zl2006 Intersil Corporation, zl2006 Datasheet - Page 30

• Manufacturer Part Number: zl2006
• Description: Adaptive Digital Dc-dc Controller With Drivers And Current Sharing
• Manufacturer: Intersil Corporation

6. Power Management Functional Description
6.1 Input Undervoltage Lockout
The input undervoltage lockout (UVLO) prevents the
ZL2006 from operating when the input falls below a
preset threshold, indicating the input supply is out of
its specified range. The UVLO threshold (V
be set between 2.85 V and 16 V using the UVLO pin.
The simplest implementation is to connect the UVLO
pin as shown in Table 24. If the UVLO pin is left
unconnected, the UVLO threshold will default to 4.5
V.
Table 24. UVLO Threshold Settings
If the desired UVLO threshold is not one of the listed
choices, the user can configure a threshold between
2.85 V and 16 V by connecting a resistor between the
UVLO pin and SGND by selecting the appropriate
resistor from Table 25.
Table 25. UVLO Resistor Values
17.8 kΩ
19.6 kΩ
21.5 kΩ
23.7 kΩ
26.1 kΩ
28.7 kΩ
31.6 kΩ
34.8 kΩ
38.3 kΩ
42.2 kΩ
R
UVLO
Pin Setting
OPEN
HIGH
LOW
2.85 V
3.14 V
3.44 V
3.79 V
4.18 V
4.59 V
5.06 V
5.57 V
6.13 V
6.75 V
UVLO
30
46.4 kΩ
51.1 kΩ
56.2 kΩ
61.9 kΩ
68.1 kΩ
82.5 kΩ
90.9 kΩ
100 kΩ
UVLO Threshold
75 kΩ
R
UVLO
10.8 V
4.5 V
3 V
14.54 V
7.42 V
8.18 V
8.99 V
10.9 V
13.2 V
UVLO
9.9 V
12 V
16 V
UVLO
) can
ZL2006
The UVLO voltage can also be set to any value
between 2.85 V and 16 V via the I
Once an input undervoltage fault condition occurs, the
device can respond in a number of ways as follows:
1. Continue operating without interruption.
2. Continue operating for a given delay period,
3. Initiate an immediate shutdown until the fault has
The default response from a UVLO fault is an
immediate shutdown of the device. The device will
continuously check for the presence of the fault
condition. If the fault condition is no longer present,
the ZL2006 will be re-enabled.
Please refer to Application Note AN33 for details on
how to configure the UVLO threshold or to select
specific UVLO fault response options via the
I
6.2 Output Overvoltage Protection
The ZL2006 offers an internal output overvoltage
protection circuit that can be used to protect sensitive
load circuitry from being subjected to a voltage higher
than its prescribed limits. A hardware comparator is
used to compare the actual output voltage (seen at the
VSEN pin) to a threshold set to 15% higher than the
target output voltage (the default setting). If the VSEN
voltage exceeds this threshold, the PG pin will de-
assert and the device can then respond in a number of
ways as follows:
1. Initiate an immediate shutdown until the fault has
2. Turn off the high-side MOSFET and turn on the
The default response from an overvoltage fault is to
immediately shut down. The device will continuously
check for the presence of the fault condition, and when
the fault condition no longer exists the device will be
re-enabled.
2
C/SMBus interface.
followed by shutdown if the fault still exists. The
device will remain in shutdown until instructed to
restart.
been cleared. The user can select a specific number
of retry attempts.
been cleared. The user can select a specific number
of retry attempts.
low-side MOSFET. The low-side MOSFET
remains ON until the device attempts a restart.
2
C/SMBus interface.
December 15, 2010
FN6850.1