Data Sheet

LT8349

analog.com

Rev B

4 of 29

SPECIFICATIONS

Table 1. Electrical Characteristics

(Specifications are for TA = 25°C, VIN = 3.6V, VEN/UVLO = 1.5V unless otherwise noted1.)

PARAMETER

SYMBOL

CONDITIONS/COMMENTS

MIN

TYP

MAX

UNITS

VIN Operating Voltage

Range

VIN

–40°C ≤ TJ ≤ 125°C

2.5

5.5

V

VIN Undervoltage

Lockout Threshold

VIN_UVLO_R

Rising

2.36

2.5

V

VIN_UVLO_F

Falling

2.1

2.3

VIN Quiescent Current in

Shutdown

IQ-SD

VEN/UVLO ≤ 0.3V

0.5

3

μA

–40°C ≤ TJ ≤

125°C

0.5

10

VIN Quiescent Current

IQ

SYNC/MODE = 0V, Not Switching

15

30

μA

SYNC/MODE = Open, FB = 1.5V, RT =

54.9kΩ

11.2

15

mA

VOUT Operating Voltage

VOUT

–40°C ≤ TJ ≤ 125°C

8

V

VOUT Quiescent Current

IQ-OUT

SYNC/MODE = 0V, VOUT = 5.5V, Not

Switching

1

2

μA

SYNC/MODE = Open, VOUT = 2.5V, FB

= 1.5V, RT = 54.9kΩ

7.6

12

mA

VOUT Over Voltage

Protection Threshold

VOUT_OV_R

Rising

8.12

9

9.8

V

VOUT_OV_HYS

Hysteresis

0.1

FB Regulation Voltage3

VFB_REG

VC=1.25V

–40°C ≤ TJ ≤

125°C

0.985

1.00

1.015

V

FB Line Regulation3

2.5V < VIN < 5.5V

0.2

0.35

%/V

FB Pin Input Current

IFB

FB = 1.0V

-20

20

nA

Error Amp

Transconductance3

gm

VC = 1.25V

0.4

mS

Error Amp Gain3

Gv

400

V/V

VC Source Current

IVC

FB = 0.8V, VC = 1.25V

-80

μA

VC Sink Current

IVC

FB = 1.2V, VC = 1.25V

73

μA

VC to Switch Current

Gain, per phase, no

shedding

6.0

A/V

Switching Frequency

fSW

RT = 464kΩ

0.25

0.3

0.36

MHz

RT = 127kΩ

0.82

1

1.2

RT = 54.9kΩ

1.83

2

2.2

RT = 18.7kΩ

3.6

4

4.67