LT8570IMS8E#PBF datasheet, PDF

LT8570/LT8570-1

Boost/SEPIC/Inverting

DC/DC Converter with 65V

Switch, Soft-Start and Synchronization

FEATURES

n

DESCRIPTION

The

LT

®

8570 and LT8570-1

are PWM DC/DC converters.

The LT8570 contains a 0.5A, 65V power switch, while

the LT8570-1 contains a 0.25A, 65V power switch. The

LT8570 and LT8570-1 can be configured as either a boost,

SEPIC or inverting converter.

The LT8570/LT8570-1 have an adjustable oscillator, set

by a resistor from the RT pin to ground. Additionally, the

LT8570/LT8570-1 can be synchronized to an external

clock. The switching frequency of the part may be free

running or synchronized, and can be set between 200kHz

and 1.5MHz.

The LT8570/LT8570-1 also feature innovative

SHDN

circuitry that allows for slowly varying input signals and

an adjustable undervoltage lockout function.

Additional features such as frequency foldback and soft-

start are integrated. The LT8570/LT8570-1 are available

in tiny thermally enhanced 3mm

×

3mm 8-lead DFN and

8-lead MSOP packages.

L,

LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and

ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the

property of their respective owners. Protected by U.S. Patents, including 7579816.

n

65V Power Switch

Current Limit Options of 0.5A (LT8570) or 0.25A

(LT8570-1)

Adjustable Switching Frequency

Single Feedback Resistor Sets V

OUT

Synchronizable to External Clock

High Gain

SHDN

Pin Accepts Slowly Varying

Input Signals

Wide Input Voltage Range: 2.55V to 40V

Low V

CESAT

Switch

Integrated Soft-Start Function

Easily Configurable as a Boost, SEPIC, or Inverting

Converter

User Configurable Undervoltage Lockout (UVLO)

Pin Compatible with LT3580 and LT8580

Tiny Thermally Enhanced 8-Lead 3mm

×

3mm DFN

and 8-Lead MSOP Packages

VFD Bias Supplies

TFT-LCD Bias Supplies

GPS Receivers

DSL Modems

Local Power Supply

APPLICATIONS

n

TYPICAL APPLICATION

1.5MHz, 5V to 12V Boost Converter

V

IN

5V

10k

V

IN

SHDN

1µF

SYNC

RT

GND

56.2k

SS

0.1µF

LT8570

VC

6.19k

47pF

2.2nF

8570 TA01a

Efficiency and Power Loss

100

V

OUT

12V

125mA

EFFICIENCY (%)

90

80

70

60

50

40

30

20

0

25

EFFICIENCY

POWER LOSS

50

100

75

LOAD CURRENT (mA)

320

280

240

POWER LOSS (mW)

200

160

120

80

40

22µH

SW

FBX

130k

2.2µF

0

125

8570 TA01b

85701fa

For more information

www.linear.com/LT8570

1

LT8570/LT8570-1

ABSOLUTE MAXIMUM RATINGS

(Note 1)

V

IN

Voltage ................................................. –0.3V to 40V

SW Voltage ................................................ –0.4V to 65V

RT Voltage ................................................... –0.3V to 5V

SS Voltage ................................................ –0.3V to 2.5V

FBX Voltage.................................................................5V

FBX Current............................................................–1mA

VC Voltage ................................................... –0.3V to 2V

SHDN

Voltage ............................................ –0.3V to 40V

SYNC Voltage............................................ –0.3V to 5.5V

Operating Junction Temperature Range

LT8570E, LT8570-1E (Notes 2, 5) ...... –40°C to 125°C

LT8570I, LT8570-1I (Notes 2, 5) ........ –40°C to 125°C

LT8570H, LT8570-1H (Notes 2, 5) .....–40°C to 150°C

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

Lead Temperature (Soldering, 10 sec)

MS8E Package Only.......................................... 300°C

PIN CONFIGURATION

TOP VIEW

FBX 1

VC 2

V

IN

3

SW 4

9

GND

8 SYNC

7 SS

6 RT

5

SHDN

TOP VIEW

FBX

VC

V

IN

SW

1

2

3

4

9

GND

8

7

6

5

SYNC

SS

RT

SHDN

MS8E PACKAGE

8-LEAD PLASTIC MSOP

θ

JA

= 35°C/W TO 40°C/W

EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB

DD PACKAGE

8-LEAD (3mm

×

3mm) PLASTIC DFN

θ

JA

= 43°C/W

EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB

ORDER INFORMATION

LEAD FREE FINISH

LT8570EDD#PBF

LT8570IDD#PBF

LT8570HDD#PBF

LT8570EMS8E#PBF

LT8570IMS8E#PBF

LT8570HMS8E#PBF

LT8570EDD-1#PBF

LT8570IDD-1#PBF

LT8570HDD-1#PBF

LT8570EMS8E-1#PBF

LT8570IMS8E-1#PBF

LT8570HMS8E-1#PBF

TAPE AND REEL

LT8570EDD#TRPBF

LT8570IDD#TRPBF

LT8570HDD#TRPBF

LT8570EMS8E#TRPBF

LT8570IMS8E#TRPBF

LT8570HMS8E#TRPBF

LT8570EDD-1#TRPBF

LT8570IDD-1#TRPBF

LT8570HDD-1#TRPBF

http://www.linear.com/product/LT8570#orderinfo

PART MARKING*

LGRY

LTGRZ

LGSB

LTGSC

PACKAGE DESCRIPTION

8-Lead (3mm

×

3mm) Plastic DFN

8-Lead (3mm

×

3mm) Plastic DFN

8-Lead (3mm

×

3mm) Plastic DFN

8-Lead Plastic MSOP

8-Lead (3mm

×

3mm) Plastic DFN

8-Lead (3mm

×

3mm) Plastic DFN

8-Lead (3mm

×

3mm) Plastic DFN

8-Lead Plastic MSOP

TEMPERATURE RANGE

– 40°C to 125°C

– 40°C to 150°C

– 40°C to 125°C

– 40°C to 150°C

– 40°C to 125°C

– 40°C to 150°C

– 40°C to 125°C

– 40°C to 150°C

LT8570EMS8E-1#TRPBF

LT8570IMS8E-1#TRPBF

LT8570HMS8E-1#TRPBF

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/.

Some packages are available in 500 unit reels through

designated sales channels with #TRMPBF suffix.

2

85701fa

For more information

www.linear.com/LT8570

LT8570/LT8570-1

ELECTRICAL CHARACTERISTICS

PARAMETER

Operating Voltage Range

Positive Feedback Voltage

Negative Feedback Voltage

Positive FBX Pin Bias Current

Negative FBX Pin Bias Current

Error Amplifier Transconductance

Error Amplifier Voltage Gain

Quiescent Current

Quiescent Current in Shutdown

Reference Line Regulation

Switching Frequency, f

OSC

Switching Frequency in Foldback

Switching Frequency Set Range

SYNC High Level for Synchronization

SYNC Low Level for Synchronization

SYNC Clock Pulse Duty Cycle

Recommended Minimum SYNC Ratio

f

SYNC

/f

OSC

Minimum Off-Time

Minimum On-Time

Switch Current Limit

V

SHDN

= 2.5V, Not Switching

V

SHDN

= 0V

2.55V ≤ V

IN

≤ 40V

R

T

= 56.2k

R

T

= 422k

Compared to Normal f

OSC

SYNCing or Free Running

CONDITIONS

– 40°C to 125°C

– 40°C to 150°C

l

The

l

denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at T

A

= 25°C. V

IN

= 5V, V

SHDN

= V

IN

unless otherwise noted. (Note 2)

MIN

2.55

2.9

1.185

–3

81

1.204

3

83.3

200

60

1.2

0

0.01

1.5

200

1/6

1.7

1

0.05

1.77

235

1500

0.4

65

3/4

100

0.75

0.5

0.4

0.375

0.25

0.2

250

0.01

6

1.31

1.27

40

44

12

0

ns

A

mV

µA

V

mV

V

µA

TYP

MAX

40

1.220

12

85

86

UNITS

V

mV

µA

µmhos

V/V

mA

µA

%/V

MHz

kHz

Ratio

kHz

V

%

V

FBX

= Positive Feedback Voltage, Current Into Pin

V

FBX

= Negative Feedback Voltage, Current Out of Pin

l

1.23

165

200

1.3

35

l

V

SYNC

= 0V to 2V

Switch V

CESAT

Switch Leakage Current

Soft-Start Charging Current

SHDN

Minimum Input

Voltage High

SHDN

Minimum Input Voltage Hysteresis

SHDN

Input Voltage Low

SHDN

Pin Bias Current

Minimum Duty Cycle (Note 3), LT8570

Maximum Duty Cycle (Notes 3, 4), LT8570, f

OSC

= 1.5MHz

Maximum Duty Cycle (Notes 3, 4), LT8570, f

OSC

= 200kHz

Minimum Duty Cycle (Note 3), LT8570-1

Maximum Duty Cycle (Notes 3, 4), LT8570-1, f

OSC

= 1.5MHz

Maximum Duty Cycle (Notes 3, 4), LT8570-1, f

OSC

= 200kHz

I

SW

= 0.4A (LT8570)

I

SW

= 0.2A (LT8570-1)

V

SW

= 5V

V

SS

= 0.5V

Active Mode,

SHDN

Rising

Active Mode,

SHDN

Falling

Shutdown Mode

V

SHDN

= 3V

V

SHDN

= 1.3V

V

SHDN

= 0V

l

0.6

0.27

0.15

0.3

0.15

0.075

1

0.85

0.8

0.5

0.43

0.4

l

4

1.23

1.21

1

8

1.4

1.33

0.3

56

15

0.1

l

9

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.

Note 2:

The LT8570E/LT8570-1E are guaranteed to meet performance

specifications from 0°C to 125°C junction temperature. Specifications over

the –40°C to 125°C operating junction temperature range are assured by

design, characterization and correlation with statistical process controls. The

LT8570I/LT8570-1I are guaranteed over the full –40°C to 125°C operating

junction temperature range. The LT8570H/LT8570-1H are guaranteed over

the full –40°C to 150°C operating junction temperature range. Operating

lifetime is derated at junction temperatures greater than 125°C.

Note 3:

Current limit guaranteed by design and/or correlation to static test.

Note 4:

Current limit measured at equivalent of listed switching frequency.

Note 5:

This IC includes overtemperature protection that is intended

to protect the device during momentary overload conditions. Junction

temperature will exceed 150°C when overtemperature protection is active.

Continuous operation above the specified maximum operating junction

temperature may impair device reliability.

85701fa

For more information

www.linear.com/LT8570

3

LT8570/LT8570-1

TYPICAL PERFORMANCE CHARACTERISTICS

Switch Current Limit vs Duty Cycle

1.00

LT8570, 1.5MHz

LT8570, 200kHz

SATURATION VOLTAGE (mV)

700

600

500

400

300

200

100

80

90

0

0.2

0.4

0.6

SWITCH CURRENT (A)

0.8

8570 G02

T

A

= 25°C, unless otherwise specified

Switch Saturation Voltage

LT8570

LT8570-1

SWITCH CURRENT (A)

1.0

Maximum Switch Current vs SS

LT8570

LT8570-1

SWITCH CURRENT (A)

0.75

0.8

0.6

0.50

0.4

0.25

LT8570-1, 1.5MHz

LT8570-1, 200kHz

10

20

30

40 50 60 70

DUTY CYCLE (%)

0.2

0

0.0

0

0.2

0.4

0.6

0.8

SS VOLTAGE (V)

1

1.2

8570 G03

8570 G01

Switch Current Limit

vs Temperature

1.0

0.8

SWITCH CURRENT (A)

1.220

1.215

POSITIVE FBX VOLTAGE (V)

1.210

1.205

1.200

1.195

1.190

1.185

1.180

1.175

Positive and Negative Output

Voltage Regulation

30

25

20

15

10

5

0

–5

–10

–15

0

–20

25 50 75 100 125 150

TEMPERATURE (°C)

8570 G05

NEGATIVE FBX VOLTAGE (mV)

0.6

0.4

0.2

LT8570

LT8570-1

0

25 50 75 100 125 150

TEMPERATURE (°C)

8570 G04

0.0

–50 –25

1.170

–50 –25

Positive and Negative FBX Current

at Output Voltage Regulation

86

POSITIVE FBX CURRENT INTO PIN (µA)

85

84

83

82

81

80

–50 –25

86

NEGATIVE FBX CURRENT OUT OF PIN (µA)

85

84

83

82

81

80

25 50 75 100 125 150

TEMPERATURE (°C)

8570 G06

Oscillator Frequency

1.8

1.6

1.4

FREQUENCY (MHz)

1.2

1.0

0.8

0.6

0.4

0.2

0

–50 –25

0

R

T

= 422k

R

T

= 56.2k

0

100 125 150

TEMPERATURE (°C)

8570 G07

25

50

75

4

85701fa

For more information

www.linear.com/LT8570

LT8570/LT8570-1

TYPICAL PERFORMANCE CHARACTERISTICS

Oscillator Frequency During

Soft-Start

NORMALIZED OSCILLATOR FREQUENCY (F/F

NOM

)

1

2.7

2.6

V

IN

VOLTAGE (V)

2.5

2.4

2.3

2.2

2.1

–50 –25

SHDN

PIN CURRENT (µA)

T

A

= 25°C, unless otherwise specified

Internal UVLO

30

25

20

15

10

5

0

SHDN

Pin Current

125°C

25°C

–40°C

1/2

1/3

1/4

1/5

1/6

0

INVERTING

CONFIGURATIONS

0

0.2

NONINVERTING

CONFIGURATIONS

1

1.2

8570 G08

0.4

0.6

0.8

FBX VOLTAGE (V)

0

25 50 75 100 125 150

TEMPERATURE (°C)

8570 G09

0

0.25 0.5 0.75 1 1.25 1.5 1.75

SHDN

VOLTAGE (V)

2

8570 G10

SHDN

Pin Current

400

350

SHDN

PIN CURRENT (µA)

300

250

200

150

100

50

0

5

10

15

20

25

30

35

40

SHDN

VOLTAGE (V)

125°C

25°C

–40°C

1.40

1.38

1.36

Active/Lockout Threshold

280

240

MINIMUM ON TIME (ns)

200

160

120

80

40

Minimum On-Time vs Temperature

RECOMMENDED MINIMUM ON-TIME

1.34

1.32

1.30

1.28

1.26

1.24

1.22

1.20

–50 –25

0

25 50 75 100 125 150

TEMPERATURE (°C)

8570 G12

SHDN

RISING

SHDN

FALLING

MEASURED MINIMUM ON-TIME

0

–50 –25

0

SHDN

VOLTAGE (V)

8570 G11

25 50 75 100 125 150

TEMPERATURE (°C)

8570 G13

85701fa

For more information

www.linear.com/LT8570

5

Parameter Name	Attribute value
EU restricts the use of certain hazardous substances	Compliant
ECCN (US)	EAR99
Part Status	Active
HTS	8542.39.00.01
Type	Inverting\|Step Up
Output Type	Adjustable
Switching Frequency (kHz)	200 to 1500
Switching Regulator	Yes
Number of Outputs	1
Output Voltage (V)	65(Max)
Minimum Input Voltage (V)	2.55
Maximum Input Voltage (V)	40
Operating Supply Voltage (V)	2.55 to 40
Typical Quiescent Current (uA)	1200
Minimum Operating Temperature (°C)	-40
Maximum Operating Temperature (°C)	125
Supplier Temperature Grade	Industrial
Packaging	Tube
Pin Count	8
Standard Package Name	SOP
Supplier Package	MSOP EP
Mounting	Surface Mount
Package Height	0.86
Package Length	3
Package Width	3
PCB changed	8
Lead Shape	Gull-wing

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