Datasheet

LTC3035
5
3035f
BLOCK DIAGRA
W
BIAS
UVLO
+
–
–
+
BIAS
5V
1.9 • V
IN
CP
800kHz
OSCILLATOR
CHARGE
PUMP
EN
REFERENCE
SHDN
0.400V
SOFT-START BIAS
2.5k
8
1
CM
2
OUT
5
ADJ
6
V
MIN
V
IN
4
SHDN
7
GND
PINS 3, 9
3035 BD
UU
U
PI FU CTIO S
CP (Pin 1): Flying Capacitor Positive Terminal.
CM (Pin 2): Flying Capacitor Negative Terminal.
GND (Pin 3): Ground. Connect to a ground plane.
IN (Pin 4): Input Supply Voltage. The output load current
is supplied directly from IN. The IN pin should be locally
bypassed to ground if the LTC3035 is more than a few
inches away from another source of bulk capacitance. In
general, the output impedance of a battery rises with
frequency, so it is usually adviseable to include an input
bypass capacitor when supplying IN from a battery. A
capacitor of 1µF is usually sufficient.
OUT (Pin 5): Regulated Output Voltage. The OUT pin
supplies power to the load. A minimum ceramic output
capacitor of at least 1µF is required to ensure stability.
Larger output capacitors may be required for applications
with large transient loads to limit peak voltage transients.
See the Applications Information section for more infor-
mation on output capacitance.
ADJ (Pin 6): Adjust Input Pin. This is the input to the error
amplifier. The ADJ pin reference voltage is 0.4V referenced
to ground. The output voltage range is 0.4V to 3.6V and is
set by connecting ADJ to a resistor divider from OUT to
GND.
SHDN (Pin 7): Shutdown Input, Active Low. This pin is
used to put the LTC3035 into shutdown. The SHDN pin
current is typically less than 10nA. The SHDN pin cannot
be left floating and must be tied to a valid logic level if
not used.
BIAS (Pin 8): BIAS Output Voltage Pin. BIAS is the output
of the charge pump and provides the high side supply for
the LTC3035 LDO circuitry. This pin should be locally
bypassed to ground by a 1µF or greater capacitor as close
as possible to the pin. Nothing else should be connected
to this pin.
Exposed Pad (Pin 9): Ground and Heat Sink. Must be
soldered to PCB ground plane or large pad for optimal
thermal performance.