SONY CXA3188N

CXA3188N
2ch. Read/Write Amplifier for Thin Film Head of Hard Disk Drive
For the availability of this product, please contact the sales office.
Description
The CXA3188N is a Read/Write Amplifier for the
thin film head of hard disk drive and designed to
handle up to 2 channel heads.
Features
• Operate on single +5 V power supply
• Low power consumption
Read : 90 mW
Write : 115 mW + IW × 5
Idle
: 8 mW
• Designed for two terminal thin-film or MIG heads.
• Read amplifier emitter follower output featuring
200 times gain(typ).
• Differential input capacitance for Read : 6pF (typ)
• Input noise : 0.47 nV / √ Hz (typ)
• Write current range : 10 to 20 mA
• 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.
• Read data outputs are high impedance in write
mode.
• Unselected head voltage is high impedance.
• Self switching damping resistor 380 Ω.
• Built-in supply voltage monitor circuit prohibits
incorrect write during power on or abnormal
voltage.
16 pin SSOP (Plastic)
Absolute Maximum Ratings (Ta=25 °C)
• Supply voltage
VCC
6
V
• Operating temperature Topr
–20 to +70
°C
• Storage temperature
Tstg –55 to +150 °C
• Allowable power dissipation (on board)
PD
760
mW
• Write current
IW
22
mA
• WUS/SE pin input current
ISEH
15
mA
Operating Conditions
Supply voltage
VCC
5±0.5
V
Function
Read, Write and Write unsafe detection for HDD,
power supply ON/OFF detection.
Structure
Bipolar silicon monolithic IC
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—
E98128-TE
CXA3188N
Block Diagram and Pin Configuration
GND
16 XCS
1
MODE
CONTROL
H0X
2
H0Y
3
H1X
4
DRIVER
WRITE
CURRENT
SOURCE
AMP
15
R/W
14
WC
13 RDY
DRIVER
AMP
H1Y
VCC
5
AMP
12 RDX
HEAD
SELECT
6
11
HS
POWER
ON/OFF
DETECTOR
NC
10 WDX
7
WD BUF
WUS/SE
8
WRITE
UNSAFE
DETECTOR
9
—2—
WDY
CXA3188N
Pin Description
No.
Symbol
1
GND
Description
Equivalent circuit
VCC
2
3
4
5
H0X
H0Y
H1X
H1Y
2
2k
2k
4
Head.
2 channels provided.
3
5
100k
GND
6
7
VCC
NC
5 V power supply.
VCC
8
Write unsafe detection output /
Servo Enable signal input.
8
WUS/SE
GND
VCC
9
10
WDY
WDX
9
Differential P-ECL write data
input.
10
GND
—3—
CXA3188N
No.
Symbol
Description
Equivalent circuit
VCC
11
HS
Head select signal input.
At “Low” : Head0
at “High” : Head1
11
2.1V
180k
GND
VCC
12
13
12
RDY
RDX
Read amplifier output.
13
GND
VCC
14
A setting resistor for the write
current value is connected
between this pin and GND.
WC
14
2.5V
GND
VCC
Read/Write signal input.
At “High” : Read
at “Low” : Write
180k
15
R/W
15
2.1V
GND
VCC
16
XCS
Power save signal input
At “High” : Power saving.
16
2.1V
100k
GND
—4—
CXA3188N
Electrical Characteristics
Item
(Unless otherwise specified, VCC=5 V, Ta=25 °C, Write current IW=20 mA)
Symbol
Current consumption for read
ICCR
Current consumption for write
ICCW
Current consumption for idle
ICCI
Digital input
“Low” input voltage
Digital input
“High” input voltage
Digital input
“Low” input current
Digital input
“High” input current
Write data input current
Test condition
IW=20 mA
Min.
Typ.
Max.
Unit.
11
18
25
mA
14
+IW
23
33
+IW
+IW
1.1
1.6
2.1
mA
0.8
V
VIL
VIH
IIL
IIH
“H” applied voltage: 5 V
“L” applied voltage: 0 V
mA
2.0
V
–100
µA
IWD
100
µA
50
µA
Write data input voltage range
VWDV
VCC–2.5
VCC
V
WD input amplitude
VWDA
0.3
1
V
VTH
3.4
4.3
V
IW
10
20
mAo-p
Write current voltage
VWC
2.25
2.5
2.75
V
Write current gain
AW
IW=AW • VWC/RWC
18
20
22
mA/mA
Write current setting constant
KW
When write current is “Iw[mA]”,
IW=KW/RWC. (RWC=3.3 kΩ)
46
51
56
Power supply ON/OFF detector
threshold voltage
Write current setting range
Write unsafe output
leak current
Write unsafe output
Low voltage
IWUS
3.9
50
µA
0.5
V
VWUSL
Output current: 1 mA
WUS/SE input current
ISEH
Servo write Enabled
5
14
mA
WUS/SE High input voltage
VSEH
Servo write Enabled
VCC
+1.5
VCC
+1.6
V
—5—
CXA3188N
Item
Read amplifier differential
voltage gain
Symbol
AV
BW1
Frequency band width
BW 2
Input referred noise voltage
EN
Common mode rejection ratio
CMRR
Supply voltage rejection ratio
PSRR
Channel Separation
Read data output offset voltage
for Read
RDX, RDY common mode output
voltage difference between modes
RDX, RDY common mode output
voltage for Read
CS
Test condition
Input voltage:1 mVp-p,300 kHz
load resistor: (RDX, RDY) 1 kΩ
Frequency at which Av lower
by 1dB
Frequency at which Av lower
by 3dB
Typ.
Max.
Unit.
170
200
230
V/V
35
60
MHz
75
120
MHz
Head impedance: 0 Ω
Common input voltage:
100 mVp-p, 20 MHz
Ripple voltage:
100 mVp-p, 20 MHz
Selected head input voltage:
0 mVp-p
Unselected head input voltage:
100 mVp-p, 20 MHz
VOFF
Vdiff
Min.
CRD=0.1 µ
0.47
—6—
nV
√ Hz
50
dB
50
dB
50
dB
–300
300
mV
–300
300
mV
VCC
–2.3
VRD
0.65
V
CXA3188N
Unless otherwise specified, VCC=5 V, Ta=25 °C, fWD (Write data frequency) =5 MHz, IW=15 mA, LH (Head
inductance) =1 µH, RH (Head DC resistance value) =30 Ω
Item
Head differential
voltage amplitude
Mode switching time
Read to Write
Symbol
Measurement conditions
VSW
Differential voltage between HX pin and HY pin
at switching of Write current
Typ.
Max.
9
Unit.
Vp-p
TRW is the time required for Write current to turn
TRW
TWR1
Mode switching time
Write to Read
TWR2
Mode switching time
Power saving
to Read
TIR
Mode switching time
safe to unsafe
TSA1
Mode switching time
unsafe to safe
TSA2
Head switching time
TH
Write current
propagation delay
time
TPD
Write current
rise/fall time
Min.
TR/TF
to 90 % after Pin 15 changes from “High” to
“Low”.
TWR1 is the time required for the Read amplifier
output∗ to turn to 90 % after Pin 15 changes
from “Low” to “High”.
TWR2 is the time required for Write current to
decreases to 10 % after Pin 15 changes from
“Low” to “High”.
TIR is the time required for the Read amplifier
output∗ to turn to 90 % after Pin 16 changes
from “High” to “Low”.
TSA1 is the time required for Pin 8 to turn “High”
after the last transition of Write data when Write
data is stopped in Write mode.
TSA2 is the time required for Pin 8 to turn “Low”
after the first transition of Write data in Write
mode.
TH is the time required for the Read amplifier
output∗ to reach 90 % when the selected head
switched in Read mode.
1.0
0.13
0.3
µs
0.2
0.3
µs
0.1
0.3
µs
1
µs
3.0
µs
0.6
µs
0.6
µs
2.3
TPD is the time required for Write current to
reach 90 % after the Write data falling edge.
2
7
ns
TR is the time required for Write current to reach
90 % from 10 %; TF is the same time required
to reach 10 % from 90 %. LH=0 µH, RH=0 Ω
1
3
ns
∗Read amplifier output 100 mVp-p 10 MHz
—7—
CXA3188N
Test Circuit 1
V
1k
1k
1µ
1µ
V
V
×100
LPF
to 15MHz
AMP
×1
PG
AMP
V
5V PG
a b
a b c
a b
a b
A
A
16
15
14
13
1
2
3
4
3V
a b
PG
4V
a b c a b c
A
A
A
12
11
10
9
5
6
7
8
2.7k
A
a b a b
a b a b
V
a
a b c d e
5.1k
a b c d e
A
b
0.1µ
a
6V
b
33
0.1µ
A
VCC
5V
0.1µ
1µ
Fig. 1
Test Circuit 2
1k
1k
1µ
1µ
×1
AMP
PG
PG
16
15
14
13
1
2
3
4
PG
PG
PG
12
11
10
9
5
6
7
8
RWC
2.7k
5.1k
LH
1µH
LH
1µH
Fig. 2
—8—
5V
1µ
VCC
5V
CXA3188N
Timing Chart 1
WDX
WDY
R/W
50%
50%
50%
PS
TRW
TWR 2
90%
90%
IWX
IWY
10%
10%
TWR1
TIR
90%
RDX
RDY
90%
Fig. 3
Timing Chart 2
WDX
WDY
TPD
IWX
IWY
90%
90%
10%
10%
TR
WUS
90%
TF
50%
TSA1
50%
TSA2
Fig. 4
—9—
CXA3188N
Description of 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, the X side of the head input and RDX pin and
the Y side of the head inputs and RDY pin have the same polarity.
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.
CS
R/W
WUS/SE
L
L
X
L
H
X
L
L
∗∗
H
X
X
Table 1. Mode selection
Mode
Write
Read
Servo Write
Power Save
Servo write mode ∗∗
This mode allows for writing to multiple channels at once. In this mode the write driver will drive all channels
simultaneously.
To enable servo write mode follow these steps:
(1) Place the device in the Read mode.
(2) Set WUS/SE to VSEH volts, or input ISEH to WUS/SE.
(3) Initiate the write operation by setting R/W Low.
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 input 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 VCC to detect erroneous Writes. The error status is established when VCC falls below the
threshold voltage (VTH) of the power supply ON/OFF detector, in which case the recording and playback
functions are prohibited. When VCC rises above, VTH, the prohibition of these functions is released.
—10—
CXA3188N
Application Circuit
RWC
2.7k
1µ
1µ
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
5.1k
LH
LH
1µ
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.
—11—
CXA3188N
Notes on operation
• This device handles high frequency and high gain signals. Please note the following;
♦ Connect VCC decoupling capacitor of approximately 1000 pF near the device.
♦ Make the GND area as large as possible.
• The WC pin is a constant voltage pin. When noise affects this pin, it creates noise in Write current.
Therefore, locate RWC as close to the device as possible.
• Write unsafe detection circuit
This circuit uses the voltage waveforms of the head pins for detection.
Wave form of write data
Voltage waveform
of head pins (HX, HY)
VFB
VTH=1.4V
VTH
GND
♦ VFB must be more than 2 V. When VFB < 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.
—12—
CXA3188N
Application Notes
Use the following characteristics for reference
VCC=5 V, Ta=25 °C
Item
Symbol
Differential output capacitance
Differential output resistance
Differential input capacitance
Read mode Differential input resistance
Output resistance
Unselected head differential current at write
mode
CO
RD
CI
RI
RRD
Write current symmetry
TASY
Write mode
Condition
Between head input pins
Between head input pins
f=5MHz
RDX or RDY, f=5MHz
LH=2 µH, RH=30 Ω
IW=15 mA
LH=0 µH, RH=0 Ω
IW=15 mA
IUS
Min. Typ. Max.
Unit
4.5
380
6
1.2
45
pF
Ω
pF
kΩ
Ω
250
0.4
6
490
10
60
0.2 mAp-p
–0.5
0.5
∗TAS=T1–T2
IWX+IWY
50%
T1
50%
50%
T2
Setting of Write current
Write current can be set with resistor RWC (kΩ) at Pin 14.
IW=K/RWC (mA) Refer to Fig. 5.
Write current setting constant
vs. Write current
Write current setting constant kw
Write current vs. RWC
Write current IW (mA)
20
10
5
2
5
10
VCC=5V
Ta=25°C
55
52.5
50
47.5
45
10m
20
15m
Write current IW (mA)
RWC (kΩ)
Fig. 5
Fig. 6
—13—
20m
ns
CXA3188N
Normalized read amplifier voltage gain
vs. Supply voltage
Ta=25°C
1.04
1.02
1
0.98
0.96
1.02
1
0.98
0.96
4.0
4.5
5.0
5.5
6.0
–25
0
25
50
Supply voltage VCC (V)
Ambient temperature Ta (°C)
Normalized write current
vs. Supply voltage
Normalized write current
vs. Ambient temperature
Ta=25°C
RWC=24k Ω
1.04
1.02
1
0.98
0.96
75
VCC=5V
RWC=2.4k Ω
1.02
IW/IW (Ta=25°C)
IW/IW (VCC=5V)
VCC=5V
1.04
AV/AV (Ta=25°C)
AV/AV (Ta=25°C)
Normalized read amplifier voltage gain
vs. Ambient temperature
1
0.98
4.0
4.5
5.0
5.5
6.0
–25
Supply voltage VCC (V)
0
25
50
Ambient temperature Ta (°C)
—14—
75
CXA3188N
Input referred noise voltage
vs. Supply voltage
Input referred noise voltage
vs. Ambient temperature
VCC=5V
Ta=25°C
0.55
EN (VCC=5V) (mV/ Hz)
EN (Ta=25°C) (mV/ Hz)
0.49
0.47
0.45
0.45
0.4
4.0
4.5
5.0
5.5
6.0
–25
Supply voltage VCC (V)
4.0
OFF → ON
3.9
ON → OFF
3.8
–25
0
25
50
0
25
50
Ambient temperature Ta (°C)
Power supply ON/OFF detector threshold
voltage vs. Ambient temperature
Power supply ON/OFF detector
Threshold Voltage (V)
0.5
75
Ambient temperature Ta (°C)
—15—
75
CXA3188N
Package Outline
Unit : mm
16PIN SSOP (PLASTIC)
+ 0.2
1.25 – 0.1
∗5.0 ± 0.1
0.1
16
9
1
6.4 ± 0.2
∗4.4 ± 0.1
A
8
+ 0.05
0.15 – 0.02
0.65
+ 0.1
0.22 – 0.05
0.13 M
0.5 ± 0.2
0.1 ± 0.1
0° to 10°
DETAIL A
NOTE: Dimension “∗” does not include mold protrusion.
PACKAGE STRUCTURE
PACKAGE MATERIAL
EPOXY RESIN
SONY CODE
SSOP-16P-L01
LEAD TREATMENT
SOLDER / PALLADIUM
PLATING
EIAJ CODE
SSOP016-P-0044
LEAD MATERIAL
42/COPPER ALLOY
PACKAGE MASS
0.1g
JEDEC CODE
NOTE : PALLADIUM PLATING
This product uses S-PdPPF (Sony Spec.-Palladium Pre-Plated Lead Frame).
—16—