LTC1474 Ver la hoja de datos (PDF) - Linear Technology

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componentes Descripción

Fabricante

LTC1474

Low Quiescent Current High Efficiency Step-Down Converters

Linear Technology 

LTC1474/LTC1475

ELECTRICAL CHARACTERISTICS TA = 25°C, VIN = 10V, VRUN = open, RSENSE = 0, unless otherwise noted.

SYMBOL

VFB

VOUT

IFB

ISUPPLY

∆VOUT

IQ

RON

IPEAK

PARAMETER

Feedback Voltage

LTC1474/LTC1475

Regulated Output Voltage

LTC1474-3.3/LTC1475-3.3

LTC1474-5/LTC1475-5

Feedback Current

LTC1474/LTC1475 Only

No Load Supply Current (Note 3)

Output Voltage Line Regulation

Output Voltage Load Regulation

Output Ripple

Input DC Supply Current (Note 2)

Active Mode (Switch On)

Sleep Mode (Note 3)

Shutdown

Switch Resistance

Current Comp Max Current Trip Threshold

VSENSE

VHYST

tOFF

Current Comp Sense Voltage Trip Threshold

Voltage Comparator Hysteresis

Switch Off-Time

VLBI, TRIP

VRUN

VLBI, OFF

ILBO, SINK

IRUN, SOURCE

ISW, LEAK

ILBI, LEAK

ILBO, LEAK

Low Battery Comparator Threshold

Run/ON Pin Threshold

OFF Pin Threshold (LTC1475 Only)

Sink Current into Pin 2

Source Current from Pin 8

Switch Leakage Current

Leakage Current into Pin 3

Leakage Current into Pin 2

CONDITIONS

ILOAD = 50mA

ILOAD = 50mA

MIN TYP MAX UNITS

q 1.205 1.230 1.255

V

q 3.234 3.300 3.366

V

q 4.900 5.000 5.100

V

q

0

30

nA

ILOAD = 0 (Figure 1 Circuit)

VIN = 7V to 12V, ILOAD = 50mA

ILOAD = 0mA to 50mA

ILOAD = 10mA

(Exclusive of Driver Gate Charge Current)

VIN = 3V to 18V

VIN = 3V to 18V

VIN = 3V to 18V, VRUN = 0V

ISW = 100mA

RSENSE = 0Ω

325

RSENSE = 1.1Ω

70

q 90

VOUT at Regulated Value

VOUT = 0V

VLBI = 0V, VLBO = 0.4V

VRUN = 0V

VIN = 18V, VSW = 0V, VRUN = 0V

VLBI = 18V, VIN = 18V

VLBI = 2V, VLBO = 5V

3.5

q 1.16

0.4

0.4

0.45

0.4

10

5

2

50

100

9

6

1.4

400

76

100

5

4.75

65

1.23

0.7

0.7

0.70

0.8

0.015

0

0

µA

20

mV

15

mV

mVP-P

175

µA

15

µA

12

µA

1.6

Ω

mA

85

mA

110

mV

mV

6.0

µs

µs

1.27

V

1.0

V

1.0

V

mA

1.2

µA

1

µA

0.1

µA

0.5

µA

The q denotes specifications which apply over the full operating

temperature range.

Note 1: TJ is calculated from the ambient temperature TA and power

dissipation PD according to the following formulas:

LTC1474CS8/LTC1475CS8: TJ = TA + (PD • 110°C/W)

LTC1474CMS8/LTC1475CMS8: TJ = TA + (PD • 150°C/W)

Note 2: Dynamic supply current is higher due to the gate charge being

delivered at the switching frequency. See Applications Information.

Note 3: No load supply current consists of sleep mode DC current (9µA

typical) plus a small switching component (about 1µA for Figure 1 circuit)

necessary to overcome Schottky diode and feedback resistor leakage.

3

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