Data Sheet

LT8638-2

analog.com

Rev.0

3 of 35

SPECIFICATIONS

Table 1. Electrical Characteristics

(Specifications are at TJ = -40°C to +150°C, unless otherwise noted. Typical values are at TA = +25°C. All voltages

are referenced to GND, unless otherwise noted.)

PARAMETER

SYMBOL

CONDITIONS/COMMENTS

MIN

TYP

MAX

UNITS

Minimum Input Voltage

VIN

fSW = 2MHz

2.6

2.8

V

VIN Quiescent Current in

Shutdown

IQ(SHDN)

VEN/UV = 0V, VIN = 12V, TA = +25°C

6

9

µA

VIN Quiescent Current in

Sleep

IQ

VEN/UV= 2V, VFB> 0.6V, VSYNC= 0V, VBIAS=

0V, TA = +25°C

125

195

µA

VEN/UV = 2V, VFB> 0.6V, VSYNC = 0V, VBIAS =

0V

125

245

VEN/UV = 2V, VFB > 0.6V, VSYNC = 0V, VBIAS =

5V, TA = +25°C

20

29

BIAS Quiescent Current

in Sleep

IQ(BIAS)

VEN/UV= 2V, VFB > 0.6V, VSYNC = 0V, VBIAS =

5V, TA = +25°C

100

145

µA

Feedback Reference

Voltage

VFB

VIN = 12V, TA = +25°C

0.598

0.6

0.602

V

VIN= 12V

0.594

0.6

0.604

Feedback Voltage Line

Regulation

ΔVFB(LINE)

VIN = 4.0V to 40V, VC = 1.25V

0.004

0.03

%/V

Feedback Pin Input

Current

IFB

VFB = 0.6V, TA = +25°C

-20

20

nA

Error Amp

Transconductance

gm(EA)

VC = 1.25V, TA = +25°C

1.05

1.4

1.75

mS

Error Amp Gain

AV

700

VC Source Current

IVC

VFB= 0.4V, VC = 1.25V

320

µA

VC Sink Current

IVC

VFB = 0.8V, VC = 1.25V

320

µA

VC Pin to Switch Current

Gain

GM

12

A/V

VC Clamp Voltage

VC_MAX

2.3

V

BIAS Pin Current

Consumption

IBIAS

VBIAS= 3.3V, fSW = 2MHz, VIN = 12V

45

mA

Minimum On-Time

tON(MIN)

ILOAD = 3A, FCM

25

40

ns

Minimum Off-Time

tOFF(MIN)

TA = +25°C

80

100

ns

Oscillator Frequency

fsw

RT = 226k

170

200

230

kHz

RT = 38.3k

0.96

1

1.04

MHz

RT = 16.9k

1.85

2

2.15

Top Power NMOS On-

Resistance

RTOP

ISW = 1A

20

mΩ