zl2106 Intersil Corporation, zl2106 Datasheet - Page 13

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

In general, the size of components L
as the overall efficiency of the circuit are inversely
proportional
Therefore, the highest efficiency circuit may be
realized by switching the MOSFETs at the lowest
possible frequency; however, this will result in the
largest component size. Conversely, the smallest
possible footprint may be realized by switching at the
fastest possible frequency but this gives a somewhat
lower efficiency. Each user should determine the
optimal combination of size and efficiency when
determining
application.
The block diagram for the ZL2106 is illustrated in
Figure 10. In this circuit, the target output voltage is
regulated by connecting the VSEN pin directly to the
output regulation point. The VSEN signal is then
compared to an internal reference voltage that had been
set to the desired output voltage level by the user. The
error signal derived from this comparison is converted
to a digital value with an analog to digital (A/D)
converter. The digital signal is also applied to an
adjustable
compensated signal is used to derive the appropriate
PWM duty cycle for driving the internal MOSFETs in
a way that produces the desired output.
5.3 Power Management Overview
The ZL2106 incorporates a wide range of configurable
power management features that are simple to
implement without additional components. Also, the
ZL2106 includes circuit protection features that
continuously safeguard the device and load from
damage due to unexpected system faults. The ZL2106
can continuously monitor input voltage, output
voltage/current and internal temperature. A Power
Good output signal is also included to enable power-on
reset functionality for an external processor.
All power management functions can be configured
using either pin configuration techniques (see Figure
12) or via the I
parameters can also be pre-configured to provide alerts
for specific conditions. See Application Note AN33 for
more details on SMBus monitoring.
digital
the
to
the
2
switching
13
C/SMBus interface. Monitoring
compensation
switching
frequency
1
frequency,
and C
filter
OUT
for
and
as well
each
f
the
SW
.
ZL2106
5.4 Multi-mode Pins
In order to simplify circuit design, the ZL2106
incorporates patented multi-mode pins that allow the
user to easily configure many aspects of the device
without programming. Most power management
features can be configured using these pins. The multi-
mode pins can respond to four different connections as
shown in Table 5. These pins are sampled when power
is applied or by issuing a PMBus Restore command
(See Application Note AN33).
Pin-strap Settings: This is the simplest method, as no
additional components are required. Using this method,
each pin can take on one of three possible states: LOW,
OPEN, or HIGH. These pins can be connected to the
V2P5 pin for logic HIGH settings as this pin provides a
regulated voltage higher than 2 V. Using a single pin
one of three settings can be selected.
Table 5. Multi-mode Pin Configuration
Figure 12. Pin-strap and Resistor Setting Examples
Resistor to SGND
(Logic HIGH)
(Logic LOW)
Pin Tied To
OPEN
HIGH
(N/C)
LOW
Data Sheet Revision 2/19/2009
Set by resistor value
No connection
< 0.8 VDC
> 2.0 VDC
Value
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