LTC3221/
LTC3221-3.3/LTC3221-5
Micropower,
Regulated Charge Pump
in 2 × 2 DFN
U
FEATURES
DESCRIPTIO
TheLTC®3221familyaremicropowerchargepumpDC/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
■
Ultralow Power: 8µA Quiescent Current
■
Regulated Output Voltages: 3.3V 4%, 5V 4%, ADJ
■
V Range:
IN
1.8V to 4.4V (LTC3221-3.3)
2.7V to 5.5V (LTC3221-5)
■
Output Current: Up to 60mA
capacitors at V and V ) make them ideally suited for
IN
OUT
■
No Inductors Needed
small, battery-powered applications.
■
Very Low Shutdown Current: <1µA
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
■
Shutdown Disconnects Load from V
Burst Mode Control
Short-Circuit Protected
Solution Profile < 1mm
Tiny 2mm × 2mm 6-Pin DFN Package
IN
■
■
■
■
a continuous short-circuit from V
to GND. The FB pin
OUT
of the adjustable LTC3221 can be used to program the
U
desired output voltage.
APPLICATIO S
The LTC3221 family is available in a low profile (0.75mm)
■
Low Power 2 AA Cell to 3.3V Supply
2mm × 2mm 6-pin DFN package.
■
Memory Backup Supplies
, 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.
■
Tire Pressure Sensors
General Purpose Low Power Li-Ion to 5V Supply
RF Transmitters
Glucose Meters
■
■
■
U
TYPICAL APPLICATIO
No-Load Input Current
vs Supply Voltage
1µF
16
14
12
2
–
1
+
C
V
C
6
5
V
V
V
OUT
IN
IN
OUT
2.2µF
4.7µF
LTC3221-X
GND
T
= 90°C
A
4,7
3
10
8
T
= 25°C
A
OFF ON
SHDN
3221 TA01
T
= –45°C
A
6
REGULATED 3.3V OUTPUT FROM 1.8V TO 4.4V INPUT
4
V
I
I
= 3.3V 4%
= OmA TO 25mA; V >1.8V
= OmA TO 60mA; V >2V
OUT
OUT
OUT
IN
IN
2
REGULATED 5V OUTPUT FROM 2.7V TO 5.5V INPUT
0
V
I
I
= 5V 4%
= OmA TO 25mA; V >2.7V
= OmA TO 60mA; V >3V
OUT
OUT
OUT
1.5
2.0
2.5
3.0
3.5
4.0
4.5
IN
IN
SUPPLY VOLTAGE (V)
3221 TA01b
3221f
1