LTC1154HS8_技术文档

LTC1154

High Side Micropower

MOSFET Driver

FEATURES

DESCRIPTION

TheLTC^®1154singlehighsidegatedriverallowsusinglow

costN-channelFETsforhighsideswitchingapplications.An

internal charge pump boosts the gate drive voltage above

thepositiverail, fullyenhancinganN-channelMOSswitch

withnoexternalcomponents. Micropoweroperation, with

8μA standby current and 85μA operating current, allows

use in virtually all systems with maximum efﬁciency.

n

Fully Enhances N-Channel Power MOSFETs

n

8μA I Standby Current

Q

n

85μA I ON Current

Q

n

No External Charge Pump Capacitors

n

4.5V to 18V Supply Range

Short-Circuit Protection

n

Thermal Shutdown via PTC Thermistor

n

Status Output Indicates Shutdown

Included on chip is programmable overcurrent sensing.

A time delay can be added to prevent false triggering on

high inrush current loads. An active high shutdown input

is also provided and interfaces directly to a standard PTC

thermistor for thermal shutdown. An open-drain output

is provided to report switch status to the μP. An active

low enable input is provided to control multiple switches

in banks.

n

Available in 8-Pin SOIC and PDIP Packages

APPLICATIONS

n

Laptop Computer Power Switching

n

SCSI Termination Power Switching

n

Cellular Telephone Power Management

Battery Charging and Management

High Side Industrial and Automotive Switching

Stepper Motor and DC Motor Control

n

The LTC1154 is available in both 8-pin DIP and 8-pin SOIC

packages.

n

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

Technology Corporation. All other trademarks are the property of their respective owners.

TYPICAL APPLICATION

Ultralow Voltage Drop High Side Switch with

Short-Circuit Protection

Standby Supply Current

50

V

J

= 0V

= 25°C

IN

5V

45

40

35

30

25

20

15

10

5

T

51k

0.036Ω*

2.7A MAX

IN

V

S

0.1μF**

200k**

μP

EN

DS

G

LTC1154

STATUS

GND

IRLR024

SD

5V

LOAD

0

5

10

15

20

LTC1154 • TA01

ALL COMPONENTS SHOWN ARE SURFACE MOUNT.

* IMS026 INTERNATIONAL MANUFACTURING SERVICE, INC. (401) 683-9700

** NOT REQUIRED IF LOAD IS RESISTIVE OR INDUCTIVE.

SUPPLY VOLTAGE (V)

LTC1153 • TA02

1154fb

1

LTC1154

ABSOLUTE MAXIMUM RATINGS

(Note 1)

Supply Voltage..........................................................22V

Operating Temperature

Input Voltage.......................(V + 0.3V) to (GND – 0.3V)

LTC1154C ................................................ 0°C to 70°C

LTC1154H .......................................... –40°C to 150°C

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

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

S

Enable Input Voltage ...........(V + 0.3V) to (GND – 0.3V)

S

Gate Voltage.........................(V + 24V) to (GND – 0.3V)

S

Status Output Voltage ...............................................15V

Current (Any Pin)...................................................50mA

PIN CONFIGURATION

TOP VIEW

IN

ENABLE

STATUS

GND

1

2

3

4

8

7

6

5

V

IN

ENABLE

STATUS

GND

1

2

3

4

V

S

8

7

6

5

S

DRAIN SENSE

GATE

DRAIN SENSE

GATE

SHUTDOWN

S8 PACKAGE

8-LEAD PLASTIC SOIC

= 100°C, θ = 150°C/W

N8 PACKAGE

8-LEAD PLASTIC DIP

= 100°C, θ = 130°C/W

T

JMAX

JA

JMAX

JA

ORDER INFORMATION

LEAD FREE FINISH

LTC1154CN8#PBF

LTC1154CS8#PBF

LTC1154HS8#PBF

LEAD BASED FINISH

LTC1154CN8

TAPE AND REEL

PART MARKING

PACKAGE DESCRIPTION

8-Lead Plastic DIP

TEMPERATURE RANGE

0°C to 70°C

LTC1154CN8#TRPBF

LTC1154CS8#TRPBF

LTC1154HS8#TRPBF

TAPE AND REEL

1154

8-Lead Plastic SIOC

PACKAGE DESCRIPTION

8-Lead Plastic DIP

0°C to 70°C

1154H

–40°C to 150°C

TEMPERATURE RANGE

0°C to 70°C

PART MARKING

LTC1154CN8#TR

LTC1154CS8#TR

LTC1154HS8#TR

LTC1154CS8

1154

8-Lead Plastic SIOC

0°C to 70°C

LTC1154HS8

1154H

–40°C to 150°C

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

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/

ELECTRICAL CHARACTERISTICS ^Thel denotes the speciﬁcations which apply over the full operating

temperature range, otherwise speciﬁcations are at T_A= 25°C. V_S= 4.5V to 18V, T_A= 25°C, V_EN= 0V, V_SD= 0V unless otherwise noted.

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

18

UNITS

V

l

V

S

Supply Voltage

4.5

I

Quiescent Current OFF

Quiescent Current ON

Input High Voltage

V = 5V, V = 0V

8

20

μA

V

Q

S

IN

V = 5V, V = 5V

85

120

400

S

IN

V = 12V, V = 5V

180

S

IN

l

V

2

INH

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2

LTC1154

ELECTRICAL CHARACTERISTICS ^Thel denotes the speciﬁcations which apply over the full operating

temperature range, otherwise speciﬁcations are at T_A= 25°C. V_S= 4.5V to 18V, T_A= 25°C, V_EN= 0V, V_SD= 0V unless otherwise noted.

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

0.8

1

UNITS

V

l

V

Input Low Voltage

INL

I

IN

Input Current

0V < V < V

μA

pF

V

IN

S

C

V

Input Capacitance

5

2.6

1

IN

l

ENABLE Input High Voltage

ENABLE Input Low Voltage

ENABLE Input Current

Shutdown Input High Voltage

Shutdown Input Low Voltage

Shutdown Input Current

Drain Sense Threshold Voltage

3.5

2

ENH

ENL

0.6

1

V

I

EN

0V < V < V

μA

V

IN

S

V

SDH

0.8

1

V

SDL

I

SD

0V < V < V

μA

IN

V

SEN

80

75

100

120

125

mV

l

I

Drain Sense Input Current

Gate Voltage Above Supply

0V < V

< V

0.1

μA

SEN

S

l

V

GATE

– V

V = 5V

6

7.5

15

7

8.3

18

9

15

25

V

S

V = 6V

S

V = 12V

S

l

V

Status Output Low Voltage

Status Output Leakage Current

Turn-ON Time

I

= 400μA

= 12V

0.05

0.4

1

V

STAT

ON

STAT

I

t

V

μA

STAT

V = 5V, C

= 1000pF

GATE

Time for V

S

> V + 2V

30

100

110

450

300

1000

μs

GATE

S

> V + 5V

S

V = 12V, C

= 1000pF

GATE

S

Time for V

> V + 5V

20

50

80

160

200

500

μs

GATE

S

> V + 10V

t

Turn-OFF Time

V = 5V, C

= 1000pF, Time for V < 1V

GATE

10

5

36

28

25

23

17

13

60

40

35

μs

OFF

S

GATE

V = 12V, C

S

= 1000pF, Time for V

< 1V

GATE

Short-Circuit Turn-OFF Time

Shutdown Turn-OFF Time

V = 5V, C

S

= 1000pF, Time for V

< 1V

SC

GATE

V = 12V, C

S

= 1000pF, Time for V < 1V

GATE

5

GATE

V = 5V, C

S

= 1000pF, Time for V

< 1V

SD

GATE

V = 12V, C

S

= 1000pF, Time for V

< 1V

GATE

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.

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3

LTC1154

TYPICAL PERFORMANCE CHARACTERISTICS

Standby Supply Current

Supply Current ON

High Side Gate Voltage

24

22

20

18

16

14

12

10

8

50

45

40

35

30

25

20

15

10

5

1000

900

800

700

600

500

400

300

200

100

0

T

= 25°C

V

A

= 0V

A

IN

T

= 25°C

6

0

5

10

15

20

0

5

10

15

20

0

5

10

15

20

SUPPLY VOLTAGE (V)

LTC1154 • TPC01

LTC1154 • TPC02

LTC1154 • TPC03

Input Threshold Voltage

Drain Sense Threshold Voltage

Low Side Gate Voltage

2.4

2.2

2.0

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

150

140

130

120

110

100

90

30

27

24

21

V

ON

18

15

V

OFF

12

9

80

70

6

3

0

60

50

0

5

10

SUPPLY VOLTAGE (V)

20

0

2

4

6

8

10

0

5

10

15

20

SUPPLY VOLTAGE (V)

LTC1154 • TPC04

LTC1154 • TPC06

-5$ꢀꢀꢁꢂꢃtꢃ51$ꢄꢁ

Short-Circuit Turn-OFF Delay

Time

Turn-ON Time

Turn-OFF Time

1000

900

800

700

600

500

400

300

200

100

0

50

45

40

35

30

25

20

15

10

5

50

45

40

35

30

25

20

15

10

5

C

= 1000pF

C

= 1000pF

C

= 1000pF

GATE

TIME FOR V

< 1V

TIME FOR V

< 1V

GATE

V

= V – 1V

S

SEN

NO EXTERNAL DELAY

V

= 5V

GS

V

= 2V

GS

0

5

10

SUPPLY VOLTAGE (V)

20

0

5

10

15

20

0

5

10

15

20

SUPPLY VOLTAGE (V)

LTC1153 • TPC07

LTC1154 • TPC08

LTC1154 • TPC09

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4

LTC1154

TYPICAL PERFORMANCE CHARACTERISTICS

Standby Supply Current

Supply Current ON

Input ON Threshold Voltage

50

45

40

35

30

25

20

15

10

5

1000

900

800

700

600

500

400

300

200

100

0

2.4

2.2

2.0

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

V

= 0V

V

= 5V

= 0V

IN

EN

IN

EN

V

= 5V

S

V

= 18V

V

= 12V

= 5V

S

V

= 18V

S

V

S

V

= 5V

S

0

–50

0

25

50

75 100 125

–25

–50 –25

0

25

50

75 100 125

–50 –25

0

25

50

75 100 125

TEMPERATURE (°C)

LTC1154 • TPC10

LTC1154 • TPC11

LTC1154 • TPC12

Shutdown Threshold Voltage

ENABLE Threshold Voltage

Gate Drive Current

2.4

2.2

2.0

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

1000

100

10

V

= 12V

T

= 25°C

S

A

V

= 18V

S

DISABLE

V

= 12V

S

V

= 5V

S

= 18V

V

= 5V

S

1

ENABLE

0.1

–50 –25

0

25

50

75 100 125

–50 –25

0

25

50

75 100 125

0

4

8

12

16

20

TEMPERATURE (°C)

GATE VOLTAGE ABOVE SUPPLY (V)

LTC1154 • TPC13

LTC1154 • TPC14

LTC1154 • TPC15

PIN FUNCTIONS

Input and Shutdown Pins

ENABLE Input Pin

TheLTC1154inputpinisactivehighandactivatesallofthe

protection and charge pump circuitry when switched ON.

The shutdown pin is designed to immediately disable the

switch if a secondary fault condition (over temperature,

etc.) is detected. The LTC1154 logic and shutdown inputs

are high impedance CMOS gates with ESD protection

diodes to ground and supply and therefore should not be

forced beyond the power supply rails. The shutdown pin

should be connected to ground when not in use.

The ENABLE input can be used to enable a number of

LTC1154 high side switches in banks or to provide a sec-

ondary means of control. It can also act as an inverting

input. The ENABLE input is a high impedance CMOS gate

withESDclampdiodestogroundandsupplyandtherefore

should not be forced beyond the power supply rails. This

pin should be grounded when not in use.

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5

LTC1154

PIN FUNCTIONS

Gate Drive Pin

Drain Sense Pin

Thegatedrivepiniseitherdriventogroundwhentheswitch

isturnedOFFordrivenabovethesupplyrailwhentheswitch

is turned ON. This pin is a relatively high impedance when

driven above the rail (the equivalent of a few hundred kΩ).

Care should be taken to minimize any loading of this pin

by parasitic resistance to ground or supply.

The drain sense pin is compared against the supply pin

voltage. If the voltage at this pin is more than 100mV

below the supply pin, the input latch will be reset and the

MOSFET gate will be quickly discharged. Cycle the input,

or ENABLE input, to reset the short-circuit latch and turn

the MOSFET back on.

This pin is also a high impedance CMOS gate with ESD

protection and therefore should not be forced beyond the

power supply rails. To defeat the overcurrent protection,

short the drain sense to supply.

Supply Pin

The supply pin of the LTC1154 serves two vital purposes.

The ﬁrst is obvious: it powers the input, gate drive, regula-

tion and protection circuitry. The second purpose is less

obvious: it provides a Kelvin connection to the top of the

drain sense resistor for the internal 100mV reference.

Some loads, such as large supply capacitors, lamps, or

motors require high inrush currents. An RC time delay

can be added between the sense resistor and the drain

sense pin to ensure that the drain sense circuitry does not

false-trigger during start-up. This time constant can be

set from a few microseconds to many seconds. However,

very long delays may put the MOSFET in risk of being

destroyed by a short-circuit condition. (see Applications

Information Section).

The LTC1154 is designed to be continuously powered so

that the gate of the MOSFET is actively driven at all times.

If it is necessary to remove power from the supply pin

and then re-apply it, the input pin (or enable pin) should

be cycled a few milliseconds after the power is re-applied

to reset the input latch and protection circuitry. Also, the

inputandenablepinsshouldbeisolatedwith10kresistors

to limit the current ﬂowing through the ESD protection

diodes to the supply pin.

Status Pin

The status pin is an open-drain output which is driven

low whenever a fault condition is detected. A 51k pull-up

resistor should be connected between this output and a

logic supply. The status pins of multiple LTC1154s can be

OR’d together if independent fault sensing is not required.

No connection is required to this pin when not in use.

The supply pin of the LTC1154 should never be forced

below ground as this may result in permanent damage to

the device. A 300Ω resistor should be inserted in series

with the ground pin if negative supply voltage transients

are anticipated.

BLOCK DIAGRAM

DRAIN

SENSE

ANALOG SECTION

V

S

SHUTDOWN

TTL-TO-CMOS

CONVERTER

SHUTDOWN

10μs

DELAY

COMP

LOW STANDBY

CURRENT

REGULATOR

100mV

REFERENCE

GATE CHARGE

AND DISCHARGE

CONTROL LOGIC

GATE

ANALOG DIGITAL

R

INPUT

LATCH

TTL-TO-CMOS

CONVERTER

VOLTAGE

REGULATORS

INPUT

OSCILLATOR

AND CHARGE

PUMP

FAST/SLOW

GATE CHARGE

LOGIC

ONE

SHOT

S

ENABLE

GND

FAULT DETECTION

AND STATUS

OUTPUT DRIVER

STATUS

LTC1154 • BD01

1154fb

6

LTC1154

TRUTH TABLE

The Truth Table demonstrates how the LTC1154 receives

inputs and returns status information to the μP. The

ENABLE and input signal from the μP controls the switch

in its normal operating mode, where the rise and fall

time of the gate drive are controlled to limit EMI and RFI

emissions. The shutdown and overcurrent detection cir-

cuitry however, switch the gate off at a much higher rate

to limit the exposure of the MOSFET switch and the load

to dangerous conditions. The status pin remains high as

long as the switch is operating normally, and is driven

low only when a fault condition is detected. Note that the

shutdown pin is edge-sensitive and latches the output off

even if the shutdown pin returns to a low state.

INPUTS

OUTPUTS

SD GATE STATUS

SWITCH

CONDITION

IN

X

EN

H

X

L

H

L

H

L

SWITCH OFF

SWITCH ON

L

H

L

SWITCH LATCHED OFF

(OVER CURRENT)

H

L

SWITCH LATCHED OFF

(SHUTDOWN)

L = LOGIC LOW

H = LOGIC HIGH

X = IRRELEVANT

= EDGE TRIGGERED

OPERATION

The LTC1154 is a single micropower MOSFET driver

with built-in protection, status feedback and gate charge

pump. The LTC1154 consists of the following functional

blocks:

from each other so that the noise generated by the charge

pump logic is not coupled into the 100mV reference or

the analog comparator.

Gate Charge Pump

TTL and CMOS Compatible Inputs

Gate drive for the MOSFET switch is produced by an adap-

tive charge pump circuit which generates a gate voltage

substantially higher than the power supply voltage. The

charge pump capacitors are included on chip and there-

fore no external components are required to generate the

gate drive.

TheLTC1154inputandshutdowninputhavebeendesigned

to accommodate a wide range of logic families. Both in-

put thresholds are set at about 1.3V with approximately

100mV of hysteresis.

A low standby current voltage regulator provides continu-

ousbiasfortheTTL-to-CMOSconverter.TheTTL-to-CMOS

converter output enables the rest of the circuitry. In this

way the power consumption is kept to a minimum in the

standby mode.

Drain Current Sense

The LTC1154 is conﬁgured to sense the current ﬂowing

into the drain of the power MOSFET in a high side ap-

plication. An internal 100mV reference is compared to

the drop across a sense resistor (typically 0.002Ω to

0.10Ω) in series with the drain lead. If the drop across

this resistor exceeds the internal 100mV threshold, the

input latch is reset and the gate is quickly discharged via

a large N-channel transistor.

ENABLE Input

The ENABLE input is CMOS compatible and inhibits the

input signal whenever it is held logic high. This input

should be grounded when not in use.

Internal Voltage Regulation

Controlled Gate Rise and Fall Times

The output of the TTL-to-CMOS converter drives two

regulated supplies which power the low voltage CMOS

logicandanalogblocks.Theregulatoroutputsareisolated

WhentheinputisswitchedONandOFF, thegateischarged

bytheinternalchargepumpanddischargedinacontrolled

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7

LTC1154

OPERATION

manner. The charge and discharge rates have been set to

minimize RFI and EMI emissions in normal operation. If

a short-circuit or current overload condition is encoun-

tered, the gate is discharged very quickly (typically a few

microseconds) by a large N-channel transistor.

Status Output Driver

The status circuitry continuously monitors the fault de-

tection logic. This open-drain output is driven low when

the gate of the MOSFET is driven low by the protection

circuitry. The status circuitry is reset along with the input

latch when the input, or ENABLE input, is cycled.

APPLICATIONS INFORMATION

MOSFET and Load Protection

stored energy to ground. Many inductive loads have these

diodes included. If not, a diode of the proper current rating

should be connected across the load, as shown in Figure

2, to safely divert the stored energy.

TheLTC1154protectsthepowerMOSFETswitchbyremov-

ingdrivefromthegateassoonasanovercurrentcondition

isdetected. Resistiveandinductiveloadscanbeprotected

with no external time delay in series with the drain sense

pin. Lamp loads, however, require that the overcurrent

protection be delayed long enough to start the lamp but

short enough to ensure the safety of the MOSFET.

12V

+

100μF

IN

V

S

0.036Ω

IRFZ24

EN

DS

G

LTC1154

Resistive Loads

STATUS

GND

15V

Loads that are primarily resistive should be protected with

asshortadelayaspossibletominimizetheamountoftime

thattheMOSFETissubjectedtoanoverloadcondition.The

drain sense circuitry has a built-in delay of approximately

10μs to eliminate false triggering by power supply or load

transient conditions. This delay is sufﬁcient to “mask”

short load current transients and the starting of a small

capacitor (<1μF) in parallel with the load. The drain sense

pincanthereforebeconnecteddirectlytothedraincurrent

sense resistor as shown in Figure 1.

SD

R

LOAD

C

≤ 1μF

LOAD

12Ω

LTC1154 • F01

Figure 1. Protecting Resistive Loads

12V

+

100μF

IN

V

S

0.036Ω

IRFZ24

Inductive Loads

EN

DS

G

Loadsthatareprimarilyinductive,suchasrelays,solenoids

and stepper motor windings should be protected with as

short a delay as possible to minimize the amount of time

that the MOSFET is subjected to an overload condition.

The built-in 10μs delay will ensure that the overcurrent

protection is not false-triggered by a supply or load

transient. No external delay components are required as

shown in Figure 2.

LTC1154

STATUS

15V

GND

SD

12V, 1A

SOLENOID

1N5400

LTC1154 • F02

Large inductive loads (>0.1mH) may require diodes con-

nected directly across the inductor to safely divert the

Figure 2. Protecting Inductive Loads

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8

LTC1154

APPLICATIONS INFORMATION

Capacitive Loads

Lamp Loads

Largecapacitiveloads,suchascomplexelectricalsystems

with large bypass capacitors, should be powered using

the circuit shown in Figure 3. The gate drive to the power

MOSFET is passed through an RC delay network, R1 and

C1, which greatly reduces the turn-on ramp rate of the

switch. And since the MOSFET source voltage follows the

gatevoltage,theloadispoweredsmoothlyandslowlyfrom

ground. This dramatically reduces the start-up current

ﬂowingintothesupplycapacitor(s)which,inturn,reduces

supplytransientsandallowsforsloweractivationofsensi-

tive electrical loads. (Diode, D1, provides a direct path for

the LTC1154 protection circuitry to quickly discharge the

gate in the event of an overcurrent condition).

Theinrushcurrentcreatedbyalampduringturn-oncanbe

10to20timesgreaterthantheratedoperatingcurrent.The

circuit shown in Figure 4 shifts the current limit threshold

up by a factor of 11:1 (to 30A) for 100ms when the bulb

is ﬁrst turned on. The current limit then drops down to

2.7A after the inrush current has subsided.

12V

+

470μF

10k

0.036Ω

IN

V

S

100k

EN

DS

G

VN2222LL

0.1μF

LTC1154

STATUS

GND

1M

SD

MTP3055EL

12V

+

9.1V

470μF

IN

V

S

0.036Ω

C

R

D

100k

D

12V/1A

BULB

0.01μF

EN

DS

G

D1

1N4148

LTC1154

LTC1154 • F04

STATUS

GND

R1

100k

R2

Figure 4. Lamp Driver with Delayed Protection

100k

MTP3055E

OUT

SD

C1

0.33μF

Selecting R and C

D

15V

Figure 5 is a graph of normalized overcurrent shutdown

time versus normalized MOSFET current. This graph is

+

C

LOAD

100μF

used to select the two delay components, R and C ,

D

LTC1154 • F03

which make up a simple RC delay between the drain sense

resistor and the drain sense input.

Figure 3. Powering Large Capacitive Loads

The RC network, R and C , in series with the drain sense

10

1

D

inputshouldbesettotripbasedontheexpectedcharacter-

isticsoftheloadafter start-up.Withthiscircuit,itispossible

to power a large capacitive load and still react quickly to

an overcurrent condition. The ramp rate at the output of

the switch as it lifts off ground is approximately:

0.1

0.01

dV/dt = (V

– V )/(R1 • C1)

TH

GATE

Andthereforethecurrentﬂowingintothecapacitorduring

start-up is approximately:

1

10

100

I

= C

• dV/dt

START-UP

LOAD

MOSFET CURRENT (1 = SET CURRENT)

LTC1154 • F05

Using the values shown in Figure 3, the start-up current

is less than 100mA and does not false-trigger the drain

sense circuitry which is set at 2.7A with a 1ms delay.

Figure 5. Overcurrent Shutdown Time vs MOSFET Current

1154fb

9

LTC1154

APPLICATIONS INFORMATION

12V

The Y axis of the graph is normalized to one RC time

constant. The X axis is normalized to the current. (The

set current is deﬁned as the current required to develop

100mV across the drain sense resistor).

5V

+

10μF

120k

10k

IN

V

S

0.05Ω

5V

μP OR

CONTROL

LOGIC

EN

DS

G

Notethattheshutdowntimeisshorterforincreasinglevels

of MOSFET current. This ensures that the total energy

dissipated by the MOSFET is always within the bounds

established by the manufacturer for safe operation. (See

MOSFET data sheet for further information).

LTC1154

STATUS

GND

MTP12N06

15V

SD

LOAD

10k

300Ω

Using a Speed-Up Diode

LTC1154 • F07

To reduce the amount of time that the power MOSFET is

in a short-circuit condition, “bypass” the delay resistor

with a small signal diode as shown in Figure 6. The diode

will engage when the drop across the drain sense resistor

exceedsabout0.7V,providingadirectpathtothesensepin

anddramaticallyreducingtheamountoftimetheMOSFET

is in an overload condition. The drain sense resistor value

Figure 7. Reverse Battery Protection

SincetheLTC1154drawsverylittlecurrentwhileinnormal

operation, the drop across the ground resistor is minimal.

The 5V μP (or control logic) is protected by the 10k resis-

tors in series with the input and status pins.

Current Limited Power Supplies

12V

The LTC1154 requires at least 3.5V at the supply pin to

ensure proper operation. It is therefore necessary that the

supplytotheLTC1154beheldhigherthan3.5Vatalltimes,

even when the output of the switch is short circuited to

ground. The output voltage of a current limited regulator

may drop very quickly during short-circuit and pull the

supplypinoftheLTC1154below3.5Vbeforetheshutdown

circuitry has had time to respond and remove drive from

the gate of the power MOSFET. A supply ﬁlter should be

+

100μF

1N4148

IN

V

S

0.036Ω

IRF530

0.01μF

100k

EN

DS

G

LTC1154

STATUS

GND

15V

SD

LOAD

LTC1154 • F06

5V/2A

REGULATOR

>7V

+

Figure 6. Using a Speed-Up Diode

*20Ω

10μF

0.1Ω

100μF

is selected to limit the maximum DC current to 2.8A. The

diode conducts when the drain current exceeds 20A and

reduces the turn-off time to 15μs.

+

1N4148

100k

47μF*

IN

V

S

0.1μF

EN

DS

G

LTC1154

Reverse Battery Protection

IRLR024

STATUS

GND

The LTC1154 can be protected against reverse battery

conditions by connecting a resistor in series with the

ground lead as shown in Figure 7. The resistor limits the

supply current to less than 50mA with –12V applied.

SHORT-

CIRCUIT

SD

LTC1154 • F08

*SUPPLY FILTER COMPONENTS

Figure 8. Supply Filter for Current Limited Supplies

1154fb

10

LTC1154

APPLICATIONS INFORMATION

added as shown in Figure 8 which holds the supply pin of

theLTC1154highlongenoughfortheovercurrentshutdown

circuitry to respond and fully discharge the gate.

be able to hold the supply pin of the LTC1154 above 3.5V

sufﬁciently long that this extra ﬁltering is not required.

Because the LTC1154 is micropower in both the standby

and ON state, the voltage drop across the supply ﬁlter is

lessthan2mV,anddoesnotsigniﬁcantlyaltertheaccuracy

of the 100mV drain sense threshold voltage.

Five volt linear regulators with small output capacitors are

the most difﬁcult to protect as they can “switch” from a

voltage mode to a current limited mode very quickly. The

largeoutputcapacitorsonmanyswitchingregulatorsmay

TYPICAL APPLICATIONS

High Side Driver with Thermal Shutdown

High Side Driver with Overvoltage Shutdown

6V

4.75V TO 5.25V

5V

+

100μF

10μF

IN

V

IN

V

S

100Ω

5.6V

μP OR

CONTROL

LOGIC

μP OR

CONTROL

LOGIC

EN

DS

G

EN

DS

G

LTC1154

STATUS^†

IRLZ24

STATUS^†

IRLD024

30k

GND

SD

GND

SD

6V

LOAD

5V

LOAD

PTC

THERMISTOR

(100°C)*

*RL3006-50-100-25-PT0 KEYSTONE

SWITCH IS SHUTDOWN WHEN V > 5.7V

S

LTC1154 • TA03

LTC1154 • TA05

†

A 51k pullup resistor should be connected between Status Output and 5V Logic Supply.

High Side Driver with Undervoltage Shutdown

24V to 28V High Side Switch with Thermal Shutdown

5V

24V TO 28V

+

10k

3k

100μF

1N4148*

+

1μF**

5V

18V

10μF

2N2907

IN

V

IN

V

S

μP OR

CONTROL

LOGIC

μP OR

CONTROL

LOGIC

EN

DS

G

EN

DS

G

LTC1154

STATUS^†

IRLZ24

STATUS^†

MTP12N06

200k

GND

SD

GND

SD

PTC

THERMISTOR

(100°C)*

6V

LOAD

24V TO 28V

LOAD

10k

*OPTIONAL IF SUPPLY VOLTAGE LESS THAN 6V.

*KEYSTONE RL2006-100-100-30-PT.

MOUNT ON MOSFET OR LOAD HEAT SINK

**CAPACITOR CHARGED TO SUPPLY VOLTAGE.

SHUTDOWN OCCURS WHEN SUPPLY VOLTAGE

DROPS BY 0.6V.

LTC1154 • TA06

LTC1154 • TA04

1154fb

11

LTC1154

TYPICAL APPLICATIONS

24V to 28V Switch with Bootstrapped Supply

High Side Relay Driver with Overcurrent

Protection and Status Feedback

24V TO 28V

12V

+

100k

100μF

2Ω

0.02Ω

+

5V

18V

10μF

10k

6.2k

IN

V

IN

V

S

0.01μF

1N4148

μP OR

CONTROL

LOGIC

μP OR

CONTROL

LOGIC

1N4148

EN

DS

G

EN

DS

G

MTD3055E

15V

LTC1154

STATUS^†

MTP15N06E

STATUS^†

TO 12V

LOAD

200k

GND

SD

GND

SD

PTC

THERMISTOR

(100°C)*

1N4001

24V TO 28V

LOAD

*KEYSTONE RL2006-100-100-30-PT.

COIL CURRENT LIMITED TO 350mA.

CONTACT CURRENT LIMITED TO 5A.

MOUNT ON MOSFET OR LOAD HEAT SINK.

LTC1154 • TA07

LTC1154 • TA08

I

= 60MA, I

= 1mA.

Q(OFF)

Q(ON)

†

A 51k pullup resistor should be connected between Status Output and 5V Logic Supply.

“4-Cell-to-5V” Extremely Low Voltage Drop Regulator with

Overcurrent Shutdown, Status Feedback, Ramped Turn-ON

and 8μA Standby Current

4-CELL

BATTERY

PACK

+

100μF

0.036Ω

5V

IN

V

S

μP OR

CONTROL

LOGIC

IRLR024

1N4148

100k 100k

0.22μF

EN

DS

G

200pF

10k

LTC1154

STATUS^†

1

8

3

4

5V/2A

470μF

LT1431

7

GND

SD

+

ESR < 0.5Ω

6

5

LTC1154 • TA09

1154fb

12

LTC1154

TYPICAL APPLICATIONS

Bank Controlled High Side Switches with “Global” Thermal

and Overvoltage Shutdown

12V

IN

V

S

+

100Ω

470μF

EN

DS

G

LTC1154

STATUS

GND

IRLR024

15V

SD

OUTPUT 1

OUTPUT 2

OUTPUT 3

IN

V

S

5V

EN

DS

G

LTC1154

51k

STATUS

GND

SD

μP OR

CONTROL

LOGIC

IN

V

S

EN

DS

G

LTC1154

STATUS

GND

SD

IN

V

S

120k

EN

DS

G

LTC1154

STATUS

GND

SD

OUTPUT 4

PTC

THERMISTOR

(100°C)*

15V

*KEYSTONE RL2006-100-100-30-PT.

MOUNT ON COMMON HEAT SINK.

LTC1154 • TA10

1154fb

13

LTC1154

TYPICAL APPLICATIONS

12V Step-Up Regulator with Ultralow Standby Current,

Overcurrent Protection and Status Feedback

1N5820

50μH

0.02Ω

IRLZ24

12V/1A

330μF

5V

+

20Ω

470μF

5

+

10.72k

1%

+

10k

1N4148

V

47μF

IN

150μF

4

2

V

SW

FB

ON/OFF

STATUS

IN

V

S

LT1070

0.22μF

1N4148

100k 100k

V

GND

C

1

51k

EN

DS

G

3

1.24k

1%

LTC1154

STATUS

GND

1k

0.1μF

SD

1μF

LTC1154 • TA11

12V Step-Up Regulator with 1A Overcurrent Protection,

Switch Status Feedback and Ramped Output

1N5820

50μH

5V

+

150μF

330μF

0.1Ω

5

1N4148

10k

V

IN

10.72k

1%

4

V

SW

FB

ON/OFF

STATUS

IN

V

S

LT1070

2

0.1μF

1N4148

V

GND

C

1

51k

EN

DS

G

1.24k

1%

3

LTC1154

100k

STATUS

GND

IRF530

1k

1μF

12V

SD

12V/1A

47μF

+

0.22μF

LTC1154 • TA12

1154fb

14

LTC1154

PACKAGE DESCRIPTION

N8 Package

8-Lead PDIP (Narrow .300 Inch)

(Reference LTC DWG # 05-08-1510)

.400*

(10.160)

MAX

8

7

6

5

4

.255 .015*

(6.477 0.381)

1

2

3

.130 .005

.300 – .325

.045 – .065

(3.302 0.127)

(1.143 – 1.651)

(7.620 – 8.255)

.065

(1.651)

TYP

.008 – .015

(0.203 – 0.381)

.120

.020

(0.508)

MIN

(3.048)

MIN

+.035

.325

–.015

.018 .003

(0.457 0.076)

.100

(2.54)

BSC

+0.889

8.255

(

)

N8 1002

–0.381

NOTE:

INCHES

1. DIMENSIONS ARE

MILLIMETERS

*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.

MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)

1154fb

15

LTC1154

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

1154fb

16

LTC1154

REVISION HISTORY ^{(Revision history begins at Rev B)}

REV

DATE

DESCRIPTION

PAGE NUMBER

B

4/11

Updated Graph TPC05

4

Updated SCSI Termination Typical Application

Updated Related Parts

18

1154fb

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.

17

LTC1154

TYPICAL APPLICATIONS

Auto-Reset High Side Switch with Overcurrent and Overcurrent Temperature Shutdown

12V

+

100μF

R

T

1M

1M**

0.036Ω

ON/OFF

IN

V

S

EN

DS

G

LTC1154

+

C

T

STATUS

GND

MTP12N06

100μF**

18V

VN2222LL

200k

PTC

SD

12V

LOAD

THERMISTOR

(100°C)*

*KEYSTONE RL2006-100-100-30-PT.

**AUTO-RESET PERIOD ≈ 800ms WITH COMPONENTS SHOWN

LTC1154 • TA13

SCSI Termination Power Switch with 1A Overcurrent Shutdown, Auto-Reset and Load Soft-Start

1N5817

0.1Ω

MTD3055EL

ꢂꢅꢆꢁ7ꢇꢀ"

5V

+

100μF

10μF

1M

20Ω

10k

1N4148

+

ON/OFF

IN

V

S

47μF

0.1μF

1N4148

100k 100k

EN

DS

G

LTC1154

+

45"564

1μF

VN2222LL

0.22μF

GND

SD

-5$ꢀꢀꢁꢂꢃtꢃ5"ꢀꢂ

RELATED PARTS

PART NUMBER

DESCRIPTION

COMMENTS

LTC4440/LTC4440-5

High Speed, High Voltage High Side Gate Driver

Up to 80V Supply Voltage, 8V ≤ V ≤ 15V, 2.4A Peak Pull-Up/1.5Ω

CC

Peak Pull-Down

LTC4441/LTC4441-1

LT1910

N-Channel MOSFET Gate Driver

Protected High Side Gate Driver

Up to 25V Supply Voltage, 5V ≤ V ≤ 25V, 6A Peak Output Current

CC

Up to 48V Supply Voltage, Short Circuit Protected

LTC4446

High Voltage Synchronous N-Channel MOSFET

Driver without Shoot Thru Protection

Up to 100V Supply Voltage, 7.2V ≤ V ≤ 13.5V, 3A Peak Pull-Up/0.55Ω

CC

Peak Pull-Down

LTC4444/LTC4444-5

LTC4442/LTC4449

High Voltage Synchronous N-Channel MOSFET

Driver with Shoot Thru Protection

Up to 100V Supply Voltage, 4.5V/7.2V ≤ V ≤ 13.5V, 3A Peak Pull-Up/

CC

0.55Ω Peak Pull-Down

High Speed Synchronous N-Channel MOSFET

Driver

Up to 38V Supply Voltage, 4.5V/6V ≤ V ≤ 9.5V, 3.2A Peak Pull-Up/

CC

4.5A Peak Pull-Down

1154fb

LT 0411 REV B • PRINTED IN USA

LinearTechnology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

18

●

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


型号：	LTC1154HS8
厂家：	Linear
描述：	LTC1154 - High-Side Micropower MOSFET Driver; Package: SO; Pins: 8; Temperature Range: -40°C to 125°C 驱动光电二极管接口集成电路驱动器
文件：	总18页 (文件大小：195K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

LTC1154HS8 [Linear]

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