Philips TZA1038HW Technical data

INTEGRATED CIRCUITS

DATA SH EET

TZA1038HW

High speed advanced analog DVD
signal processor and laser supply

Product specification 2003 Sep 03

Philips Semiconductors Product specification

High speed advanced analog DVD signal
processor and laser supply

CONTENTS

1 FEATURES
2 GENERAL DESCRIPTION
3 ORDERING INFORMATION
4 QUICK REFERENCE DATA
5 BLOCK DIAGRAM
6 PINNING
7 FUNCTIONAL DESCRIPTION

7.1 RF data processing

7.2 Servo signal processing

7.2.1 Servo signal path set-up

7.2.2 Focus servo

7.2.3 Radial servo

7.2.4 Differential phase detection

7.2.4.1 Drop-out concealment

7.2.4.2 Push-pull and three-beam push-pull

7.2.4.3 Enhanced push-pull (dynamic offset
compensation for beam landing)

7.2.4.4 Offset compensation

7.2.5 Automatic dual laser supply

7.2.6 Power-on reset and general power on

7.2.7 Compatibility with TZA1033HL/V1

7.2.7.1 Software compatibility

7.2.7.2 Hardware compatibility

7.2.8 Interface to the system controller

7.3 Control registers

7.3.1 Register 0: power control

7.3.2 Register 1: servo and RF modes

7.3.3 Register 2: focus offset DAC

7.3.4 Register 3: RF path gain

7.3.5 Register 4: RF left and right, or sum offset
compensation

7.3.6 Register 5: RF sum offset compensation

7.3.7 Register 6: servo gain and dynamic radial
offset compensation factor

7.3.8 Register 7: servopath gain and bandwidth and
RF path bandwidth and pre-emphasis

7.3.9 Register 8: RF channel selection

7.3.10 Register 11: radial servo offset cancellation

7.3.11 Register 12: central servo offset cancellation
inputs A and B

7.3.12 Register 13: central servo offset cancellation
inputs C and D

7.3.13 Register 14: RF filter settings

7.3.14 Register 15: DPD filter settings

TZA1038HW

7.4 Internal digital control, serial bus and external
digital input signal relationships

7.4.1 STANDBY mode

7.4.2 RF only mode

7.5 Signal descriptions

7.5.1 Data path signals through pins A to D

7.5.2 Data signal path through input pins RFSUMP
and RFSUMN

7.5.3 HF filtering

7.5.4 Focus signals

7.5.5 Radial signals

7.5.5.1 DPD signals (DVD-ROM mode) with no
drop-out concealment

7.5.5.2 DPD signals (DVD-ROM mode) with
drop-out concealment

7.5.5.3 Three-beam push-pull (CD mode)

7.5.5.4 Enhanced push-pull

8 LIMITING VALUES
9 THERMAL CHARACTERISTICS
10 CHARACTERISTICS
11 APPLICATION INFORMATION

11.1 Signal relationships

11.1.1 Data path

11.1.2 Servo path

11.2 Programming examples

11.3 Energy saving

11.4 Initial DC and gain setting strategy

11.4.1 Electrical offset from pick-up

11.4.2 Gain setting servo

11.4.3 DC level in RF path

11.4.4 Gain setting RF path

12 PACKAGE OUTLINE
13 SOLDERING

13.1 Introduction to soldering surface mount
packages

13.2 Reflow soldering

13.3 Wave soldering

13.4 Manual soldering

13.5 Suitability of surface mount IC packages for
wave and reflow soldering methods

14 DATA SHEET STATUS
15 DEFINITIONS
16 DISCLAIMERS

2003 Sep 03 2

Philips Semiconductors Product specification

High speed advanced analog DVD signal
processor and laser supply

1 FEATURES

• Operates with DVD-ROM, DVD+RW, DVD-RW,
CD-ROM and CD-RW

• Operates up to 64 × CD-ROM and 12 × DVD-ROM

• RF data amplifier with wide, fine pitch programmable

noise filter and equalizer equivalent to 64 × CD or
12 × DVD

• Programmable RF gain for DVD-ROM, CD-RW and
CD-ROM applications (approximately 50 dB range to
cover a large range of disc-reflectivity and OPUs)

• Additional RF sum input

• Balanced RF data signal transfer

• Universal photodiode IC interface using internal

conversion resistors and offset cancellation

• Input buffers and amplifiers with low-pass filtering

• Three different tracking servo strategies:

– Conventional three-beam tracking for CD
– Differential Phase Detection (DPD) for DVD-ROM,

including option to emulate traditional drop-out
detection: Drop-Out Concealment (DOC)

– Advanced push-pull with dynamic offset

compensation.

• Enhanced signal conditioning in DPD circuit for optimal
tracking performance under noisy conditions

• Radial error signal for Fast Track Counting (FTC)

• RF onlymode: servo outputs canbeset to 3-state, while

RF data path remains active

• Radial servo polarity switch

• Flexible adaption to different light pen configurations

• Two fully automatic laser controls for red and infrared

lasers, including stabilization and an on/off switch

• Automatic selection of monitor diode polarity

• Digital interface with 3 and 5 V compatibility.

TZA1038HW

2 GENERAL DESCRIPTION

The TZA1038HW is an analog preprocessor and laser
supply circuit for DVD and CD read-only players. The
device contains data amplifiers, several options for radial
tracking and focus control. The preamplifier forms a
versatile, programmable interface between single light
path voltage output CD or DVD mechanisms to Philips
digital signal processor family for CD and DVD (for
example, Gecko, HDR65 or Iguana). A separate
high-speed RFSUM input is available.

The device contains several options for radial tracking:

• Conventional three-beam tracking for CD

• Differential phase detector for DVD

• Push-pull with flexible left and right weighting to

compensate dynamic offsets e.g. beam landing offset

• A radial error signal to allow Fast Track Count (FTC)
during track jumps.

The dynamic range of this preamplifier and processor
combination can be optimized for LF servo and RF data
paths. The gain in both channels can be programmed
separately and so guarantees optimal playability for all
disc types.

The RF path is fully DC coupled. The DC content
compensation techniques provide fast settling after disc
errors.

The device can accommodate astigmatic, single foucault
anddoublefoucault detectors and can beusedwithP-type
lasers with N-sub or P-sub monitor diodes. After an initial
adjustment, the circuit will maintain control over the laser
diode current. With an on-chip reference voltage
generator, a constant stabilized output power is ensured
and is independent of ageing.

An internal Power-on reset circuit ensures a safe start-up
condition.

2003 Sep 03 3

Philips Semiconductors Product specification

High speed advanced analog DVD signal

TZA1038HW

processor and laser supply

3 ORDERING INFORMATION

TYPE NUMBER

NAME DESCRIPTION VERSION

TZA1038HW HTQFP48 plastic thermal enhanced thin quad flat package; 48 leads;

body 7 × 7 × 1 mm; exposed die pad

4 QUICK REFERENCE DATA

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

T

amb

ambient temperature −40 − +85 °C

Supplies

V

DDA1

V

DDA3

V

DDD3

V

DDD5

I

DD

, V
, V

DDA2
DDA4

,

analog supply voltage 4.5 5.0 5.5 V

3 V digital supply voltage 2.7 3.3 5.5 V
5 V digital supply voltage 4.5 5.0 5.5 V
supply current without laser supply − 98 120 mA

STANDBY mode −− 1mA

V

I(logic)

logic input compatibility note 1 2.7 3.3 5.5 V

Servo signal processing

B

LF(−3dB)

−3 dB bandwidth of
LF path

I

O(LF)

output current focus servo output 0 − 12 µA

radial servo output 0 − 12 µA

V

O(FTC)(p-p)

FTC output voltage
(peak-to-peak value)

B

FTC

FTC bandwidth FTCHBW = 0 − 600 − kHz

FTCHBW = 1; note 2 − 1200 − kHz

V

I(FTCREF)

FTC reference input
voltage

RF data processing

A

RF

linear current gain programmable gain

RF channels 6 − 49 dB
RFSUM channels −6 − +31 dB

B

RF(−3dB)

f

0(RF)

t

d(RF)

−3 dB bandwidth of RFP
and RFN signal path

noise filter and equalizer
corner frequency

flatness delay in RF data
path

RFEQEN = 0;
RFNFEN = 0

BWRF = 0 8 12.0 14.5 MHz
BWRF = 127 100 145 182 MHz
equalizer on; flat from

0 to 100 MHz;
BWRF = 127

Z

i

input impedance of
pins A to D

PACKAGE

SOT545-2

60 75 100 kHz

2.0 −−V

1.25 − 2.75 V

200 300 − MHz

−− 0.5 ns

100 −−kΩ

2003 Sep 03 4

Philips Semiconductors Product specification

High speed advanced analog DVD signal

TZA1038HW

processor and laser supply

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

V

i(RF)(FS)

V

i(SUM)(dif)

V

I(DC)

V

o(RF)(dif)(p-p)

V

O(RF)(DC)

V

i(RFREF)(CM)

Laser supply

I

o(laser)(max)

V

i(mon)

input voltage on
pins A to D for full-scale at
output

differential input voltage
on pins RFSUMP and
RFSUMN

DC input voltage range on
pins RFSUMP and
RFSUMN

differential output voltage
on pins RFP and RFN
(peak-to-peak value)

DC output voltage on
pins RFP and RFN

input reference voltage on
pin RFREF for common
mode output

maximum current output
to laser

input voltage from laser
monitor diode

atthe appropriate signal
path gain setting

RF signal path −− 600 mV
LF signal path −− 700 mV

G

with respect to V

= −6dB −− 1800 mV

RFSUM

SS

1.3 − V

DDA

− 1.0 V

−− 1.4 V

0.35 − V

DDA

− 1.9 V

0.8 1.2 2.1 V

−120 −−mA

P-type monitor diode

LOW level voltage − V
HIGH level voltage − V

− 0.155 − V

DDA4

− 0.190 − V

DDA4

N-type monitor diode

LOW level voltage − 0.155 − V
HIGH level voltage − 0.185 − V

Notes

1. Input logic voltage level follows the supply voltage applied at pin V

2. High FTC bandwidth is achieved when IS1and IS2> 1.5 µA.

2003 Sep 03 5

DDD3

.

Philips Semiconductors Product specification

High speed advanced analog DVD signal
processor and laser supply

5 BLOCK DIAGRAM

handbook, full pagewidth

RFSUMP
RFSUMN

OPUREF

FTCREF

V

DDL

REXT

CDMI

CDLO

DVDMI

DVDLO

V

DDA1

1
2

OPUREF

8

A

9

B

10

C

11

D

3

E

4

F

12

27

47

44

46
45

7
48

6

V

SSA1

5

A to D

5

VOLTAGE AND

REFERENCES

42

V

SSA2

V

DDA2

CURRENT

LASER 1

LASER 2

V

DDA3

43

SERVO SIGNAL PROCESSING

COMPENSATION

V

SSA3

37

RF DATA PROCESSING

MULTIPLEXER

4

3-BEAM

TRACKING

DPD

PUSH-PULL

OFFSET

41

V

SSA4

31

V

DDA4

DUAL

LASER

SUPPLY

V

SSD

RFREF

32

VARIABLE

GAIN STAGES

SELECT; SWAP

S1 S2

19

SIDA

38

FTC

16

V

DDD3

V

15

TZA1038HW

4

FTC

COMPARATOR

SERIAL

INTERFACE

17 18

SICL SILD

DDD5

23

TZA1038HW

39

RFP

40

RFN

36

OA

35

OB

34

OC

33

OD

30

S1

29

S2

28

OCENTRAL

25

FTC

20

COP

21

COM

22

COO

14

TM

26

TDO

MCE466

Fig.1 Block diagram.

2003 Sep 03 6

Philips Semiconductors Product specification

High speed advanced analog DVD signal
processor and laser supply

6 PINNING

SYMBOL PIN DESCRIPTION

RFSUMP 1 positive RF sum input
RFSUMN 2 negative RF sum input
E 3 input E
F 4 input F
V

DDA1

V

SSA1

DVDMI 7 input signal from DVD laser monitor diode
A 8 input A
B 9 input B
C 10 input C
D 11 input D
OPUREF 12 reference input from Optical Pick-Up (OPU)
n.c. 13 not connected
TM 14 test mode input (factory test only)
V

DDD3

SIDA 16 serial host interface data input
SICL 17 serial host interface clock input
SILD 18 serial host interface load
V

SSD

COP 20 positive FTC comparator input
COM 21 inverting FTC comparator input
COO 22 FTC comparator output
V

DDD5

n.c. 24 not connected
FTC 25 fast track count output
TDO 26 test data output (factory test only)
FTCREF 27 FTC reference input
OCENTRAL 28 test pin for offset cancellation
S2 29 servo current output 2 for radial tracking
S1 30 servo current output 1 for radial tracking
V

SSA4

V

DDA4

OD 33 servo current output for focus D
OC 34 servo current output for focus C
OB 35 servo current output for focus B
OA 36 servo current output for focus A
V

DDA3

RFREF 38 DC reference input for RF channel common mode output voltage
RFP 39 positive RF output
RFN 40 negative RF output

5 analog supply voltage 1 (RF input stage)
6 analog ground 1

15 digital supply voltage (serial interface 3 V I/O pads and FTC comparator)

19 digital ground

23 digital supply voltage (5 V digital core)

31 analog ground 4
32 analog supply voltage 4 (servo signal processing)

37 analog supply voltage 3 (RF output stage)

TZA1038HW

2003 Sep 03 7

Philips Semiconductors Product specification

High speed advanced analog DVD signal
processor and laser supply

SYMBOL PIN DESCRIPTION

V

SSA3

V

SSA2

V

DDA2

REXT 44 reference current input (connect via 12.1 kΩ to V
CDLO 45 CD laser output
CDMI 46 input signal from CD laser monitor diode
V

DDL

DVDLO 48 DVD laser output

41 analog ground 3
42 analog ground 2
43 analog supply voltage 2 (internal RF data processing)

47 laser supply voltage

SSA4

TZA1038HW

)

handbook, full pagewidth

RFSUMP
RFSUMN

V

DDA1

V

SSA1

DVDMI

OPUREF

SSA3

SSA2

DDL

CDLO

CDMI

V

DVDLOn.c.
48

47

46

45

1
2
3

E

4

F

5
6
7
8

A

9

B

10

C
D

11
12

13

14

15

16

TM

SIDA

DDD3

V

DDA2

V

V

REXT

43

42

44

TZA1038HW

17

18

19

SILD

SSD

V

SICL

V
41

20

COP

RFN
40

21

COM

RFP

39

22

COO

RFREF
38

23

DDD5

V

DDA3

V

37

24
n.c.

36

OA

35

OB

34

OC

33

OD
V

32

V

31
30

S1

29

S2

28

OCENTRAL

27

FTCREF

26

TDO

25

FTC

MCE467

DDA4
SSA4

Fig.2 Pin configuration.

2003 Sep 03 8

Philips Semiconductors Product specification

High speed advanced analog DVD signal
processor and laser supply

7 FUNCTIONAL DESCRIPTION

7.1 RF data processing

The RF data path is a fully DC-coupled, multi-stage
amplifier (see Fig.3). The input signal for data can be
selected from RF inputs A to D or from the summed
RF inputsRFSUMPandRFSUMN.Switchingbetweenthe
two sets of signals is performed by an internal multiplexer.
The signals are fully balanced internally to improve signal
quality and reduce power supply interference.

RF outputs RFP and RFN can be DC coupled to the
Analog-to-Digital Converter (ADC) of the decoder.

The RF input signals are from photodiodes and have
a largeDC content by nature. This DCcomponentmust be
removed from the signals for good system performance.
Built-in DACs, located after the input stages
G1and RFSUM,have the ability to dothis. The DAC range
and resolution is scaled with the gain setting of the first
amplifier stage. When the DC content is removed, the
RF signal can be DC coupled to the decoder. The main
advantage of DC coupling is fast recovery from signal
swings due to disc defects since there is no AC coupling
capacitance to slow the recovery. When using DC
coupling, both AC and DC content in the data signal is
known. The Philips Iguana decoders have on-chip control
loops to support Automatic Gain Control (AGC) and DC
cancellation.

Two separate DACs are available for cases where the left
and right side DC conditions can be different.

TZA1038HW

When it is not possible to have a DC connection between
the TZA1038HW and the decoder, the signals on servo
outputs OA to OD can be used as they contain the same
LP-filtered and DC coupled information.

Summing of the photodiode signals A to D is performed in
the second amplifier stage G2. Each individual diode
channel can be switched on, off or inverted with switches
SW-A to SW-D.

Switching between photodiode signals and RFSUM input
is performed immediately before the third amplifier
stage G3. This stage has a variable gain with fine
resolution to allow automatic gain adjustment to be
controlled by the decoder.

The filter stage limits the bandwidth according to the
maximum playback speed of the disc. This is to optimize
the noise performance. The filter stage consists of an
equalizer and a noise filter, both of which can be
bypassed,alsothe boost factor of the equalizer canbeset.
Thecorner frequencies ofthe equalizer and noisefilter are
equal and can be programmed to a 7-bit resolution.

The RF output signals RFP and RFN can be DC coupled
to a decoder with a differential input pair (as with Philips
Iguana decoders). The common mode output voltage can
be set externally at pin RFREF.

The signals for differential phase detection are tapped
from the inputs A to D at the RF amplifier G1stages.
DC cancellation for the A to D and RFSUM signal paths
can be set independently or simultaneously.

2003 Sep 03 9

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2003 Sep 03 10

ndbook, full pagewidth

RFREF

Philips Semiconductors Product specification

High speed advanced analog DVD signal

processor and laser supply

RFSUMP

RFSUMN

OPUREF

RF

inputs

38

39

RFP
RFN

outputs

servo
radial

outputs

RF

40

30

S1

29

S2

TZA1038HW

MCE468

RF

RF

DPD-A

OFFSL

DPD-B

DPD-C

OFFSR

DPD-D

RFSUM

SW-A

SW-B

SW-C

SW-D

RF

OFFSS

G

3

EQUALIZER

NOISE

FILTER

TZA1038HW

G

2

DPD-A
DPD-D
DPD-C

DPD-B

central aperture signal

DPD

FILTER

DOC

1
2

12

G

8

A

9

B

10

C

11

D

1

G

1

G

1

G

1

Fig.3 RF data and DPD processing.

Philips Semiconductors Product specification

High speed advanced analog DVD signal
processor and laser supply

7.2 Servo signal processing

The photodiode configurations and naming conventions
are shown in Figs 4 and 5.

7.2.1 SERVO SIGNAL PATH SET-UP
A block diagram of theservo signal path is shown in Fig.6.

In general, the servo signal path comprises:

• Avoltage-to-currentconverterwith programmable offset
voltage source V

• A 4-bit DAC for each of the six channels to compensate
for offset per channel

• A variable gain stage to adapt the signal level to the
specific pick-up and disc properties

• Low-pass filtering and output stage for the photodiode
current signals

• Error output stage in the radial data path for fast track
counting.

Servo output signals OA to OD, S1 and S2 are unipolar
current signals which represent the low-pass filtered
photodiode signals. In DPD radial tracking, the S1 and S2
signalsaretheequivalentofthe satellite signals commonly
found in traditional CD systems.

The servo output signals OA to OD, S1 and S2 are set to
3-state if bit RFonly = 1 (register 13, bit 11).

handbook, halfpage

Data=A+B+C+D
Push-pull = (A + B) − (C + D)
Focus = (A + C) − (B + D)
DPD2 = phase (A + B, C + D)
DPD4 = phase (A,D) + phase (C,B)

that is common to all inputs

LFOFFS

BA

CD

left

tangential direction

right

MGW553

TZA1038HW

handbook, halfpage

Data=A+B+C+D
Push-pull = A − D
Focus = C − B
DPD2 = phase (A, D)
DPD4 not applicable

Fig.5 Foucault diode configuration.

7.2.2 F

OCUS SERVO

Focus information is reflected in the four outputs
OA to OD. Gain and offset can be programmed.

For optical pick-ups where only channels B and C are
used for focus, channels A and D can be switched off
(bit Focus_mode = 0).

For initial alignment, a copy of the output currents can be
made available on pin OCENTRAL.

7.2.3 RADIAL SERVO
Radial information can be obtained from the two output

signals S1 and S2, and the gain and offset can be
programmed. The TZA1038HW provides differential
phase detection, push-pull and three-beam push-pull for
radial tracking. The signal FTC is made available for fast
track counting and is primarily the voltage error signal
derived from signals S1 or S2.

left

tangential direction

right

DCBA

MGW554

Fig.4 Astigmatic diode configuration.

2003 Sep 03 11

Thepolarityofthe radial loop can be reversed via theserial
control bus (RAD_pol).

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2003 Sep 03 12

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Philips Semiconductors Product specification

High speed advanced analog DVD signal

processor and laser supply

RF

inputs

DPD

8

A

9

B

10

C

11

D

3

E

4

F

V

/

C

OFFSA

V

/

C

OFFSB

V

/

C

OFFSC

V

/

C

OFFSD

V

/

R

OFFSE

V

/

R

OFFSF

26k

I

14k

30k

I

14k

30k

I

14k

30k

I

14k

15k

I

15k

I

MUX

2−α

G

G

G

G

α

LFC

LFC

LFC

LFC

G

G

LFR

LFR

MUX

SWAP

CA

FTC

25

FTC

27

FTCREF

30

S1

servo
radial

S2

OA

OB

OC

OD

outputs

servo
focus

outputs

29

36

35

34

33

OPUREF

V

LFOFFS

12

LF

OFFS

TZA1038HW

F

OFFS

OCENTRAL

28

MCE469

OCENTRAL

TZA1038HW

Fig.6 Servo signal path.

Philips Semiconductors Product specification

High speed advanced analog DVD signal
processor and laser supply

7.2.4 DIFFERENTIAL PHASE DETECTION

The TZA1038HW provides differential phase detection to
support DVD in various ways:

• DPD2withfour channels programmed to be activegives
DPD as required in the standard specification

• Two of the four channels can be excluded from the DPD
for pick-ups with analternative photodiode arrangement

• An increase in performance, dedicated for DVD+RW,
can be obtained by using the DPD4 method. Then two
truly separated phase detectors are active. After the
phase detection of the two input pairs the result is
summed.

InputsignalsforDPD are taken from input pins A to D after
thefirst gain stage G1(seeFig.3). Pre-emphasis is applied
by means of a programmable lead/lag filter. Additionally, a
programmable low-pass filter is available to improve the
signal quality under noisy signal conditions at lower
speeds. For further signal improvements the DPD pulse
stretcher can be programmed to higher values at lower
speeds.

The DPD signal is low-pass filtered by two internal
capacitors. The signal is then fed to pins S1 and S2, or
directedviathe drop-out concealment circuit to theoutputs
(see Section 7.5).

7.2.4.1 Drop-out concealment

A special function is built in for compatibility with drop-out
detection strategies, based on level detection in the
S1 and S2 signals. When using DPD in a fundamental
way, there is no representation of mirror level information
from the light pen.

When the drop-out concealment function is enabled
(bit DOCEN = 1), a portion of the Central Aperture (CA)
signal is added to S1 and S2. Also, when the CA signal
drops below the DOC threshold, the DPD signal is
gradually attenuated.

The DPD detection cannot work properly when the input
signal becomes very small. The output of the DPD may
then show a significant offset. The DOC may not conceal
this offset completely because:

• DOC is gradually controlled from the CA signal

• The CA signal may not become 0 during disc-defect.

For details see Section 7.5.5.2

7.2.4.2 Push-pull and three-beam push-pull

The TZA1038HW can also provide radial information by
means of push-pull signals (from the photodiodeinputs) or

TZA1038HW

in a three-spot optical system with Three-Beam Push-Pull
(TBPP). The built-in multiplexer gives a flexible method of
dealing with many detector arrangements. For push-pull,
the input signals are taken from channels A to D. There is
also a command that switches off channels B and C,
leaving channels A and D for push-pull
(bits RT_mode[2:0]).

ForTBPP, the input signal is takenfromchannels E and F,
irrespective of bit RFSUM setting.

7.2.4.3 Enhanced push-pull (dynamic offset
compensation for beam landing)

Thisoptioncancels offsets due to beam landing.Afactor α
canbe programmed to re-balancethe signal gain between
channels S1 and S2. In a simplified form this can be
described as:

S1 = A
S2 = A

Factor α can be programmed in a range from 0.6 to 1.35,
with 1.0 as the balanced condition (bits α[3:0]).

7.2.4.4 Offset compensation

A provision is made to compensate electrical offset from a
light pen. The offset voltage from the light pen can be
positiveornegative.In general, the offset between any two
channels is smaller than the absolute offsets. As negative
input signals cannot be handled by the TZA1038HW
internal servo channels, a two-step approach is adopted:

• A coarse DAC, common to all the input channels, adds

an offset that shifts the input signals in positive direction
until all inputs are ≥0. The DAC used (LF
2-bit resolution (bits LF

• A fine setting per channel is provided to cancel the

remainder of the offset between the channels. This is
achieved by DACs subtracting the DC component from
thesignalsandbringingtheinputs to approximately zero
offset (within ≈ 1 mV). The DACs (registers 11 to 13)
have a 4-bit resolution.

The range of both DACs can be increased by a factor of
three to compensate for higher offset values by means of
control parameter bit SERVOOS.

With a switched-off laser, the result of the offset
cancellation can be observed at each corresponding
output pin, OA to OD, S1 and S2, or via a built-in
multiplexer to pin OCENTRAL (central channels only).
See registers 11 to 13 for DAC and multiplexer control.

×α×input left

LFR

× (2 −α)×input right.

LFR

OFF

[1:0]).

OFFS

) has a

2003 Sep 03 13

Philips Semiconductors Product specification

High speed advanced analog DVD signal
processor and laser supply

7.2.5 AUTOMATIC DUAL LASER SUPPLY
The TZA1038HW can control the output power of two

lasers; it has an Automatic Laser Power Control (ALPC)
that stabilizes the laser output power and compensates
the effects of temperature and ageing of the laser.

ALPC automatically detects if there is a P-type or N-type
monitor diode in use in either of the laser circuits. The
regulation loop formed by the ALPC, the laser, the monitor
diode and the associated adjustment resistor will settle at
themonitorinputvoltage. The monitor input voltage can be
programmed to HIGH (≈ 180 mV) or LOW (≈ 150 mV),
according to frequently-used pre-adjustments of the light
pen. This set point can be set independently for both
ALPCs. Bandwidth limitation and smooth switch-on
behaviour is realized using an internal capacitor.

A protection circuit is included to prevent laser damage
dueto dips in laser supplyvoltage V
dip occurs, the output can saturate and restrict the
required laser current. Without the protection circuit, the
ALPC would try to maximize the output power with
destructive results for the laser when the supply voltage
recovers. The protection circuit monitors the supply
voltage and shuts off the laser when the voltage drops
belowasafe value. The ALPC recovers automaticallyafter
the dip has passed.

Only one laser can be activated at the same time.
An internal break-before-make circuit ensures safe
start-up for the laser when a toggle situation between the
two lasers is detected. When both lasers are programmed
on, neither laser will be activated.

7.2.6 POWER-ON RESET AND GENERAL POWER ON
When the supply voltage is switched on, bit PWRON is

reset by the Power-On Reset (POR) signal. This
concludes in a STANDBY mode at power up. POR is
intended to prevent the lasers being damaged due to
randomsettings.Allotherfunctionsmay be switched when
power is on. The TZA1038HW becomes active when
bit PWRON = 1.

.If a supply voltage

DDL

TZA1038HW

7.2.7 COMPATIBILITY WITH TZA1033HL/V1

7.2.7.1 Software compatibility

The TZA1038HW is highly software compatible with the
TZA1033HL/V1. Provided that some conditions are met,
the software of the TZA1038HW can be used as a
successor with just minor modifications. This compatibility
is achieved with the implementation of the TZA1038HW
mode control bit (bit K2_Mode). When bit K2_Mode = 0,
the TZA1038HW will act as a TZA1033HL/V1. When
bit K2_Mode = 1, the TZA1038HW will act as a
TZA1033HL/K2 and the new functions will be available
(but require a software update).

Other conditions or restrictions are:

• Registerbits of the TZA1038HW whichwere not defined

areprogrammedto a logic 0. Registers 9, 10, 14 and 15
may be left undefined

• The G4stage high gain setting of the TZA1033HL/V1 is

not available in the TZA1038HW; if this value was set to
logic 0, there will be no difference

• Whenbit K2_Mode = 0the RF bandwidth will be fixed to

theminimumvalueof10 MHz(typical);bit K2_Mode = 1
toselect a higher bandwidth; the bandwidthisnow lower
than using a TZA1033HL/V1.

7.2.7.2 Hardware compatibility

Thepackageis changed from LQFP64 for theTZA1033HL
to LQFP48 for the TZA1038HW.

The hardware differences are:

• Input pins STB, HEADER and LAND of the TZA1033HL

are not present

• Input pins CD of TZA1033HL/V1 are not used;

TZA1038HW has RFSUM inputs instead; the RFSUM
inputs of TZA1038HW may be connected to ground
when not used.

2003 Sep 03 14