cxa3171n Sony Electronics, cxa3171n Datasheet - Page 12

• Manufacturer Part Number: cxa3171n
• Description: 4ch. Read/write Amplifier For Three Terminal Mig Head Of Hard Disk Drive
• Manufacturer: Sony Electronics

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.
Head selection
The heads are selected as shown in Table 2 by the HS0, HS1 and HS2 pins.
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
(4) While maintaing step (2) and (3) above make R/W low, placing the device in servo write mode.
SEH
, or input I
R/W
H
L
L
HS0
H
H
L
L
SEH
WUS/SE
to WUS/SE.
Table 2. Head selection
Table 1. Mode selection
X
X
—12—
HS1
H
H
HS0
See Table 2
See Table 3
L
L
HS1
Head
Servo Write
0
1
2
3
Mode
Read
Write
CXA3171N