LTC1255I View Datasheet(PDF) - Linear Technology

Part Name

Description

Manufacturer

LTC1255I

Dual 24V High-Side MOSFET Driver

Linear Technology 

LTC1255

UU W U

APPLICATIO S I FOR ATIO

The switches can either be turned OFF by the controlling

logic during these transients or latched OFF above 30V by

holding the drain sense pin low as shown in Figure 9.

Switch status can be ascertained by means of an XNOR

gate connected to the input and switch output through

100k current limiting resistors (see Typical Applications

section for more detail on this scheme). The switch is reset

after the overvoltage event by cycling the input low and

then high again.

The power MOSFET switch should be selected to have a

breakdown voltage sufficiently higher than the 40V supply

clamp voltage to ensure that no current is conducted to the

load during the transient.

U

TYPICAL APPLICATIO S

14V +

1µF

50V

FROM 10k

µP, ETC.

VS

DS1

1/2 LTC1255

IN1

G1

GND

D1

MR2535L

1k*

RSENSE

0.036Ω

12V

1N5242B

IRF530

100Ω

30V*

1N5256B

LOAD

LTC1255 • F09

*OPTIONAL OVERVOLTAGE (30V) LATCH-OFF COMPONENTS

Figure 9. Overvoltage Transient Protection

Dual Automotive High-Side Switch with Overvoltage Protection,

XNOR Status and 12µA Standby Current

14V

0.036Ω

10k** MTD3055E

14V/1A

SOLENOID

10k

12V

MMBZ5242B 100k

1N5400

+

1µF

50V

VS

DS1

DS2

G1 LTC1255 G2

IN1

IN2

GND

MR2535L*

10k

100k

1/4 74C266†

FAULT FROM

TO µP µP, ETC.

100Ω

1/4 74C266†

FROM FAULT

µP, ETC. TO µP

0.036Ω

12V

MMBZ5242B

1N5400

MTD3055E 10k**

14V/1A

SOLENOID

LTC1255 • TA03

TRUTH TABLE

IN OUT

CONDITION

00

SWITCH OFF

1 0 OVERCURRENT

01

OPEN LOAD**

11

SWITCH ON

FAULT

1

0

0

1

*LIMITS VS TRANSIENTS TO <40V. SEE MANUFACTURER DATA SHEET FOR

FURTHER DETAIL.

**OPTIONAL OPEN LOAD DETECTION REQUIRES 10k PULL-UP RESISTORS.

(ULTRA LOW STANDBY QUIESCENT CURRENT IS SACRIFICED)

†POWER FROM 5V LOGIC SUPPLY.

10

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