LTC3221_15 Datasheet, PDF (1/12 Pages) Linear Technology – Micropower, Regulated Charge Pump

LTC3221/
LTC3221-3.3/LTC3221-5
Micropower,
Regulated Charge Pump
in 2 × 2 DFN
FEATURES
■ _{Ultralow Power: 8µA Quiescent Current}
■ _{Regulated Output Voltages: 3.3V ±4%, 5V ±4%, ADJ}
■ _{VIN Range:}
1.8V to 4.4V (LTC3221-3.3)
2.7V to 5.5V (LTC3221-5)
■ _{Output Current: Up to 60mA}
■ _{No Inductors Needed}
■ _{Very Low Shutdown Current: <1µA}
■ _{Shutdown Disconnects Load from VIN}
■ _{Burst Mode Control}
■ _{Short-Circuit Protected}
■ _{Solution Profile < 1mm}
■ _{Tiny 2mm × 2mm 6-Pin DFN Package}
U
APPLICATIO S
■ _{Low Power 2 AA Cell to 3.3V Supply}
■ _{Memory Backup Supplies}
■ _{Tire Pressure Sensors}
■ _{General Purpose Low Power Li-Ion to 5V Supply}
■ _{RF Transmitters}
■ _{Glucose Meters}
DESCRIPTIO
The LTC^®3221 family are micropower charge pump DC/DC
converters that produce a regulated output at up to 60mA.
The input voltage range is 1.8V to 5.5V. Extremely low
operating current (8µA typical at no load) and low external
parts count (one flying capacitor and two small bypass
capacitors at V_IN and V_OUT) make them ideally suited for
small, battery-powered applications.
The LTC3221 family includes fixed 5V and 3.3V output
versions plus an adjustable version. All parts operate
as Burst Mode^® switched capacitor voltage doublers
to achieve ultralow quiescent current. The chips use a
controlled current to supply the output and will survive
a continuous short-circuit from V_OUT to GND. The FB pin
of the adjustable LTC3221 can be used to program the
desired output voltage.
The LTC3221 family is available in a low profile (0.75mm)
2mm × 2mm 6-pin DFN package.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Burst
Mode is a registered trademark of Linear Technology Corporation. All other trademarks are
the property of their respective owners.
TYPICAL APPLICATIO
1µF
V_IN
2.2µF
2
5
C^–
V_IN
1
C⁺
V_OUT
6
LTC3221-X
4,7 _GND
V_OUT
4.7µF
OFF ON ³ SHDN
3221 TA01
REGULATED 3.3V OUTPUT FROM 1.8V TO 4.4V INPUT
V_OUT = 3.3V ±4%
I_OUT = OmA TO 25mA; V_IN >1.8V
I_OUT = OmA TO 60mA; V_IN >2V
REGULATED 5V OUTPUT FROM 2.7V TO 5.5V INPUT
V_OUT = 5V ±4%
I_OUT = OmA TO 25mA; V_IN >2.7V
I_OUT = OmA TO 60mA; V_IN >3V
No-Load Input Current
vs Supply Voltage
16
14
12
10 ^{TA = 90°C}
T_A = 25°C
8
6 ^TA ^{= –45°C}
4
2
0
1.5 2.0 2.5 3.0 3.5 4.0 4.5
SUPPLY VOLTAGE (V)
3221 TA01b
3221f
1