Philips TZA1038HW Technical data

INTEGRATED CIRCUITS

DATA SHEET

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

TZA1038HW

processor and laser supply

CONTENTS

1FEATURES

2GENERAL DESCRIPTION

3ORDERING INFORMATION

4QUICK REFERENCE DATA

5BLOCK DIAGRAM

6PINNING

7FUNCTIONAL DESCRIPTION

7.1RF data processing

7.2Servo signal processing

7.2.1Servo signal path set-up

7.2.2Focus servo

7.2.3Radial servo

7.2.4Differential phase detection

7.2.4.1Drop-out concealment

7.2.4.2Push-pull and three-beam push-pull

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

7.2.4.4Offset compensation

7.2.5Automatic dual laser supply

7.2.6Power-on reset and general power on

7.2.7Compatibility with TZA1033HL/V1

7.2.7.1Software compatibility

7.2.7.2Hardware compatibility

7.2.8Interface to the system controller

7.3Control registers

7.3.1Register 0: power control

7.3.2Register 1: servo and RF modes

7.3.3Register 2: focus offset DAC

7.3.4Register 3: RF path gain

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

7.3.6Register 5: RF sum offset compensation

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

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

7.3.9Register 8: RF channel selection

7.3.10Register 11: radial servo offset cancellation

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

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

7.3.13Register 14: RF filter settings

7.3.14Register 15: DPD filter settings

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

7.4.1STANDBY mode

7.4.2RF only mode

7.5Signal descriptions

7.5.1Data path signals through pins A to D

7.5.2Data signal path through input pins RFSUMP and RFSUMN

7.5.3HF filtering

7.5.4Focus signals

7.5.5Radial signals

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

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

7.5.5.3Three-beam push-pull (CD mode)

7.5.5.4Enhanced push-pull

8LIMITING VALUES

9THERMAL CHARACTERISTICS

10CHARACTERISTICS

11APPLICATION INFORMATION

11.1Signal relationships

11.1.1Data path

11.1.2Servo path

11.2Programming examples

11.3Energy saving

11.4Initial DC and gain setting strategy

11.4.1Electrical offset from pick-up

11.4.2Gain setting servo

11.4.3DC level in RF path

11.4.4Gain setting RF path

12PACKAGE OUTLINE

13SOLDERING

13.1Introduction to soldering surface mount packages

13.2Reflow soldering

13.3Wave soldering

13.4Manual soldering

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

14DATA SHEET STATUS

15DEFINITIONS

16DISCLAIMERS

2003 Sep 03

2

Philips Semiconductors	Product specification

High speed advanced analog DVD signal

TZA1038HW

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 only mode: servo outputs can be set 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.

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 and double foucault detectors and can be used with P-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				PACKAGE
		NAME		DESCRIPTION				VERSION
TZA1038HW		HTQFP48	plastic thermal enhanced thin quad flat package; 48 leads;					SOT545-2
			body 7 × 7 × 1 mm; exposed die pad
4	QUICK REFERENCE DATA
	SYMBOL	PARAMETER		CONDITIONS	MIN.	TYP.	MAX.		UNIT
Tamb		ambient temperature			−40	−	+85		°C
Supplies
VDDA1, VDDA2,		analog supply voltage			4.5	5.0	5.5		V
VDDA3, VDDA4
VDDD3		3 V digital supply voltage			2.7	3.3	5.5		V
VDDD5		5 V digital supply voltage			4.5	5.0	5.5		V
IDD		supply current		without laser supply	−	98	120		mA
				STANDBY mode	−	−	1		mA
VI(logic)		logic input compatibility		note 1	2.7	3.3	5.5		V
Servo signal processing
BLF(−3dB)		−3 dB bandwidth of			60	75	100		kHz
		LF path
IO(LF)		output current		focus servo output	0	−	12		μA
				radial servo output	0	−	12		μA
VO(FTC)(p-p)		FTC output voltage			2.0	−	−		V
		(peak-to-peak value)
BFTC		FTC bandwidth		FTCHBW = 0	−	600	−		kHz
				FTCHBW = 1; note 2	−	1200	−		kHz
VI(FTCREF)		FTC reference input			1.25	−	2.75		V
		voltage
RF data processing
ARF		linear current gain		programmable gain
				RF channels	6	−	49		dB
				RFSUM channels	−6	−	+31		dB
BRF(−3dB)		−3 dB bandwidth of RFP		RFEQEN = 0;	200	300	−		MHz
		and RFN signal path		RFNFEN = 0
f0(RF)		noise filter and equalizer		BWRF = 0	8	12.0	14.5		MHz
		corner frequency		BWRF = 127	100	145	182		MHz
td(RF)		flatness delay in RF data		equalizer on; flat from	−	−	0.5		ns
		path		0 to 100 MHz;
				BWRF = 127
Zi		input impedance of			100	−	−		kΩ
		pins A to D

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
Vi(RF)(FS)	input voltage on	at the appropriate signal
	pins A to D for full-scale at	path gain setting
	output	RF signal path	−	−	600	mV
		LF signal path	−	−	700	mV
Vi(SUM)(dif)	differential input voltage	GRFSUM = −6 dB	−	−	1800	mV
	on pins RFSUMP and
	RFSUMN
VI(DC)	DC input voltage range on	with respect to VSS	1.3	−	VDDA − 1.0	V
	pins RFSUMP and
	RFSUMN
Vo(RF)(dif)(p-p)	differential output voltage		−	−	1.4	V
	on pins RFP and RFN
	(peak-to-peak value)
VO(RF)(DC)	DC output voltage on		0.35	−	VDDA − 1.9	V
	pins RFP and RFN
Vi(RFREF)(CM)	input reference voltage on		0.8	1.2	2.1	V
	pin RFREF for common
	mode output
Laser supply
Io(laser)(max)	maximum current output		−120	−	−	mA
	to laser
Vi(mon)	input voltage from laser	P-type monitor diode
	monitor diode	LOW level voltage	−	VDDA4 − 0.155	−	V
		HIGH level voltage	−	VDDA4 − 0.190	−	V
		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 VDDD3.

2.High FTC bandwidth is achieved when IS1 and IS2 > 1.5 μA.

2003 Sep 03

5

Philips Semiconductors	Product specification

High speed advanced analog DVD signal

TZA1038HW

processor and laser supply

5 BLOCK DIAGRAM

VDDA1		VDDA2		VDDA3	VDDA4	RFREF	VDDD3		VDDD5
	5		43	37	32	38	15		23
1
RFSUMP				RF DATA PROCESSING						39
2
RFSUMN						VARIABLE				RFP
			MULTIPLEXER							40
						GAIN STAGES				RFN
	A to D
OPUREF
		5			4		TZA1038HW
										36
8			SERVO SIGNAL PROCESSING							OA
										35
A								4		OB
9
										34
B				3-BEAM
										OC
10			TRACKING
										33
C
										OD
11
D										30
3				DPD		SELECT; SWAP				S1
E										29
4										S2
F						S1	S2
12										28
OPUREF			PUSH-PULL							OCENTRAL
				OFFSET		FTC				25
			COMPENSATION							FTC
27
FTCREF
47										20
VDDL
										COP
		VOLTAGE AND			DUAL					21
44										COM
REXT		CURRENT			LASER
		REFERENCES			SUPPLY		FTC			22
							COMPARATOR			COO
46
CDMI			LASER 1
45
CDLO							SERIAL
7							INTERFACE
DVDMI			LASER 2
48										14
DVDLO										TM
										26
										TDO
6		42	41	31	19	16	17		18	MCE466
VSSA1	VSSA2		VSSA3	VSSA4	VSSD	SIDA	SICL	SILD

Fig.1 Block diagram.

2003 Sep 03

6

Philips Semiconductors	Product specification

High speed advanced analog DVD signal

TZA1038HW

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
VDDA1	5	analog supply voltage 1 (RF input stage)
VSSA1	6	analog ground 1
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)
VDDD3	15	digital supply voltage (serial interface 3 V I/O pads and FTC comparator)
SIDA	16	serial host interface data input
SICL	17	serial host interface clock input
SILD	18	serial host interface load
VSSD	19	digital ground
COP	20	positive FTC comparator input
COM	21	inverting FTC comparator input
COO	22	FTC comparator output
VDDD5	23	digital supply voltage (5 V digital core)
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
VSSA4	31	analog ground 4
VDDA4	32	analog supply voltage 4 (servo signal processing)
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
VDDA3	37	analog supply voltage 3 (RF output stage)
RFREF	38	DC reference input for RF channel common mode output voltage
RFP	39	positive RF output
RFN	40	negative RF output

2003 Sep 03

7

Philips Semiconductors	Product specification

High speed advanced analog DVD signal

TZA1038HW

processor and laser supply

SYMBOL	PIN	DESCRIPTION
VSSA3	41	analog ground 3
VSSA2	42	analog ground 2
VDDA2	43	analog supply voltage 2 (internal RF data processing)
REXT	44	reference current input (connect via 12.1 kΩ to VSSA4)
CDLO	45	CD laser output
CDMI	46	input signal from CD laser monitor diode
VDDL	47	laser supply voltage
DVDLO	48	DVD laser output

	DVDLO	V	CDMI	CDLO	REXT	V	V	V	RFN	RFP	RFREF	V
		DDL				DDA2	SSA2	SSA3				DDA3
	48	47	46	45	44	43	42	41	40	39	38	37
RFSUMP	1											36	OA
RFSUMN	2											35	OB
E	3											34	OC
F	4											33	OD
VDDA1	5											32	VDDA4
VSSA1	6				TZA1038HW							31	VSSA4
DVDMI	7											30
													S1
A	8											29	S2
B	9											28	OCENTRAL
C 10												27	FTCREF
D 11												26	TDO
OPUREF 12												25	FTC

13		14		15		16		17		18		19		20		21		22		23		24
n.c.		TM		DDD3		SIDA		SICL		SILD		SSD		COP		COM		COO		DDD5		n.c.
				V								V								V

MCE467

Fig.2 Pin configuration.

2003 Sep 03

8

Philips Semiconductors	Product specification

High speed advanced analog DVD signal

TZA1038HW

processor and laser supply

7 FUNCTIONAL DESCRIPTION

7.1RF 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 inputs RFSUMP and RFSUMN. Switching between the 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 large DC content by nature. This DC component must be removed from the signals for good system performance. Built-in DACs, located after the input stages

G1 and RFSUM, have the ability to do this. 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.

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, also the boost factor of the equalizer can be set. The corner frequencies of the equalizer and noise filter 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 G1 stages. DC cancellation for the A to D and RFSUM signal paths can be set independently or simultaneously.

2003 Sep 03

9

	_
03 Sep 2003
		pagewidthfullandbook,
		RFREF

		RFSUM				38
	1
	RFSUMP
	2
	RFSUMN
		RFOFFSS
	12
	OPUREF	SW-A
	8	G1				39
	A		G3	EQUALIZER	NOISE	RFP		RF
					FILTER	40		outputs
		DPD-A				RFN
		RFOFFSL
		SW-B
10	9	G1		TZA1038HW
	B
	RF	DPD-B	G2
	inputs	SW-C
	10	G1	DPD-A	DPD		30
	C							servo
			DPD-D		FILTER	S1
		DPD-C						radial
					DOC	29
			DPD-C			S2	outputs
		RFOFFSR	DPD-B
		SW-D
		G1	central aperture signal
	11
	D
		DPD-D
						MCE468

Fig.3 RF data and DPD processing.

signal DVD analog advanced speed High supply laser and processor

TZA1038HW

Semiconductors Philips

specification Product

Philips Semiconductors	Product specification

High speed advanced analog DVD signal

TZA1038HW

processor and laser supply

7.2Servo signal processing

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

7.2.1SERVO SIGNAL PATH SET-UP

A block diagram of the servo signal path is shown in Fig.6. In general, the servo signal path comprises:

∙A voltage-to-current converter with programmable offset voltage source VLFOFFS that is common to all inputs

∙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 signals are the equivalent of the 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	B
A		left

tangential direction

D

C

right

MGW553

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)

Fig.4 Astigmatic diode configuration.

handbook, halfpage			left
			right
			tangential direction
A	B C	D	MGW554

Data = A + B + C + D

Push-pull = A − D

Focus = C − B

DPD2 = phase (A, D)

DPD4 not applicable

Fig.5 Foucault diode configuration.

7.2.2FOCUS 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.

7.2.3RADIAL 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.

The polarity of the radial loop can be reversed via the serial control bus (RAD_pol).

2003 Sep 03

11

	_
03 Sep 2003						pagewidth full andbook,
								FTC	25
							DPD		FTC
		8			MUX				27
	A		26k						FTCREF
		V/I
			14k			α		MUX	30
							GLFR
		COFFSA						SWAP	S1
									servo
		9
	B		30k						radial
		V/I							outputs
			14k		2−α		GLFR		29
		COFFSB							S2
	C	10	30k					CA
		V/I
			14k						36
	RF	COFFSC			GLFC
									OA
	inputs
12	D	11	30k
		V/I
			14k						35
		COFFSD			GLFC				OB
									servo
	E	3	15k						focus
		V/I							outputs
					GLFC				34
		ROFFSE							OC
	F	4	15k
		V/I							33
					G	LFC
									OD
		ROFFSF
		VLFOFFS		TZA1038HW	FOFFS			OCENTRAL	28
		12							OCENTRAL
	OPUREF	LFOFFS
									MCE469

Fig.6 Servo signal path.

signal DVD analog advanced speed High supply laser and processor

TZA1038HW

Semiconductors Philips

specification Product

Philips Semiconductors	Product specification

High speed advanced analog DVD signal

TZA1038HW

processor and laser supply

7.2.4DIFFERENTIAL PHASE DETECTION

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

·DPD2 with four channels programmed to be active gives DPD as required in the standard specification

·Two of the four channels can be excluded from the DPD for pick-ups with an alternative 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.

Input signals for DPD are taken from input pins A to D after the first gain stage G1 (see Fig.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 directed via the drop-out concealment circuit to the outputs (see Section 7.5).

7.2.4.1Drop-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

7.2.4.2Push-pull and three-beam push-pull

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

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]).

For TBPP, the input signal is taken from channels E and F, irrespective of bit RFSUM setting.

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

This option cancels offsets due to beam landing. A factor a can be programmed to re-balance the signal gain between channels S1 and S2. In a simplified form this can be described as:

S1 = ALFR ´ a ´ input left

S2 = ALFR ´ (2 - a) ´ input right.

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

7.2.4.4Offset compensation

A provision is made to compensate electrical offset from a light pen. The offset voltage from the light pen can be positive or negative. 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 ³0. The DAC used (LFOFFS) has a 2-bit resolution (bits LFOFF[1:0]).

·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

the signals and bringing the inputs 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.

2003 Sep 03

13

Philips Semiconductors	Product specification

High speed advanced analog DVD signal

TZA1038HW

processor and laser supply

7.2.5AUTOMATIC 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 the monitor input voltage. 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 due to dips in laser supply voltage VDDL. If a supply voltage 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 below a safe value. The ALPC recovers automatically after 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.

7.2.6POWER-ON RESET AND GENERAL POWER ON

7.2.7COMPATIBILITY WITH TZA1033HL/V1

7.2.7.1Software 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:

∙Register bits of the TZA1038HW which were not defined are programmed to a logic 0. Registers 9, 10, 14 and 15 may be left undefined

∙The G4 stage 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

∙When bit K2_Mode = 0 the RF bandwidth will be fixed to the minimum value of 10 MHz (typical); bit K2_Mode = 1 to select a higher bandwidth; the bandwidth is now lower than using a TZA1033HL/V1.

7.2.7.2Hardware compatibility

The package is changed from LQFP64 for the TZA1033HL to LQFP48 for the TZA1038HW.

The hardware differences are:

∙Input pins STB, HEADER and LAND of the TZA1033HL are not present

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 random settings. All other functions may be switched when power is on. The TZA1038HW becomes active when

bit PWRON = 1.

∙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

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