LINEAR TECHNOLOGY LT3150 Technical data

查询LT3150CGN供应商

Low Input Voltage, Very Low Dropout

FEATURES

■

Fast Transient Response Optimized with
Ceramic Output Capacitors

■

FET R

■

±1% Reference Tolerance Over Temperature

■

Multifunction LDO Shutdown Pin with Latchoff

■

Fixed Frequency 1.4MHz Boost Converter Generates

Defines Dropout Voltage

DS(ON)

MOSFET Gate Drive

■

Internally Compensated Boost Converter Uses Tiny
Capacitors and Inductor

■

Independent Boost Converter Shutdown Control
Permits LDO Output Voltage Supply Sequencing

■

16-Lead SSOP Package

U

APPLICATIO S

■

Microprocessor, ASIC and I/O Supplies

■

Very Low Dropout Input-to-Output Conversion

■

Logic Termination Supplies

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

LT3150

Fast Transient Response,

Linear Regulator Controller

U

DESCRIPTIO

The LT®3150 drives a low cost external N-channel MOSFET
as a source follower to produce a fast transient response,
very low dropout voltage linear regulator. Selection of the
N-channel MOSFET R
300mV for low VIN to low V

The LT3150 includes a fixed frequency boost regulator
that generates gate drive for the N-channel MOSFET. The
internally compensated current mode PWM architecture
combined with the 1.4MHz switching frequency permits
the use of tiny, low cost capacitors and inductors.

The LT3150’s transient load performance is optimized
with ceramic output capacitors. A precision 1.21V refer­ence accommodates low voltage supplies.

Protection includes a high side current limit amplifier that
activates a fault timer circuit. A multifunction shutdown
pin provides either current limit time-out with latchoff,
overvoltage protection or thermal shutdown. Independent
shutdown control of the boost converter provides on/off
and sequencing control of the LDO output voltage.

allows dropout voltages below

DS(ON)

applications.

OUT

TYPICAL APPLICATIO

1.8V to 1.5V, 4A Very Low Dropout Linear Regulator
(Typical Dropout Voltage = 65mV at I

MBR0520L

+

C1

6.19k

4.7µF

1%

1.37k
1%

C

: PANASONIC SP SERIES EEFUE0E221R 20%

IN

C1: AVX TAJA475M020R 20V 20%
L1: MURATA LQH32CN100K11 OR SUMIDA CDRH3D16100

LT3150

V

IN2

FB1
SHDN2
SWGND
GND
GND

SW

V

IN1

SHDN1

I

POS

I

NEG

GATE

FB2

COMP

6800pF 50pF

L1

10µH

5.1Ω

1.5k

U

OUT

Si4410

243Ω
1%

1020Ω
1%

= 4A)

+

C

IN

220µF

2.5V
×2

2.2µF ×10
X5R CERAMIC
0805 CASE

3150 TA01

V

IN

1.8V

V

OUT

1.5V
4A

50mV/DIV

2A/DIV

Transient Response for

0.1A to 4A Output Load Step

20µs/DIV

3150 TA02

3150f

1

LT3150

PACKAGE/ORDER I FOR ATIO

UU

W

GN PACKAGE

16-LEAD PLASTIC SSOP

1
2
3
4
5
6
7
8

TOP VIEW

16
15
14
13
12
11
10

9

SW

SWGND

V

IN1

SHDN2

V

IN2

GND

NC

FB2

FB1
GND
SHDN1
I

POS

I

NEG

GATE
NC
COMP

WWWU

ABSOLUTE AXI U RATI GS

(Note 1)

V

, SHDN1 Voltage .............................................. 10V

IN1

SW Voltage .............................................. –0.4V to 36V

FB1 Voltage ................................................ V

Current into FB1, FB2 Pin .................................... ±1mA

V

, I

, I

IN2

POS

....................................................... 22V

NEG

SHDN2.................................................................... V

Operating Ambient Temperature Range..... 0°C to 70°C

Junction Temperature (Note 2)........................... 125°C

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

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

ELECTRICAL CHARACTERISTICS

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

= 1.5V, V

IN1

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Boost Switching Regulator

V

FB1

I

Q1

Linear Regulator Controller

I

Q2

V

FB2

2

= V

, V

SHDN1

V

IN1

V

IN1

FB1 Reference Voltage ● 1.20 1.23 1.255 V
FB1 Input Bias Current Current Flows into Pin ● 27 80 nA
V

IN1

V

IN1

FB1 Reference Line Regulation 1.5V ≤ V
Switching Frequency ● 1 1.4 1.9 MHz
Maximum Duty Cycle ● 82 86 %
Switch Current Limit (Note 3) 550 800 mA
Switch V
Switch Leakage Current VSW = 5V 0.01 1 µA
SHDN1 Input Voltage High 1 V
SHDN1 Input Voltage Low 0.3 V
SHDN1 Input Bias Current V

V

IN2

FB2 Reference Voltage 1.203 1.210 1.217 V

FB2 Line Regulation 10V ≤ V
FB2 Input Bias Current FB2 = V

IN1

Minimum Operating Voltage 0.9 1.1 V
Maximum Operating Voltage 10 V

Quiescent Current V
Quiescent Current in Shutdown V

CESAT

Quiescent Current ● 51219 mA

= 12V, GATE = 6V, I

IN2

ORDER PART

NUMBER

+ 0.3V

IN1

LT3150CGN

IN2

GN PART

MARKING

3150

T

= 125°C, θJA = 130°C/W, θJC = 40°C/W

JMAX

Consult LTC Marketing for parts specified with wider operating temperature ranges.

= I

POS

SHDN1

SHDN1

V

SHDN1

ISW = 300mA 300 350 mV

SHDN1

V

SHDN1

= 5V, V

NEG

= 1.5V 3 4.5 mA
= 0V, V

= 0V, V

IN1

= 3V, Current Flows into Pin 25 50 µA
= 0V, Current Flows into Pin 0.01 0.1 µA

IN2

FB2,

= 2V 0.01 0.5 µA

IN1

= 5V 0.01 1.0 µA

IN1

≤ 10V 0.02 0.2 %/V

≤ 20V ● 0.01 0.03 %/V

Current Flows out of Pin ● –0.6 –4 µA

= 0.75V unless otherwise noted.

SHDN2

● 1.198 1.210 1.222 V

3150f

LT3150

ELECTRICAL CHARACTERISTICS

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

= 1.5V, V

IN1

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

A

VOL

V

OL

V

OH

= V

, V

SHDN1

Large-Signal Voltage Gain V
GATE Output Swing Low (Note 4) I
GATE Output Swing High I

I

POS

Current Limit Threshold Voltage 42 50 58 mV

Current Limit Threshold Voltage 3V ≤ I
Line Regulation

SHDN2 Sink Current Current Flows Into Pin ● 2.5 5.0 8.0 µA
SHDN2 Source Current Current Flows Out of Pin ● –8 –15 –23 µA
SHDN2 Low Clamp Voltage ● 0.1 0.25 V
SHDN2 High Clamp Voltage ● 1.50 1.85 2.20 V
SHDN2 Threshold Voltage ● 1.18 1.21 1.240 V
SHDN2 Threshold Hysteresis ● 50 100 150 mV

IN1

+ I

Supply Current 3V ≤ I

NEG

= 12V, GATE = 6V, I

IN2

= I

POS

GATE

GATE

GATE

= 5V, V

NEG

= 3V to 10V ● 69 84 dB
= 0mA ● 2.5 3 V
= 0mA ● V

≤ 20V ● 0.3 0.625 1 mA

POS

≤ 20V ● –0.20 –0.50 %/V

POS

= 0.75V unless otherwise noted.

SHDN2

IN2

● 37 50 63 mV

– 1.6 V

– 1 V

IN2

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

Note 2: T
dissipation P

is calculated from the ambient temperature TA and power

J

according to the following formula:

D

TJ = TA + (PD • 130°C/W)

Note 3: Switch current limit is guaranteed by design and/or correlation to
static test.

Note 4: The V

OUT

.

3V – V

of the external MOSFET must be greater than

GS(th)

3150f

3

LT3150

TEMPERATURE (°C)

–50

FB1 REFERENCE VOLTAGE (V)

3150 G05

1.25

1.24

1.23

1.22

1.21

1.20

VOLTAGE

–25 0 25 50 75 100

UW

TYPICAL PERFOR A CE CHARACTERISTICS

Boost Switching Regulator

Switch V

700

TA = 25°C

600

500

400

(mV)

300

CESAT

V

200

100

0

0 100 200 300 400 500 600 700

vs Switch Current

CESAT

SWITCH CURRENT (mA)

Switch Current Limit vs Duty Cycle

1000

900

800

700

600

500

400

SWITCH CURRENT LIMIT (mA)

300

200

10 20 30 40 50 60 70 80

Linear Regulator Controller

3150 G01

DUTY CYCLE (%)

Oscillator Frequency
vs Temperature

2.00

1.75

1.50

1.25

1.00

0.75

0.50

SWITCHING FREQUENCY (MHz)

0.25

70°C

25°C

–40°C

VIN = 5V

VIN = 1.5V

0

–50 –25 0 25 50 75 100

TEMPERATURE (°C)

3150 G04

SHDN1 Input Bias Current
vs V

50

TA = 25°C

40

30

20

10

SHDN1 INPUT BIAS CURRENT (µA)

0

012345

3150 G02

FB1 Reference Voltage
vs Temperature

SHDN1

SHDN1 PIN VOLTAGE (V)

3150 G03

V

IN2

vs Temperature

19
18
17
16
15
14
13
12
11
10

9

QUIESCENT CURRENT (mA)

8

IN2

V

7
6
5

–50 0

–75

4

Quiescent Current

= 12V

V

IN

V

= 20V

IN

VIN = 8V

–25

50 150

75

25

TEMPERATURE (°C)

100

125

3150 G06

1.222

1.220

1.218

1.216

1.214

1.212

1.210

1.208

1.206

1.204

FB2 REFERENCE VOLTAGE (V)

1.202

1.200

175

1.198
–75

FB2 Reference Voltage
vs Temperature

–25

–50 150

0
TEMPERATURE (°C)

75

100

25

50

125

3150 G07

175

FB2 Input Bias Current
vs Temperature

4.0

3.5

3.0

2.5

2.0

1.5

1.0

FB2 INPUT BIAS CURRENT (µA)

0.5

0

–50 150

–75

VIN = 20V

–25

0

25

TEMPERATURE (°C)

V

= 12V

IN

= 8V

V

IN

75

100

125

50

175

3150 G08

3150f

FREQUENCY (Hz)

50

100

ERROR AMPLIFIER GAIN (dB) AND PHASE (DEG)

150

200

1k 100k 1M 100M

3150 G11

0

10k

10M

PHASE

GAIN

TEMPERATURE (°C)

–75

300

I

POS

+ I

NEG

SUPPLY CURRENT (µA)

400

600

700

800

1000

–50

50

100

3150 G14

500

900

25

150

175

–25

0

75 125

I

POS

= I

NEG

= 3V

I

POS

= I

NEG

= 5V

I

POS

= I

NEG

= 12V

I

POS

= I

NEG

= 20V

UW

TYPICAL PERFOR A CE CHARACTERISTICS

LT3150

Linear Regulator Controller

FB2 Line Regulation
vs Temperature

0.030

0.025

0.020

0.015

0.010

FB2 LINE REGULATION (%/V)

0.005

0

–25 25 75 125

TEMPERATURE (°C)

Gate Output Swing Low
vs Temperature

3.00

2.75

2.50

2.25

2.00

1.75

1.50

GATE OUTPUT SWING LOW (V)

1.25

1.00
–50 150

–75

I

LOAD

NO LOAD

–25

0

25

TEMPERATURE (°C)

= 50mA

75

50

100

125

3150 G09

3150 G12

175–50–75 0 50 100 150

175

Error Amplifier Large-Signal
Voltage Gain vs Temperature

120
115
110
105
100

95
90
85
80

LARGE-SIGNAL VOLTAGE GAIN (dB)

75
70

–25

–50 150

–75

0

25

50

TEMPERATURE (°C)

Gate Output Swing High (V
V

) vs Temperature

GATE

3.0

2.5

2.0

I

= 50mA

1.5

1.0

GATE OUTPUT SWING HIGH (V)

0.5

0

LOAD

NO LOAD

–25 25 75 125

TEMPERATURE (°C)

Gain and Phase vs Frequency

75

100

125

175

3150 G10

I

+ I

IN2

–

POS

Supply Current

NEG

vs Temperature

175–50–75 0 50 100 150

3150 G13

Current Limit Threshold Voltage
vs Temperature

65

60

I

55

50

45

40

CURRENT LIMIT THRESHOLD VOLTAGE (mV)

35

–25 25 75 125

= 5V

POS

= 3V

I

POS

TEMPERATURE (°C)

I

POS

= 20V

3150 G15

Current Limit Threshold Voltage
Line Regulation vs Temperature

0

–0.1

–0.2

–0.3

–0.4

CURRENT LIMIT THRESHOLD

VOLTAGE LINE REGULATION (%/V)

175–50–75 0 50 100 150

–0.5

–25

0

–50 150

–75

25

50

TEMPERATURE (°C)

75

100

125

175

3150 G16

SHDN2 Sink Current
vs Temperature

7.5

7.0

6.5

6.0

5.5

5.0

4.5

4.0

SHDN2 SINK CURRENT (µA)

3.5

3.0

2.5
–25

–50 150

–75

0

25

TEMPERATURE (°C)

75

100

125

50

175

3150 G17

3150f

5

LT3150

UW

TYPICAL PERFOR A CE CHARACTERISTICS

Linear Regulator Controller

SHDN2 Source Current
vs Temperature

–10
–11
–12
–13
–14
–15
–16
–17
–18

SHDN2 SOURCE CURRENT (µA)

–19
–20

–25

–50 150

–75

0

25

50

TEMPERATURE (°C)

SHDN2 High Clamp Voltage
vs Temperature

2.1

2.0

1.9

1.8

1.7

1.6

SHDN2 HIGH CLAMP VOLTAGE (V)

1.5
–25 25 75 125

TEMPERATURE (°C)

SHDN2 Low Clamp Voltage
vs Temperature

0.25

0.20

0.15

0.10

0.05

SHDN2 LOW CLAMP VOLTAGE (V)

75

100

125

175

3150 G18

0

–25

–50 150

–75

0
TEMPERATURE (°C)

75

25

50

100

125

175

3150 G19

SHDN2 Hysteresis vs Temperature

150
140
130
120
110
100

90
80

SHDN2 HYSTERESIS (mV)

70
60

3150 G20

175–50–75 0 50 100 150

50

–25

–50 150

–75

0
TEMPERATURE (°C)

75

25

100

50

125

175

3150 G21

U

UU

PI FU CTIO S

SW (Pin 1): Boost Converter Switch Pin. Connect induc­tor/diode here. Minimize trace area at this pin to keep EMI
down.

SWGND (Pin 2): Switch Ground. Tie directly to the local
ground plane and the GNDs at Pins 6 and 15.

V

(Pin 3): Boost Converter Input Supply Pin. Must be

IN1

locally bypassed.
SHDN2 (Pin 4): This is a multifunction shutdown pin that

provides GATE drive latchoff capability. A 15µA current
source, that turns on when current limit is activated,

6

charges a capacitor placed in series with SHDN2 to GND
and performs a current limit time-out function. The pin is
also the input to a comparator referenced to V
When the pin pulls above V

, the comparator latches the

REF

(1.21V).

REF

gate drive to the external MOSFET off. The comparator
typically has 100mV of hysteresis and the SHDN2 pin can
be pulled low to reset the latchoff function. This pin
provides overvoltage protection or thermal shutdown
protection when driven from various resistor divider
schemes.

3150f