ZL6100EVAL1Z Intersil, ZL6100EVAL1Z Datasheet - Page 25

• Manufacturer Part Number: ZL6100EVAL1Z
• Description: EVAL BOARD USB ZL6100
• Manufacturer: Intersil

Specifications of ZL6100EVAL1Z

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

output. The ZL6100 provides pre-bias protection by
sampling the output voltage prior to initiating an output ramp.
If a pre-bias voltage lower than the target voltage exists after
the pre-configured delay period has expired, the target
voltage is set to match the existing pre-bias voltage and both
drivers are enabled. The output voltage is then ramped to
the final regulation value at the ramp rate set by the SS pin.
The actual time the output will take to ramp from the pre-bias
voltage to the target voltage will vary depending on the pre-
bias voltage but the total time elapsed from when the delay
period expires and when the output reaches its target value
will match the pre-configured ramp time. See Figure 18.
If a pre-bias voltage higher than the target voltage exists
after the pre-configured delay period has expired, the target
voltage is set to match the existing pre-bias voltage and both
drivers are enabled with a PWM duty cycle that would ideally
create the pre-bias voltage.
Once the pre-configured soft-start ramp period has expired, the
PG pin will be asserted (assuming the pre-bias voltage is not
higher than the overvoltage limit). The PWM will then adjust its
duty cycle to match the original target voltage and the output
will ramp down to the pre-configured output voltage.
If a pre-bias voltage higher than the overvoltage limit exists,
the device will not initiate a turn-on sequence and will
declare an overvoltage fault condition to exist. In this case,
the device will respond based on the output overvoltage fault
response method that has been selected. See “Output
FIGURE 18. OUTPUT RESPONSES TO PRE-BIAS VOLTAGES
25
ZL6100
Overvoltage Protection” on page 24. for response options
due to an overvoltage condition.
Pre-bias protection is not offered for current sharing groups
that also have tracking enabled.
Output Overcurrent Protection
The ZL6100 can protect the power supply from damage if
the output is shorted to ground or if an overload condition is
imposed on the output. Once the current limit threshold has
been selected (see section “Current Limit Threshold
Selection” on page 19), the user may determine the desired
course of action in response to the fault condition. The
following Steps 1 through 5 overcurrent protection response
options are available:
The default response from an overcurrent fault is an immediate
shutdown of the device. The device will continuously check for
the presence of the fault condition, and if the fault condition no
longer exists the device will be re-enabled.
Please refer to Application Note AN2033 for details on how
to select specific overcurrent fault response options via
I
Thermal Overload Protection
The ZL6100 includes an on-chip thermal sensor that
continuously measures the internal temperature of the die
and shuts down the device when the temperature exceeds
the preset limit. The default temperature limit is set to
+125°C in the factory, but the user may set the limit to a
different value if desired. See Application Note AN2033 for
details. Note that setting a higher thermal limit via the
I
device. Once the device has been disabled due to an
internal temperature fault, the user may select one of several
fault response options as shown in Steps 1 through 5:
2
2
1. Initiate a shutdown and attempt to restart an infinite
2. Initiate a shutdown and attempt to restart a preset
3. Continue operating for a given delay period, followed by
4. Continue operating through the fault (this could result in
5. Initiate an immediate shutdown.
1. Initiate a shutdown and attempt to restart an infinite
2. Initiate a shutdown and attempt to restart a preset
3. Continue operating for a given delay period, followed by
C/SMBus.
C/SMBus interface may result in permanent damage to the
number of times with a preset delay period between
attempts.
number of times with a preset delay period between
attempts.
shutdown if the fault still exists.
permanent damage to the power supply).
number of times with a preset delay period between
attempts.
number of times with a preset delay period between
attempts.
shutdown if the fault still exists.
December 15, 2010
FN6876.2