Linear Technology LTC1516 Datasheet

FEATURES

OUTPUT CURRENT (mA)

50

60

70

80

90

EFFICIENCY (%)

100

1516 • TA01

0.01 0.1 1 10

SHDN = 0V

V

IN

= 3V

LOW IQ MODE
(SEE FIGURE 3)

LTC1516

Micropower, Regulated

5V Charge Pump

DC/DC Converter

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DESCRIPTION

■

Ultralow Power: Typical Operating ICC = 12µA

■

Short Circuit/Thermal Protection

■

Regulated 5V ±4% Output

■

2V to 5V Input Range

■

No Inductors

■

ICC in Shutdown: <1µA

■

Output Current:20mA (VIN > 2V)

50mA (VIN > 3V)

■

Shutdown Disconnects Load from V

■

Internal Oscillator: 600kHz

■

Compact Application Circuit (0.1 in2)

■

8-Pin SO Package

IN

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APPLICATIONS

■

2-Cell to 5V Conversion

■

Li-Ion Battery Backup Supplies

■

Local 3V to 5V Conversion

■

5V Flash Memory Programmer

■

Smart Card Readers

The LTC®1516 is a micropower charge pump DC/DC
converter that produces a regulated 5V output from a 2V
to 5V supply. Extremely low supply current (12µ A typical
with no load, <1µA in shutdown) and low external parts
count (two 0.22µ F flying capacitors and two 10µ F capaci­tors at VIN and V

) make the LTC1516 ideally suited for

OUT

small, light load battery-powered applications. Typical
efficiency (VIN = 3V) exceeds 70% with load currents
between 50µ A and 50mA. Modulating the SHDN pin keeps
the typical efficiency above 70% with load currents all the
way down to 10µA.

The LTC1516 operates as either a doubler or a tripler
depending on VIN and output load conditions to improve
overall efficiency. The part has thermal shutdown and can
survive a continuous short from V

to GND. In shut-

OUT

down the load is disconnected from VIN.
The LTC1516 is available in an 8-pin SO package in both

commercial and industrial temperature grades.

, LTC and LT are registered trademarks of Linear Technology Corporation.

TYPICAL APPLICATION

VIN = 2V TO 5V

Figure 1. Regulated 5V Output from a 2V to 5V Input

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0.22µF

1

C1+

2



V

+



10µF

+

10µF

V
I

OUT

I

OUT

IN

LTC1516

3

V



OUT

4

+

C2

0.22µF

= 5V ±4%

OUT

= 0mA TO 20mA, VIN ≥ 2V
= 0mA TO 50mA, VIN ≥ 3V

C1–

SHDN

GND

C2

8

7

ON/OFF

6

5

–



1516 • F01

Efficiency vs Output Current

1

LTC1516

WW

W

ABSOLUTE MAXIMUM RATINGS

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W

PACKAGE/ORDER INFORMATION

(Note 1)

VIN to GND...................................................–0.3V to 6V

V

to GND ................................................–0.3V to 6V

OUT

SHDN to GND ..............................................–0.3V to 6V

V

Short-Circuit Duration............................. Indefinite

OUT

Operating Temperature Range

Commercial .............................................0°C to 70°C

Industrial ............................................ –40°C to 85°C

Storage Temperature Range................. –65°C to 150°C

Lead Temperature (Soldering, 10 sec)..................300°C

TOP VIEW

–

1

C1+

V

2

IN



V

3

OUT

+

C2

4

S8 PACKAGE

8-LEAD PLASTIC SO

T

= 125°C, θJA = 150°C/W

JMAX

Consult factory for Military grade parts.

C1



8

SHDN

7

GND

6

–

C2

5

ORDER PART

NUMBER

LTC1516CS8
LTC1516IS8

S8 PART MARKING

1516
1516I

ELECTRICAL CHARACTERISTICS

VIN = 2V to 5V, C1 = C2 = 0.22µF, CIN = C

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

IN

V

OUT

I

CC

f

OSC

V

IH

V

IL

I

IH

I

IL

t

ON

The ● denotes specifications which apply over the full operating
temperature range.

Note 1: Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired

Input Voltage ● 25V
Output Voltage 2V ≤ VIN ≤ 5V, I

Supply Current 2V ≤ VIN ≤ 5V, I

Output Ripple Full Load 100 mV
Efficiency VIN = 3V, I
Switching Frequency Full Load 600 kHz
SHDN Input Threshold ● (0.7)(VIN)V

SHDN Input Current V

V

Turn-On Time VIN = 3V, I

OUT

= 10µF, T

OUT

≤ V

≤ 3.6V, I

3V

IN

3.6V ≤ VIN ≤ 5V, I

2V ≤ VIN ≤ 5V, I

= V

SHDN

V

= 0V ● –1 1 µA

SHDN

to T

MIN

OUT

OUT
OUT

OUT
OUT

= 20mA 82 %

OUT

IN

= 0mA (Note 3) 500 µs

OUT

unless otherwise specified (Note 3).

MAX

≤ 20mA ● 4.8 5.2 V

≤ 50mA ● 4.8 5.2 V
≤ 50mA, TA = 25°C (Note 2) 4.8 5.2 V

= 0mA, SHDN = 0V ● 12 20 µA
= 0mA, SHDN = V

Note 2: At input voltages >3.6V and ambient temperatures >70°C,
continuous power dissipation must be derated to maintain junction
temperatures below 125°C. Derate 6mW/°C above 70°C in SO-8.

Note 3: The LTC1516 is tested with the capacitors shown in Figure 1.

IN

● 0.005 1 µA

● 0.4 V

● –1 1 µA

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2

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TYPICAL PERFORMANCE CHARACTERISTICS

Efficiency vs Input Voltage

90

= 10mA

I

OUT

80

Output Current vs Input Voltage

120

C

= 10µF

OUT

= 25°C

T

A

100

C1 = C2

80

= 0.22µF

C1 = C2
= 0.1µF

LTC1516

No Load Supply Current vs
Input Voltage

20

15

70

EFFICIENCY (%)

60

50

2.0 2.5 3.0 4.0 4.53.5
INPUT VOLTAGE (V)

Output Voltage vs Input Voltage

5.10

5.05

5.00

OUTPUT VOLTAGE (V)

4.95

4.90

= 20mA

I

OUT

2134

INPUT VOLTAGE (V)

1516 • G01

1516 • G04

5.0

5.10

5.05

5.00

OUTPUT VOLTAGE (V)

4.95

4.90

65

60

40

20

MAXIMUM OUTPUT CURRENT (mA)

0

234

C1 = C2
= 0.047µF

C1 = C2 = 0.01µF

INPUT VOLTAGE (V)

C1 = C2
= 0.022µF

Output Voltage vs Output Current

VIN = 3V

0.01 0.1 1 10 100
OUTPUT CURRENT (mA)

1516 • G05

1516 • G02

5

0mA TO 25mA,

10mA/DIV

AC COUPLED,

100mV/DIV

10

SUPPLY CURRENT (µA)

5

234

INPUT VOLTAGE (V)

Load Transient Response, VIN = 3V

I

,

OUT

V

,

OUT

1516 • G03

1516 • G04

5



UUU

PIN FUNCTIONS

C1+ (Pin 1): Flying Capacitor 1, Positive Terminal.
VIN (Pin 2): Input Supply Voltage.
V

(Pin 3): 5V Output Voltage (V

OUT

C2+ (Pin 4): Flying Capacitor 2, Positive Terminal.
C2– (Pin 5): Flying Capacitor 2, Negative Terminal.

= 0V in Shutdown).

OUT

GND (Pin 6): Ground.
SHDN (Pin 7): Active High CMOS Logic-Level Shutdown

Input.
C1– (Pin 8): Flying Capacitor 1, Negative Terminal.

3