LTC3330 Datasheet, PDF (10/20 Pages) Linear Technology – Energy Harvesting DC/DC with Battery Backup Low Noise LDO Post Regulator

LTC3330
Pin Functions
BAL (Pin 1): Supercapacitor Balance Point. The common
node of a stack of two supercapacitors is connected to
BAL. A source/sink balancing current of up to 10mA is
available. Tie BAL along with SCAP to GND to disable the
balancer and its associated quiescent current.
SCAP (Pin 2): Supply and Sense Point for Supercapacitor
Balancer. Tie the top of a 2-capacitor stack to SCAP and
the middle of the stack to BAL to activate balancing. Tie
SCAP along with BAL to GND to disable the balancer and
its associated quiescent current.
V_IN2 (Pin 3): Internal Low Voltage Rail to Serve as Gate
Drive for Buck NMOS Switch. Connect a 4.7µF (or larger)
capacitor from V_IN2 to GND. This pin is not intended for
use as an external system rail.
UV3, UV2, UV1, UV0 (Pins 4, 5, 6, 7): UVLO Select Bits
for the Buck Switching Regulator. Tie high to V_IN2 or
low to GND to select the desired UVLO rising and falling
thresholds (see Table 4). Do not float.
AC1 (Pin 8): Input Connection for Piezoelectric Element
or Other AC Source (used in conjunction with AC2 for
differential AC inputs).
AC2 (Pin 9): Input Connection for Piezoelectric Element
or Other AC Source (used in conjunction with AC1 for
differential AC inputs).
V_IN (Pin 10): Rectified Input Voltage. A capacitor on this
pin serves as an energy reservoir and input supply for the
buck regulator. The V_IN voltage is internally clamped to a
maximum of 20V (typical).
CAP (Pin 11): Internal Rail Referenced to V_IN to Serve
as Gate Drive for Buck PMOS Switch. Connect a 1μF (or
larger) capacitor between CAP and V_IN. This pin is not
intended for use as an external system rail.
SW (Pin 12): Switch Node for the Buck Switching Regula-
tor. Connect a 22µH or greater external inductor between
this node and V_OUT.
V_OUT (Pin 13): Regulated Output Voltage Derived from the
Buck or Buck-Boost Switching Regulator.
SWB (Pin 14): Switch Node for the Buck-Boost Switching
Regulator. Connect an external inductor between this node
and SWA of value per Table 3.
SWA (Pin 15): Switch Node for the Buck-Boost Switching
Regulator. Connect an external inductor between this node
and SWB of value per Table 3.
BAT (Pin 16): Input for Battery. BAT serves as the input
to the buck-boost switching regulator.
IPK0, IPK1, IPK2 (Pins 17, 18, 19): IPEAK Select Bits
for the Buck-Boost Switching Regulator. Tie high to V_IN3
or low to GND to select the desired IPEAK (see Table 3).
Do not float.
LDO_OUT (Pin 20): Regulated LDO Output. This output
can be used as a quiet supply. One mode is provided to run
the LDO as a current limited switch to alternately power
up and power down circuitry without low power modes.
LDO_IN (Pin 21): Input Voltage for the LDO regulator.
LDO2, LDO1, LDO0 (Pins 22, 23, 24): LDO Voltage Select
Bits. Tie high to LDO_IN or low to GND to select the desired
LDO_OUT voltage (see Table 2). Do not float.
LDO_EN (Pin 25): LDO Enable Input. Active high input with
logic levels referenced to LDO_IN. Do not float.
V_IN3 (Pin 26): Internal Low Voltage Rail Used by the Priori-
tizer. Connect a 1µF (or larger) capacitor from V_IN3 to GND.
This pin is not intended for use as an external system rail.
PGLDO (Pin 27): Power Good Output for LDO_OUT. Logic
level output referenced to an internal maximum rail (see
Operation). PGLDO transitioning high indicates 92.5%
(typical) regulation has been reached on LDO_OUT. PGLDO
remains high until LDO_OUT falls to 90.0% (typical) of
the programmed regulation point.
PGVOUT (Pin 28): Power Good Output for V_OUT. Logic
level output referenced to an internal maximum rail (see
Operation). PGVOUT transitioning high indicates regula-
tion has been reached on V_OUT (V_OUT = Sleep Rising).
PGVOUT remains high until V_OUT falls to 92.5% (typical)
of the programmed regulation point.
BAT_ON (Pin 29): Switcher Status. Logic level output
referenced to V_IN3. EH_ON is high when the buck switch-
ing regulator is in use. It is pulled low when buck-boost
switching regulator is in use.
3330p
10
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