--1--
E97305A7X-TE
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.
4ch. Read/Write Amplifier for three terminal MIG Head of Hard Disk Drive
24 pin SSOP (Plastic)
CXA3171N
Description
The CXA3171N is a Read/Write Amplifier for the
special three terminal MIG head of hard disk drive
and designed to handle up to 4 channel heads.
Features
Operate on single +5 V power supply
Low power consumption
Read : 95 mW
Write : 115 mW + I
W
5
Designed for special three terminal MIG heads
Read amplifier emitter follower output featuring
420 times gain (typ).
Differential input capacitance for Read : 6.7 pF (typ)
Input noise : 0.46nV /
Hz (typ)
Differential Head voltage swing : 9 Vp-p (typ)
Differential P-ECL write data input
Built-in write unsafe detection circuit.
Built-in Servo write function (2/4 ch).
Built-in IC protection circuit for short of head and
GND.
Read data outputs are high impedance in write
mode.
Built-in supply voltage monitor circuit prohibits
incorrect write during power on or abnormal
voltage.
Self switching damping resistance (R
D
=420
).
Function
Read, Write and Write unsafe detection for HDD,
power supply ON/OFF detection.
Structure
Bipolar silicon monolithic IC
Absolute Maximum Ratings (Ta=25 C)
Supply voltage
V
CC
6
V
Write current
I
W
23
mAo-p
Operating temperature
Topr
20 to +75
C
Storage temperature
Tstg
55 to +150
C
Allowable power dissipation
P
D
800
mW
WUS/SE pin input current
I
SEH
15
mA
Recommended Operating Conditions
Supply voltage
V
CC
5.0 V10
%
Write current
I
W
10 to 22 mAo-p
For the availability of this product, please contact the sales office.
--2--
CXA3171N
H0X
H0C
H0Y
H1X
H1C
H1Y
H2X
H2C
H2Y
H3X
H3C
H3Y
WRITE
CURRENT
SOURCE
MODE
CONTROL
AMP
HEAD
SELECT
WRITE
UNSAFE
DETECTOR
POWER
ON/OFF
DETECTOR
IC
PROTECTOR
GND
R/W
WC
RDY
RDX
HS0
HS1
NC
WDX
WDY
WUS/SE
V
CC
DRIVER
AMP
DRIVER
AMP
AMP
AMP
DRIVER
DRIVER
1
2
3
4
5
6
7
8
9
10
11
12
13
21
22
24
23
20
17
18
19
16
15
14
--3--
CXA3171N
Pin Description
No.
24
1
2
3
4
5
6
7
8
9
10
11
12
14
15
16
13
17
Symbol
GND
H0X
H0C
H0Y
H1X
H1C
H1Y
H2X
H2C
H2Y
H3X
H3C
H3Y
WUS/SE
WDY
WDX
V
CC
NC
Equivalent circuit
1
3
5
7
9
11
2
4
6
8
10
12
2k
2k
V
CC
GND
Description
Head.
4 channels provided.
Write unsafe detection output /
Servo Enable signal input.
Differential P-ECL write data
input.
5 V power supply.
14
V
CC
GND
16
V
CC
GND
15
--4--
CXA3171N
No.
18
19
23
20
21
22
Symbol
HS1
HS0
R/W
RDX
RDY
WC
Equivalent circuit
V
CC
GND
18
19
R
2.1V
HS0:R=78K, HS1:R=100K
V
CC
GND
180k
2.1V
23
V
CC
GND
21
20
2V
V
CC
GND
22
Description
Head select signal input.
Selects one of 4 heads according
to Table 2.
Read/Write signal input
At "High" : Read,
at "Low" : Write.
Read Amplifier output.
A setting resistor for the write
current value is connected
between this pin and GND.
--5--
CXA3171N
Electrical Characteristics
(Unless otherwise specified, V
CC
=5 V, Ta=25
C, Write current I
W
=20 mA)
No.
1-1
1-2
2-1
2-2
2-3
2-4
2-5
2-6
2-7
3-1
3-2
4
Item
Current consumption
for Read
Current consumption
for Write
Digital input "Low"
input voltage
Digital input "High"
input voltage
Digital input "Low"
input current
Digital input "High"
input current
Write data input
"Low" input voltage
Write data input
"Hig
h
" input voltage
Write data
input current
Write unsafe output
saturation voltage
Write unsafe output
leak current
Supply power
ON/OFF detector
threshold voltage
Symbol
I
R
I
WR
V
IL
V
IH
I
IL
I
IH
V
WDL
V
WDH
I
WD
V
WUS
I
WUS
V
TH
SW conditions
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
a
a
a
a
a
a
a
a
e
b
a
a
b
a
a
b
b
b
b
b
b
a
a
a
a
e
b
a
a
b
a
a
b
a
a
a
a
a
a
a
a
a
e
b
a
a
b
a
a
b
a
a
a
a
a
a
a
a
a
e
b
a
a
b
b
b
b
b
b
b
b
b
a
a
a
a
e
b
a
a
b
a
a
a
a
b
b
b
b
b
a
a
a
b
b
a
c
c
a
a
b
a
b
b
b
b
a
a
a
a
e
b
a
a
b
a
a
b
a
b
b
b
b
b
a
a
a
a
b
a
a
b
a
a
b
a
Measurement conditions
Test point : l
2
Test point : l
2
Digital input :
Pins 18, 19, 23
"High" applied voltage : 5 V
"Low" applied voltage : 0 V
Test point : l
6
, l
7
, l
8
, I
9
Input voltage : 4 V
Output current : 1 mA
Test point : V
1
Test point : l
3
When V
CC
is lowered from 5 V in
Write mode and I
W
does not flow
anymore, V
CC
voltage is set to
V
THOFF
. When V
CC
is raised from
3 V and I
W
starts to flow, V
CC
voltage is set to V
THON
.
Min.
Typ.
Max.
Unit
12
19
28
mA
17
23
36
mA
+I
W
+I
W
+I
W
0.8
V
2.0
V
100
A
100
A
V
WDH
V
WDH
V
2.0
0.25
V
CC
V
CC
V
1.1
0.4
50
A
0.5
V
50
A
3.4
3.9
4.3
V
--6--
CXA3171N
No.
5-1
5-2
5-3
5-4
6-1
6-2
7
8
9
Item
Write current
setting range
Write current voltage
Write current gain
Write current
setting constant
WUS/SE voltage
WUS/SE sink current
Read amplifier
differential voltage
gain
Frequency band
width (3 dB)
Input referred noise
Symbol
I
W
V
WC
A
W
K
W
V
SEH
I
SEH
A
V
BW
E
N
SW conditions
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
b
b
b
b
a
a
a
a
e
b
a
a
b
a
a
a
a
b
b
b
b
b
a
a
a
a
b
a
a
b
a
a
b
a
b
b
b
b
b
a
a
a
a
b
b
a
a
a
a
b
a
b
b
b
b
b
a
a
a
a
b
b
a
a
a
a
b
a
a
a
a
a
b
a
a
a
c
b
a
a
b
a
a
b
b
a
a
a
a
b
a
a
a
c
b
a
a
b
a
a
b
b
a
a
a
a
a
a
a
a
e
b
a
a
b
a
a
b
b
Measurement conditions
I
W
=A
W
V
WC
/R
WC
I
W
=K
W
/R
WC
Servo write enabled
Servo write enabled
Input voltage SG1 :
1 mVp-p, 300 kHz
Load resistance (RDX, RDY) :
1 k
Test point : V4 [Vp-p]
AV
=
V4
SG1
Frequency at which A
V
lowers
by 3 dB
Head impedance : 0
,
when the read amplifier output
voltage is amplified 100 times
and voltage passed though a
LPF (low pass filter of cutoff
frequency 15 MHz) is V
N
[Vrms],
EN
=
V
N
100 AV
15
10
6
Test point : V
5
Min.
Typ.
Max.
Unit
10
22
mA
o-p
2.25
2.5
2.75
V
18
20
22
mA/mA
45
50
55
V
CC
V
CC
V
+1.5
+1.6
5
14
mA
355
420
485
V/V
100
140
MHz
nV
0.46
0.65
Hz
--7--
CXA3171N
No.
10
11
12
13
Item
Common mode
rejection ration
Power supply
rejection ratio
Channel
separation
Read data output
offset voltage for Read
Symbol
CMRR
PSRR
CS
V
OFFR
SW conditions
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
a
a
a
a
b
a
a
a
d
b
a
a
b
a
a
b
b
a
a
a
a
a
a
a
a
e
a
a
a
b
a
a
b
b
a
a
a
a
a
b
a
a
c
b
a
a
b
a
a
b
b
a
a
a
a
a
a
a
a
e
b
a
a
b
a
a
a
b
Measurement conditions
In-phase input voltage
SG2 : 100 mVp-p, 20 MHz
When the Read amplifier output
is V
CM
[mVp-p],
100
CMRR
=
20 log
V
CM
+20 log
A
V
Test point : V
4
Ripple voltage SG3 :
100 mVp-p, 20 MHz
When the Read amplifier output
is V
P
[mVp-p],
100
PSRR
=
20 log
V
P
+20 log
A
V
Test point : V
4
Selected head input voltage
: 0 mVp-p
Unselected head input voltage
SG1 : 100 mVp-p, 20 MHz
When the Read amplifier output
is V
CS
[mVp-p],
100
CS
=
20 log
V
CS
+20 log
A
V
Test point : V
4
V
OFFR
= V
2
V
3
Test point : V
2
, V
3
Min.
Typ.
Max.
Unit
50
dB
50
dB
50
dB
300
300
mV
--8--
CXA3171N
No.
14
15
Item
RDX, RDY common
mode output voltage
difference between
modes
RDX, RDY common
mode output voltage
for Read
Symbol
Vdiff
V
RD
SW conditions
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
a
a
a
a
a
a
a
a
e
b
a
a
b
a
a
a
c
a
a
a
a
a
a
a
a
e
b
a
a
b
a
a
a
b
Measurement conditions
Test point : Pin 20, 21
Test Point : V
2
, V
3
Min.
Typ.
Max.
Unit
300
300
mV
V
CC
V
CC
V
CC
V
2.6
2.3
2.0
--9--
CXA3171N
Unless otherwise specified, V
CC
=5 V, Ta=25 C, f
WD
(Write data frequency) =5 MHz, I
W
=20 mA, L
H
(Head
inductance) =1 H, R
H
(Head DC resistance value) =12
Refer to Fig. 2 to Fig. 4
No.
14
15-1
15-2
16-1
16-2
17
18
19
Item
Head differential
voltage amplitude
Mode switching time
Read to Write
Mode switching time
Write to Read
Mode switching time
safe to unsafe
Mode switching time
unsafe to safe
Head switching time
Write current
propagation delay
time
Write current
rise/fall time
Measurement conditions
Differential voltage between HX pin and HY pin
at switching of Write current
T
RW
is the time required for Write current to turn
to 90 % after Pin 23 changes from "High" to
"Low".
T
WR1
is the time required for the Read amplifier
output
to turn to 90 % after Pin 23 changes
from "Low" to "High".
T
WR2
is the time required for Write current to
decreases to 10 % after Pin 23 changes from
"Low" to "High".
T
SA1
is the time required for Pin 14 to turn
"High" after the last transition of Write data
when Write data is stopped in Write mode.
T
SA2
is the time required for Pin 14 to turn "Low"
after the first transition of Write data in Write
mode.
T
H
is the time required for the Read amplifier
output
to reach 90 % when the selected head
switched in Read mode.
T
PD
is the time required for Write current to
reach 90 % after the Write data falling edge.
L
H
=0 H, R
H
=0
T
R
is the time required for Write current to reach
90 % from 10 %; T
F
is the same time required
to reach 10 % from 90 %. L
H
=0 H, R
H
=0
Symbol
V
SW
T
RW
T
WR1
T
WR2
T
SA1
T
SA2
T
H
T
PD
T
R
/T
F
Min. Typ. Max. Unit
9
Vp-p
130 150
ns
180 220
ns
100 200
ns
1.0
2.3
3
s
0.6
s
0.6
s
2
7
ns
1
3
ns
Read amplifier output 100 mVp-p 10 MHz
--10--
CXA3171N
Test Circuit 1
A
2.7k
I8
a
b
A
I7
a b
A
I6
a b
A
I5
a b
A
I4
A
I3
a
b
a
a
b
b
S15
S14
S13
S12
S11
c
a bc
13
24
23
22
19
20
21
14
15
16
17
18
V4
5V
V3
V2
1
1
V
100
1
AMP
AMP
V5
V
LPF
to15MHz
3V
PG
SG5
SG4
PG
4V
1
5.1k
a b
V
CC
5V
SG3
V
CC
5V
A
I2
6V
V
V1
S10
a b
a b
a b
a b
S9
a
b c d
e
A
I1
33
SG1
0.1
0.1
0.1
a b c
d e
SG2
S16
S17
V
V
S5
a b
a b
a
b
a b
2
3
4
5
6
7
8
9
10
11
12
1
S6
a
b
a
b
a
b
a b
S7
S8
S1
S2
S3
S4
c
PG
SG6
Test Circuit 2
2.7k
1
1
AMP
1
L
H
1H
PG
1
PG
PG
PG
13
24
23
22
19
20
21
14
15
16
17
18
5V
1k
1k
5.1k
L
H
1H
L
H
1H
L
H
1H
2
3
4
5
6
7
8
9
10
11
12
1
Fig. 1
Fig. 2
--11--
CXA3171N
Timing Chart 1
50%
50%
T
RW
T
WR
2
10%
10%
T
WR
1
90%
WDX
WDY
I
WX
I
WY
RDX
RDY
90%
90%
R/W
Fig. 3
Fig. 4
Timing Chart 2
T
PD
90%
90%
90%
10%
10%
T
R
T
F
50%
T
SA2
T
SA1
50%
WDX
WDY
I
WX
I
WY
WUS
--12--
CXA3171N
Description Functions
Read amplifier
This is a low noise amplifier for amplifying the signals from the heads with an emitter follower output.
The RDX and RDY are the outputs of the differential amplifier whose polarity between the RDX and X side of
the head input is same.
Write circuit
The Write data input to WDX pin and WDY pin passes through the buffer amp. It drives the Write switch
circuit which supplies the Write current to the heads.
The Write current flows into the X side when WDX is "Low" and WDY is "High".
Mode control
The mode are set as shown Table 1 by R/W and WUS/SE.
Table 1. Mode selection
Head selection
The heads are selected as shown in Table 2 by the HS0, HS1 and HS2 pins.
Table 2. Head selection
Servo write mode
This mode allows for writing to multiple channels at once.
To enable servo write mode follow these steps:
(1) Place the device in the Read mode.
(2) Set HS0 and HS1 following Table 3.
(3) Set WUS/SE to V
SEH
, or input I
SEH
to WUS/SE.
(4) While maintaing step (2) and (3) above make R/W low, placing the device in servo write mode.
R/W
L
H
L
WUS/SE
X
X
HS0
HS1
See Table 2
See Table 3
Mode
Write
Read
Servo Write
HS0
L
H
L
H
HS1
L
L
H
H
Head
0
1
2
3
--13--
CXA3171N
Write unsafe detection circuit
This circuit detects write errors.
In normal Write mode, the WUS output is low; in the conditions listed below, it is high.
Head inputs is open (under the condition which. RH=
and Write data frequency is
10 MHz)
Head input is shorted to GND or VCC.
Write data frequency is abnormally low.
No write current.
In read mode.
Supply voltage is abnormal (see power supply ON/OFF detection).
Power supply ON/OFF detection
This circuit monitors V
CC
to detect erroneous Writes. The error status is established when V
CC
falls below the
threshold voltage (V
TH
) of the power supply ON/OFF detector, in which case the recording and playback
functions are prohibited. When V
CC
rises above V
TH
, the prohibition of these functions is released.
Table 3. Head selection in Servo Write mode
HS0
L
H
L
H
HS1
L
L
H
H
Head
0, 1
0, 1, 2, 3
2, 3
0, 1, 2, 3
--14--
CXA3171N
Application Circuit
2.7k
1
5.1k
R
WC
+5V
13
24
23
22
19
20
21
14
15
16
17
18
L
H
1H
L
H
1H
L
H
1H
L
H
1H
2
3
4
5
6
7
8
9
10
11
12
1
1
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.
--15--
CXA3171N
Notes on operation
This device handles high frequency and high gain signals. Please note the following;
Connect V
CC
decoupling capacitor of approximately 1000 pF near the device.
Make the GND area as large as possible.
When using as 2-channel, short-circuit the X and Y sides of unused head pins or leave them open.
The WC pin is a constant voltage pin. When noise affects this pin, it creates noise in Write c current.
Therefore, locate R
WC
as close to the device as possible.
Write unsafe detection circuit
This circuit uses the voltage waveforms of the head pins for detection.
VFB must be more than 2 V. When V
FB
< 2 V, it is possible that Write unsafe detection maximum
frequency becomes more than 1 MHz.
The normal operating area of write unsafe detection circuit is changed by head inductance, head DC
resistance, write current and other.
V
TH
GND
Voltage waveform
of head pins (HX, HY)
V
TH
=1.4V
V
FB
Wave form of write data
--16--
CXA3171N
Application Notes
Use the following characteristics for reference.
V
CC
=5V, Ta=25 C
Item
Write mode
Differential output capacitance
Differential output resistance
Differential input capacitance
Read mode
Differential input resistance
Output resistance
Unselected head differential current in Write
mode
Write current symmetry
Symbol
C
O
R
O
C
I
R
I
R
RD
I
US
T
AS
Conditions
Between head input pins
Between head input pins
f=5 MHz
RDX or RDY, f=5 MHz
L
H
=1 H, R
H
=12
I
W
=20 mA
L
H
=0 H, R
H
=0
I
W
=20 mA
Min. Typ. Max.
Unit
4.5
6
pF
300
420
545
6.7
10
pF
520 1200 2400
50
0.2 mAp-p
0.5
0.5
ns
Fig.5 Write current vs. R
WC
I
W
-
W
r
i
t
e
c
u
r
r
e
n
t
(
m
A
)
5
10
2
5
10
20
R
WC
(k
)
TAS=T
1
T
2
Setting of Write current
Write current can be set with resistor R
WC
(k
) at Pin 22.
I
W
=K/R
WC
(mA) Refer to Fig. 5.
I
WX
+I
WY
50%
50%
50%
T
1
T
2
22
WC
R
WC
--17--
CXA3171N
Normalized write current
vs. Supply voltage
1.04
1.02
1
0.98
0.96
I
W
/
I
W
(
V
C
C
=
5
V
)
4
5
6
Supply voltage V
CC
[V]
Ta=25C
R
WC
=3.3k
1.04
1.02
1
0.98
0.96
I
W
/
I
W
(
T
a
=
2
5
C
)
25
25
75
Ambient temperature Ta [C]
V
CC
=5V
R
WC
=3.3k
0
50
1.04
1.02
1
0.98
0.96
A
V
/
A
V
(
V
C
C
=
5
V
)
4
5
6
Supply voltage V
CC
[V]
1.04
1.02
1
0.98
0.96
A
V
/
A
V
(
T
a
=
2
5
C
)
25
25
75
Ambient temperature Ta [C]
0
50
4
3.6
P
o
w
e
r
s
u
p
p
l
y
O
N
/
O
F
F
D
e
t
e
c
t
o
r
T
h
r
e
s
h
o
l
d
V
o
l
t
a
g
e
[
V
]
25
25
75
Ambient temperature Ta [C]
Normalized write current
vs. Ambient temperature
Normalized read amplifier voltage tgain
vs. Supply voltage
Normalized read amplifier voltage gain
vs. Ambient temperature
Power supply ON/OFF detector threshold
voltage vs. Ambient temperature
0
50
3.8
4.2
OFF ON
ON OFF
V
CC
=5V
Ta=25C
SONY CODE
EIAJ CODE
JEDEC CODE
SSOP-24P-L01
SSOP024-P-0056
PACKAGE MATERIAL
LEAD TREATMENT
LEAD MATERIAL
PACKAGE MASS
EPOXY RESIN
SOLDER/PALLADIUM
42/COPPER ALLOY
PACKAGE STRUCTURE
PLATING
0.1g
24PIN SSOP(PLASTIC)
5
.
6
0
.
1
24
7.8 0.1
13
0.65
12
1
0.22 0.05
+ 0.1
0.15 0.02
+ 0.05
7
.
6
0
.
2
0.1
1.25 0.1
+ 0.2
A
0.1 0.1
0 to 10
0
.
5
0
.
2
DETAIL A
NOTE: Dimensions "
" does not include mold protrusion.
0.13 M
Package Outline Unit : mm
CXA3171N
--18--
NOTE : PALLADIUM PLATING
This product uses S-PdPPF (Sony Spec.-Palladium Pre-Plated Lead Frame).
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