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TDA1302_1
2 Wed Sep 14 13:30:56 1994
Philips Semiconductors
Preliminary specification
Data amplifier and laser supply circuit for CD player and read only optical systems
FEATURES * Six input buffer amplifiers with low-pass filtering and with virtually no offset * HF data amplifier with a high or low gain mode * Two built-in equalizers for single or double-speed mode ensuring high performance in both modes * Fully automatic laser control including stabilization and an ON/OFF switch, plus a separate supply (VDDL) for power reduction * Adjustable laser bandwidth and laser switch-on current slope * Protection circuit to prevent laser damage due to supply voltage dip * Optimized interconnectiion between pick-up detector and digital servo processor (TDA1301T) * Wide supply voltage range * Wide temperature range * Low power consumption. QUICK REFERENCE DATA SYMBOL VDD Gdn Ios(d) B PARAMETER supply voltage (pin 18) CONDITIONS MIN. 3.4 - - Ii(d) = 1.67 A fi = 0.3 MHz double-speed 50 - - - - TYP. GENERAL DESCRIPTION
TDA1302T
The TDA1302T is a data amplifier and laser supply circuit for three-beam pick-up detectors applied in a wide range of mechanisms for Compact Disc and read only optical systems. The device contains 6 amplifiers which amplify and filter the focus and radial diode signals and provides an equalized RF signal suitable for single or double speed mode; the mode can be switched by means of the speed control pin. The device can accommodate astigmatic, single foucault and double foucault detectors and can be applied to all N-sub laser/monitor diode units even though the circuit has been optimized for the Philips CDM12 mechanisms and the digital servo controller TDA1301T. After a single initial adjustment the circuit will maintain control over the laser diode current thus resulting in a constant light output power which is independent of ageing. The IC is mounted in a small-outline package to enable it to be mounted close to the laser pick-up unit on the sledge.
MAX. 5.5 - 100 - - - -100 V
UNIT
Diode current amplifiers amplification diode output offset current 3 dB bandwidth 1.55 - - dB nA kHz
RFE amplifier (built-in equalizer) td(eq) td(f) Laser supply Io(l) output current VDDL = 3 V - mA equalization delay flatness delay 320 5 ns ns
ORDERING INFORMATION PACKAGE TYPE NUMBER NAME TDA1302T SO24 DESCRIPTION plastic small outline package; 24 leads; body width 7.5 mm VERSION SOT137-1
September 1994
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Philips Semiconductors
Preliminary specification
Data amplifier and laser supply circuit for CD player and read only optical systems
SCHEMATIC DIAGRAM
TDA1302T
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V
V
TDA1302_1
September 1994
V
V
3
Fig.1 Schematic diagram for CD player.
TDA1302_1
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Philips Semiconductors
Preliminary specification
Data amplifier and laser supply circuit for CD player and read only optical systems
BLOCK DIAGRAM
TDA1302T
Fig.2 Block diagram.
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TDA1302_1
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Philips Semiconductors
Preliminary specification
Data amplifier and laser supply circuit for CD player and read only optical systems
PINNING SYMBOL O4 O6 O3 O1 O5 O2 LDON VDDL RFE RF HG LS CL ADJ GND LO MI VDD I2 I5 I1 I3 I6 I4 PIN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 DESCRIPTION output of diode current amplifier 4 output of diode current amplifier 6 output of diode current amplifier 3 output of diode current amplifier 1 output of diode current amplifier 5 output of diode current amplifier 2 control pin for switching the laser ON and OFF laser supply voltage equalized output voltage of sum signal of amplifiers 1 to 4 unequalized output control pin for gain switch control pin for speed switch external capacitor reference input normally connected to ground via a resistor 0 V supply; substrate connection (ground) current output to the laser diode laser monitor diode input amplifier supply voltage photo detector input 2 (central) photo detector input 5 (satellite) photo detector input 1 (central) photo detector input 3 (central) photo detector input 6 (satellite) photo detector input 4 (central)
TDA1302T
Fig.3 Pin configuration.
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TDA1302_1
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Philips Semiconductors
Preliminary specification
Data amplifier and laser supply circuit for CD player and read only optical systems
FUNCTIONAL DESCRIPTION The TDA1302T can be divided into two main sections, the laser control circuit and the photo diode signal filter and amplification section. Laser control circuit The main function of the laser control circuit is to control the laser diode current in order to achieve a constant light output power which is based on the current of the monitor diode which is continuously monitored. The circuit is built up into three parts. The first part is the input stage which compares the monitor diode current with a current which is 10 times the value of the adjustable current. The adjustable current is derived from a bandgap reference source, to be temperature independent, and can be further adjusted by the external resistor RADJ in order to adapt the circuit to the parameters of the laser/monitor diode unit to be used. The difference is fed to the second part. The second part is the integrator stage which makes use of an external capacitor CL. This capacitor has two different functions. During switch-on of the laser current, it provides a current slope of typically: dILO/dt 10-6/CL (A/s). After switch-on it ensures that the bandwidth conforms to the typical formula: fB K x Aext x 90-9/(CL x IMON) (Hz). where Aext represents the AC gain of an extra loop amplifier, if applied, and K = dImonitor/dIlaser which is determined by the laser/monitor unit. IMON is the average current (pin 17) at typical light emission power of the laser diode.
TDA1302T
The third part is the power output stage, its input being the integrator output signal. This stage has a separate supply voltage (VDDL) thereby offering the possibility of reduced power consumption by supplying this pin with the minimum voltage necessary. It also has a laser diode protection circuit which is enabled prior to the output drive transistor becoming saturated due to a large voltage dip on VDDL. Saturation will result in a lower current from the laser diode, which is normally followed immediately by an increment of the voltage from the external capacitor CL, which could cause damage to the laser diode at the end of the voltage dip. The protection circuit prevents an increment of the capacitor voltage and thus offers full protection to the laser diode under these circumstances. Photo diode signal filter and amplification section This section has 6 identical current amplifiers. Amplifiers 1 to 4 are designed to amplify the focus photo diode signals. Each amplifier has two outputs, an LF output and an internal RF output. Amplifiers 5 and 6 are used for the radial photo diode currents and have only an LF output. All 6 output signals are low-pass filtered with a corner frequency at 65 kHz. The internal RF output signals are summed together and converted into a voltage by means of a selectable transresistance of 120 k or 240 k. This signal is available directly at pin 10, however, there is also an unfiltered signal available at pin 9. The equalization filter used has 2 different filter curves, one for single-speed mode and one for double-speed mode.
Table 1 Operational modes. IF NOT CONNECTED DEFAULT 1 1 1 MODE(1) GAIN HIGH 1 X X LOW 0 X X SPEED SINGLE X 1 X DOUBLE X 0 X ON X X 1 LASER OFF X X 0
SWITCH
PIN
HG Control pin LS LDON Note 1. Where X = don't care.
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TDA1302_1
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Philips Semiconductors
Preliminary specification
Data amplifier and laser supply circuit for CD player and read only optical systems
LIMITING VALUES In accordance with the Absolute Maximum Rating System (IEC 134). SYMBOL VDD Ptot Tstg Tamb HANDLING Classification A: human body model; C = 100 pF; R = 1500 ; V = 2000 V. Charge device model: C = 200 pF; L = 2.5 H; R = 0 ; V = 250 V. THERMAL RESISTANCE SYMBOL Rth j-a PARAMETER from junction to ambient in free air supply voltage total power dissipation storage temperature operating ambient temperature PARAMETER - - -65 -40 MIN. 8.0 300 +150 +85 MAX.
TDA1302T
UNIT V mW C C
THERMAL RESISTANCE 60 K/W
QUALITY SPECIFICATION In accordance with "SNW-FQ-611 part E". The numbers of the quality specification can be found in the "Quality Reference Handbook". The handbook can be ordered using the code 9398 510 63011. CHARACTERISTICS VDD = 3.4 V; VDDL = 2.5 V; Tamb = 25 C; RADJ = 48 k; HG = logic 1; LS = logic 1; with an external LP filter (Rext = 750 , Cext = 47 pF) at pin 9; unless otherwise specified. SYMBOL Supply IDD VDD VDDL Pdiss Ii(d) Neq Vi(d) Vo(d) Gdn Ios(d) Zo(d) B Gmm amplifier supply current amplifier supply voltage laser control supply voltage power dissipation laser OFF; VDD = 3.4 V note 1 Ii(d) = 1.67 A Ii(d) = 1.67 A; Vo(dn) = 0 V; note 2 Icsin = Itsin = 0; note 3 Idi = 1.67 A; Vo(dn) = 0 V Ii(d) = 1.67 A Idi = 1.67 A; Vo(dn) = Vo(dm) 7 laser OFF - 3.4 2.5 - - - - -0.2 1.43 - 500 50 - 8 - - 27 - 1 0.9 - 1.55 - - 68 - - 5.5 5.5 - mA V V mW A pA/Hz V V dB nA k kHz % PARAMETER CONDITIONS MIN. TYP. MAX. UNIT
Diode current amplifiers (1 to 6) diode input current equivalent noise input diode input voltage diode output voltage amplification diode output offset current output impedance 3 dB bandwidth mismatch in amplification 10 - - VDD - 1 1.67 100 - - 3
September 1994
TDA1302_1
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Philips Semiconductors
Preliminary specification
Data amplifier and laser supply circuit for CD player and read only optical systems
SYMBOL PARAMETER CONDITIONS - 100 200 - - - - 4.5 3 -0.2 VDD - 1 - -0.2 - Ii(mon) = -1 mA - - MIN. TYP. -
TDA1302T
MAX.
UNIT
Data amplifier; equalized single and double speed VRFO RRF VRFMO SRRF ZoRF td(eq) td(f) GR BRF VIL VIH IIL Vo(l) Io(l) Vi(mon) Ii(mon) DC output voltage transresistance output voltage slew rate output impedance equalization delay flatness delay (/) gain ratio unequalized output bandwidth Icsin = 0 fi = 100 kHz; note 4 fi = 100 kHz; note 5 note 6 VSR = 1 V (p-p) fi = 1 MHz note 7 note 8 Ii(d) = 1.67 A 0.3 120 240 - 6 100 320 10.5 6 5 - - - - - V k k V V/s ns ns dB MHz 143 285 VDD - 1.2 - - - - - -
LS = 1 or 0; notes 7 and 8 -
Control pins LDON, LS and HG (with 47 k internal pull-up resistor) LOW level input voltage HIGH level input voltage LOW level input current +0.5 VDD + 0.2 100 VDD - 0.7 -100 V V A
Laser output output voltage output current Io(l) = 100 mA V mA
Monitor diode input monitor input voltage monitor input current VDD - 0.7 - - 2 V mA
Reference source VGAP and laser adjustment current IADJ Vref T SRref IADJ Zi dlo(l)/dt M reference voltage reference temperature drift reference supply rejection adjustment current input impedance slew rate output current multiplying factor (Ii(mon)/IADJ) RADJ = 5.6 k RADJ = 48 k CL = 1 nF RADJ = 48 k RADJ = 48 k 1.15 - - - - - - 1.24 40 x - - 1 1 10 10-6 1.31 - 1 200 - - - % A k mA/s V
September 1994
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TDA1302_1
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Philips Semiconductors
Preliminary specification
Data amplifier and laser supply circuit for CD player and read only optical systems
Notes to the characteristics
TDA1302T
1. The maximum input current is defined as the current in which the gain reaches its minimum. Increasing the supply voltage to VDD = 5 V increases the maximum input current (see also Figs 4 and 5). 2. The gain increases if a larger supply voltage is used (see also Fig.6). 3. Icsin is the sum of the diode input currents 1 to 4; Itsin is the sum of the diode input currents 5 and 6. 4. Transresistance 120 k means LOW gain, selected if HG = logic 0 (see Table 1). 5. Transresistance 240 k means HIGH gain, selected if HG = logic 1 (see Table 1). 6. Output voltage swing will be: VSRRF = VRFMO = VRFO(p-p). 7. Refers to equalized output only. 8. For single speed the gain ratio is defined as gain difference between 1 MHz and 100 kHz, while the flatness delay is defined up to 1 MHz (see also Fig.7). For double speed the gain ratio is defined as gain difference between 2 MHz and 200 kHz, while the flatness delay is defined up to 2 MHz.
Transfer function The equalized amplifier including Cext and Rext has the following transfer functions, where `rfe' refers to equalized output only and `rf' refers to equalized and not equalized outputs. FOR SINGLE SPEED (SP = LOGIC 1) 2 2 V rfe 1 1 1 - ks os --------- = R rf x ------------------------------------------------------------------------ x ---------------------- x ----------------------------------------2 2 1 + s 1 1 + sR ext x C ext I csin 1+1Qxs +s
os os
(1)
FOR DOUBLE SPEED (SP = LOGIC 0) 2 2 V rfe 1 1 - ks os --------- = R rf x ------------------------------------------------------------------------ x ----------------------------------------2 2 1 + sR ext x C ext I csin 1+1Qxs +s
od od
(2)
The denominator forms the denominator of a Bessel low-pass filter. Table 2 Transresistance. SYMBOL k os/1 = od/2 Q od = 2 x os RRF Rext Cext DESCRIPTION internally defined internally defined internally defined internally defined see Chapter "Characteristics" external resistor external capacitor 4 1.094 0.691 17.6 x 10-6 - 750 47 pF rad/s TYP. UNIT
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TDA1302_1
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Philips Semiconductors
Preliminary specification
Data amplifier and laser supply circuit for CD player and read only optical systems
TDA1302T
V
V
= test limit.
Fig.4 Maximum input current as a function of VDD.
V
= test limit.
Fig.5 Output current as a function of input current.
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BBBB BBBBBBB BBB BBBB BBBB
TDA1302_1
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Philips Semiconductors
Preliminary specification
Data amplifier and laser supply circuit for CD player and read only optical systems
TDA1302T
I
= test limit.
Fig.6 Gain as a function of VDD.
The dashed line = delay (ns); the solid line = gain (dB).
Fig.7 Transfer for single speed.
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TDA1302_1
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Philips Semiconductors
Preliminary specification
Data amplifier and laser supply circuit for CD player and read only optical systems
INTERNAL PIN CONFIGURATION
TDA1302T
Fig.8 Equivalent internal pin diagrams.
September 1994
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TDA1302_1
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Philips Semiconductors
Preliminary specification
Data amplifier and laser supply circuit for CD player and read only optical systems
APPLICATION INFORMATION The TDA 1302T is optimized for Philips CDM12 mechanisms and, subsequently, this application is preferred. Application with Philips CDM12 The CDM12 mechanism uses an N sub-laser diode together with a P sub-monitor diode and, since TDA1302T
TDA1302T
is optimized for this type, besides the standard components CL and RADJ, no other external components are required as illustrated in Fig.9. As two central spot diodes are summed together inside the pick-up unit, one input pin remains unused as shown in Fig.10. Unused central spot inputs should be connected to ground in order to eliminate noise contribution to the RF and RFE signals.
Fig.9 Application of the CDM12 laser/monitor diode unit.
Fig.10 Application of the CDM12 pick-up unit.
September 1994
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TDA1302_1
14 Wed Sep 14 13:30:56 1994
Philips Semiconductors
Preliminary specification
Data amplifier and laser supply circuit for CD player and read only optical systems
Application of other mechanisms The TDA1302T can accommodate all laser/monitor configurations with an N sub-laser diode. When an N sub-monitor diode is used, external circuitry is required as illustrated in Figs 11(a) to 11(d). Most of these laser/monitor diode units have a variable resistor (Rm) in parallel with the monitor diode which has been pre-adjusted so that the voltage drop across this resistor has a specific value at nominal laser diode output power. The four circuits given each detail specific values for some frequently used pick-up units as given in Table 3. Each circuit has its own advantages. All circuits illustrated make use of the fixed voltage (<200 mV) across the built-in monitor resistor. Table 3 Pick-up units. PICK-UP UNIT SLD104U LT022MS RLD-78MA MANUFACTURER Sony corporation Sharp corporation Rohm corporation
TDA1302T
APPLICATION KSM210 (Sony) KSM210 (Sony) KSM210 (Sony) HOP-M3TR (Hitachi)
SF91
Sony corporation
CDV90V1 (Sanyo)
Fig.11 Applications of the laser/monitor units.
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TDA1302_1
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Philips Semiconductors
Preliminary specification
Data amplifier and laser supply circuit for CD player and read only optical systems
PROPERTIES OF CIRCUIT FIG.11(a) It is important that the Vd(D1) approaches Vbe(T1) at approximately 150 A, that is why a small diode has been applied such as the BA482. Additional adjustment may be necessary. this depends on the matching of Vd(D1) and Vbe(T1) and the permitted tolerance on the laser current. The advised adjustment procedure is as follows: 1. Ensure that RADJ has the highest impedance at the beginning of the adjustment. 2. Adjust RADJ until the voltage across Rm has the value as indicated in Table 4. Table 4 Variable resistor (Rm) voltage adjustment. PICK-UP UNIT SLD104U LT022MS RLD-78MA SF90 SF91 MANUFACTURER Sony corporation Sharp corporation Rohm corporation Sanyo corporation Sanyo corporation VRm (mV) 150 150 150 180 180
TDA1302T
In Figs 11(b) to 11(d) solutions have been given requiring no adjustment. RADJ and Re can be calculated as follows: RADJ = 12.4Re/VRm at Po(nom). Examples of advised values applicable to Fig.11(b), (c) and (d) are given in Table 6. Table 6 Advised circuit values. PICK-UP UNIT SLD104U LT022MS RLD-78MA SF90 SF91(1) Note 1. Notwithstanding that the SF91 specification details an astigmatic detection system, TDA1301T requires a single Foucault parameter setting. Figures 12 and 13 give the application diagrams of the pick-up unit of the mechanisms as previously indicated. MANUFACTURER Re () RADJ (k) Sony corporation Sharp corporation Rohm corporation Sanyo corporation Sanyo corporation 620 620 620 750 750 51 51 51 51 51
Table 5 Further circuit properties of Fig.11. FIGURE PROPERTIES single supply voltage (a) only a few components are required; 2R, 1T and 1D supply voltage independent single supply voltage only a few components are required; 1R, 2T and 1D supply voltage independent no extra adjustment necessary if T1 and T2 match only a few components are required; 1R and 2T (c) supply voltage independent no extra adjustment necessary better power efficiency than (b) single supply voltage (d) supply voltage independent no extra adjustment necessary no matching components required
(b)
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TDA1302_1
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Philips Semiconductors
Preliminary specification
Data amplifier and laser supply circuit for CD player and read only optical systems
TDA1302T
Fig.12 Application of pick-up units SLD104U, LT022MS and RLD-78MA.
Fig.13 Application of pick-up unit SF91.
September 1994
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TDA1302_1
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Philips Semiconductors
Preliminary specification
Data amplifier and laser supply circuit for CD player and read only optical systems
Circuit recommendations PRINTED-CIRCUIT BOARD LAY-OUT ITEMS It is advised to keep the output wires of the diode current amplifiers separated from the input as much as possible to prevent oscillations. EXTERNAL MONITOR DIODE CIRCUITRY TDA1302T protects the laser diode against damage due to supply voltage transients. When any external circuitry is used in the `laser diode-monitor diode' chain, the safety of the laser diode completely relies on the quality of this external circuitry. Therefore, it should be noted that: 1. If such a circuit requires a supply voltage, make sure that this voltage is present at least at the same moment as VDDL or earlier. 2. It is advised not to implement integrating actions in this external circuitry as this may conflict with the internal integrator, especially during possible supply voltage drops. MEASUREMENT OF THE LASER DIODE CURRENT It is advised not to connect any current meter directly in series with the laser diode. A safe method is the inclusion of a 1 resistor, connected in series with the laser diode, and measuring the voltage across this resistor.
TDA1302T
September 1994
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TDA1302_1
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Philips Semiconductors
Preliminary specification
Data amplifier and laser supply circuit for CD player and read only optical systems
PACKAGE OUTLINE
TDA1302T
handbook, full pagewidth
15.6 15.2
7.6 7.4
A
S 0.9 (4x) 0.4
0.1 S
10.65 10.00
24
13 2.45 2.25 1.1 1.0 0.3 0.1 0.32 0.23 2.65 2.35
pin 1 index 1 12 detail A 1.1 0.5 0 to 8o
MBC235 - 1
1.27
0.49 0.36
0.25 M (24x)
Dimensions in mm.
Fig.14 Plastic small outline package; 24 leads; body width 7.5 mm (SO24L; SOT137AH).
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TDA1302_1
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Philips Semiconductors
Preliminary specification
Data amplifier and laser supply circuit for CD player and read only optical systems
SOLDERING Plastic small-outline packages BY WAVE During placement and before soldering, the component must be fixed with a droplet of adhesive. After curing the adhesive, the component can be soldered. The adhesive can be applied by screen printing, pin transfer or syringe dispensing. Maximum permissible solder temperature is 260 C, and maximum duration of package immersion in solder bath is 10 s, if allowed to cool to less than 150 C within 6 s. Typical dwell time is 4 s at 250 C. A modified wave soldering technique is recommended using two solder waves (dual-wave), in which a turbulent wave with high upward pressure is followed by a smooth laminar wave. Using a mildly-activated flux eliminates the need for removal of corrosive residues in most applications. BY SOLDER PASTE REFLOW Reflow soldering requires the solder paste (a suspension of fine solder particles, flux and binding agent) to be
TDA1302T
applied to the substrate by screen printing, stencilling or pressure-syringe dispensing before device placement. Several techniques exist for reflowing; for example, thermal conduction by heated belt, infrared, and vapour-phase reflow. Dwell times vary between 50 and 300 s according to method. Typical reflow temperatures range from 215 to 250 C. Preheating is necessary to dry the paste and evaporate the binding agent. Preheating duration: 45 min at 45 C. REPAIRING SOLDERED JOINTS (BY HAND-HELD SOLDERING
IRON OR PULSE-HEATED SOLDER TOOL)
Fix the component by first soldering two, diagonally opposite, end pins. Apply the heating tool to the flat part of the pin only. Contact time must be limited to 10 s at up to 300 C. When using proper tools, all other pins can be soldered in one operation within 2 to 5 s at between 270 and 320 C. (Pulse-heated soldering is not recommended for SO packages.) For pulse-heated solder tool (resistance) soldering of VSO packages, solder is applied to the substrate by dipping or by an extra thick tin/lead plating before package placement.
DEFINITIONS Data sheet status Objective specification Preliminary specification Product specification Limiting values Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended periods may affect device reliability. Application information Where application information is given, it is advisory and does not form part of the specification. LIFE SUPPORT APPLICATIONS These products are not designed for use in life support appliances, devices, or systems where malfunction of these products can reasonably be expected to result in personal injury. Philips customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Philips for any damages resulting from such improper use or sale. This data sheet contains target or goal specifications for product development. This data sheet contains preliminary data; supplementary data may be published later. This data sheet contains final product specifications.
September 1994
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