tda5153x NXP Semiconductors, tda5153x Datasheet - Page 16

• Manufacturer Part Number: tda5153x
• Description: Pre-amplifier Hard Disk Drive With Mr-read/inductive Write Heads
• Manufacturer: NXP Semiconductors

Philips Semiconductors
8.11
The HUS pin is an open-collector output. Consequently,
when the pin is not connected to an external pull-up
resistor, HUS is LOW. HUS pins can be connected
together in case of operation with more than one amplifier.
It is used to detect abnormal/unexpected operation.
Sleep mode: HUS is HIGH, to permit working with more
than one amplifier.
Standby mode: HUS is HIGH, to permit working with
more than one amplifier.
Read mode:
Detection of low V
voltage below 4.0 V 5% is flagged to the HUS pin.
The voltage detection range is then 4.2 to 3.8 V with an
hysteresis of 110 mV 10%. Detection of low V
(writer dedicated supply): a fault will be flagged at HUS pin
if V
aware that such a detection is only aimed to warn for a
catastrophic situation. Indeed, V
below V
8.12
Notes
1. HUS survey: A-test mode = analog test mode.
2. In servo mode, the performance of the IC is not guaranteed.
1997 Jul 02
if in the configuration register d3 = 1, HUS is HIGH
if in the configuration register d3 = 0, HUS goes LOW
for:
– R
– Low V
Pre-amplifier for Hard Disk Drive (HDD)
with MR-read/inductive write heads
CC(WD)
Standby mode
Active mode
(read current too low or too high)
voltage detector is placed close to the V
V
Sleep mode
CC(WD)
ext
Head unsafe
HUS survey
MODE
CC
pin open, short-circuited to ground or to V
drops 0.8 V 10% below V
.
CC
pins.
and V
CC
CC(WD)
(main general supply): a V
conditions. A low supply
Read
Write
CC(WD)
CC
HUS
should never be
. One must be
CC
Read mode
A-test mode
TAS mode
Write mode
A-test mode
Servo mode
CC(WD)
CC
and
STATE
supply
CC
(1)
(1)
(2)
16
Test mode: HUS is HIGH except when the TAS detector
is ON. If a thermal asperity is detected, HUS goes LOW.
Servo write mode: HUS is LOW
Write mode:
The same detector is used for read and write mode. HUS
goes LOW again between 0.5 and 1 s after the last
unsafe condition was detected.
if in the configuration register d3 = 1, HUS is LOW
if in the configuration register d3 = 0, HUS goes HIGH
for: the write current may be inhibited if d1 = 0 in the
configuration register.
– R
– Write data input frequency too low (WDIx
– Write head Wx
– Write-head still left biased while not selected
– Low V
(write current too low or too high)
to ground (switching to write mode makes HUS LOW;
after the transient the HUS detection circuitry is
activated; the target for the head-open detect time is
15 ns)
can be active or inactive).
ext
pin open, short-circuited to ground or to V
CC
and V
CC(WD)
HIGH
HIGH
ACTIVE
HIGH
ACTIVE
ACTIVE
HIGH
LOW
Wy open, Wx or Wy short-circuited
conditions (write current inhibit
0
DATA BIT D3
Preliminary specification
HIGH
HIGH
HIGH
HIGH
ACTIVE
LOW
HIGH
LOW
TDA5153
1
WDIy)
CC