CXA3031Q Read/Write Amplifier (with Built-in Filters) for FDDs For the availability of this product, please contact the sales office. Description The CXA3031Q is a monolithic IC designed for use with three-mode Floppy Disk Drives, and contains a read circuit (with a four-mode filter system), a write circuit, an erase circuit, and a supply voltage detection circuit, all on a single chip. Features • Single 5V power supply • Filter system can be switched among four modes: 1M, 1.6M/2M, which are each inner track/outer track • Filter characteristics can be set to Chebyshev (1dB ripple) for 1.6M, 2M/inner track only, and to Butterworth for the other modes • A custom selection can be made between Chebyshev (1dB ripple) and Butterworth for the filter characteristics for 1.6M, 2M/inner track only • Permits customization of the fc ratio • Low preamplifier input conversion noise voltage of 2.0nV/√ Hz (typ.) keeps read data output jitter to a minimum • Preamplifier voltage gain can be switched between 39dB and 45dB • In inner track mode (OTF = Low), the voltage gain is boosted by 3dB, making it possible to minimize peak shift in inner tracks. • Time domain filter can be switched between two modes: 1M, 1.6M/2M • Write current can be switched among three modes: 1M/1.6M/2M. The inner/outer track current ratio is fixed for each mode, but can be customized. • Erase current can be set by an external resistor, and remains constant. In addition, the current rise time Tr and fall time Tf are determined according to the head inductance and current. (Refer to page 20.) • Damping resistor can be built in. Resistance can be customized between 2kΩ and 15kΩ in 1kΩ steps. A damping resistor can not be connected to this IC, however. • Supply voltage detection circuit 32 pin QFP (Plastic) Applications Three-mode FDDs Structure Bipolar silicon monolithic IC Absolute Maximum Ratings (Ta = 25°C) 7.0 V • Supply voltage VCC • Operating temperature Topr –20 to +75 °C • Storage temperature Tstg –65 to +150 °C • Allowable power dissipation PD 500 mW • Digital signal input pin Input voltage –0.5 to VCC + 0.3 V • Power ON output voltage applied VCC + 0.3 V • Erase output voltage applied VCC + 0.3 V • Write head voltage applied 15 V • Write current IW 20 mAo-p • Erase current IE 30 mA • Power on output current 7 mA Operating Conditions Supply voltage 4.4 to 6.0 V Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits. –1– E95318-ST CXA3031Q HEAD0A HEAD0B HEAD1A HEAD1B XHG PREOUTA X360 PREOUTB Block Diagram and Pin Configuration 24 23 22 21 20 19 18 17 WCLD 25 FILTER DIFF + LPF (BPF) WCMD 26 PREAMP WCHD 27 IESET 28 16 NC 15 FILTER OUTA 14 FILTER OUTB 13 A.GND WRITE DRIVER COMP D.GND 29 12 MMVA ERA0 30 ERASE DRIVER ERA1 31 POWER MONITOR 11 FCSET TIME DOMAIN FILTER CONTROL LOGIC XWD RD XCI 5 6 7 8 OTF 4 XS1 3 XEG 2 XWG 1 POWER ON XPS 32 –2– 10 VCC 9 XHD CXA3031Q Pin Description Pin No. Symbol Pin voltage Equivalent circuit Description VCC 100k 1 POWER ON Reduced voltage detection output. This is an open collector pin that outputs a low signal when VCC is below the specified value. 1 — A.GND VCC 2 XWD Write data input. This pin is a Schmitt-type input that is triggered when the logical voltage goes from High to Low. 1k — 2 2.3V A.GND VCC 140 3 RD Read data output. This pin is active when the logical voltage of the write gate signal and the erase gate signal is High. 3 — D.GND 4 XCI — Write current control. The write current increases when the logical voltage is Low. 5 XWG — Write gate signal input. The write system becomes active when the logical voltage is Low. 6 XEG — VCC 100k 4 5 1k 6 7 XS1 — 7 2.1V 8 9 A.GND Erase gate signal input. The erase system becomes active when the logical voltage is Low. Head side switching signal input. The HEAD1 system is active when the logical voltage is Low, and the HEAD0 system is active when the logical voltage is High, but only when the logical voltage for the write gate and the erase gate is High. 8 OTF — Filter inner track/outer track mode control. Inner track mode is selected when the logical voltage is Low. 9 XHD — Filter, time domain filter and write current 1M/2M mode control. 2M mode is selected when the logical voltage is Low. –3– CXA3031Q Pin No. Symbol Pin voltage Equivalent circuit Description VCC 18 X360 — 100k 18 Filter, time domain filter and write current 1M/1.6M mode control. 1.6M mode is selected when the logical voltage is Low. 1k 20 20 XHG 2.1V — A.GND 10 VCC Preamplifier voltage gain selection. Gain is boosted by 6dB when the logical voltage is Low compared to when the logical voltage is High. Power supply (5V) connection. — VCC 1k 1.2V 11 147 11 FCSET 3.8V Filter cutoff frequency setting resistor connection. Connect the filter cutoff frequency setting resistor RF between this pin and VCC in order to set the cutoff frequency. A.GND VCC 12 MMVA 0.5V 147 12 1.2V Time domain filter 1st monostable multivibrator pulse width setting. Connect the 1st monostable multivibrator pulse width setting resistor RA between this pin and A.GND. A.GND 13 A.GND 14 FILTER OUTB Analog system GND connection. — VCC 3.4V 140 140 14 15 15 FILTER OUTA 16 (NC) 17 PRE OUTB 3.4V 300µ A.GND 300µ Not connected. VCC 3.4V 140 140 17 19 19 PRE OUTA Filter differential outputs. 3.4V 200µ 200µ A.GND –4– Preamplifier differential outputs. CXA3031Q Pin No. Symbol Pin voltage 21 HEAD 1B — 22 HEAD 1A — 23 HEAD 0B — 24 HEAD 0A — 25 26 WCLD 5V when XWG = High Equivalent circuit Description 24 23 22 21 Magnetic head input/output connections. Connect the recording/playback magnetic head to these pins, and connect the center tap to VCC. When the logical voltage for Pin 7 (XS1) is Low, the HEAD1 system is active; when the logical voltage is High, the HEAD0 system is active. A.GND VCC 1.2V 147 25 147 26 27 WCMD 147 3.8V when XWG = Low 27 28 A.GND WCHD 5V when XEG = High 2M write current setting resistor connection. Connect the write current setting resistor RWHD between this pin and VCC to set the write current. VCC 147 28 IESET D.GND 1.6M write current setting resistor connection. Connect the write current setting resistor RWMD between this pin and VCC to set the write current. 1.2V 3.8V when XEG = Low 29 1M write current setting resistor connection. Connect the write current setting resistor RWLD between this pin and VCC to set the write current. Erase current setting resistor connection. Connect the erase current setting resistor RE between this pin and VCC to set the erase current. A.GND — Digital system GND connection. VCC 30 ERA0 — 30 31 31 ERA1 Erase current connection for the HEAD0 system. Erase current connection for the HEAD1 system. — A.GND –5– CXA3031Q Pin No. Symbol Pin voltage Equivalent circuit Description VCC 162k 1k 32 XPS — 32 2.1V A.GND –6– Power saving signal input. When the logical voltage is Low, the IC is in power saving mode. In power saving mode, only the power supply on/off detector operates. CXA3031Q Electrical Characteristics Current Consumption (Ta = 25°C, VCC = 5V) Measure- MeasureMin. ment circuit ment Point Item Symbol Conditions Typ. Max. Current consumption in read mode ICCR XWG = High — — 16 26 36 mA Current consumption in write/erase mode ICCWE XWG = Low, XEG = Low — — 7 13 19 mA Current consumption in power saving mode ICCPS XPS = Low — — — 0.95 1.9 mA Power Supply Monitoring System Item Symbol Power supply on/off detector threshold voltage VTH Power on output saturation voltage VSP (Ta = 25°C) Measure- MeasureMin. ment circuit ment Point Conditions VCC = 3.5V I = 1mA Typ. Max. Unit — — 3.5 3.9 4.3 V — — — — 0.5 V Read System Item Unit (Ta = 25°C, VCC = 5V) Symbol Measure- MeasureMin. ment circuit ment Point Conditions Typ. Max. Unit Preamplifier voltage gain GVLO Low gain/outer track f = 100kHz OTF = High, XHG = High 1 D, E 37.1 39.0 40.6 dB Preamplifier voltage gain GVLI Low gain/inner track f = 100kHz OTF = Low, XHG = High 1 D, E 40.1 42.0 43.6 dB f = 100kHz Preamplifier voltage gain GVHO OTF = High, XHG = Low High gain/outer track 1 D, E 43.1 45.0 46.6 dB Preamplifier voltage gain GVHI High gain/inner track f = 100kHz OTF = Low, XHG = Low 1 D, E 46.1 48.0 49.6 dB Preamplifier frequency response BW GV/GV (100kHz) = –3dB 1 D, E 5 — — MHz Preamplifier input conversion noise voltage EN Band Width = 400Hz to 1MHz, VI = 0 1 D, E — 2.0 2.9 nV/√ Hz Preamplifier differential output offset voltage VOFSP VI = 0 1 D, E –500 — +500 mV Filter differential output offset voltage VOFSF VI = 0 1 B, C –100 — +100 mV Filter differential output voltage amplitude VOF 1 B, C 2.8 — — Vp-p –7– CXA3031Q Read System Item (Ta = 25°C, VCC = 5V) Symbol A, F 2.25 2.5 2.75 µs X360 = Low, XHD = Low (1.6M mode) or X360 = High, XHD = Low (2M mode) Refer to Fig. 1 1 A, F 1.13 1.25 1.38 µs Refer to Fig. 1 1 A 260 400 540 ns IOL = 2mA 1 A — — 0.5 V VOH IOH = –0.4mA 1 A 2.8 — — V tr RL = 2kΩ CL = 20pF 1 A — — 100 ns tf RL = 2kΩ CL = 20pF 1 A — — 100 ns PS VI = 0.25mVp-p to 3.5mVp-p XHG = Low, XHD = Low OTF = Low, X360 = High f = 125kHz, 2M/ inner track mode Refer to Fig. 1 1 A — — 1 % Read data pulse width T2 Read data output low VOL output voltage Peak shift∗2 Unit 1 T1 fall time Typ. Max. X360 = X, XHD = High (1M mode) Time domain filter monostable multivibrator pulse width Read data output high output voltage Read data output∗1 rise time Read data output∗1 Measure- MeasureMin. ment circuit ment Point Conditions ∗1 Read data output: 0.5V to 2.4V ∗2 Signal input level Low gain/outer track: VI = 0.5mVp-p to 10mVp-p Low gain/inner track: VI = 0.5mVp-p to 7mVp-p High gain/outer track: VI = 0.25mVp-p to 5mVp-p High gain/inner track: VI = 0.25mVp-p to 3.5mVp-p –8– CXA3031Q External Comparator Output (Measurement point F) Read data output (Measurement point A) 1.4V T1 T2 TA TB Fig. 1 1st and 2nd monostable multivibrator pulse width precision and peak shift measurement conditions • 1st monostable multivibrator pulse width precision When X360 = X and XHD = High: T1 – 1) × 100 [%] 2.5µs ETM1 = ( When X360 = Low and XHD = Low, or X360 = High and XHD = Low: ETM1' = ( T1 – 1) × 100 [%] 1.25µs • 1st monostable multivibrator pulse width = T2 • Peak shift PS = 1 2 TA – TB TA + TB × 100 [%] –9– CXA3031Q Read System (Filters) Item 1M outer track 1M inner track 1.6M/ 2M outer track (Ta = 25°C, VCC = 5V) Symbol Peak frequency fo1 Peak voltage gain∗3 Gp1 Frequency response (1) G11 Frequency response (2) G12 Peak frequency fo2 Peak voltage gain∗3 Gp2 Frequency response (1) G21 Frequency response (2) G22 Peak frequency fo3 Peak voltage gain∗3 Gp3 Frequency response (1) G31 Frequency response (2) G32 Conditions X360 = X XHD = High OTF = High Refer to Fig. 2 at f01 Refer to Fig. 2 at 1/3f01 Refer to Fig. 2 at 3f01 X360 = X XHD = High OTF = Low Refer to Fig. 2 at f02 Refer to Fig. 2 at 1/3f02 Refer to Fig. 2 at 3f02 X360 = Low XHD = Low OTF = High (1.6M/outer track) or X360 = High XHD = Low OTF = High (2M/outer track) Refer to Fig. 2 at f03 Refer to Fig. 2 at 1/3f03 Refer to Fig. 2 at 3f03 – 10 – Measure- MeasureMin. ment circuit ment Point Typ. Max. Unit 153.0 170.0 187.0 kHz 1 B, C 1 D, E B, C 4.3 6.2 7.8 dB 1 B, C –7.6 –7.1 –6.6 dB 1 B, C –24.7 –22.8 –21.2 dB 1 B, C 163.8 182.0 200.2 kHz 1 D, E B, C 4.3 6.2 7.8 dB 1 B, C –7.6 –7.1 –6.6 dB 1 B, C –24.7 –22.8 –21.2 dB 1 B, C 288.0 320.0 352.0 kHz 1 D, E B, C 4.4 6.3 7.9 dB 1 B, C –7.6 –7.1 –6.6 dB 1 B, C –25.0 –23.1 –21.5 dB CXA3031Q Item 1.6M/ 2M inner track Symbol Peak frequency fo4 Peak voltage gain∗3 Gp4 Frequency response (1) G41 Frequency response (2) G42 Conditions Measure- MeasureMin. ment circuit ment Point X360 = Low XHD = Low OTF = Low (1.6M/inner track) or X360 = High XHD = Low OTF = Low (2M/inner track) Refer to Fig. 2 at f04 Refer to Fig. 2 at 1/3f04 Refer to Fig. 2 at 3f04 1 B, C 310.5 345.0 379.5 kHz 1 D, E B, C 5.9 7.8 9.4 dB 1 B, C –8.5 –8.0 –7.5 dB 1 B, C –36.9 –35.0 –33.4 dB ∗3 Gpn = 20 log10 (VFilterout/Vpreout) VFilterout = Filter differential output voltage (n = 1 to 4) [dB] Gpn Gn1 Gn2 1/3fon fon 3fon f [Hz] (n = 1 to 4) Fig. 2. Filter frequency response measurement conditions – 11 – Typ. Max. Unit CXA3031Q Write/Erase System Item (Ta = 25°C, VCC = 5V) Symbol Measure- MeasureMin. ment circuit ment Point Conditions Typ. Max. Unit Write current output precision∗4 EW XWG = Low RW = 1.3kΩ 2 J, K L, M –7 — +7 % Write current output unbalance DW XWG = Low RW = 1.3kΩ 2 J, K L, M –1 — +1 % Head I/O pin leak current for writes ILKW XWG = Low 2 J, K L, M — — 10 µA Write head pin current at saturation ISW XWG = Low RW = 1.3kΩ VSW = 1V SW1 = b 2 J, K L, M 2.47 2.70 2.97 mAo-p Erase current output precision∗5 EE XEG = Low RE = 1.3kΩ 2 N, O –10 — +10 % Erase current output pin leak current ILKE XEG = Low 2 N, O — — 10 µA Erase current rise time∗6 TRE Defined at 10% to 90% of IE 2 N', O' 0.6 1.3 2.1 µs Erase current fall time∗6 TFE Defined at 90% to 10% of IE 2 N', O' 0.6 1.3 2.1 µs ∗4 Write current output precision EW = ( IW – 1) × 100 [%] 2.72mAo-p ∗5 Erase current output precision EE = ( IE – 1) × 100 [%] 9.08mA ∗6 Erase current rise/fall times show the values when the output pin is shorted with the power supply. Logic Input Block Item (Ta = 25°C, VCC = 5V) Symbol Measure- MeasureMin. ment circuit ment Point Conditions Typ. Max. Unit Digital signal input low input voltage VLD 2 BCDE FGHIP — — 0.8 V Digital signal input high input voltage VHD 2 BCDE FGHIP 2.0 — — V Schmitt-type digital signal input low input VLSD voltage 2 A — — 0.8 V Schmitt-type digital signal input high input voltage VHSD 2 A 2.0 — — V Digital signal input low input current ILD VL = 0V 2 ABCDE FGHIP –20 — — µA Digital signal input high input current IHD VH = 5V 2 ABCDE FGHIP — — 10 µA – 12 – CXA3031Q Electrical Characteristics Measurement Circuit 1 E –1/2Vi 1/2Vi b SW6 a D a b a b a b SW5 SW4 20 19 18 XHG PREOUTA X360 PREOUTB 21 HEAD1B WCLD 22 HEAD1A 25 1.3k 23 HEAD0B 24 HEAD0A ∗7 3300p 17 12k 16 NC 3300p 26 WCMD FILTER 15 OUTA C 27 WCHD FILTER OUTB 14 B 1.3k 1.3k 28 IESET F External Comparator A.GND 13 1.3k CXA3031Q 29 D.GND MMVA 12 27k FCSET 11 30 ERA0 3.26k 5V VCC 10 XCI XWG XEG XS1 2 3 4 5 6 7 SW1 a b XHD OTF RD 1 XWD XPS 32 POWER ON 31 ERA1 9 SW3 8 a SW2 b a b A Note) Unless otherwise specified, switches are assumed to be set to “a”. ∗7 CR time constant of external comparator input stage is equivalent to the time constant of comparater with a built-in IC. – 13 – CXA3031Q Electrical Characteristics Measurement Circuit 2 SW1 I H a b L L' M' a b a 23 22 21 20 19 18 PREOUTA X360 b XHG WCLD b a HEAD1B 25 1.3k J' K' HEAD1A 24 VSW HEAD0B b a HEAD0A SW2 J K PREOUTB M 17 16 NC 26 WCMD FILTER 15 OUTA 27 WCHD FILTER OUTB 14 1.3k 1.3k 28 IESET A.GND 13 1.3k CXA3031Q 29 D.GND MMVA 12 27k a N 3.26k 5V O P XS1 2 3 4 5 6 7 A XHD OTF XEG 1 XWG XPS 32 XCI b SW3 RD 200 VCC 10 31 ERA1 XWD O' FCSET 11 30 ERA0 b a POWER ON N' 200 9 8 B C D E F Note) Unless otherwise specified, switches are assumed to be set to "a". – 14 – G CXA3031Q Description of Operation (1) Read system Preamplifier The preamplifier amplifies input signals. The voltage gain can be switched between 39dB and 45dB, using Pin 20. In addition, an additional 3dB boost in the voltage gain is possible by setting Pin 8 low. Filters The filters differentiate the signals amplified by the preamplifier. The high-band noise components are attenuated by the low-pass filter. The filters can be switched among four modes, depending on the settings of Pins 8, 9 and 18. In 1M/outer track mode, the peak frequency fO1 is set by external resistor RF. fO for the other three modes is switched by the internal settings of the IC, with fO1 used as a reference (1.00). Active filter block 19 Preamplifier output A 17 Preamplifier output B Preamplifier output BPF LPF Secondary fOB = 1.2 × fC Q = 0.577 Tertiary fc: variable HPF Primary fCH = 5kHz 15 Filter output A 14 Filter output B Amp Gain: 8dB The center frequency fOB of the BPF is fixed to 1.2 times the cutoff frequency fO of the LPF. The LPF characteristics are set to Chebyshev (1dB ripple) for 1.6M, 2M/inner track mode only, and to Butterworth for all other modes. Pin8 OTF Pin9 XHD Pin18 X360 H H X 1M/outer track: Butterworth 1.00 L H X 1M/inner track: Butterworth 1.07 H L L 1.6M/outer track: Butterworth 1.88 L L L 1.6M/inner track: Chebyshev 1dB ripple 2.03 H L H 2M/outer track: Butterworth 1.88 L L H 2M/inner track: Chebyshev 1dB ripple 2.03 LPF characteristics fo ratio The formula for determining the peak frequency fO1 for 1M/outer track mode is shown below: fo1 = 534/RF + 6.2 [kHz] RF: filter setting resistance [kΩ] – 15 – CXA3031Q Comparator The comparator detects the crosspoint of the filter differential output. Time domain filter The time domain filter converts the comparator output to read data. This filter is equipped with two monostable multivibrators. 1st monostable multivibrator eliminates unnecessary pulses, and 2nd monostable multivibrator determines the pulse width of the read data. The 1st monostable multivibrator pulse width T1 is determined by the resistor RA between Pin 12 and A.GND. T1 can be switched as follows by the settings of Pins 9 and 18: When XHD = High and X360 = X T1(1M) = 88RA + 124 [ns] RA [kΩ] When XHD = Low and X360 = Low or XHD = Low and X360 = High T1(1.6M/2M) = 44RA + 62 [ns] The pulse width for 2nd monostable multivibrator is fixed at 400ns. (2) Write system Write data input through Pin 2 is frequency-divided by the T flip-flop and generates the recording current for the head. The recording current can be switched by the settings of Pins 9 and 18. The write current IW is set by the resistors RW connected between Pin 25 and VCC, between Pin 26 and VCC, and between Pin 27 and VCC. IW = 3.53/RW [mAO-P] RW [kΩ] Furthermore, the inner/outer track write current IW can be changed for each mode by switching Pin 4. However, the current ratio between the inner and outer tracks is fixed. (3) Erase current The erase current IE is set by the resistor RE between Pin 28 and VCC. IE = 11.8/RE [mA] RE [kΩ] Pins 30 and 31 are constant current outputs. In addition, in order to minimize the R/W head crosstalk time constants are provided for the rise and fall of the erase current. For details, refer to page 20 and page 21. (4) Power on/off detection system The power on/off detection system detects a reduced voltage in the supply voltage. When VCC is below the specified value, the write system and erase system cease operation, disabling the write and erase functions. Notes on Operation • Select the voltage gain so that the preamplifier output amplitude is 1Vp-p or less. If the preamplifier output amplitude exceeds 1Vp-p, the filter output waveform becomes distorted. • Observe the following point when mounting this device. • The ground should be as large as possible. – 16 – CXA3031Q 24 23 22 19 20 21 PREOUTB X360 PREOUTA XHG HEAD1B HEAD1A HEAD0A HEAD0B Application Circuit 18 17 WCLD 16 25 NC RWLD WCMD FILTER DIFF + LPF (BPF) 26 PREAMP RWMD WCHD 15 FILTER OUTA FILTER 27 14 RWHD IESET OUTB VCC A.GND 28 13 WRITE DRIVER RE COMP D.GND MMVA 29 12 RA ERA0 FCSET ERASE DRIVER 30 ERA1 11 RF CONTROL LOGIC POWER MONITOR 31 TIME DOMAIN FILTER VCC 10 XHD XPS 32 9 6 8 OTF 7 XS1 5 XEG XCI RD XWD POWER ON 4 3 XWG 2 1 Application circuits shown are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits or for any infringement of third party patent and other right due to same. Notes 1. If a resistor for setting the write current is not used, connect that pin to VCC. However, if connected to VCC, do not select that mode for writes, as doing so could cause a large current flow that could damage the IC. 2. When using two modes (1M and 2M), connect X360 (Pin 18) to VCC and set XHD (Pin 9) high or low to switch modes. – 17 – CXA3031Q Filter Frequency Response The LPF characteristics are set to Chebyshev (1dB ripple) for 1.6M, 2M/inner track mode only, and to Butterworth for the other modes. In addition, a custom selection can be made between Chebyshev (1dB ripple) and Butterworth for the filter characteristics for 1.6M, 2M/inner track mode only; in that case, it is not possible to change between 1.6M/inner track and 2M/inner track. As a result, the 1.6M and 2M characteristics and fc ratio are identical. B.P.F Q = 0.577 (Differential characteristics) fOB 1M/outer track, inner track 1.6M, 2M/outer track 1.6M, 2M/inner track L.P.F L.P.F Tertiary Butterworth Tertiary Chebyshev 1dBRp fcn (High-band noise cutoff) fc4 (n = 1, 2, 3) (Comprehensive characteristics) fo4 fon The BPF center frequency fOB is fixed at 1.2 times the LPF cutoff frequency. fOB = 1.2fc In the comprehensive characteristics, the relationship between the peak frequencies fo and fc is as follows, depending on the differences of the LPF type: Butterworth characteristics fcn = 1.28fon (n = 1, 2, 3) Chebyshev (1 dB ripple characteristics) fc4 = 1.12fo4 – 18 – CXA3031Q Custom Selection of Filters Regarding the LPF cutoff frequency fo, assuming the LPF cutoff frequency fC1 in 1M/outer track mode as 1.00, the fc ratio can be selected for the other three modes. In addition, the LPF characteristics are set to Chebyshev (1dB ripple) for 1.6M, 2M/inner track mode only, and to Butterworth for the other modes. However, a custom selection can be made between Chebyshev (1dB ripple) and Butterworth for the filter characteristics for 1.6M, 2M/inner track mode only. (However, the 1.6M and 2M characteristics and fc ratio are identical.) Note that the BPF center frequency fOB is fixed at 1.2 times fC. In addition, the ratio between fO and fC conforms with the relationship shown on the previous page. Mode LPF type 1M/outer track Butterworth 1.0 1M/inner track Butterworth 1.07 , 1.14 , 1.23 , 1.33 , 1.45 , 1.60 , 2.00 1.6M, 2M/outer track Butterworth 1.33 , 1.39 , 1.45 , 1.52 , 1.60 , 1.68 , 1.78 , 1.88 , 2.00 , 2.13 , 2.29 , 2.46 , 2.67 1.6M, 2M/inner track Butterworth Chebyshev (1dB ripple) 1.33 , 1.39 , 1.45 , 1.52 , 1.60 , 1.68 , 1.78 , 1.88 , 2.00 , 2.13 , 2.29 , 2.46 , 2.67 fc ratio when fC1 is assumed as 1 ∗ The boxed ratio indicates the setting for the CXA3031Q. Write Current Setting Method Assuming the outer track as 1.00, the write current ratio is fixed within the IC for each mode. The write current for the outer track is set in each mode by the resistors connected to Pins 25, 26, and 27. The current ratio for the inner track in each mode can be selected according to the following table. The setting is for the outer track current when XCI is Low, and for the inner track current when XCI is High. Write current inner track setting ratios Track Write current inner track setting ratio 1M mode 1.00 , 0.92 , 0.86 , 0.80 , 0.75 , 0.71 , 0.66 , 0.63 1.6M mode 1.00 , 0.92 , 0.86 , 0.80 , 0.75 , 0.71 , 0.66 , 0.63 2M mode 1.00 , 0.92 , 0.86 , 0.80 , 0.75 , 0.71 , 0.66 , 0.63 ∗ The boxed ratio indicates the setting for the CXA3031Q. The write current setting for the outer track is determined according to the following formula: IW = 3.53/RW (mAO-P) RW: [kΩ] – 19 – CXA3031Q Erase Current Setting Method The erase circuit in this IC generates the erase current by using a constant current circuit; the current value is determined according to the following formula, based on the resistor RE connected to Pin 28. IE = 11.8/RE [mA] RE: [kΩ] Erase Current Rise and Fall Times (Refer to Fig. 3) In this IC, time constants are provided for the erase current rise and fall in order to prevent bad writes due to write head crosstalk. The current rise and fall times of the constant current circuit in the IC is 1.3µs, but the potential difference VA that develops in the head when the erase current is turned on and off is as shown below. Because the circuit clamp is generated according to this VA value, the rise and fall times differ. Therefore, refer to the explanation provided below when using this IC. VA = L × di (L: head inductance; di: erase current; dt: 1.3µs) dt 1. When erase current turns on (1) When the potential difference VA in the head is (VCC – 1.8V) or more When the current turns on, potential difference VA is generated in the head; if VA is equal to (VCC – 1.8V) or more, the erase output transistor Q1 shown in the circuit in Fig. 3 becomes saturated, and the pin voltage is clamped at approximately 1.8V. Voltage driving results, and the rise time Tr is as follows: Tr = L × IE × 1 [µs] L: [µH], IE: [mA], VCC: [V] VCC – 1.8 1000 (2) When the potential difference VA in the head is (VCC – 1.8V) or less In this case, because VA does not reach clamping level, the rise time becomes the rise time of IE in the circuits within the IC. Current rise time Tr = 1.3µs – 20 – CXA3031Q 2. When erase current turns off (1) When the potential difference VA in the head is 0.7V or more When the current turns off, potential difference VA is generated in the head by counterelectromotive force; if VA is equal to approximately 0.7V or more, the positive protective diode D1 shown in the circuit in Fig. 3 turns on, and the pin voltage is clamped at approximately (VCC + 0.7V). As when the erase current is turned on, voltage driving results, and the fall time Tf is as follows: 1 Tf = L × IE × [µs] L: [µH], IE: [mA] 1000 0.7 (2) When the potential difference VA in the head is 0.7V or less In this case, because VA does not reach clamping level, the fall time becomes the fall time of IE in the circuits within the IC. Current fall time Tf = 1.3µs Circuits within IC Vcc IE D1 (positive protective diode) L For ERA1 30 ERA0 Q1 Q2 High = approx. 2.25V Low = 0V D2 (negative protective diode) IE (rise/fall time: 1.3µs) GND Fig. 3. Erase equivalent circuit However, in the specifications, because the value indicated is with the erase head pin shorted with the power supply so that the head voltage described earlier is not generated, the rise and fall times for the constant current circuit itself are given. – 21 – CXA3031Q Voltage gain 0 –2 –4 –6 0 Phase –8 45 –10 90 VCC = 5V, Ta = 25°C XHG = High, Low Phase [deg] Normalized preamplifier voltage gain [dB] Normalized preamplifier voltage gain and phase vs. Frequency 135 180 100k 1M 10M f – Frequncy [Hz] 1M/outer track 1M/inner track 180 Phase [deg] 0 –40 –60 –90 VCC = 5V, Ta = 25°C RF = 3.26kΩ 40k 100k 90 –20 0 –40 –60 –90 VCC = 5V, Ta = 25°C RF = 3.26kΩ –80 400k 1M 4M –180 10k f01 = 170 [kHz] Frequency [Hz] –60 –90 Normalized filter voltage gain [dB] 0 –40 Phase [deg] Normalized filter voltage gain [dB] 0 90 VCC = 5V, Ta = 25°C RF = 3.26kΩ 100k –180 Voltage gain 90 –20 Phase –40 1M 4M –180 –90 VCC = 5V, Ta = 25°C RF = 3.26kΩ 10k 40k 100k 400k f04 = 345 [kHz] Frequency [Hz] f03 = 320 [kHz] Frequency [Hz] – 22 – 0 –60 –80 400k 4M 180 –20 40k 1M 1.6M, 2M/inner track Voltage gain 10k 400k 180 Phase –80 100k f02 = 182 [kHz] Frequency [Hz] 1.6M, 2M/outer track 0 40k 1M 4M –180 Phase [deg] 10k Voltage gain Phase [deg] 90 –20 –80 Phase 0 Voltage gain Normalized filter voltage gain [dB] 0 Normalized filter voltage gain [dB] 180 Phase Normalized preamplifier voltage gain + filter voltage gain NGv vs. Ambient temperature Ta 1.50 1.00 11 VCC = 5V f = 100kHz NGV = GV/GV (Ta = 25°C) RF 3.26kΩ VCC 0.50 –20 0 20 40 60 80 Ta – Ambient temperature [°C] NGv – Normalized preamplifier voltage gain + filter voltage gain NGv – Normalized preamplifier voltage gain + filter voltage gain CXA3031Q Normalized preamplifier voltage gain + filter voltage gain NGv vs. Supply voltage Vcc 1.50 1.00 11 Ta = 25°C f = 100kHz NGV = GV/GV (VCC = 5V) 5.0 6.0 Vcc – Supply voltage [V] 1.05 Nf0 – Normalized filter peak frequency Nf0 – Normalized filter peak frequency 4.0 Normalized filter peak frequency Nf0 vs. Supply voltage Vcc 1.05 1.00 11 VCC = 5V Nf0 = f0/f0 (Ta = 25°C) RF 3.26kΩ 1.00 11 Ta = 25°C Nf0 = f0/f0 (VCC = 5V) VCC 0 20 40 60 RF 3.26kΩ VCC 0.95 80 4.0 5.0 6.0 Ta – Ambient temperature [°C] Vcc – Supply voltage [V] Normalized 1st monostable multivibrator pulse width NTA vs. Ambient temperature Ta Normalized 1st monostable multivibrator pulse width NTA vs. Supply voltage Vcc 1.05 1.00 12 VCC = 5V NTA = T1/T1 (Ta = 25°C) 0.95 –20 RA 27kΩ 0 20 40 60 Ta – Ambient temperature [°C] 80 NTA – Normalized 1st monostable multivibrator pulse width NTA – Normalized 1st monostable multivibrator pulse width 3.26kΩ VCC 0.50 Normarized filter peak frequency Nf0 vs. Ambient temperature Ta 0.95 –20 RF – 23 – 1.05 1.00 12 Ta = 25°C NTA = T1/T1 (VCC = 5V) 0.95 4.0 RA 5.0 Vcc – Supply voltage [V] 27kΩ 6.0 CXA3031Q Normalized read data pulse width NTB vs. Ambient temperature Ta Normalized read data pulse width NTB vs. Supply voltage Vcc 1.05 NTB – Normalized read data pulse width NTB – Normalized read data pulse width 1.05 1.00 VCC = 5V NTB = T2/T2 (Ta = 25°C) 0.95 –20 0 20 40 60 5.0 Normalized write current NIw vs. Ambient temperature Ta Normalized write current NIw vs. Supply voltage Vcc 1.05 1.00 25 26 27 RW1 RW2 RW3 VCC = 5V NIW = IW/IW (Ta = 25°C) 1.3 1.3 1.3 kΩ kΩ kΩ VCC VCC VCC 0 20 40 60 Ta – Ambient temperature [°C] 1.00 Ta = 25°C NIW = IW/IW (VCC = 5V) 0.95 80 4.0 25 26 27 RW1 RW2 RW3 1.3 1.3 1.3 kΩ kΩ kΩ VCC VCC VCC 5.0 6.0 Vcc – Supply voltage [V] Normalized erase current NIE vs. Supply voltage Vcc 1.05 NIE – Normalized erase current 1.05 1.00 28 VCC = 5V NIE = IE/IE (Ta = 25°C) RE 1.3kΩ 1.00 28 Ta = 25°C NIE = IE/IE (VCC = 5V) 0 20 40 60 RE 1.3kΩ VCC VCC 0.95 –20 6.0 Vcc – Supply voltage [V] Normalized erase current NIE vs. Ambient temperature Ta NIE – Normalized erase current 4.0 Ta – Ambient temperature [°C] NIw – Normalized write current NIw – Normalized write current Ta = 25°C NTB = T2/T2 (VCC = 5V) 0.95 80 1.05 0.95 –20 1.00 0.95 80 Ta – Ambient temperature [°C] 4.0 5.0 Vcc – Supply voltage [V] – 24 – 6.0 CXA3031Q 11 250 VCC = 5V Ta = 25°C f01 = 534/RF + 6.2 RF VCC 200 150 2.0 3.0 1st monostable multivibrator pulse width TA vs. RA TA – 1st monostable multivibrator pulse width [µs] 1M/outer track peak frequency f01 [kHz] 1M/outer track peak frequency f01 vs. RF 10.0 12 5.0 VCC = 5V Ta = 25°C T1 1M = 88RA + 124 T1 2M = 44RA + 62 RA [kΩ] RA T1 1M 1.0 T1 2M 0.5 0.3 4.0 3 5 10 RF [kΩ] RA [kΩ] Write current IW vs. RW Erase current IE vs. RE 50 IE – Erase current [mA] IW – Write current [mA] 50 10 VCC = 5V Ta = 25°C IW = 3.53/RW RW [kΩ] 5 25 26 27 RW1 RW2 RW3 10 5 27 1 VCC = 5V Ta = 25°C IE = 11.8/RE RE [kΩ] RE 1 0.5 VCC VCC VCC 0.1 0.5 VCC 1 5 0.5 10 RW [kΩ] VTH – Power supply on/off detector threshold voltage [V] 50 RE [kΩ] Power supply on/off detector threshold voltage VTH vs. Ambient temperature Ta 4.1 4.0 3.9 3.8 3.7 3.6 –20 0 20 40 60 Ta – Ambient temperature [°C] 5 1 80 – 25 – 10 100 CXA3031Q Package Outline Unit: mm 32PIN QFP (PLASTIC) 9.0 ± 0.2 24 0.1 + 0.35 1.5 – 0.15 + 0.3 7.0 – 0.1 17 16 32 9 (8.0) 25 1 + 0.2 0.1 – 0.1 0.8 + 0.15 0.3 – 0.1 0.24 M + 0.1 0.127 – 0.05 0° to 10° PACKAGE MATERIAL EPOXY RESIN SOLDER PLATING SONY CODE QFP-32P-L01 LEAD TREATMENT EIAJ CODE QFP032-P-0707 LEAD MATERIAL 42 ALLOY PACKAGE MASS 0.2g JEDEC CODE – 26 – 0.50 8