Page 1
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CXA3031Q
E95318-ST
Read/Write Amplifier (with Built-in Filters) for FDDs
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
Applications
Three-mode FDDs
Structure
Bipolar silicon monolithic IC
Absolute Maximum Ratings (Ta = 25°C)
• Supply voltage VCC 7.0 V
• 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.
32 pin QFP (Plastic)
For the availability of this product, please contact the sales office.
Page 2
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CXA3031Q
Block Diagram and Pin Configuration
XHD
FILTER
MMVA
FCSET
A.GND
HEAD0A
HEAD0B
HEAD1B
HEAD1A
PREOUTA
XWD
RD
XWG
XEG
XS1
XCI
FILTER
OUTA
OUTB
XPS
ERA1
ERA0
D.GND
POWER ON
WCLD
WCMD
IESET
XHG
PREOUTB
VCC
NC
OTF
X360
WCHD
WRITE
DRIVER
ERASE
DRIVER
POWER
MONITOR
CONTROL
LOGIC
COMP
TIME
DOMAIN
FILTER
PREAMP
FILTER
DIFF + LPF
(BPF)
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
1
Page 3
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CXA3031Q
Pin Description
Pin
No.
Symbol
Pin
voltage
Equivalent circuit Description
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.
VCC
A.GND
100k
1
2 XWD —
Write data input.
This pin is a Schmitt-type input that is
triggered when the logical voltage goes from
High to Low.
VCC
1k
A.GND
2.3V
2
3 RD —
4 XCI —
5 XWG —
6 XEG —
7 XS1 —
8 OTF —
9 XHD —
Read data output.
This pin is active when the logical voltage of
the write gate signal and the erase gate
signal is High.
Write current control. The write current
increases when the logical voltage is Low.
Write gate signal input. The write system
becomes active when the logical voltage is
Low.
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.
Filter inner track/outer track mode control.
Inner track mode is selected when the
logical voltage is Low.
Filter, time domain filter and write current
1M/2M mode control. 2M mode is selected
when the logical voltage is Low.
140
V
CC
D.GND
3
VCC
100k
1k
A.GND
2.1V
4
5
6
7
8
9
Page 4
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CXA3031Q
Pin
No.
Symbol
Pin
voltage
Equivalent circuit Description
18 X360 —
Filter, time domain filter and write current
1M/1.6M mode control. 1.6M mode is
selected when the logical voltage is Low.
18
20
VCC
100k
1k
A.GND
2.1V
VCC
A.GND
1.2V
11
1k
147
147
VCC
A.GND
1.2V
12
140
V
CC
A.GND
300µ
140
300µ
14
15
140
V
CC
A.GND
200µ
140
200µ
17
19
20 XHG
—
Preamplifier voltage gain selection. Gain is
boosted by 6dB when the logical voltage is
Low compared to when the logical voltage is
High.
10 VCC
—
Power supply (5V) connection.
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.
12 MMVA
0.5V
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.
13 A.GND
—
Analog system GND connection.
14
FILTER
OUTB
3.4V
15
FILTER
OUTA
3.4V
17
PRE
OUTB
3.4V
Filter differential outputs.
19
PRE
OUTA
3.4V
Preamplifier differential outputs.
16 (NC) Not connected.
Page 5
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CXA3031Q
Pin
No.
Symbol
Pin
voltage
Equivalent circuit Description
21 HEAD 1B —
22 HEAD 1A —
23 HEAD 0B —
24 HEAD 0A —
25 WCLD
26 WCMD
27 WCHD
5V
when
XWG
= High
3.8V
when
XWG
= Low
28 IESET
29 D.GND
—
30 ERA0
—
31 ERA1
—
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.
1M write current setting resistor connection.
Connect the write current setting resistor
RWLD between this pin and VCC to set the
write current.
1.6M write current setting resistor connection.
Connect the write current setting resistor
RWMD between this pin and VCC to set the
write current.
2M write current setting resistor connection.
Connect the write current setting resistor
RWHD 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.
Digital system GND connection.
Erase current connection for the HEAD0
system.
Erase current connection for the HEAD1
system.
A.GND
21
22
23
24
VCC
A.GND
1.2V
147
147
147
25
26
27
VCC
A.GND
1.2V
147
28
VCC
A.GND
30
31
5V
when
XEG
= High
3.8V
when
XEG
= Low
Page 6
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CXA3031Q
Pin
No.
Symbol
Pin
voltage
Equivalent circuit Description
32 XPS
—
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.
VCC
162k
1k
A.GND
2.1V
32
Page 7
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CXA3031Q
Electrical Characteristics
Current Consumption (Ta = 25°C, VCC = 5V)
Item Symbol Conditions Min. Typ. Max. Unit
Current consumption
in read mode
Current consumption
in write/erase mode
Current consumption
in power saving mode
ICCR
ICCWE
ICCPS
XWG = High
XWG = Low,
XEG = Low
XPS = Low
—
—
—
—
—
—
16
7
—
26
13
0.95
36
19
1.9
mA
mA
mA
Power Supply Monitoring System (Ta = 25°C)
Item Symbol Conditions Min. Typ. Max. Unit
Power supply on/off
detector threshold
voltage
Power on output
saturation voltage
VTH
VSP
VCC = 3.5V
I = 1mA
—
—
—
—
3.5—3.9—4.3
0.5
V
V
Read System (Ta = 25°C, VCC = 5V)
Item Symbol Conditions
Measure-
ment circuit
Measure-
ment Point
Min. Typ. Max. Unit
Preamplifier voltage gain
Low gain/outer track
Preamplifier voltage gain
Low gain/inner track
Preamplifier voltage gain
High gain/outer track
Preamplifier voltage gain
High gain/inner track
Preamplifier
frequency response
Preamplifier input
conversion noise
voltage
Preamplifier
differential output
offset voltage
Filter differential
output offset voltage
Filter differential
output voltage
amplitude
GVLO
GVLI
GVHO
GVHI
BW
EN
VOFSP
VOFSF
VOF
f = 100kHz
OTF = High, XHG = High
f = 100kHz
OTF = Low, XHG = High
f = 100kHz
OTF = High, XHG = Low
f = 100kHz
OTF = Low, XHG = Low
GV/GV (100kHz) = –3dB
Band Width
= 400Hz to 1MHz, VI = 0
VI = 0
VI = 0
1
1
1
1
1
1
1
1
1
D, E
D, E
D, E
D, E
D, E
D, E
D, E
B, C
B, C
37.1
40.1
43.1
46.1
5
—
–500
–100
2.8
39.0
42.0
45.0
48.0
—
2.0
—
—
—
40.6
43.6
46.6
49.6
—
2.9
+500
+100
—
dB
dB
dB
dB
MHz
nV/√ Hz
mV
mV
Vp-p
Measure-
ment circuit
Measure-
ment Point
Measure-
ment circuit
Measure-
ment Point
Page 8
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CXA3031Q
Read System (Ta = 25°C, VCC = 5V)
Time domain filter
monostable
multivibrator pulse
width
Read data pulse width
Read data output low
output voltage
Read data output
high output voltage
Read data output
∗1
rise time
Read data output
∗1
fall time
Peak shift
∗2
T1
T2
VOL
VOH
tr
tf
PS
X360 = X, XHD = High
(1M mode)
X360 = Low, XHD = Low
(1.6M mode)
or
X360 = High, XHD = Low
(2M mode) Refer to Fig. 1
Refer to Fig. 1
IOL = 2mA
IOH = –0.4mA
RL = 2kΩ
CL = 20pF
RL = 2kΩ
CL = 20pF
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
1
1
1
1
1
1
1
A, F
A, F
A
A
A
A
A
A
2.25
1.13
260
—
2.8
—
—
—
2.5
1.25
400
—
—
—
—
—
2.75
1.38
540
0.5
—
100
100
1
µs
µs
ns
V
V
ns
ns
%
∗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
Item Symbol Conditions Min. Typ. Max. Unit
Measure-
ment circuit
Measure-
ment Point
Page 9
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CXA3031Q
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:
ETM1 = ( – 1) × 100 [%]
When X360 = Low and XHD = Low, or X360 = High and XHD = Low:
ETM1' = ( – 1) × 100 [%]
• 1st monostable multivibrator pulse width = T2
• Peak shift
PS = × 100 [%]
T1
2.5µs
12TA – TB
TA + TB
T1
1.25µs
External
Comparator Output
(Measurement point F)
T1 T2
TA TB
1.4V
Read data output
(Measurement point A)
Page 10
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CXA3031Q
Read System (Filters) (Ta = 25°C, VCC = 5V)
Peak frequency
Peak voltage
gain
∗3
Frequency
response (1)
Frequency
response (2)
Peak frequency
Peak voltage
gain
∗3
Frequency
response (1)
Frequency
response (2)
Peak frequency
Peak voltage
gain
∗3
Frequency
response (1)
Frequency
response (2)
fo1
Gp1
G11
G12
fo2
Gp2
G21
G22
fo3
Gp3
G31
G32
1M
outer
track
1M
inner
track
1.6M/
2M
outer
track
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
1
1
1
1
1
1
1
1
1
1
1
1
B, C
D, E
B, C
B, C
B, C
B, C
D, E
B, C
B, C
B, C
B, C
D, E
B, C
B, C
B, C
153.0
4.3
–7.6
–24.7
163.8
4.3
–7.6
–24.7
288.0
4.4
–7.6
–25.0
170.0
6.2
–7.1
–22.8
182.0
6.2
–7.1
–22.8
320.0
6.3
–7.1
–23.1
187.0
7.8
–6.6
–21.2
200.2
7.8
–6.6
–21.2
352.0
7.9
–6.6
–21.5
kHz
dB
dB
dB
kHz
dB
dB
dB
kHz
dB
dB
dB
Item Symbol Conditions Min. Typ. Max. Unit
Measure-
ment circuit
Measure-
ment Point
Page 11
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CXA3031Q
Peak frequency
Peak voltage
gain
∗3
Frequency
response (1)
Frequency
response (2)
fo4
Gp4
G41
G42
1.6M/
2M
inner
track
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
1
1
1
B, C
D, E
B, C
B, C
B, C
310.5
5.9
–8.5
–36.9
345.0
7.8
–8.0
–35.0
379.5
9.4
–7.5
–33.4
kHz
dB
dB
dB
∗3
Gpn = 20 log10 (VFilterout/Vpreout)
VFilterout = Filter differential output voltage
(n = 1 to 4)
Gn1
Gn2
f [Hz]
3fonfon1/3fon
[dB]
Gpn
(n = 1 to 4)
Fig. 2. Filter frequency response measurement conditions
Item Symbol Conditions Min. Typ. Max. Unit
Measure-
ment circuit
Measure-
ment Point
Page 12
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CXA3031Q
Write/Erase System (Ta = 25°C, VCC = 5V)
Write current output
precision
∗4
Write current output
unbalance
Head I/O pin leak
current for writes
Write head pin
current at saturation
Erase current output
precision
∗5
Erase current output
pin leak current
Erase current rise
time
∗6
Erase current fall
time
∗6
EW
DW
ILKW
ISW
EE
ILKE
TRE
TFE
XWG = Low
RW = 1.3kΩ
XWG = Low
RW = 1.3kΩ
XWG = Low
XWG = Low
RW = 1.3kΩ
VSW = 1V
SW1 = b
XEG = Low
RE = 1.3kΩ
XEG = Low
Defined at 10% to 90%
of IE
Defined at 90% to 10%
of IE
2
2
2
2
2
2
2
2
J, K
L, M
J, K
L, M
J, K
L, M
J, K
L, M
N, O
N, O
N', O'
N', O'
–7
–1
—
2.47
–10
—
0.6
0.6
—
—
—
2.70
—
—
1.3
1.3
+7
+1
10
2.97
+10
10
2.1
2.1
%
%
µA
mAo-p
%
µA
µs
µs
∗4
Write current output precision EW = ( – 1) × 100 [%]
∗5
Erase current output precision EE = ( – 1) × 100 [%]
∗6
Erase current rise/fall times show the values when the output pin is shorted with the power supply.
IW
2.72mAo-p
IE
9.08mA
Logic Input Block (Ta = 25°C, VCC = 5V)
Digital signal input
low input voltage
Digital signal input
high input voltage
Schmitt-type digital
signal input low input
voltage
Schmitt-type digital
signal input high
input voltage
Digital signal input
low input current
Digital signal input
high input current
VLD
VHD
VLSD
VHSD
ILD
IHD
VL = 0V
VH = 5V
2
2
2
2
2
2
BCDE
FGHIP
BCDE
FGHIP
A
A
ABCDE
FGHIP
ABCDE
FGHIP
—
2.0
—
2.0
–20
—
—
—
—
—
—
—
0.8
—
0.8
—
—
10
V
V
V
V
µA
µA
Item Symbol Conditions Min. Typ. Max. Unit
Measure-
ment circuit
Measure-
ment Point
Item Symbol Conditions Min. Typ. Max. Unit
Measure-
ment circuit
Measure-
ment Point
Page 13
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CXA3031Q
Electrical Characteristics Measurement Circuit 1
XHD
FILTER
MMVA
FCSET
A.GND
HEAD0A
HEAD0B
HEAD1B
HEAD1A
PREOUTA
XWD
RD
XWG
XEG
XS1
XCI
FILTER
OUTA
OUTB
XPS
ERA1
ERA0
D.GND
POWER ON
WCLD
WCMD
IESET
XHG
PREOUTB
VCC
NC
OTF
X360
WCHD
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
1
CXA3031Q
1.3k
1.3k
1.3k
1.3k
SW1 SW2
a b a b
SW3
a
b
5V
3.26k
27k
SW4
ab
SW5
ab
ba
–1/2V
i1/2Vi
ba
SW6
A
C
B
E
D
12k
3300p
3300p
F
∗7
External
Comparator
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.
Page 14
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CXA3031Q
Electrical Characteristics Measurement Circuit 2
XHD
FILTER
MMVA
FCSET
A.GND
HEAD0A
HEAD0B
HEAD1B
HEAD1A
PREOUTA
XWD
RD
XWG
XEG
XS1
XCI
FILTER
OUTA
OUTB
XPS
ERA1
ERA0
D.GND
POWER ON
WCLD
WCMD
IESET
XHG
PREOUTB
VCC
NC
OTF
X360
WCHD
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
1
CXA3031Q
1.3k
1.3k
1.3k
1.3k
5V
3.26k
27k
SW1
a
b
VSW
b
a
SW2
A
G
I
H
B C D E F
P
M
M'
b
a
L
L'
b
a
K
K'
b
a
J
J'
a
b
a
b
SW3
200
200
N
N'
O
O'
Note) Unless otherwise specified, switches are assumed to be set to "a".
Page 15
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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
BPF
LPF HPF
Preamplifier output A
Preamplifier output
Filter output A
Filter output B
Secondary
f
OB = 1.2 × fC
Q = 0.577
Tertiary
fc: variable
Primary
fCH = 5kHz
Gain: 8dB
Preamplifier output B
Amp
19
17
15
14
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
LPF characteristics
fo ratio
H
L
H
L
H
L
H
H
L
L
L
L
X
X
L
L
H
H
1M/outer track: Butterworth
1M/inner track: Butterworth
1.6M/outer track: Butterworth
1.6M/inner track: Chebyshev 1dB ripple
2M/outer track: Butterworth
2M/inner track: Chebyshev 1dB ripple
1.00
1.07
1.88
2.03
1.88
2.03
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]
Page 16
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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.
Page 17
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CXA3031Q
Application Circuit
XHD
FILTER
MMVA
FCSET
A.GND
HEAD0A
HEAD0B
HEAD1B
HEAD1A
PREOUTA
FILTER
OUTA
OUTB
XPS
ERA1
ERA0
D.GND
WCLD
WCMD
IESET
XHG
PREOUTB
VCC
NC
XWD
RD
XWG
XEG
XS1
XCI
POWER ON
OTF
X360
WCHD
WRITE
DRIVER
ERASE
DRIVER
POWER
MONITOR
CONTROL
LOGIC
COMP
TIME
DOMAIN
FILTER
PREAMP
FILTER
DIFF + LPF
(BPF)
2
3
4
5
6
7
8
9
10
11
12
13
14
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
1
15
VCC
RA
RF
RWLD
RWMD
RWHD
RE
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.
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.
Page 18
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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.
fon
(Differential characteristics)
f
OB
B.P.F
Q = 0.577
fcn
(Comprehensive characteristics)
(High-band noise cutoff)
L.P.F
Tertiary Butterworth
L.P.F
Tertiary Chebyshev
1dBRp
(n = 1, 2, 3)
fc
4
fo4
1M/outer track, inner track
1.6M, 2M/outer track
1.6M, 2M/inner track
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
Page 19
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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.
1.0
1.07 , 1.14 , 1.23 , 1.33 , 1.45 , 1.60 , 2.00
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
1.33 , 1.39 , 1.45 , 1.52 , 1.60 , 1.68 , 1.78 ,
1.88 , 2.00 , 2.13 , 2.29 , 2.46 , 2.67
Butterworth
Butterworth
Butterworth
Butterworth
Chebyshev (1dB ripple)
1M/outer track
1M/inner track
1.6M, 2M/outer track
1.6M, 2M/inner track
Mode LPF type
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
1.00 , 0.92 , 0.86 , 0.80 , 0.75 , 0.71 , 0.66 , 0.63
1.00 , 0.92 , 0.86 , 0.80 , 0.75 , 0.71 , 0.66 , 0.63
1.00 , 0.92 , 0.86 , 0.80 , 0.75 , 0.71 , 0.66 , 0.63
1M mode
1.6M mode
2M mode
Track
Write current inner track setting ratio
∗
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]
Page 20
– 20 –
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 × (L: head inductance; di: erase current; dt: 1.3µs)
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 = × [µs] L: [µH], IE: [mA], VCC: [V]
(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
di
dt
1
1000
L × IE
VCC – 1.8
Page 21
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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:
Tf = × [µs] L: [µH], IE: [mA]
(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
1
1000
L × IE
0.7
Vcc
GND
D1 (positive protective diode)
Q1
Q2
I
E (rise/fall time: 1.3µs)
ERA0
Circuits within IC
For ERA1
D2
(negative protective diode)
IE
High = approx. 2.25V
Low = 0V
L
30
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.
Page 22
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CXA3031Q
Frequency [Hz]
Normalized preamplifier voltage gain and phase vs. Frequency
f – Frequncy [Hz]
100k 10M1M
Normalized preamplifier voltage gain [dB]
–10
0
–8
–6
–4
–2
Phase [deg]
180
135
90
45
0
VCC = 5V, Ta = 25°C
XHG = High, Low
Voltage gain
Phase
1M/outer track
10k 4M1M
Normalized filter voltage gain [dB]
0
–80
–60
–40
–20
40k 100k 400k
f
01 = 170 [kHz]
Phase [deg]
180
90
0
–90
–180
Voltage gain
Phase
1M/inner track
10k 4M1M
Normalized filter voltage gain [dB]
0
–80
–60
–40
–20
40k 100k 400k
Phase [deg]
180
90
0
–90
–180
Frequency [Hz]
f02 = 182 [kHz]
1.6M, 2M/outer track
10k 4M1M
Normalized filter voltage gain [dB]
0
–80
–60
–40
–20
40k 100k 400k
Phase [deg]
180
90
0
–90
–180
Frequency [Hz]
f
03 = 320 [kHz]
Voltage gain
Phase
1.6M, 2M/inner track
10k 4M1M
Normalized filter voltage gain [dB]
0
–80
–60
–40
–20
40k 100k 400k
Phase [deg]
180
90
0
–90
–180
Frequency [Hz]
f
04 = 345 [kHz]
Voltage
gain
Phase
Voltage gain
Phase
VCC = 5V, Ta = 25°C
RF = 3.26kΩ
VCC = 5V, Ta = 25°C
RF = 3.26kΩ
V
CC = 5V, Ta = 25°C
RF = 3.26kΩ
VCC = 5V, Ta = 25°C
RF = 3.26kΩ
Page 23
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CXA3031Q
Normalized preamplifier voltage gain + filter
voltage gain NGv vs. Ambient temperature Ta
Ta – Ambient temperature [°C]
–20 0 20 40 60 80
0.50
1.00
1.50
NGv – Normalized preamplifier voltage gain + filter voltage gain
VCC = 5V
f = 100kHz
NGV = GV/GV (Ta = 25°C)
VCC
RF 3.26kΩ
11
Normarized filter peak frequency Nf0 vs.
Ambient temperature Ta
Ta – Ambient temperature [°C]
0 20 40 60 80
0.95
1.00
1.05
Nf
0
– Normalized filter peak frequency
VCC = 5V
Nf0 = f0/f0 (Ta = 25°C)
VCC
RF 3.26kΩ
11
Vcc – Supply voltage [V]
4.0 5.0 6.0
0.95
1.00
1.05
VCC
RF 3.26kΩ
11
Normalized filter peak frequency Nf0 vs.
Supply voltage Vcc
Nf
0
– Normalized filter peak frequency
Ta = 25°C
Nf0 = f0/f0 (VCC = 5V)
Normalized 1st monostable multivibrator pulse
width NTA vs. Ambient temperature Ta
Ta – Ambient temperature [°C]
0.95
1.00
1.05
NTA – Normalized 1st monostable multivibrator pulse width
VCC = 5V
NTA = T1/T1 (Ta = 25°C)
RA 27kΩ
12
Vcc – Supply voltage [V]
4.0 5.0 6.0
0.95
1.00
1.05
Normalized 1st monostable multivibrator
pulse width NTA vs. Supply voltage Vcc
NTA – Normalized 1st monostable multivibrator pulse width
Ta = 25°C
NTA = T1/T1 (VCC = 5V)
RA 27kΩ
12
Normalized preamplifier voltage gain + filter
voltage gain NGv vs. Supply voltage Vcc
Vcc – Supply voltage [V]
4.0 5.0 6.0
0.50
1.00
1.50
Ta = 25°C
f = 100kHz
NGV = GV/GV (VCC = 5V)
VCC
RF 3.26kΩ
11
–20
0 20 40 60 80–20
NGv – Normalized preamplifier voltage gain + filter voltage gain
Page 24
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CXA3031Q
Normalized read data pulse width NTB vs.
Ambient temperature Ta
Ta – Ambient temperature [°C]
0.95
1.00
1.05
NTB – Normalized read data pulse width
VCC = 5V
NTB = T2/T2 (Ta = 25°C)
Vcc – Supply voltage [V]
4.0 5.0 6.0
0.95
1.00
1.05
Normalized read data pulse width NTB vs.
Supply voltage Vcc
NTB – Normalized read data pulse width
Ta = 25°C
NTB = T2/T2 (VCC = 5V)
Normalized write current NIw vs.
Ambient temperature Ta
Ta – Ambient temperature [°C]
0.95
1.00
1.05
NIw – Normalized write current
VCC
1.3
kΩ
25
VCC
RW2
1.3
kΩ
26
VCC
RW3
1.3
kΩ
27
Vcc – Supply voltage [V]
4.0 5.0 6.0
0.95
1.00
1.05
Normalized write current NIw vs.
Supply voltage Vcc
NIw – Normalized write current
Ta = 25°C
NIW = IW/IW (VCC = 5V)
VCC
RW1
1.3
kΩ
25
VCC
RW2
1.3
kΩ
26
VCC
RW3
1.3
kΩ
27
Ta – Ambient temperature [°C]
0.95
1.00
1.05
VCC = 5V
NIE = IE/IE (Ta = 25°C)
Normalized erase current NIE vs.
Ambient temperature Ta
NI
E
– Normalized erase current
1.3kΩ
28
VCC
RE
Vcc – Supply voltage [V]
4.0 5.0 6.0
0.95
1.00
1.05
Normalized erase current NIE vs.
Supply voltage Vcc
NI
E
– Normalized erase current
Ta = 25°C
NIE = IE/IE (VCC = 5V)
1.3kΩ
28
VCC
RE
0 20 40 60 80–20
0 20 40 60 80–20
0 20 40 60 80–20
VCC = 5V
NIW = IW/IW (Ta = 25°C)
R
W2RW1
Page 25
– 25 –
CXA3031Q
1M/outer track peak frequency f01 vs. RF
RF [kΩ]
2.0 3.0 4.0
150
200
250
1M/outer track peak frequency f
01
[kHz]
RF
11
VCC
VCC = 5V
Ta = 25°C
f01 = 534/RF + 6.2
Ta – Ambient temperature [°C]
–20
0 20 40 60 80
3.6
4.1
Power supply on/off detector threshold
voltage VTH vs. Ambient temperature Ta
V
TH
– Power supply on/off detector threshold voltage [V]
3.8
4.0
3.7
3.9
3 10
0.3
1.0
10.0
1st monostable multivibrator pulse width TA vs. RA
RA [kΩ]
T
A
– 1st monostable multivibrator pulse width [µs]
5 10050
0.5
RA
12
VCC = 5V
Ta = 25°C
T1 1M
T1 2M
5.0
0.5 1
1
5
50
Erase current IE vs. RE
RE [kΩ]
I
E
– Erase current [mA]
RE
27
VCC
10
5 10
VCC = 5V
Ta = 25°C
VCC
RW1
25
VCC
RW2
26
VCC
RW3
27
0.1 1
0.5
5
50
Write current IW vs. RW
RW [kΩ]
I
W
– Write current [mA]
0.5 105
1
10
VCC = 5V
Ta = 25°C
T1 1M = 88RA + 124
T1 2M = 44RA + 62
RA [kΩ]
IE = 11.8/RE
RE [kΩ]
IW = 3.53/RW
RW [kΩ]
Page 26
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CXA3031Q
Package Outline Unit: mm
SONY CODE
EIAJ CODE
JEDEC CODE
PACKAGE MATERIAL
LEAD TREATMENT
LEAD MATERIAL
PACKAGE MASS
EPOXY RESIN
SOLDER PLATING
42 ALLOY
32PIN QFP (PLASTIC)
9.0 ± 0.2
7.0 – 0.1
1.5 – 0.15
(8.0)
0.1 – 0.1
+ 0.2
+ 0.35
+ 0.3
0.50
0.127 – 0.05
+ 0.1
0° to 10°
0.8
0.3 – 0.1
+ 0.15
1
8
9
32
16
1724
25
M
0.24
0.2g
QFP-32P-L01
QFP032-P-0707
0.1
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