zl2106 Intersil Corporation, zl2106 Datasheet - Page 26

• Manufacturer Part Number: zl2106
• Description: 6a Digital-dc Synchronous Step-down Dc-dc Converter
• Manufacturer: Intersil Corporation

3. Continue operating for a given delay period,
4. Continue operating through the fault (this could
5. Initiate an immediate shutdown.
If the user has configured the device to restart, the
device will wait the preset delay period (if configured
to do so) and will then check the device temperature. If
the temperature has dropped below a threshold that is
approx 15 °C lower than the selected temperature fault
limit, the device will attempt to re-start. If the
temperature still exceeds the fault limit the device will
wait the preset delay period and retry again.
The default response from a temperature fault is an
immediate shutdown of the device. Please refer to
Application Note AN33 for details on how to select
specific temperature fault response options via
I
7.6 Voltage Tracking
Numerous high performance systems place stringent
demands on the order in which the power supply
voltages are turned on. This is particularly true when
powering FPGAs, ASICs, and other advanced
processor devices that require multiple supply voltages
to power a single die. In most cases, the I/O interface
operates at a higher voltage than the core and therefore
the core supply voltage must not exceed the I/O supply
voltage according to the manufacturers' specifications.
Voltage tracking protects these sensitive ICs by
limiting the differential voltage between multiple
power supplies during the power-up and power down
sequence. The ZL2106 integrates a lossless tracking
scheme that allows its output to track a voltage that is
applied to the VTRK pin with no additional
components required. The VTRK pin is an analog
input that, when tracking mode is enabled, configures
the voltage applied to the VTRK pin to act as a
reference for the device’s output regulation.
The ZL2106 offers two modes of tracking. Figure
18 illustrates the output voltage waveform for the
two tracking modes.
1. Coincident. This mode configures the ZL2106 to
2
C/SMBus.
followed by shutdown if the fault still exists.
result in permanent damage to the power supply).
ramp its output voltage at the same rate as the
voltage applied to the VTRK pin.
26
ZL2106
2. Ratiometric. This mode configures the ZL2106 to
The master device in a tracking group is defined as the
device that has the highest target output voltage within
the group. This master device will control the ramp
rate of all tracking devices and is not configured for
tracking mode. A delay of at least 10 ms must be
configured into the master device using the SS pin, and
the user may also configure a specific ramp rate using
the SS pin. Tracking mode is enabled through the CFG
pin, as shown in Table 20, and configured through the
SS pin, as show in Table
Any device that is configured for tracking mode will
ignore its soft-start delay and ramp time settings (SS
pin) and its output will take on the turn-on/turn-off
characteristics of the reference voltage present at the
VTRK pin. All of the ENABLE pins in the tracking
group must be connected together and driven by a
single logic source.
Tracking mode can also be configured via the
I
2
C/SMBus interface by using the TRACK_CONFIG
ramp its output voltage at a rate that is a percentage
of the voltage applied to the VTRK pin. The
default setting is 50%, but an external resistor may
be used to configure a different tracking ratio.
Figure 18. Tracking Modes
17
Data Sheet Revision 2/19/2009
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