Linear Technology LTC1682-5, LTC1682-3.3, LTC1682 Datasheet

FEATURES

■

Low Output Noise: 60µV

■

Adjustable or Fixed Boosted Output

■

Adjustable Output Voltage Range: 2.5V to 5.5V

■

Fixed Output Voltages: 3.3V, 5V

■

Wide Input Voltage Range: 1.8V to 4.4V

■

Uses Small Ceramic Capacitors

■

No Inductors Required

■

Output Current up to 50mA

■

550kHz Switching Frequency

■

Low Operating Current: 150µA

■

Low Shutdown Current: 1µA

■

Internal Thermal Shutdown and Current Limiting

■

Available in 8-Pin MSOP and SO Packages

(100kHz BW)

RMS

U

APPLICATIO S

■

VCO Power Supplies in Cellular Phones

■

2-Way Pagers

■

Wireless PCMCIA Cards

■

Portable Medical Instruments

■

Low Power Data Acquisition

■

Remote Transmitters

LTC1682/LTC1682-3.3/LTC1682-5

Doubler Charge Pumps with

Low Noise Linear Regulator

U

DESCRIPTIO

The LT C®1682/LTC1682-3.3/LTC1682-5 are doubler charge
pumps with an internal low noise, low dropout (LDO) linear
regulator. These parts are designed to provide a low noise
boosted supply voltage for powering noise sensitive devices
such as high frequency VCOs in wireless applications.

An internal doubler charge pump converts a 1.8V to 4.4V
input to a boosted output, while the internal LDO regulator
converts the boosted voltage to a low noise regulated output.
The adjustable version allows the user to set V
resistors connected to FB. The regulator is capable of supply­ing up to 50mA of output current. Shutdown reduces the
supply current to < 5µA, removes the load from VIN by
disabling the regulator and discharges V
through a 100Ω switch.

The LTC1682 LDO regulator is stable with only 2µF on the
output. Small ceramic capacitors can be used, reducing PC
board area.

The LTC1682/LTC1682-3.3/LTC1682-5 are short-circuit and
over temperature protected. The parts are available in 8-pin
MSOP and SO packages.

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

via external

OUT

to ground

OUT

TYPICAL APPLICATIO

4.2V VCO Power Supply, VIN = 2.5V to 4.4V

SHUTDOWN

V

2.5V TO

4.4V

8

CPO

4.7µF

IN

0.22µF

4.7µF

7

C

6

V

5

C

+

LTC1682

IN

–

V

OUT

SHDN

GND

FB

U

Open-Loop Close-In Phase Noise

4.2V

1

2

3

4

36k

15k

4.7µF

1µF

1k

1000pF

B

VCO

MURATA

MQE001-902
M

1000pF

1000pF

P

C

100k

f

OUT

902MHz

V

4.7µF

1682 TA01

C

AMPLITUDE

10dB/DIV

CENTER = 902MHz RES BW = 1kHz
SPAN = 100kHz VBW = 30Hz
SWP = 10 sec REF = 0dBm

1682 TA02

1

LTC1682/LTC1682-3.3/LTC1682-5

TOP VIEW

S8 PACKAGE

8-LEAD PLASTIC SO

1

2

3

4

8

7

6

5

V

OUT

SHDN

FILT/FB*

GND

CPO
C

+

V

IN

C

–

*PIN3 = FILT FOR LTC1682-3.3/LTC1682-5
= FB FOR LTC1682

WW

W

ABSOLUTE MAXIMUM RATINGS

U

(Note 1)

VIN to Ground ..............................................–0.3V to 5V

V

Voltage................................................–0.3V to 6V

OUT

CPO to Ground ........................................................ 10V

SHDN, FILT/FB Voltage to

Ground ..................................... – 0.3V to (VIN + 0.3V)

V

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

OUT

I

...................................................................... 90mA

OUT

UUW

PACKAGE/ORDER INFORMATION

ORDER PART

NUMBER

TOP VIEW

V

1

OUT

2

SHDN

3

FILT/FB*

4

GND

MS8 PACKAGE

8-LEAD PLASTIC MSOP

*PIN3 = FILT FOR LTC1682-3.3/LTC1682-5
= FB FOR LTC1682

T

= 125°C, θJA = 140°C/ W

JMAX

8

CPO

+

7

C
V

6

IN
–

C

5

LTC1682CMS8
LTC1682CMS8-3.3
LTC1682CMS8-5
LTC1682IMS8
LTC1682IMS8-3.3
LTC1682IMS8-5

MS8 PART MARKING

LTER
LTGT
LTGV

LTHM

LTGU

LTGW

Operating Temperature Range

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

Extended Commercial (Note 2)........... – 40°C to 85°C

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

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

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

Maximum Junction Temperature..........................125°C

ORDER PART

NUMBER

LTC1682CS8
LTC1682CS8-3.3
LTC1682CS8-5
LTC1682IS8
LTC1682IS8-3.3
LTC1682IS8-5

S8 PART MARKING

= 125°C, θJA = 120°C/W

T

JMAX

1682
168233
16825

1682I
1682I33
1682I5

Consult factory for Military grade parts.

ELECTRICAL CHARACTERISTICS

range, otherwise specifications are TA = 25°C. SHDN = VIN = 3V; C1 = 0.22µF; C2, C3, C4 = 4.7µF, unless otherwise noted.

PARAMETER CONDITIONS MIN TYP MAX UNITS

VIN Operating Voltage LTC1682 ● 1.8 4.4 V

I

Shutdown Current SHDN = 0V ● 15 µA

VIN

I

Operating Current I

VIN

FB Input Current LTC1682, FB = 1.235V ● –50 50 nA
FB Voltage LTC1682 ● 1.210 1.235 1.260 V
Regulated Output Voltage LTC1682-3.3, I

V

Temperature Coefficient ±50 ppm

OUT

Charge Pump Oscillator Frequency I

Burst Mode is a trademark of Linear Technology Corporation.

2

The ● denotes specifications that apply over the full operating temperature

LTC1682-3.3
LTC1682-5

= 0mA, Burst Mode

OUT

0°C to 70°C
–40°C to 85°C

LTC1682-5, I

> 200µA, VIN = 1.8V to 4.4V ● 480 550 620 kHz

OUT

OUT

OUT

TM

Operation

= 1mA ● 3.23 3.30 3.37 V

= 1mA ● 4.9 5.0 5.1 V

● 2 4.4 V

● 2.7 4.4 V

● 150 250 µA

● 150 300 µA

LTC1682/LTC1682-3.3/LTC1682-5

ELECTRICAL CHARACTERISTICS

The ● denotes specifications that apply over the full operating temperature

range, otherwise specifications are TA = 25°C. SHDN = VIN = 3V; C1 = 0.22µF; C2, C3, C4 = 4.7µF, unless otherwise noted.

PARAMETER CONDITIONS MIN TYP MAX UNITS

CPO (Charge Pump Output) VIN = 1.8V, I
Output Resistance V

V

Dropout Voltage (Note 3) LTC1682, I

OUT

= 3V, I

IN

= 4.4V, I

V

IN

LTC1682/LTC1682-3.3, I
LTC1682/LTC1682-5, I

V

Enable Time I

OUT

V

Output Noise Voltage LTC1682 I

OUT

= 10mA 2 ms

OUT

LTC1682-3.3 I

LTC1682-5 I

V

Line Regulation VIN = 3V to 4V, I

OUT

V

Load Regulation I

OUT

V

Shutdown Resistance SHDN = 0V, Resistance Measured to Ground, VIN = 1.8V ● 150 350 Ω

OUT

= 1mA to 10mA ● 310 mV

OUT

I

= 1mA to 50mA (Note 4) 10 mV

OUT

SHDN = 0V, Resistance Measured to Ground, V
SHDN Input Threshold VIN = 1.8V to 4.4V ● 0.4 1 1.6 V
SHDN Input Current SHDN = V

SHDN = 0V

= 10mA ● 18 30 Ω

OUT

= 10mA ● 13 20 Ω

OUT

= 10mA ● 11 17 Ω

OUT

= 10mA, V

OUT

IN

OUT

I

OUT

OUT

I

OUT

OUT

I

OUT

= 0mA (Note 6) ● 520 mV

OUT

= 2.57V (Note 5) ● 100 160 mV

OUT

= 10mA, V

OUT

= 10mA, V

OUT

= 10mA, 10Hz ≤ f ≤ 100kHz, V
= 10mA, 10Hz ≤ f ≤ 2.5MHz, V

= 10mA, 10Hz ≤ f ≤ 100kHz, C
= 10mA, 10Hz ≤ f ≤ 2.5MHz, C

= 10mA, 10Hz ≤ f ≤ 100kHz, C
= 10mA, 10Hz ≤ f ≤ 2.5MHz, C

= 3.3V ● 75 120 mV

OUT

= 5V ● 50 90 mV

OUT

= 5V 88 µV

OUT

= 5V 800 µV

OUT

= 1nF 58 µV

FILT

= 1nF 500 µV

FILT

= 1nF 64 µV

FILT

= 1nF 600 µV

FILT

= 4.4V ● 50 150 Ω

IN

● –1 1 µA

● –1 1 µA

RMS

P-P

RMS

P-P

RMS

P-P

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

Note 2: The LTC1682C is guaranteed to meet specified performance from
0°C to 70°C and is designed, characterized and expected to meet these
extended temperature limits, but is not tested at –40°C and 85°C. The
LTC1682I is guaranteed to meet the extended temperature limits.

Note 3: Dropout voltage is the minimum input/output voltage required to
maintain regulation at the specified output current. In dropout the output
voltage will be equal to: V

CPO

– V

DROPOUT

(see Figure 4).

Note 4: Operating conditions are limited by maximum junction
temperature. The regulated output specification will not apply for all
possible combinations of input voltage and output current. When
operating at maximum input voltage, the output current range may be
limited. When operating at maximum output current, the input voltage
range may be limited.

Note 5: Limited by the LDO disable switch point of 1.45V

.

IN

Note 6: The LTC1682 is set to 5V. The feedback current is 25µA.

3

LTC1682/LTC1682-3.3/LTC1682-5

UW

TYPICAL PERFOR A CE CHARACTERISTICS

CPO Output Resistance vs V

35

30

25

(Ω)

20

CPO

R

15

10

5

1.5

2.5 3.0 3.5

2.0
VIN (V)

LTC1682-5 Output Noise
(BW = 10Hz to 2.5MHz)

IN

TA = 25°C
C1 = 0.22µF

= 10mA

I

OUT

4.0 4.5

1682 G01

Min and Max V

9

TA = 25°C

8

7

6

(V)

CPO

V

5

4

3

1.5

(A) THE MAXIMUM GENERATED NO LOAD

(B) THE MINIMUM ALLOWABLE CPO VOLTAGE,

V

2.5 3.0 3.5

2.0

CPO VOLTAGE

AT FULL LOAD, TO ENSURE THAT THE LDO
IS NOT DISABLED

Shutdown to Enable Timing

CPO

vs V

CPO

= 2(VIN)

(A)

V

VIN (V)

IN

(B)

= 1.45(VIN)

CPO

4.0 4.5

1682 G02

V

Transient Response

OUT

10

5

(mV)I

0

OUT

TA = 25°C

∆V

(mA)

OUT

V

–5

IN

V

OUT

C

–10

OUT

15

10

5

0

050

= 3V

= 4V
= 10µF

100 200150

TIME (µs)

Enable to Shutdown Timing

250

300

1682 G02

V

OUT

200µV/DIV

C

= C

CPO

= 10mA TA = 25°C

I

OUT

= 3V C

V

IN

100µs/DIV 1682 G04

= 4.7µFV

OUT

Oscillator Frequency vs
Temperature

565

VIN = 3V

560

555

550

545

540

OSCILLATION FREQUENCY (kHz)

535

530

–50

= 5V

OUT

= 1nF

FILT

–25 0

50 100 125

25 75

TEMPERATURE (°C)

SHDN (V)V

(V)

OUT

2

0

4

3

2

1

0

1682 G07

TA = 25°C

= 3V

V

IN

= 4V

V

OUT

= 10mA

I

OUT

= C

C

CPO

OUT

= 10µF

200µs/DIV

1682 G05

Operating Current vs V
(No Load)

220

TA = 25°C

200

180

160

140

120

100

OPERATING CURRENT (µA)

80

60

1.5

LTC1682-3.3

LTC1682-5

2.5 3.0 3.5 4.0 4.5

2.0

2

0

SHDN (V)V

4

3

(V)

2

OUT

1

0

VIN (V)

NO LOAD

= 25°C

T

A

= 3V

V

IN

= 4V

V

OUT

= 10µF

C

OUT

IN

LTC1682

1ms/DIV

1682 G06

1682 G08

4