ZL2105ALNF Intersil, ZL2105ALNF Datasheet - Page 26

• Manufacturer Part Number: ZL2105ALNF
• Description: IC DGTL DC-DC CTRLR 3A 36QFN
• Manufacturer: Intersil
• Type: Step-Down (Buck), PWM - Voltage Moder

Specifications of ZL2105ALNF

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 0.6 V ~ 5.5 V
• Current - Output: 3A
• Frequency - Switching: 200kHz ~ 2MHz
• Voltage - Input: 4.5 V ~ 14 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: *
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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 Section 6.3 “Output Overvoltage
Protection,” for response options due to an overvoltage
condition.
6.5 Output Overcurrent Protection
The ZL2105 can protect the power supply from
damage if the output is shorted to ground or if an
Figure 17. Output Responses to Pre-bias Voltages
26
ZL2105
overload condition is imposed on the output. Once the
current limit threshold has been selected (see Section
5.10 “Current Limit Threshold Selection”), the user
may determine the desired course of action in response
to the fault condition. The following overcurrent
protection response options are available:
1. Initiate a shutdown and attempt to restart an
2. Initiate a shutdown and attempt to restart a preset
3. Continue operating for a given delay period,
4. Continue operating through the fault (this could
5. Initiate an immediate shutdown.
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 AN2013 for details on
how to select specific overcurrent fault response
options via I
6.6 Thermal Overload Protection
The ZL2105 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. The user may select
one of the following overtemperature protection
response options:
1. Initiate a shutdown and attempt to restart an
2. Initiate a shutdown and attempt to restart a preset
3. Continue operating for a given delay period,
infinite number of times with a preset delay period
between attempts.
number of times with a preset delay period
between attempts.
followed by shutdown if the fault still exists.
result in permanent damage to the power supply).
infinite number of times with a preset delay period
between attempts.
number of times with a preset delay period
between attempts.
followed by shutdown if the fault still exists.
2
C/SMBus.
March 30, 2011
FN6851.2