Datasheet CXA3170AN Datasheet (Sony)

—1—

E97640

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.

6ch. Read/Write Amplifier for
Thin Film Head of Hard Disk Drive

24 pin SSOP (Plastic)

CXA3170AN

Description

The CXA3170AN is a Read/Write Amplifier for the
thin film head of hard disk drive and designed to
handle up to 6 channel heads.

Features

• Operate on single +5 V power supply

• Low power consumption

Read : 85 mW
Write : 115 mW + IW ×5

• Designed for two terminal thin-film or MIG heads

• Read amplifier emitter follower output featuring

360 times gain (typ).

• Differential input capacitance for Read : 6 pF (typ)

• Input noise : 0.47 nV / √ Hz (typ)

• Write current range : 5 to 15 mA

• Differential Head voltage swing : 9 Vp-p (typ)

• IW Rise / Fall times : 3.7 ns (typ)

(LH=540 nH, RH=25 Ω, IW=10 mA)

• Differential P-ECL write data input

• Built-in write unsafe detection circuit.

• Built-in Servo write function (3/6 ch).

• Built-in IC protection circuit for short of head and

GND.

• Read data outputs are high impedance in write

mode.

• Unselected head voltage is GND potential.

• Built-in supply voltage monitor circuit prohibits

incorrect write during power on or abnormal

voltage.

• Self switching damping resistance (RD = 360 Ω).

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 VCC 6V

•Write current IW 20 mAo-p

• Operating temperature Topr –20 to +75 °C

• Storage temperature Tstg –55 to +150 °C

• Allowable power dissipation

PD 800 mW

• WUS/SE pin input current
ISEH 15 mA

Recommended Operating Conditions

• Supply voltage VCC 5.0 V±10 %

• Write current IW 5 to 15 mAo-p

For the availability of this product, please contact the sales office.

—2—

CXA3170AN

DRIVER

AMP

DRIVER

AMP

AMP

DRIVER

AMP

DRIVER

DRIVER

AMP

DRIVER

AMP

1

2

3

4

5

6

7

8

9

10

11

12

H0X

H0Y

H1X

H1Y

H2X

H2Y

H3X

H3Y

H4X

H4Y

H5X

H5Y

GND

R/W

WC

RDY

RDX

HS0

HS1

HS2

WDX

WDY

WUS/SE

V

CC

WRITE

CURRENT

SOURCE

MODE

CONTROL

AMP

HEAD

SELECT

WRITE

UNSAFE

DETECTOR

13

21

22

24

23

20

17

18

19

16

15

14

POWER
ON/OFF

DETECTOR

IC

PROTECTOR

—3—

CXA3170AN

Pin Description

No.

24

1
2
3
4
5
6
7
8

9
10
11
12

14

15
16

13

Symbol

GND

H0X
H0Y
H1X
H1Y
H2X
H2Y
H3X
H3Y
H4X
H4Y
H5X
H5Y

WUS/SE

WDY
WDX

VCC

Equivalent circuit

1
3

5
7

9

11

2
4

6
8

10
12

2k 2k

VCC

GND

100K

Description

Head.
6 channels provided.

Write unsafe detection output /
Servo Enable signal input.

Differential P-ECL write data
input.

5 V power supply.

14

VCC

GND

16

VCC

GND

15

—4—

CXA3170AN

No.

17
18
19

23

20
21

22

Symbol

HS2
HS1
HS0

R/W

RDX
RDY

WC

Equivalent circuit

VCC

GND

17
18

19

100k

2.1V

VCC

GND

100k

2.1V

23

VCC

GND

21

20

VCC

GND

22

2.5V

Description

Head select signal input.
Selects one of 6 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—

CXA3170AN

Electrical Characteristics (Unless otherwise specified, VCC=5 V, Ta=25 °C, Write current IW=15 mA)

No.

1-1

1-2

2-1

2-2

2-3

2-4

2-5

2-6

2-7

2-8

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

“High” input voltage

Write data

input current

Unselected

head voltage

Write unsafe output

saturation voltage

Write unsafe output

leak current

Supply power

ON/OFF detector

threshold voltage

Symbol

I

R

IWR

VIL

VIH

IIL

IIH

VWDL

VWDH

IWD

Vunsel

VWUS

IWUS

VTH

SW conditions

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

a a a a a a e b a a b a a a b b

a a a a a a e b a a b a a a b a

a a a a a a e b a a b a a a b a

a a a a a a e b a a b b b b b b

a a a a a a e b a a b a a a a a

b a a a a a b b a c c a a a b a

a a a a a a e b a a b a a a b a

b a a a a a a b a a b a a a b a

Measurement conditions

Test point : l

2

Test point : l2

Digital input :

Pins 17, 18, 19, 23

“High” applied voltage : 5 V

“Low” applied voltage : 0 V

Test point : l6, l7, l8, I9

Input voltage : 4 V

Output current : 1 mA

Test point : V1

Test point : l

3

When VCC is lowered from 5 V in

Write mode and IW does not flow

anymore, VCC voltage is set to

VTHOFF. When VCC is raised from

3 V and IW starts to flow, VCC

voltage is set to VTHON.

Min. Typ. Max. Unit

11 17 26 mA

16 22 36

mA

+IW +IW +IW

0.8 V

2.0 V

–100 µA

100 µA

VWDH VWDH

V

–2.0 –0.25

VCC VCC

V

–1.1 –0.4

50 µA

0.3 V

0.5 V

50 µA

3.4 3.9 4.3 V

—6—

CXA3170AN

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

VWC

AW

KW

VSEH

ISEH

AV

BW

EN

SW conditions

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

a a a a a a e b a a b a a a a a

b a a a a a a b a a b a a a b a

b a a a a a a b b a a a a a b a

b a a a a a a b b a a a a a b a

b a a a a a c b a a b a a a b b

b a a a a a c b a a b a a a b b

a a a a a a e b a a b a a a b b

Measurement conditions

I

W=AW • VWC/RWC

IW=KW/RWC

Servo write enabled

Servo write enabled

Input voltage SG1 :

1 mVp-p, 300 kHz

Load resistance (RDX, RDY) :

1 kΩ

Test point : V4 [Vp-p]

AV =

V4

SG1

Frequency at which AV lowers

by 3 dB

Head impedance : 0 Ω,

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 VN [Vrms],

EN =

VN

100 • AV√ 15 × 10

6

Test point : V5

Min. Typ. Max. Unit

5 15 mAo-p

2.25 2.5 2.75 V

18 20 22

mA/mA

45 50 55

VCC VCC V

+1.5 +1.6

5 14 mA

305 360 415 V/V

100 140 MHz

nV

0.47 0.6

√ Hz

—7—

CXA3170AN

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

b a a a a a d b a a b a a a b b

a a a a a a e a a a b a a a b b

a b a a a a c b a a b a a a b b

a a a a a a e b a a b a 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

VCM

+20 log AV

Test point : V4

Ripple voltage SG3 :

100 mVp-p, 20 MHz

When the Read amplifier output

is VP [mVp-p],

100

PSRR = 20 log

VP

+20 log AV

Test point : V4

Selected head input voltage

: 0 mVp-p

Unselected head input voltage

SG1 : 100 mVp-p, 20 MHz

When the Read amplifier output

is VCS [mVp-p],

100

CS = 20 log

VCS

+20 log AV

Test point : V4

VOFFR = V2–V3

Test point : V2, V3

Min. Typ. Max. Unit

50 dB

50 dB

50 dB

–250 250 mV

—8—

CXA3170AN

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

a a a a a a e b a a b a a a b c

a a a a a a e b a a b a a a a b

Measurement conditions

Test point : Pin 20, 21

Test point : V

2, V3

Min. Typ. Max. Unit

–300 300 mV

V

CC VCC VCC

V

–2.6 –2.3 –2.0

—9—

CXA3170AN

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

Refer to Fig. 2 to Fig. 4

No.

14

15-1

15-2

16-1

16-2

17

18

19-1

19-2

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

Write current
rise/fall time

Measurement conditions

Differential voltage between HX pin and HY pin
at switching of Write current

TRW is the time required for Write current to turn
to 90 % after Pin 23 changes from “High” to
“Low”.
TWR1 is the time required for the Read amplifier
output∗to turn to 90 % after Pin 23 changes
from “Low” to “High”.
TWR2 is the time required for Write current to
decreases to 10 % after Pin 23 changes from
“Low” to “High”.
TSA1 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.
TSA2 is the time required for Pin 14 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.

TPD is the time required for Write current to
reach 90 % after the Write data falling edge.

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
LH=540 nH, RH=25 Ω, IW=10 mA
TR is the time required for Write current to reach
90 % from 10 %; TF is the same time required
to reach 10 % from 90 %.

Symbol

VSW

TRW

TWR1

TWR2

TSA1

TSA2

TH

TPD

TR/TF

TR/TF

Min. Typ. Max. Unit

9 Vp-p

130 150 ns

180 220 ns

100 200 ns

1.0 2.3 3.0 µs

0.6 µs

0.6 µs

2 7 ns

1 3 ns

3.7 ns

∗Read amplifier output 100 mVp-p 10 MHz

—10—

CXA3170AN

Test Circuit 1

A

3.3k

I9

a

b

A

I8

a b

A

I7

a b

A

I6

a b

A

I5

ab

A

I4

A

I3

a bb ba a

S14 S13 S12 S11 S10 S9

c abc

1324 23 22 192021 1415161718

V4

5V

V3 V2

1µ 1µ

V

×100

×1

AMP

AMP

V5

V

LPF
to15MHz

3V

PG

SG5 SG4

PG

4V

1µ

5.1k

a b

VCC
5V

SG3

VCC
5V

A

I2

V

V1

S8

S1

a b a bS2a b a bS3a b a bS4a b a bS5a b a bS6a b a b

2 3 4 5 6 7 8 9

10 11 12

1

S7

a b c d e

A

I1

33

SG1

0.1µ 0.1µ

0.1µ

a b c d e

SG2

S15

S16

V V

c

PG

SG6

A

I14

6.5V

Test Circuit 2

3.3k

1µ

×1

AMP

1µ

LH

1µH

LH

1µH

LH

1µH

LH

1µH

LH

1µH

LH

1µH

2 3 4 5 6 7 8 9

10 11 12

1

PG

1µ

PG PG PG

1324 23 22 192021 1415161718

5V

1k 1k

5.1k

Fig. 1

Fig. 2

—11—

CXA3170AN

Timing Chart 1

50% 50%

TRW TWR 2

10% 10%

TWR1

90%

WDX
WDY

I

WX

IWY

RDX
RDY

90% 90%

R/W

Fig. 3

Fig. 4

Timing Chart 2

TPD

90% 90% 90%

10% 10%

TR TF

50%

TSA2

TSA1

50%

WDX
WDY

I

WX

IWY

WUS

—12—

CXA3170AN

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 VSEH, or input ISEH 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 HS2

See Table 2

See Table 3 X

Mode

Write

Read

Servo Write

HS0

L

H

L

H

L

H

HS1

L

L
H
H

L

L

HS2

L
L
L

L
H
H

Head

0
1
2
3
4
5

—13—

CXA3170AN

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 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.

Table 3. Head selection in Servo Write mode

HS0

L
H
L
H

HS1

L

L
H
H

Head

0, 1, 2

0, 1, 2, 3, 4, 5

3, 4, 5

0, 1, 2, 3, 4, 5

—14—

CXA3170AN

Application Circuit

3.3k

1µ

LH

1µH

LH

1µH

LH

1µH

LH

1µH

LH

1µH

LH

1µH

5.1k

R

WC

+5V

2 3 4 5 6 7 8 9

10 11 12

1

1324 23 22 192021 1415161718

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—

CXA3170AN

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.

• When using as 2 or 4-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 RWC 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 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.

VTH

GND

Voltage waveform
of head pins (HX, HY)

VTH=1.4VVFB

Wave form of write data

—16—

CXA3170AN

Application Notes

Use the following characteristics for reference. VCC=5 V, 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

CO
RO

CI
RI

RRD

IUS

TAS∗

Conditions

Between head input pins
Between head input pins

f=5 MHz
RDX or RDY, f=5 MHz
LH=1 µH, RH=30 Ω
IW=15 mA
LH=0 µH, RH=0 Ω
IW=15 mA

Min. Typ. Max. Unit

4.5 6 pF

260 360 470 Ω

6 10 pF

650 1500 3000 Ω

50 Ω

0.2 mAp-p

–0.5 0.5 ns

IWX+IWY 50% 50% 50%

T1 T2

Fig.5 Write current vs. RWC

I

W

-Write current (mA)

5 10 152

5

R

WC (kΩ)

Fig.6 Write current setting constant vs. Write current

Write current setting constant K

55

52.5

50

47.5

45

4 6 8 10 12 14 16

Write Current I

W (mA)

K=RWC ·IW

20

10

22

WC

R

WC

∗TAS=T1–T2

Setting of Write current

Write current can be set with resistor RWC (kΩ) at Pin 22.
IW=K/RWC (mA) Refer to Fig. 5.

—17—

CXA3170AN

Normalized write current

vs. Supply voltage

1.04

1.02

1

0.98

0.96

I

W

/I

W

(V

CC

=5V)

4 5 6

Supply voltage V

CC [V]

Ta=25°C
R

WC=3.3kΩ

1.04

1.02

1

0.98

0.96

I

W

/I

W

(Ta=25°C)

–25 25 75

Ambient temperature Ta [°C]

V

CC=5V

RWC=3.3kΩ

0 50

1.04

1.02

1

0.98

0.96

A

V

/A

V

(V

CC

=5V)

4 5 6

Supply voltage V

CC [V]

Ta=25°C

1.04

1.02

1

0.98

0.96

A

V

/A

V

(Ta=25°C)

–25 25 75

Ambient temperature Ta [°C]

0 50

4

3.6

Power supply ON/OFF Detector

Threshold Voltage [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

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

CXA3170AN

—18—

NOTE : PALLADIUM PLATING

This product uses S-PdPPF (Sony Spec.-Palladium Pre-Plated Lead Frame).