LT3021-1.8_15_技术文档

LT3021/LT3021-1.2/

LT3021-1.5/LT3021-1.8

500mA, Low Voltage,

Very Low Dropout

Linear Regulator

FEATURES

DESCRIPTION

The LT^®3021 is a very low dropout voltage (VLDO™) lin-

ear regulator that operates from input supplies down to

0.9V. This device supplies 500mA of output current with

a typical dropout voltage of 160mV. The LT3021 is ideal

for low input voltage to low output voltage applications,

providing comparable electrical efﬁciency to that of a

switching regulator.

n

V Range: 0.9V to 10V

IN

n

Dropout Voltage: 160mV Typical

n

Output Current: 500mA

Adjustable Output (V

n

= V

= 200mV)

REF

OUT(MIN)

n

Fixed Output Voltages: 1.2V, 1.5V, 1.8V

Stable with Low ESR, Ceramic Output Capacitors

(3.3μF Minimum)

n

0.2% Load Regulation from 0mA to 500mA

Quiescent Current: 120μA (Typ)

3μA Typical Quiescent Current in Shutdown

Current Limit Protection

The LT3021 regulator optimizes stability and transient

responsewithlowESR,ceramicoutputcapacitorsassmall

as 3.3μF. Other LT3021 features include 0.05% typical line

regulation and 0.2% typical load regulation. In shutdown,

quiescent current typically drops to 3μA.

Reverse-Battery Protection

No Reverse Current

Internal protection circuitry includes reverse-battery pro-

tection, current limiting, thermal limiting with hysteresis,

and reverse-current protection. The LT3021 is available as

an adjustable output device with an output range down to

the 200mV reference. Three ﬁxed output voltages, 1.2V,

1.5V and 1.8V, are also available.

Thermal Limiting with Hysteresis

16-Pin DFN (5mm × 5mm) and 8-Lead

SO Packages

APPLICATIONS

n

Low Current Regulators

The LT3021 regulator is available in the low proﬁle

(0.75mm) 16-pin (5mm × 5mm) DFN package with ex-

posed pad and the 8-lead SO package.

L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. VLDO is

a trademark of Linear Technology Corporation. All other trademarks are the property of their

respective owners.

n

Battery-Powered Systems

n

Cellular Phones

n

Pagers

n

Wireless Modems

TYPICAL APPLICATION

Minimum Input Voltage

1.1

I

= 500mA

L

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

1.8V to 1.5V, 500mA VLDO Regulator

V

OUT

V

IN

OUT

LT3021-1.5

1.5V

1.8V

500mA

3.3μF

SHDN SENSE

GND

3021 TA01

–50 –25

0

25

50

75 100 125

TEMPERATURE (°C)

3021 TA02

3021fc

1

LT3021/LT3021-1.2/

LT3021-1.5/LT3021-1.8

(Note 1)

ABSOLUTE MAXIMUM RATINGS

Operating Junction Temperature Range (E, I Grade)

(Notes 2, 3)............................................–40°C to 125°C

Storage Temperature Range

DH .....................................................–65°C to 125°C

S8......................................................–65°C to 150°C

Lead Temperature (Soldering, 10 sec, S8)............ 300°C

IN Pin Voltage ........................................................ 10V

OUT Pin Voltage...................................................... 10V

Input-to-Output Differential Voltage........................ 10V

ADJ/SENSE Pin Voltage ....................................... 10V

SHDN Pin Voltage ................................................. 10V

Output Short-Circut Duration ......................... Indeﬁnite

PIN CONFIGURATION

TOP VIEW

NC

1

2

3

4

5

6

7

8

16 NC

15 NC

14 IN

NC

1

2

3

4

5

6

7

8

16 NC

15 NC

14 IN

OUT

NC

OUT

NC

13 NC

12 IN

13 NC

12 IN

17

NC

11 NC

10 PGND

NC

11 NC

10 PGND

ADJ

AGND

SENSE

AGND

9

SHDN

9

SHDN

LT3021-ADJ

LT3021-FIXED

DH PACKAGE

16-LEAD (5mm × 5mm) PLASTIC DFN

T

= 125°C, θ = 35°C/ W*, θ = 3°C/W**

T

= 125°C, θ = 35°C/ W*, θ = 3°C/W**

JMAX

JA

JC

JMAX JA JC

EXPOSED PAD IS GND (PIN 17) CONNECT TO PINS 8, 10

EXPOSED PAD MUST BE SOLDERED TO THE PCB

*SEE THE APPLICATIONS INFORMATION SECTION

**MEASURED JUNCTION TO PIN 17

EXPOSED PAD IS GND (PIN 17) CONNECT TO PINS 8, 10

EXPOSED PAD MUST BE SOLDERED TO THE PCB

*SEE THE APPLICATIONS INFORMATION SECTION

**MEASURED JUNCTION TO PIN 17

TOP VIEW

NC

OUT

1

2

3

4

8

7

6

5

IN

NC

OUT

1

2

3

4

8

7

6

5

IN

NC

SENSE

AGND

PGND

SHDN

ADJ

PGND

SHDN

AGND

LT3021-FIXED

LT3021-ADJ

S8 PACKAGE

8-LEAD PLASTIC SO

T

= 150°C, θ = 125°C/ W*, θ = 40°C/W**

T

= 150°C, θ = 125°C/ W*, θ = 40°C/W**

JA JC

JMAX

JA JC

JMAX

*SEE THE APPLICATIONS INFORMATION SECTION

**MEASURED JUNCTION TO PIN 6

*SEE THE APPLICATIONS INFORMATION SECTION

**MEASURED JUNCTION TO PIN 6

3021fc

2

LT3021/LT3021-1.2/

LT3021-1.5/LT3021-1.8

ORDER INFORMAITON

LEAD FREE FINISH

LT3021EDH#PBF

LT3021EDH-1.2#PBF

LT3021EDH-1.5#PBF

LT3021EDH-1.8#PBF

LT3021ES8#PBF

LT3021ES8-1.2#PBF

LT3021ES8-1.5#PBF

LT3021ES8-1.8#PBF

LT3021IS8-1.8#PBF

LEAD BASED FINISH

LT3021EDH

TAPE AND REEL

PART MARKING*

3021

PACKAGE DESCRIPTION

TEMPERATURE RANGE

–40°C to 125°C

TEMPERATURE RANGE

–40°C to 125°C

LT3021EDH#TRPBF

LT3021EDH-1.2#TRPBF

LT3021EDH-1.5#TRPBF

LT3021EDH-1.8#TRPBF

LT3021ES8#TRPBF

LT3021ES8-1.2#TRPBF

LT3021ES8-1.5#TRPBF

LT3021ES8-1.8#TRPBF

LT3021IS8-1.8#TRPBF

TAPE AND REEL

16-Lead (5mm × 5mm) Plastic DFN

8-Lead Plastic SO

302112

302115

302118

3021

302112

302115

302118

PART MARKING*

3021

8-Lead Plastic SO

PACKAGE DESCRIPTION

16-Lead (5mm × 5mm) Plastic DFN

8-Lead Plastic SO

LT3021EDH#TR

LT3021EDH-1.2

LT3021EDH-1.2#TR

LT3021EDH-1.5#TR

LT3021EDH-1.8#TR

LT3021ES8#TR

302112

302115

302118

3021

LT3021EDH-1.5

LT3021EDH-1.8

LT3021ES8

LT3021ES8-1.2

LT3021ES8-1.2#TR

LT3021ES8-1.5#TR

LT3021ES8-1.8#TR

LT3021IS8-1.8#TR

302112

302115

302118

8-Lead Plastic SO

LT3021ES8-1.5

8-Lead Plastic SO

LT3021ES8-1.8

8-Lead Plastic SO

LT3021IS8-1.8

8-Lead Plastic SO

Consult LTC Marketing for parts speciﬁed with wider operating temperature ranges. *The temperature grade is identiﬁed by a label on the shipping container.

For more information on lead free part marking, go to: http://www.linear.com/leadfree/

For more information on tape and reel speciﬁcations, go to: http://www.linear.com/tapeandreel/

3021fc

3

LT3021/LT3021-1.2/

LT3021-1.5/LT3021-1.8

ELECTRICAL CHARACTERISTICS

The l denotes the speciﬁcations which apply over the full operating

temperature range, otherwise speciﬁcations are at T_J= 25°C.

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

Minimum Input Voltage

(Notes 5,14)

I

= 500mA, T > 0°C

0.9

1.05

1.10

V

LOAD

J

= 500mA, T < 0°C

J

ADJ Pin Voltage (Notes 4, 5)

V

= 1.5V, I

= 1mA

LOAD

196

193

200

204

206

mV

IN

1.15V < V < 10V, 1mA < I

< 500mA

= 1mA

l

IN

LOAD

Regulated Output Voltage

(Note 4)

LT3021-1.2

LT3021-1.5

LT3021-1.8

LT3021

V

IN

= 1.5V, I

1.176

1.157

1.200

1.224

1.236

V

LOAD

1.5V < V < 10V, 1mA < I

< 500mA

IN

LOAD

V

IN

= 1.8V, I

= 1mA

LOAD

1.470

1.447

1.500

1.530

1.545

V

1.8V < V < 10V, 1mA < I

IN

V

IN

= 2.1V, I

= 1mA

LOAD

1.764

1.737

1.800

1.836

1.854

V

2.1V < V < 10V, 1mA < I

IN

l

Line Regulation (Note 6)

Load Regulation (Note 6)

Dropout Voltage (Notes 7, 12)

ΔV = 1.15V to 10V, I

= 1mA

–1.75

–10.5

–13

0

+1.75

10.5

13

mV

IN

LOAD

LT3021-1.2 ΔV = 1.5V to 10V, I

= 1mA

IN

LOAD

LT3021-1.5 ΔV = 1.8V to 10V, I

LT3021-1.8 ΔV = 2.1V to 10V, I

–15.8

15.8

LT3021

V

IN

V

IN

V

IN

V

IN

= 1.15V, ΔI

= 1mA to 500mA

LOAD

–2

–6

–7.5

–9

0.4

1

1.5

2

6

7.5

9

mV

LT3021-1.2

LT3021-1.5

LT3021-1.8

= 1.5V, ΔI

= 1.8V, ΔI

= 2.1V, ΔI

= 1mA to 500mA

LOAD

I

= 10mA

45

75

110

mV

LOAD

l

I

= 500mA

155

190

285

mV

LOAD

l

GND Pin Current

I

= 0mA

110

920

2.25

6.20

250

μA

mA

LOAD

V

= V

+ 0.4V

OUT(NOMINAL)

= 10mA

= 100mA

= 500mA

IN

(Notes 8, 12)

l

10

Output Voltage Noise

ADJ Pin Bias Current

Shutdown Threshold

C

= 4.7μF, I

= 500mA, BW = 10Hz to 100kHz, V

= 1.2V

300

20

μV

RMS

OUT

LOAD

OUT

V

ADJ

= 0.2V, V = 1.2V (Notes 6, 9)

50

nA

IN

l

V

= Off to On

= On to Off

0.61

0.9

V

OUT

V

0.25

l

SHDN Pin Current (Note 10)

V

= 0V, V = 10V

1

μA

SHDN

IN

= 10V, V = 10V

3

9.5

IN

Quiescent Current in Shutdown

Ripple Rejection (Note 6)

V

IN

= 6V, V

= 0V

SHDN

9

μA

dB

LT3021

V

LOAD

– V

= 1V, V = 0.5V , f = 120Hz,

P-P RIPPLE

70

IN

OUT

RIP

I

= 500mA

LT3021-1.2

LT3021-1.5

LT3021-1.8

V

LOAD

– V

= 1V, V

= 0.5V , f = 120Hz,

P-P RIPPLE

60

58

56

1.8

1

dB

IN

OUT

RIPPLE

I

= 500mA

V

– V

= 500mA

= 1V, V

= 0.5V , f

P-P RIPPLE

= 120Hz,

IN

OUT

I

LOAD

V

– V

= 500mA

= 1V, V

= 0.5V , f

P-P RIPPLE

IN

OUT

I

LOAD

Current Limit (Note 12)

V

IN

V

IN

= 10V, V

= 0V

A

mA

OUT

l

= V

+ 0.5V, ΔV

= –5%

550

OUT(NOMINAL)

OUT

Input Reverse Leakage Current

V

IN

= –10V, V

= 0V

OUT

20

μA

Reverse Output Current

(Notes 11, 13)

LT3021

V

= 1.2V, V = 0V

0.5

10

5

μA

OUT

IN

LT3021-1.2

LT3021-1.5

LT3021-1.8

= 1.2V, V = 0V

15

IN

= 1.5V, V = 0V

IN

= 1.8V, V = 0V

IN

3021fc

4

LT3021/LT3021-1.2/

LT3021-1.5/LT3021-1.8

ELECTRICAL CHARACTERISTICS

The l denotes the speciﬁcations which apply over the full operating

temperature range, otherwise speciﬁcations are at T_J= 25°C.

Note 1: Stresses beyond those listed under Absolute Maximum Ratings

may cause permanent damage to the device. Exposure to any Absolute

Maximum Rating condition for extended periods may affect device

reliability and lifetime.

voltage, not the 0.5V output voltage. Speciﬁcations for ﬁxed output voltage

devices are referred to the output voltage.

Note 7: Dropout voltage is the minimum input to output voltage differential

needed to maintain regulation at a speciﬁed output current. In dropout the

Note 2: The LT3021 regulators are tested and speciﬁed under pulse load

output voltage equals: (V – V

).

IN

DROPOUT

conditions such that T ≈ T . The LT3021E regulators are 100% tested

J

A

Note 8: GND pin current is tested with V = V

+ 0.4V and a

IN

OUT(NOMINAL)

at T = 25°C. Performance at –40°C and 125°C is assured by design,

A

current source load. GND pin current will increase in dropout. See GND pin

current curves in the Typical Performance Characteristics section.

characterization and correlation with statistical process controls. The

LT3021I regulators are guaranteed over the full –40ºC to 125ºC operating

junction temperature range.

Note 9: Adjust pin bias current ﬂows out of the ADJ pin.

Note 10: Shutdown pin current ﬂows into the SHDN pin.

Note 11: Reverse output current is tested with IN grounded and OUT

forced to the rated output voltage. This current ﬂows into the OUT pin and

out of the GND pin. For ﬁxed voltage devices this includes the current in

the output resistor divider.

Note 3: This IC includes overtemperature protection that is intended

to protect the device during momentary overload conditions. Junction

temperature will exceed 125°C when overtemperature protection is active.

Continuous operation above the speciﬁed maximum operating junction

temperature may impair device reliability.

Note 4: Maximum junction temperature limits operating conditions. The

regulated output voltage speciﬁcation does not apply for all possible

combinations of input voltage and output current. Limit the output current

range if operating at maximum input voltage. Limit the input voltage range

if operating at maximum output current.

Note 12: The LT3021 is tested and speciﬁed for these conditions with an

external resistor divider (20k and 100k) setting V

resistor divider adds 10μA of load current.

to 1.2V. The external

OUT

Note 13: Reverse current is higher for the case of (rated_output) < V

OUT

< V because the no-load recovery circuitry is active in this region and is

IN,

trying to restore the output voltage to its nominal value.

Note 5: Typically the LT3021 supplies 500mA output current with a 1V

input supply. The guranteed minimum input voltage for 500mA output

current is 1.10V.

Note 14: Minimum input voltage is the minimum voltage required by the

control circuit to regulate the output voltage and supply the full 500mA

rated current. This speciﬁcation is tested at V

= 0.5V. At higher output

OUT

Note 6: The LT3021 is tested and speciﬁed for these conditions with an

voltages the minimum input voltage required for regulation will be equal to

the regulated output voltage V plus the dropout voltage.

external resistor divider (20k and 30.1k) setting V

to 0.5V. The external

OUT

resistor divider adds 10μA of output load current. The line regulation and

load regulation speciﬁcations refer to the change in the 0.2V reference

TYPICAL PERFORMANCE CHARACTERISTICS

Dropout Voltage

Minimum Input Voltage

1.2

1.1

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

250

225

200

175

150

125

100

75

250

225

200

175

150

125

100

75

I

= 500mA

V

OUT

= 1.2V

L

I

= 500mA

L

T

= 125°C

J

I

= 250mA

= 100mA

L

T

= 25°C

J

I

= 50mA

I = 10mA

L

50

25

I

= 1mA

L

0

–50 –25

0

25

50

75 100 125

0

100

200

300

400

500

–50 –25

0

25

50

75 100 125

TEMPERATURE (°C)

OUTPUT CURRENT (mA)

TEMPERATURE (°C)

3021 G16

3021 G01

3021 G02

3021fc

5

LT3021/LT3021-1.2/

LT3021-1.5/LT3021-1.8

TYPICAL PERFORMANCE CHARACTERISTICS

ADJ Pin Voltage

ADJ Pin Bias Current

Quiescent Current

206

204

202

200

198

196

194

25

20

15

10

5

250

225

200

175

150

125

100

75

V

L

= 6V

IN

OUT

= 1.2V

I

= 0

V

= V

IN

SHDN

50

25

V

= 0V

SHDN

0

–50 –25

0

25

50

75 100 125

–50 –25

0

25

50

75 100 125

–50 –25

0

25

50

75 100 125

TEMPERATURE (°C)

3021 G04

3021 G11

3021 G05

Output Voltage

1.23

1.22

1.21

1.20

1.19

1.18

1.17

1.53

1.52

1.51

1.50

1.49

1.48

1.47

1.83

1.82

1.81

1.80

1.79

1.78

1.77

I

= 1mA

I

= 1mA

LOAD

I

= 1mA

LOAD

50

TEMPERATURE (°C)

100 125

50

TEMPERATURE (°C)

100 125

–50 –25

0

25

75

–50 –25

0

25

75

50

TEMPERATURE (°C)

100 125

–50 –25

0

25

75

3021 G28

3021 G23

3021 G22

Quiescent Current

3.0

2.5

2.0

1.5

1.0

0.5

0

3.0

2.5

2.0

1.5

1.0

0.5

0

3.0

2.5

2.0

1.5

1.0

0.5

0

V

I

J

= 1.2V

V

I

J

= 1.5V

V

I

J

= 1.8V

OUT

= 0

OUT

= 0

OUT

= 0

L

T

= 25°C

T

= 25°C

T

= 25°C

V

= V

IN

V

= V

IN

V

= V

IN

SHDN

V

= 0V

7

V

= 0V

7

V

= 0V

SHDN

0

1

2

3

4

5

6

7

8

9

10

0

1

2

3

4

5

6

8

9

10

0

1

2

3

4

5

6

8

9

10

INPUT VOLTAGE (V)

3021 G03

3021 G26

3021 G27

3021fc

6

LT3021/LT3021-1.2/

LT3021-1.5/LT3021-1.8

TYPICAL PERFORMANCE CHARACTERISTICS

GND Pin Current

8

7

6

5

4

3

2

1

0

9

8

7

6

5

4

3

2

1

0

V

T

= 1.2V

V

T

= 1.5V

V

J

= 1.8V

OUT

J

OUT

J

R

L

= 2.4Ω

L

= 25°C

T

= 25°C

R

L

= 3Ω

8

7

6

5

4

3

2

1

0

L

I

= 500mA

I

= 500mA

R

L

= 3.6Ω

L

I

= 500mA

R

L

= 4.8Ω

L

R

L

= 6Ω

R

L

= 7.2Ω

L

I

= 250mA

R

I

= 24Ω

I

= 250mA

R

L

= 36Ω

I

= 250mA

L

R

L

= 30Ω

L

R

= 120Ω

= 10mA

L

R

= 50mA

= 150Ω

= 10mA

R

= 180Ω

L

= 50mA

I

= 50mA

L

I

L

I

= 10mA

L

R

L

= 12Ω

R

L

= 18Ω

L

R

L

= 15Ω

L

I

= 100mA

I

= 100mA

I

= 100mA

R

= 1.5k, I = 1mA

L

R

= 1.8k, I = 1mA

L

R

L

= 1.2k, I = 1mA

L

0

1

2

3

4

5

6

7

8

9

10

0

1

2

3

4

5

6

7

8

9

10

0

1

2

3

4

5

6

7

8

9

10

INPUT VOLTAGE (V)

3021 G06

3021 G24

3021 G25

GND Pin Current vs I_LOAD

SHDN Pin Threshold

SHDN Pin Input Current

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

10

9

8

7

6

5

4

3

2

1

0

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

I

= 1mA

V

= 10V

L

SHDN

–50 –25

0

25

50

75 100 125

0

100

200

300

400

500

0

1

2

3

4

5

6

7

8

9

10

TEMPERATURE (°C)

LOAD CURRENT (mA)

SHDN PIN VOLTAGE (V)

3021 G08

3021 G07

3021 G09

SHDN Pin Input Current

Current Limit

Reverse Output Current

5

4

3

2

1

0

2.0

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0

500

450

400

350

300

250

200

150

100

50

V

= 0V

V

= 10V

V

= 0V

OUT

SHDN

IN

OUT

= 1.2V

V

= 10V

IN

V

= 1.7V

IN

0

–50 –25

0

25

50

75 100 125

–50 –25

0

25

50

75 100 125

–50 –25

0

25

50

75 100 125

TEMPERATURE (°C)

3021 G10

3021 G12

3021 G13

3021fc

7

LT3021/LT3021-1.2/

LT3021-1.5/LT3021-1.8

TYPICAL PERFORMANCE CHARACTERISTICS

Load Regulation

Input Ripple Rejection

ΔI_L= 1mA to 500mA

70

60

50

40

30

20

10

0

100

90

80

70

60

50

40

30

20

10

0

2.5

2.0

1.5

C

= 22μF

= 4.7μF

OUT

1.0

0.5

0

–0.5

–1.0

–1.5

–2.0

–2.5

C

OUT

V

= 1.15V

OUT

IN

= 0.5V

V

= 1.5V + 50mV

= 0.5V

RIPPLE

10k

V

L

= 1.5V + 0.5V RIPPLE AT 120Hz

P-P

IN

OUT

= 500mA

RMS

IN

OUT

*LOAD REGULATION NUMBER REFERS

TO CHANGE IN THE 200mV REFERENCE

VOLTAGE

= 0.5V

I

= 500mA

L

10

100

1k

100k

1M

–50 –25

0

25

50

75 100 125

–50 –25

0

25

50

75 100 125

FREQUENCY (Hz)

TEMPERATURE (°C)

3021 G14

3021 G15

3021 G17

No-Load Recovery Threshold

Output Noise Spectral Density

10

1

18

16

14

12

10

8

V

L

C

= 1.2V

OUT

I

= 500mA

= 4.7μF

OUT

0.1

6

4

2

0.01

10

0

100

1k

10k

100k

1M

0

5

10

15

20

FREQUENCY (Hz)

OUTPUT OVERSHOOT (%)

3021 G20

3021 G18

RMS Output Noise vs Load

Current (10Hz to 100kHz)

Transient Response

300

250

200

150

100

50

V

C

= 1.2V

= 4.7μF

OUT

V

OUT

50mV/DIV

I

OUT

500mA/DIV

3021 G21

50μs/DIV

I

= 50mA TO 500mA

OUT

IN

V

C

= 1.5V

0

0.01

0.1

1

10

100

= 1.2V

OUT

= 22μF

LOAD CURRENT (mA)

3021 G19

3021fc

8

LT3021/LT3021-1.2/

LT3021-1.5/LT3021-1.8

PIN FUNCTIONS ^{(DH Package/S8 Package)}

OUT(Pins3,4/Pin2):Thesepinssupplypowertotheload.

Use a minimum output capacitor of 3.3μF to prevent oscil-

lations.Applicationswithlargeloadtransientsrequirelarger

output capacitors to limit peak voltage transients. See the

Applications Information section for more information on

output capacitance and reverse output characteristics.

drainlogic,normallyseveralmicroamperes,andtheSHDN

pin current, typically 2.5μA. If unused, connect the SHDN

pin to V . The LT3021 does not function if the SHDN pin

IN

is not connected.

IN (Pins 12, 14/Pin 8): These pins supply power to the

device. The LT3021 requires a bypass capacitor at IN if

it is more than six inches away from the main input ﬁlter

capacitor. The output impedance of a battery rises with

frequency, so include a bypass capacitor in battery-pow-

ered circuits. A bypass capacitor in the range of 3.3μF to

10μF sufﬁces. The LT3021 withstands reverse voltages

on the IN pin with respect to ground and the OUT pin. In

the case of a reversed input, which occurs if a battery is

plugged in backwards, the LT3021 acts as if a diode is

in series with its input. No reverse current ﬂows into the

LT3021 and no reverse voltage appears at the load. The

device protects itself and the load.

SENSE(Pin7/Pin3, FixedVoltageDeviceOnly):Thispin

is the sense point for the internal resistor divider. It should

be tied directly to the OUT pins for best results.

ADJ (Pin 7/Pin 3): This pin is the inverting terminal to the

error ampliﬁer. Its typical input bias current of 20nA ﬂows

out of the pin (see curve of ADJ Pin Bias Current vs Tem-

perature in the Typical Performance Characteristics). The

ADJ pin reference voltage is 200mV (referred to GND).

AGND (Pin 8/Pin 4): Ground.

PGND (Pins 10, 17/Pin 6): Ground.

EXPOSED PAD (Pin 17, DH16 Package Only): Ground.

Solder Pin 17 to the PCB ground. Connect directly to Pins

8, 10 for best performance.

SHDN (Pin 9/Pin 5): The SHDN pin puts the LT3021 into

a low power state. Pulling the SHDN pin low turns the

output off. Drive the SHDN pin with either logic or an open

collector/drain device with a pull-up resistor. The pull-up

resistor supplies the pull-up current to the open collector/

NC (Pins 1, 2, 5, 6, 11, 13, 15, 16/Pins 1, 7): NoConnect.

No connect pins may be ﬂoated, tied to IN or tied to GND.

BLOCK DIAGRAM (DH Package/S8 Package)

IN

(12, 14/8)

R3

THERMAL

SHUTDOWN

SHDN

(9/5)

SHUTDOWN

D1

Q3

–

CURRENT

Q1

ERROR AMP

+

GAIN

200mV

BIAS CURRENT

AND

REFERENCE

GENERATOR

OUT

D2

(3,4/2)

OUT SENSE

(7/3)

212mV

–

NO-LOAD

RECOVERY

Q2

R2

+

ADJ

(7/3)

25k

R1

FIXED

OUT

NOTE:

V

R1

R2

FOR LT3021 ADJUST PIN (7/3) IS CONNECTED TO

THE ADJUST PIN, R1 AND R2 ARE EXTERNAL.

FOR LT3021-1.X PIN (7/3) IS CONNECTED TO THE

OUTPUT SENSE PIN, R1 AND R2 ARE INTERNAL.

1.2V 20k 100k

1.5V 20k 130k

1.8V 20k 160k

GND

(8,10,17/4,6)

3021 BD

3021fc

9

LT3021/LT3021-1.2/

LT3021-1.5/LT3021-1.8

APPLICATIONS INFORMATION

0.4mV at V = 200mV. At V

= 1.5V, load regulation is:

The LT3021 is a very low dropout linear regulator capable

of 1V input supply operation. Devices supply 500mA of

output current and dropout voltage is typically 155mV.

Quiescent current is typically 120μA and drops to 3μA in

shutdown. The LT3021 incorporates several protection

features, making it ideal for use in battery-powered sys-

tems. The device protects itself against reverse-input and

reverse-output voltages. In battery backup applications

where the output is held up by a backup battery when the

input is pulled to ground, the LT3021 acts as if a diode is

in series with its output which prevents reverse current

ﬂow. In dual supply applications where the regulator

load is returned to a negative supply, the output can be

pulled below ground by as much as 10V without affecting

start-up or normal operation.

ADJ

OUT

(1.5V/200mV) • (0.4mV) = 3mV

Output Capacitance and Transient Response

The LT3021’s design is stable with a wide range of output

capacitors,butisoptimizedforlowESRceramiccapacitors.

The output capacitor’s ESR affects stability, most notably

with small value capacitors. Use a minimum output ca-

pacitor of 3.3μF with an ESR of 0.2Ω or less to prevent

oscillations.TheLT3021isalowvoltagedevice,andoutput

loadtransientresponseisafunctionofoutputcapacitance.

Larger values of output capacitance decrease the peak

deviations and provide improved transient response for

larger load current changes. For output capacitor values

greater than 22μF a small feedforward capacitor with a

value of 300pF across the upper divider resistor (R2 in

Figure 1) is required. Under extremely low output current

Adjustable Operation

The LT3021’s output voltage range is 0.2V to 9.5V. Figure

1 shows that the output voltage is set by the ratio of two

externalresistors.Thedeviceregulatestheoutputtomain-

tain the ADJ pin voltage at 200mV referenced to ground.

The current in R1 equals 200mV/R1 and the current in R2

is the current in R1 minus the ADJ pin bias current. The

ADJ pin bias current of 20nA ﬂows out of the pin. Use

the formula in Figure 1 to calculate output voltage. An R1

value of 20k sets the resistor divider current to 10μA. Note

that in shutdown the output is turned off and the divider

current is zero. Curves of ADJ Pin Voltage vs Temperature

and ADJ Pin Bias Current vs Temperature appear in the

Typical Performance Characteristics section.

conditions (I

< 30μA) a low frequency small signal

LOAD

oscillation (200Hz/8mV

at 1.2V output) can occur.

P-P

A minimum load of 100μA is recommended to prevent

this instability.

Give extra consideration to the use of ceramic capacitors.

Manufacturers make ceramic capacitors with a variety of

dielectrics, each with a different behavior across tempera-

ture and applied voltage. The most common dielectrics

are Z5U, Y5V, X5R and X7R. The Z5U and Y5V dielectrics

provide high C-V products in a small package at low cost,

but exhibit strong voltage and temperature coefﬁcients.

The X5R and X7R dielectrics yield highly stable character-

isiticsandaremoresuitableforuseastheoutputcapacitor

at fractionally increased cost. The X5R and X7R dielectrics

both exhibit excellent voltage coefﬁcient characteristics.

The X7R type works over a larger temperature range and

exhibits better temperature stability whereas X5R is less

expensive and is available in higher values. Figures 2 and

3 show voltage coefﬁcient and temperature coefﬁcient

comparisons between Y5V and X5R material.

IN

OUT

ADJ

V

OUT

+

V

LT3021

SHDN

GND

IN

R2

R1

3021 F01

(R2)

R2

R1

V

= 200mV 1 +

– I

ADJ

OUT

ADJ

(

)

V

= 200mV

Voltage and temperature coefficients are not the only

sources of problems. Some ceramic capacitors have a

piezoelectric response. A piezoelectric device generates

voltage across its terminals due to mechanical stress,

similar to the way a piezoelectric accelerometer or micro-

phone works. For a ceramic capacitor, the stress can be

induced by vibrations in the system or thermal transients.

I

= 20nA AT 25°C

ADJ

OUTPUT RANGE = 0.2V TO 9.5V

Figure 1. Adjustable Operation

Speciﬁcations for output voltages greater than 200mV

are proportional to the ratio of desired output voltage to

200mV; (V /200mV). For example, load regulation for

OUT

The resulting voltages produced can cause appreciable

an output current change of 1mA to 500mA is typically

3021fc

10

LT3021/LT3021-1.2/

LT3021-1.5/LT3021-1.8

APPLICATIONS INFORMATION

20

BOTH CAPACITORS ARE 16V,

1210 CASE SIZE, 10μF

0

X5R

–20

1mV/DIV

–40

–60

Y5V

3021 F04

–80

V

C

LOAD

= 1.3V

= 10F

= 0

1ms/DIV

OUT

I

–100

0

8

12 14

2

4

6

10

16

Figure 4. Noise Resulting from Tapping on a Ceramic Capacitor

DC BIAS VOLTAGE (V)

3021 F02

To eliminate this problem, the LT3021 incorporates a

no-load or light-load recovery circuit. This circuit is a

voltage-controlledcurrentsinkthatsigniﬁcantlyimproves

the light load transient response time by discharging the

output capacitor quickly and then turning off. The cur-

rent sink turns on when the output voltage exceeds 6%

of the nominal output voltage. The current sink level is

then proportional to the overdrive above the threshold

up to a maximum of approximately 15mA. Consult the

curve in the Typical Performance Characteristics for the

No-Load Recovery Threshold.

Figure 2. Ceramic Capacitor DC Bias Characteristics

40

20

X5R

0

–20

–40

Y5V

–60

–80

BOTH CAPACITORS ARE 16V,

1210 CASE SIZE, 10μF

If external circuitry forces the output above the no load

recovery circuit’s threshold, the current sink turns on in

an attempt to restore the output voltage to nominal. The

currentsinkremainsonuntiltheexternalcircuitryreleases

theoutput.However,iftheexternalcircuitrypullstheoutput

voltage above the input voltage, or the input falls below

the output, the LT3021 turns the current sink off and shuts

down the bias current/reference generator circuitry.

–100

50

TEMPERATURE (°C)

100 125

–50 –25

0

25

75

3021 F03

Figure 3. Ceramic Capacitor Temperature Characteristics

amounts of noise. A ceramic capacitor produced Figure

4’s trace in response to light tapping from a pencil. Similar

vibration induced behavior can masquerade as increased

output voltage noise.

Thermal Considerations

No-Load/Light-Load Recovery

The LT3021’s power handling capability is limited by

its maximum rated junction temperature of 125°C. The

power dissipated by the device is comprised of two

components:

Atransientloadstepoccurswhentheoutputcurrentchanges

from its maximum level to zero current or a very small load

current. The output voltage responds by overshooting until

the regulator lowers the amount of current it delivers to the

newlevel.Theregulatorloopresponsetimeandtheamount

ofoutputcapacitancecontroltheamountofovershoot.Once

the regulator has decreased its output current, the current

1. Outputcurrentmultipliedbytheinput-to-outputvoltage

differential: (I )(V – V ) and

OUT

IN

OUT

2. GND pin current multiplied by the input voltage:

(I )(V ).

provided by the resistor divider (which sets V ) is the

OUT

GND

IN

only current remaining to discharge the output capacitor

from the level to which it overshot. The amount of time it

takes for the output voltage to recover easily extends to

milliseconds with microamperes of divider current and a

few microfarads of output capacitance.

GNDpincurrentisfoundbyexaminingtheGNDpincurrent

curves in the Typical Performance Characteristics. Power

dissipation is equal to the sum of the two components

listed above.

3021fc

11

LT3021/LT3021-1.2/

LT3021-1.5/LT3021-1.8

APPLICATIONS INFORMATION

The LT3021 regulator has internal thermal limiting (with

hysteresis)designedtoprotectthedeviceduringoverload

conditions. For normal continuous conditions, do not ex-

ceed the maximum junction temperature rating of 125°C.

Carefully consider all sources of thermal resistance from

junction to ambient including other heat sources mounted

in proximity to the LT3021.

Calculating Junction Temperature

Example: Given an output voltage of 1.2V, an input voltage

range of 1.8V 10%, an output current range of 1mA to

500mA, and a maximum ambient temperature of 70°C,

what will the maximum junction temperature be for an

application using the DH package?

The power dissipated by the device is equal to:

The underside of the LT3021 DH package has exposed

2

I

(V

– V ) + I (V

)

metal (14mm ) from the lead frame to where the die is

OUT(MAX) IN(MAX)

OUT

GND IN(MAX)

attached. This allows heat to directly transfer from the

die junction to the printed circuit board metal to control

maximumoperatingjunctiontemperature.Thedual-in-line

pin arrangement allows metal to extend beyond the ends

of the package on the topside (component side) of a PCB.

Connect this metal to GND on the PCB. The multiple IN

and OUT pins of the LT3021 also assist in spreading heat

to the PCB.

where

I

= 500mA

= 1.98V

OUT(MAX)

V

IN(MAX)

I

at (I = 500mA, V = 1.98V) = 10mA

OUT IN

GND

so

P = 500mA(1.98V – 1.2V) + 10mA(1.98V) = 0.41W

The LT3021 S8 package has Pin 4 fused with the lead

frame. This also allows heat to transfer from the die to the

printedcircuitboardmetal, thereforereducingthethermal

resistance. Copper board stiffeners and plated through-

holes can also be used to spread the heat generated by

power devices.

Thethermalresistanceisintherangeof35°C/Wto70°C/W

dependingonthecopperarea.Sothejunctiontemperature

rise above ambient is approximately equal to:

0.41W(52.5°C/W) = 21.5°C

The maximum junction temperature equals the maximum

junctiontemperatureriseaboveambientplusthemaximum

ambient temperature or:

The following tables list thermal resistance for several

different board sizes and copper areas for two different

packages. Measurements were taken in still air on 3/32”

FR-4 board with one ounce copper.

T

= 21.5°C + 70°C = 91.5°C

JMAX

Protection Features

Table 1. Measured Thermal Resistance For DH Package

COPPER AREA

THERMAL RESISTANCE

The LT3021 incorporates several protection features

that make it ideal for use in battery-powered circuits.

In addition to the normal protection features associated

with monolithic regulators, such as current limiting and

thermal limiting, the device also protects against reverse-

input voltages, reverse-output voltages and reverse out-

put-to-input voltages.

TOPSIDE*

BACKSIDE BOARD AREA (JUNCTION-TO-AMBIENT)

2

2500mm

30°C/W

35°C/W

50°C/W

55°C/W

65°C/W

2

900mm

2

225mm

2

100mm

2

50mm

Current limit protection and thermal overload protection

protect the device against current overload conditions at

the output of the device. For normal operation, do not

exceed a junction temperature of 125°C.

Table 2. Measured Thermal Resistance For S8 Package

COPPER AREA THERMAL RESISTANCE

TOPSIDE* BACKSIDE BOARD AREA (JUNCTION-TO-AMBIENT)

2

2500mm

70°C/W

78°C/W

84°C/W

96°C/W

2

The IN pins of the device withstand reverse voltages of

10V. The LT3021 limits current ﬂow to less than 1μA and

no negative voltage appears at OUT. The device protects

both itself and the load against batteries that are plugged

1000mm

2

225mm

100mm

2

50mm

in backwards.

*Device is mounted on topside.

3021fc

12

LT3021/LT3021-1.2/

LT3021-1.5/LT3021-1.8

APPLICATIONS INFORMATION

The LT3021 incurs no damage if OUT is pulled below

ground. If IN is left open circuit or grounded, OUT can be

pulled below ground by 10V. No current ﬂows from the

pass transistor connected to OUT. However, current ﬂows

in (but is limited by) the resistor divider that sets the out-

put voltage. Current ﬂows from the bottom resistor in the

divider and from the ADJ pin’s internal clamp through the

top resistor in the divider to the external circuitry pulling

OUT below ground. If IN is powered by a voltage source,

OUT sources current equal to its current limit capability

and the LT3021 protects itself by thermal limiting. In this

case, grounding SHDN turns off the LT3021 and stops

OUT from sourcing current.

If the LT3021 IN pin is forced below the OUT pin or the

OUT pin is pulled above the IN pin, input current drops to

less than 10μA typically. This occurs if the LT3021 input is

connected to a discharged (low voltage) battery and either

a backup battery or a second regulator circuit holds up

the output. The state of the SHDN pin has no effect on the

reverse output current if OUT is pulled above IN.

Input Capacitance and Stability

The LT3021 is designed to be stable with a minimum

capacitance of 3.3μF placed at the IN pin. Ceramic capaci-

tors with very low ESR may be used. However, in cases

where a long wire is used to connect a power supply to

the input of the LT3021 (and also from the ground of the

LT3021backtothepowersupplyground),useoflowvalue

input capacitors combined with an output load current of

20mA or greater may result in an unstable application.

This is due to the inductance of the wire forming an LC

tank circuit with the input capacitor and not a result of the

LT3021 being unstable.

The LT3021 incurs no damage if the ADJ pin is pulled

above or below ground by 10V. If IN is left open circuit or

grounded and ADJ is pulled above ground, ADJ acts like a

25k resistor in series with a 1V clamp (one Schottky diode

in series with one diode). ADJ acts like a 25k resistor in

series with a Schottky diode if pulled below ground. If IN

is powered by a voltage source and ADJ is pulled below its

referencevoltage,theLT3021attemptstosourceitscurrent

The self-inductance, or isolated inductance, of a wire is

directly proportional to its length. However, the diameter

of a wire does not have a major inﬂuence on its self-in-

ductance. For example, the self inductance of a 2-AWG

isolated wire with a diameter of 0.26 in. is about half the

inductance of a 30-AWG wire with a diameter of 0.01 in.

One foot of 30-AWG wire has 465nH of self inductance.

limit capability at OUT. The output voltage increases to V

IN

– V

with V

set by whatever load current

DROPOUT

the LT3021 supports. This condition can potentially dam-

age external circuitry powered by the LT3021 if the output

voltage increases to an unregulated high voltage. If IN is

powered by a voltage source and ADJ is pulled above its

referencevoltage,twosituationscanoccur.IfADJispulled

slightly above its reference voltage, the LT3021 turns off

the pass transistor, no output current is sourced and the

output voltage decreases to either the voltage at ADJ or

less. If ADJ is pulled above its no load recovery threshold,

thenoloadrecoverycircuitryturnsonandattemptstosink

current. OUT is actively pulled low and the output voltage

clampsataSchottkydiodeaboveground. Pleasenotethat

thebehaviordescribedaboveappliestotheLT3021only. If

a resistor divider is connected under the same conditions,

there will be additional V/R current.

The overall self-inductance of a wire can be reduced in

two ways. One is to divide the current ﬂowing towards the

LT3021 between two parallel conductors and ﬂows in the

same direction in each. In this case, the farther the wires

are placed apart from each other, the more inductance

will be reduced, up to a 50% reduction when placed a few

inches apart. Splitting the wires basically connects two

equal inductors in parallel. However, when placed in close

proximity from each other, mutual inductance is added to

the overall self inductance of the wires. The most effective

way to reduce overall inductance is to place the forward

and return-current conductors (the wire for the input and

the wire for ground) in very close proximity. Two 30-AWG

wires separated by 0.02 in. reduce the overall self-induc-

tance to about one-ﬁfth of a single isolated wire.

In circuits where a backup battery is required, several

different input/output conditions can occur. The output

voltage may be held up while the input is either pulled to

ground, pulledtosomeintermediatevoltageorisleftopen

circuit. In the case where the input is grounded, there is

less than 1μA of reverse output current.

3021fc

13

LT3021/LT3021-1.2/

LT3021-1.5/LT3021-1.8

APPLICATIONS INFORMATION

If the LT3021 is powered by a battery mounted in close

proximityonthesamecircuitboard,a3.3μFinputcapacitor

issufﬁcientforstability.However,iftheLT3021ispowered

by a distant supply, use a larger value input capacitor fol-

lowingtheguidelineofroughly1μF(inadditiontothe3.3μF

minimum) per 8 inches of wire length. As power supply

output impedance may vary, the minimum input capaci-

tance needed to stabilize the application may also vary.

Extracapacitancemayalsobeplaceddirectlyontheoutput

of the power supply; however, this will require an order of

magnitude more capacitance as opposed to placing extra

capacitanceincloseproximitytotheLT3021.Furthermore,

series resistance may be placed between the supply and

the input of the LT3021 to stabilize the application; as little

as 0.1Ω to 0.5Ω will sufﬁce.

PACKAGE DESCRIPTION

DH Package

16-Lead Plastic DFN (5mm × 5mm)

(Reference LTC DWG # 05-08-1709)

R = 0.115

TYP

0.40 0.05

5.00 0.10

9

16

R = 0.20

TYP

0.70 0.05

5.50 0.05

4.10 0.05

3.45 0.05

(2 SIDES)

3.45 0.10

(2 SIDES)

5.00 0.10

PACKAGE

OUTLINE

PIN 1

TOP MARK

(SEE NOTE 6)

NOTCH

(DH16) DFN 0204

8

1

0.25 0.05

0.50 BSC

0.75 0.05

0.200 REF

0.25 0.05

0.50 BSC

4.10 0.10

(2 SIDES)

4.10 0.05

(2 SIDES)

0.00 – 0.05

BOTTOM VIEW—EXPOSED PAD

RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS

NOTE:

1. DRAWING PROPOSED TO BE MADE VARIATION OF VERSION (WJJD-1) IN JEDEC

PACKAGE OUTLINE MO-229

2. DRAWING NOT TO SCALE

3. ALL DIMENSIONS ARE IN MILLIMETERS

4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE

MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE

5. EXPOSED PAD SHALL BE SOLDER PLATED

6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE

3021fc

14

LT3021/LT3021-1.2/

LT3021-1.5/LT3021-1.8

PACKAGE DESCRIPTION

S8 Package

8-Lead Plastic Small Outline (Narrow .150 Inch)

(Reference LTC DWG # 05-08-1610)

.189 – .197

(4.801 – 5.004)

.045 .005

NOTE 3

.050 BSC

7

5

8

6

.245

MIN

.160 .005

.150 – .157

(3.810 – 3.988)

NOTE 3

.228 – .244

(5.791 – 6.197)

.030 .005

TYP

1

3

4

2

RECOMMENDED SOLDER PAD LAYOUT

.010 – .020

(0.254 – 0.508)

× 45°

.053 – .069

(1.346 – 1.752)

.004 – .010

(0.101 – 0.254)

.008 – .010

(0.203 – 0.254)

0°– 8° TYP

.016 – .050

(0.406 – 1.270)

.050

(1.270)

BSC

.014 – .019

(0.355 – 0.483)

TYP

NOTE:

INCHES

1. DIMENSIONS IN

(MILLIMETERS)

2. DRAWING NOT TO SCALE

3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.

MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)

SO8 0303

3021fc

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.

However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-

tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.

15

LT3021/LT3021-1.2/

LT3021-1.5/LT3021-1.8

RELATED PARTS

PART NUMBER

DESCRIPTION

COMMENTS

LT1121/LT1121HV 150mA, Micropower LDOs

V

SD

: 4.2V to 30V/36V, V : 3.75V to 30V, V = 0.42V, I = 30μA,

OUT DO Q

= 16μA, Reverse-Battery Protection, SOT-223, S8, Z Packages

IN

I

LT1129

LT1761

700mA, Micropower LDO

V : 4.2V to 30V, V : 3.75V to 30V, V = 0.4V, I = 50μA, I = 16μA,

IN OUT DO Q SD

DD, SOT-223, S8, TO220-5, TSSOP20 Packages

100mA, Low Noise Micropower LDO

V : 1.8V to 20V, V : 1.22V to 20V, V = 0.3V, I = 20μA, I < 1μA,

IN OUT DO Q SD

Low Noise: < 20μV

ThinSOT Package

, Stable with 1μF Ceramic Capacitor,

RMSP-P

LT1762

150mA, Low Noise Micropower LDO

500mA, Low Noise Micropower LDO

3A, Low Noise, Fast Transient Response LDOs

V : 1.8V to 20V, V : 1.22V to 20V, V = 0.3V, I = 25μA, I < 1μA,

IN OUT DO Q SD

Low Noise: <20μV

, MS8 Package

RMSP-P

LT1763

V : 1.8V to 20V, V : 1.22V to 20V, V = 0.3V, I = 30μA, I < 1μA,

IN OUT DO Q SD

Low Noise: < 20μV

, S8 Package

RMSP-P

LT1764/LT1764A

V : 2.7V to 20V, V : 1.21V to 20V, V = 0.34V, I = 1mA, I < 1μA,

IN OUT DO Q SD

Low Noise: <40μV

, “A” Version Stable with Ceramic Capacitors,

RMSP-P

DD, TO220-5 Packages

LTC1844

150mA, Low Noise, Micropower VLDO

300mA, Low Noise Micropower LDO

V

SD

: 1.6V to 6.5V, V

= 1.25V, V = 0.09V, I = 35μA,

RMS

IN

OUT(MIN) DO Q

I

< 1μA, Low Noise: < 30μV

, ThinSOT Package

LT1962

V : 1.8V to 20V, V : 1.22V to 20V, V = 0.27V, I = 30μA, I < 1μA,

IN OUT DO Q SD

Low Noise: < 20μV

, MS8 Package

RMSP-P

LT1963/LT1963A

1.5A, Low Noise, Fast Transient Response LDOs

V : 2.1V to 20V, V : 1.21V to 20V, V = 0.34V, I = 1mA, I < 1μA,

IN OUT DO Q SD

Low Noise: < 40μV

, “A” Version Stable with Ceramic Capacitors,

RMSP-P

DD, TO220-5, SOT223, S8 Packages

LT3010

LT3020

50mA, High Voltage, Micropower LDO

100mA, Low Voltage LDO

V : 3V to 80V, V : 1.275V to 60V, V = 0.3V, I = 30μA, I < 1μA,

IN OUT DO Q SD

RMSP-P

Exposed MS8 Package

Low Noise: <100μV

, Stable with 1μF Output Capacitor,

V

: 0.9V to 10V, V : 0.2V to 5V (min), V = 0.15V, I = 120μA,

IN

OUT

DO

Q

Noise: <250μV

, Stable with 2.2μF Ceramic Capacitors,

RMSP-P

DFN-8, MS8 Packages

V : 0.9V to 5.5V, V : 0.4V to 3.6V (min), V = 0.05V, I = 54μA,

IN

LTC3025

LTC3026

300mA, Low Voltage Micropower LDO

1.5A, Low Input Voltage VLDO Regulator

OUT

DO

Q

Stable with 1μF Ceramic Capacitors, DFN-6 Package

V

: 1.14V to 3.5V (Boost Enabled), 1.14V to 5.5V (with External 5V),

IN

= 0.1V, I = 950μA, Stable with 10μF Ceramic Capacitors,

DO

Q

10-Lead MSOP and DFN-10 Packages

LT3150

Low V , Fast Transient Response, VLDO Controller

V

IN

DS(ON)

: 1.1V to 10V, V : 1.21V to 10V, V = Set by External MOSFET

IN

OUT

DO

R

, 1.4MHz Boost Converter Generates Gate Drive, SSOP16 Package

3021fc

LT 0608 REV C • PRINTED IN USA

LinearTechnology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

16

●

(408) 432-1900 FAX: (408) 434-0507 www.linear.com


型号：	LT3021-1.8_15
厂家：	Linear
描述：	500mA, Low Voltage, Very Low Dropout Linear Regulator
文件：	总16页 (文件大小：195K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

LT3021-1.8_15 [Linear]

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