd

12V Supply 10.8 13.2 V
VCCCurrent SPINDLE + VCM 20 mA

SPINDLE ONLY 7 mA

VCM ONLY 12 mA
VCCSupply Rectified 3.5 13.2 V
5V supply 4.5 5.5 V
5V supply SPINDLE + VCM 6 mA

SPINDLE ONLY 7 mA

VCM ONLY 12 mA

4/17

ELECTRICALCHARACTERISTICS (Continued)

Symbol Parameter Test Condition Min. Typ. Max. Unit

THERMAL SENSING

T

SD

T

HYS

T

EW

SUPPLY MONITOR

V

TR

V

HYS

I

DLY

R

on_por

V

DLY

I

IN

VOLTAGE BOOST

V

BOOST

F

osc

SW1 OUTPUT

R

GATE

V

GATE

DIGITAL LOGIC LEVELS

V

IH

V

IL

V

OH

V

OL

F

SYSCLK

VCM, DAC

T

C

VCM, ERROR AMPLIFIER

A

VOL

V

OS

I

IB

Shutdown Temperature 150 180 °C
Hysteresis 60 °C
Early Warning TSD-25 °C

Trip Point Input Rising 1.92 2 2.08 V
Hysteresis Voltage Input falling 100 mV
Porb Delay Current TR_5V, TR_12V> V

TR

1.5 2 2.5 µA

Vpordly = 2V
Porb Pull Down Ron Vdd> 2V and sink 1mA

V

=2V

pordly

Porb Dly Threshold TR_5V, TR_12V> V

TR

2.5 3.0 3.5 V

500

Input Current VIN<4V -1 1

Output Voltage VCC+5 VCC+6.3 V
Internal Oscillator 130 200 250 kHz

Gate Driver for External Mosfet Internal Resistor to CP 200 kΩ
Off Gate State Voltage for

IO= 1mA VCC= 3.5V 0.7 V
External Mosfet

Input Logic ”1” VDD= 5.5V 2.4 V
Input Logic ”0” VDD= 4.5V 0.5 V
Output Logic ”1” I
Output Logic ”0” I

=20µAV

SOURCE

= -400µA 0.4 V

SOURCE

-0.2 V

dd

System Clock 20 25 MHz

Resolution 14 Bits
Differential Linearity 1 LSB Change

-Tested

By design

-1

-0.5

1

0.5
Integral Linearity 9 Bits
Midscale Offset Referenced to V

/2 -5 5 mV

CC

Convertion Time 5
Full Scale Voltage Referenced to VCC/2

1V

±

Full Scale Error -4 4 %

Open Loop Gain DC 50 db
Input Offset Voltage -5 5 mV
Input Bias Current -250 250 nA

L6268

Ω

A

µ

LSB

s

µ

5/17

L6268

ELECTRICALCHARACTERISTICS (Continued)

Symbol Parameter Test Condition Min. Typ. Max. Unit

V

ICM

Vclamp Output Clamp Voltage -1mA < I

F

ODB

VCM, POWER STAGE

R

DS(ON)

I

O

I

O(LEAK)

VCM, CURRENT SENSE ANPLIFIER

A

V

V

ICM

V

OCM

V

OS

F

3dB

CMRR Input Common Mode Rejection 50 dB

PSRR Power Supply Rejection Ratio 60 dB

VCM, RETRACT

Vpark RETRACT VOLTAGE PKV_1 = 0 & PKV_2 = 0

Tretract Retract Time

SPINDLE, PWM CURRENT SENSE COMPARATOR

T

DLY

SPINDLE, POWER STAGE

R

DS(ON)

I

O

I

O(LEAK)

dV

O/dt

BEMF

V

HYS

FLL CHARGE PUMP OUTPUT

I

LEAK

Input Common Mode Range VCC/2-

0.5

<1mA

O

Lowside/Highside clamp

VCC/2±

2.2V

VCC/2+

0.5

Unity Gain Bandwidth 10 MHz

Output ON Resistance (Each
device)

Tj=25°C
T

= 125°C

j

0.5

0.8
Operating Current 1.3 A
Output Leakage Current VCC= 14V 1.0 mA

Voltage Gain 3.88 4 4.12 V/V
Input Common Mode Range -0.3 VCC+0.3 V
Output Common Mode Range -3mA < IO<3mA 2 VCC-2 V
Output Offset Voltage SENSE_IN (±)=VCC/2 -15 15 mV
3dB Bandwidth 1 MHz

850

650
1600
1150

320

640

160

320

limited by the internal oscillator
200kHz

PKV_1 = 0 & PKV_2 = 1
PKV_1 = 1 & PKV_2 = 0
PKV_1 = 1 & PKV_2 = 1

RT0 = 0 & RT1 = 0
RT0 = 0 & RT1 = 1
RT0 = 1 & RT1 = 0
RT0 = 1 & RT1 = 1

Delay to FCOM Out 200 500 ns

Output On Resistance (Each
device)

Tj=25°C
T

= 125°C

j

0.45

0.74
Start-Up Current 2A
Output Leakage Current VCC = 14V 1.0 mA
Output Slew Rate (Linear) R
Output Slew Rate (PWM) Reg#8Eh, Bit 0 = 0

Minimum BENF Voltage for

MIN

= 100k

slew

Ω

Reg#8Eh, Bit 0 = 1

0.2 0.3 0.5 V/µs
10

20

20 28 40 mVp-p

Detection
Hysteresis 15 mV

Off State Leakage 0 < Vfll_res , 3V -50 +50 nA

V

V

Ω
Ω

mV
mV
mV
mV

ms
ms
ms
ms

Ω
Ω

V/µs
V/µs

6/17