Linear Technology LTC1551L, LTC1550L Datasheet

FEATURES

LTC1550L/LTC1551L

Low Noise, Switched

Capacitor Regulated

Voltage Inverters

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DESCRIPTIO

■

Regulated Negative Voltage from a Single
Positive Supply

■

Low Output Ripple: Less Than 1mV

■

High Charge Pump Frequency: 900kHz

■

Small Charge Pump Capacitors: 0.1µF

■

Requires Only Four External Capacitors

■

Fixed –4.1V, –2.5V, –2V or Adjustable Output

■

Shutdown Mode Drops Supply Current to <1µA

■

High Output Current: Up to 20mA (Depending on
VCC to V

■

Output Regulation: 2.5% Over Line, Load and

OUT

Range)

P-P

Typ

Temperature

■

Available in 8-Lead MSOP, 8-Lead Narrow SO and
16-Lead Narrow SSOP

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APPLICATIO S

■

GaAs FET Bias Generators

■

Negative Supply Generators

■

Battery-Powered Systems

■

Single Supply Applications

The LTC®1550L/LTC1551L are switched capacitor charge
pump voltage inverters which include internal linear post­regulators to minimize output ripple. The LTC1550L fixed
output voltage versions include –4.1V, –2.5V and –2V with
ripple voltages typically below 1mV

. The LTC1550L is

P-P

also available in an adjustable output voltage version. The
LTC1550L/LTC1551L are ideal for use as bias voltage
generators for GaAs transmitter FETs in portable RF and
cellular telephone applications.

The LTC1550L/LTC1551L operate from single 2.7V to

5.5V supplies and draw typical quiescent currents of

3.5mA with a 5V supply. Each device includes a TTL
compatible Shutdown pin which drops supply current to

0.2µA typically. The LTC1550L Shutdown pin is active low
(SHDN), while the LTC1551L Shutdown pin is active high
(SHDN). Only four external components are required: an
input bypass capacitor, two 0.1µF charge pump capacitors
and a filter capacitor at the linear regulator output. The
adjustable LTC1550L/LTC1551L require two additional re­sistors to set the output voltage. The LTC1550L/LTC1551L
will supply up to 20mA (depending on VCC to V

OUT

range),

while maintaining guaranteed output regulation of ±2.5%.

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

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TYPICAL APPLICATIO

R1
10k

8

7

6

5

–

POWER VALID

C

OUT

+

10µF

P-P

2.2µF
C

IN

1

2

3

4

SHDN

V

CC

LTC1550L-2

+

C1

V

OUT

C1

0.1µF

REG

CP

OUT

GND

C1

3.6V

+

Figure 1. –2V Generator with 1mV

C

CP

0.1µF

V

OUT

I

LOAD

C

L

0.1µF

Noise

= –2V

= 5mA

1550L/51L TA01

Both fixed voltage and adjustable LTC1550L/LTC1551L
are available in 8-lead MSOP and SO plastic packages: the
adjustable LTC1550L is also available in a 16-pin SSOP
with the REG pin.

V

Output Noise and Ripple

OUT

V

OUT

AC COUPLED

2mV/DIV

5µs/DIV 1550L/51L TA01a

1

LTC1550L/LTC1551L

WW

W

ABSOLUTE MAXIMUM RATINGS

U

(Note 1)

Supply Voltage ...................................................... 5.5V

Output Voltage............................. 0.3V to (VCC – 10.5V)

Total Voltage, VCC to CP

..........................................

OUT

10.8V

Input Voltage (SHDN Pin) ........... –0.3V to (VCC + 0.3V)

Input Voltage (REG Pin) ............................. –0.3V to 6V

Output Short-Circuit Duration.............................. 30 sec

U

W

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PACKAGE/ORDER INFORMATION

TOP VIEW

1

SHDN*

2

V

CC

+

3

C1

4

V

OUT

MS8 PACKAGE

8-LEAD PLASTIC MSOP

*SHDN FOR LTC1550L, SHDN FOR LTC1551L

*FOR ADJUSTABLE VERSION

T

= 150°C, θJA = 200°C/W

JMAX

ORDER PART NUMBER

LTC1550LCMS8
LTC1550LCMS8-2
LTC1550LCMS8-2.5
LTC1550LCMS8-4.1

MS8 PART MARKING
LTEG

LTGR
LTFV
LTEH

8

REG (ADJ*)

7

CP

OUT

6

GND

–

5

C1

LTC1551LCMS8
LTC1551LCMS8-4.1

LTFQ
LTFT

SHDN*

V

CC

C1

V

OUT

*SHDN FOR LTC1550L, SHDN FOR LTC1551L

ORDER PART NUMBER

Commercial Temperature Range ................. 0°C to 70°C

Extended Commercial Operating

Temperature Range (Note 3) .............. –40°C to 85°C

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

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

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

TOP VIEW

1

2

+

3

4

S8 PACKAGE

8-LEAD PLASTIC SO

*FOR ADJUSTABLE VERSION

T

= 150°C, θJA = 135°C/W

JMAX

LTC1550LCS8

8

REG (ADJ*)

7

CP

6

GND
C1

5

OUT

–

NC

C1

NC

V

OUT

C1
PGND
AGND

NC

T

ORDER PART NUMBER

TOP VIEW

1

+

2
3
4

–

5
6
7
8

GN PACKAGE

16-LEAD PLASTIC SSOP

= 150°C, θJA = 150°C/W

JMAX

LTC1550LCS8-2
LTC1550LCS8-2.5
LTC1550LCS8-4.1

LTC1550LCGN
LTC1550LIGN

LTC1551LCS8
LTC1551LCS8-4.1

GN PART MARKING

1550L
1550LI

16

V

CC

15

SHDN

14

REG

13

NC

12

ADJ

11

CP

OUT

10

NC

9

NC

Consult factory for Military grade parts and additional voltage options.

ELECTRICAL CHARACTERISTICS

The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
VCC = 2.7V to 5.25V, C1 = C

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

CC

V

REF

∆V

∆(VCC – V

I

S

Supply Voltage
(Adjustable, Fixed –2V)
(Fixed –2.5V)
(Fixed –4.1V) ● 4.5 5.25 V

Reference Voltage VCC = 5V, ADJ = GND, V
Reference Voltage I

REF

Line Regulation

OUT)

Supply Current VCC = 5V, V

= 0.1µF, C

CP

= 10µF, TA = 25°C unless otherwise specified. (Note 3)

OUT

= –V

REF

OUT

= 0mA, 2.7V ≤ VCC ≤ 5.25V 2.5 mV/V

OUT

= VCC (LTC1550L) or GND (LTC1551L) ● 3.65 7 mA

VCC = 5V, V

SHDN

= GND (LTC1550L) or VCC (LTC1551L) ● 0.2 10 µA

SHDN

● 2.7 5.25 V

● 3.05 5.25 V

1.225 V

2

LTC1550L/LTC1551L

ELECTRICAL CHARACTERISTICS

The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
VCC = 2.7V to 5.25V, C1 = C

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

f

OSC

V

OL

I

REG

V

IH

V

IL

I

IN

t

ON

V

OUT

V

OUT

V

OUT

V

OUT

V

OUT

V

OUT

V

OUT

I

SC

V

RIPPLE

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

Note 2: All currents into device pins are positive; all currents out of device
pins are negative. All voltages are referenced to ground unless otherwise
specified. All typicals are given at T

Internal Oscillator Frequency 900 kHz
REG Output Low Voltage I
REG Sink Current V
SHDN Input High Voltage VCC = 5V ● 2V
SHDN Input Low Voltage VCC = 5V ● 0.8 V
SHDN Input Current V

Turn-On Time VCC = 5V, I

Output Regulation 2.7V ≤ VCC ≤ 5.25V, 0 ≤ I
(LTC1550L/LTC1551L) 2.8V ≤ V

Output Regulation 2.7V ≤ VCC ≤ 5.25V, 0 ≤ I
(LTC1550L/LTC1550L-2/ 3.1V ≤ V
LTC1551L) 3.75V ≤ VCC ≤ 5.25V, 0 ≤ I

Output Regulation 3.05V ≤ VCC ≤ 5.25V, 0 ≤ I
(LTC1550L/LTC1550L-2.5/ 3.45V ≤ V
LTC1551L) 4.1V ≤ VCC ≤ 5.25V, 0 ≤ I

Output Regulation 3.45V ≤ VCC ≤ 5.25V, 0 ≤ I
(LTC1550L/LTC1551L) 3.85V ≤ V

Output Regulation 3.9V ≤ VCC ≤ 5.25V, 0 ≤ I
(LTC1550L/LTC1551L) 4.2V ≤ V

Output Regulation 4.5V ≤ VCC ≤ 5.25V, 0 ≤ I
(LTC1550L/LTC1550L-4.1) 4.75V ≤ V
(LTC1551L/LTC1551L-4.1)

Output Regulation 4.8V ≤ VCC ≤ 5.25V, 0 ≤ I
(LTC1550L/LTC1551L)) 5.1V ≤ VCC ≤ 5.25V, 0 ≤ I

Output Short-Circuit Current V
Output Ripple Voltage 1mV

= 0.1µF, C

CP

= 25°C.

A

= 10µF, TA = 25°C unless otherwise specified. (Note 3)

OUT

= 1mA, VCC = 5V ● 0.1 0.8 V

REG

= 0.8V, VCC = 5V ● 410 mA

REG

= VCC (All LTC1550L Versions) ● 0.1 1 µA

SHDN

V

= VCC (All LTC1551L Versions) ● 520 µA

SHDN

= 10mA, –1.5V ≤ V

OUT

≤ 4.1V ● 15ms

OUT

(LTC1550L/LTC1551L)
V

= 5V, I

CC

= 5mA, V

OUT

= –4.5V ● 15ms

OUT

(LTC1550L/LTC1551L)
V

= 5V, I

CC

= 10mA, V

OUT

= –2V ● 15ms

OUT

(LTC1550L-2)
V

= 5V, I

CC

= 10mA, V

OUT

= –2.5V ● 15ms

OUT

(LTC1550L-2.5)
V

= 5V, I

CC

= 10mA, V

OUT

= –4.1V ● 15ms

OUT

(LTC1550L-4.1/LTC1551L-4.1)

≤ 5mA ● –1.537 –1.5 –1.463 V

≤ 5.25V, 0 ≤ I

CC

3.5V ≤ VCC ≤ 5.25V, 0 ≤ I

≤ 5.25V, 0 ≤ I

CC

≤ 5.25V, 0 ≤ I

CC

≤ 5.25V, 0 ≤ I

CC

4.5V ≤ VCC ≤ 5.25V, 0 ≤ I

≤ 5.25V, 0 ≤ I

CC

4.85V ≤ VCC ≤ 5.25V, 0 ≤ I

≤ 5.25V, 0 ≤ I

CC

= 0V, VCC = 5.25V ● 80 200 mA

OUT

OUT

≤ 10mA ● –1.537 –1.5 –1.463 V

OUT

≤ 20mA ● –1.537 –1.5 –1.463 V

OUT

≤ 5mA ● –2.05 – 2.0 –1.95 V

OUT

≤ 10mA ● –2.05 – 2.0 –1.95 V

OUT

≤ 20mA ● –2.05 – 2.0 –1.95 V

OUT

≤ 5mA ● –2.562 –2.5 –2.438 V

OUT

≤ 10mA ● –2.562 –2.5 –2.438 V

OUT

≤ 20mA ● –2.562 –2.5 –2.438 V

OUT

≤ 5mA ● –3.075 –3.0 –2.925 V

OUT

≤ 10mA ● –3.075 –3.0 –2.925 V

OUT

≤ 20mA ● –3.075 –3.0 –2.925 V

OUT

≤ 5mA ● –3.587 –3.5 –3.413 V

OUT

≤ 10mA ● –3.587 –3.5 –3.413 V

OUT

≤ 20mA ● –3.587 –3.5 –3.413 V

OUT

≤ 5mA ● –4.203 –4.1 –3.998 V

OUT

≤ 10mA ● –4.203 –4.1 –3.998 V

OUT

≤ 5mA ● –4.613 –4.5 –4.388 V

OUT

≤ 10mA ● –4.613 –4.5 –4.388 V

OUT

Note 3: The LTC1550LC/LTC1551LC are guaranteed to meet specified
performance from 0°C to 70°C and are designed, characterized and
expected to meet these extended temperature limits, but are not tested at
–40°C and 85°C. The LTC1550LI is guaranteed to meet the extended
temperature limits.

3

LTC1550L/LTC1551L

1.24

1.238

1.236

1.234

1.232

1.230

1.228

1.226

1.224

1.222

1.220

1.218

V

CC

+ |V

OUT

| (V)

456789104.5 5.5 6.5 7.5 8.5 9.5

REFERENCE VOLTAGE (V)

1550L/51L G06

TA = 25°C

W

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TYPICAL PERFORMANCE CHARACTERISTICS

Oscillator Frequency vs
Temperature

975

VCC = 5V

= –4.1V

V

OUT

925

875

825

775

OSCILLATOR FREQUENCY (kHz)

725

675

–55 –35 –15 5 25 45 65 85 105 125

TEMPERATURE (˚C)

Maximum Output Current
vs Supply Voltage

80

TA = 25°C

70

60

50

40

30

V

= –2V V

OUT

20

MAXIMUM OUTPUT CURRENT (mA)

10

0

2.25 2.75 3.25 3.75 4.25 4.75 5.25
SUPPLY VOLTAGE (V)

V

OUT

= –2.5V

OUT

= –4.1V

1550L/51L G01

1550L/51L G04

Supply Current vs Temperature

5.0
VCC = 5V

= –4.1V

V

OUT

4.5

4.0

3.5

SUPPLY CURRENT (mA)

3.0

2.5

–55 –35 –15 5 25 45 65 85 105 125

2.5

2.0

1.5

1.0

START-UP TIME (ms)

0.5

0

2.25 2.75 3.25 3.75 4.25 4.75 5.25

TEMPERATURE (°C)

TA = 25°C

V

OUT

R

L

V

= –2V

OUT

= 390Ω

R

L

SUPPLY VOLTAGE (V)

= 820Ω

1550L/51L G02

= –4.1V

1550L/51L G05

Minimum Required V
vs V

6.0

5.6

5.2

4.8

4.4

4.0

3.6

3.2

2.8

POSITIVE SUPPLY VOLTAGE (V)

2.4

2.0
–5

and I

OUT

OUT

I

I

= 5mA

OUT

–4

–3

OUTPUT VOLTAGE (V)

OUT

= 20mA

–2

Reference Voltage vs VCC + |V

CC

I

OUT

= 10mA

–1

1550L/51L G03

OUT

0

|Start-Up Time vs Supply Voltage

Startup Time (LTC1550L Shown)

5V

SHDN

0V
0V

V

OUT

POWER VALID

4

–4.1V

5V
0V

0.2ms/DIV 1550/51 G07

Load Transient Response
(See Figure 3, VCC = 5V)

V

OUT

5mV/DIV

AC

COUPLED

10mA

I

OUT

0mA

1ms/DIV

1550/51 G08

V

5mV/DIV

COUPLED

5.25V

V

CC

4.75V

Line Transient Response
(See Figure 3, IL = 10mA)

OUT

AC

2ms/DIV

1550/51 G09