LT1738 Ver la hoja de datos (PDF) - Linear Technology

Número de pieza

componentes Descripción

Lista de partido

LT1738

Slew Rate Controlled Ultralow Noise DC/DC Controller

Linear Technology 

LT1738

ELECTRICAL CHARACTERISTICS The q denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C. VIN = 12V, VC = 0.9V, VFB = VREF, RVSL, RCSL = 16.9k, RT = 16.9k and

other pins open unless otherwise noted.

SYMBOL PARAMETER

CONDITIONS

MIN TYP MAX UNITS

Oscillator and Sync

fMAX

Max Switch Frequency

fSYNC

Synchronization Frequency Range

VSYNC

SYNC Pin Input Threshold

RSYNC SYNC Pin Input Resistance

Gate Drive

Oscillator Frequency = 250kHz

250

kHz

290

kHz

q 0.7

1.4

2

40

kΩ

DCMAX Maximum Switch Duty Cycle

RVSL = RCSL = 3.9k,

q 90

93.5

%

Osc Frequency = 25kHz

VGON

Gate On Voltage

VGOFF

Gate Off Voltage

IGSO

Max Gate Source Current

IGSK

Max Gate Sink Current

VINUVLO Gate Drive Undervoltage Lockout (Note 5)

Current Sense

VIN = 12, GCL = 12

VIN = 12, GCL = 8

VIN = 12V

VIN = 12V

VIN = 12V

VGCL = 6.5V

10

10.4 10.7

V

7.6

7.9

8.1

V

0.2 0.35

V

0.3

A

0.3

A

7.3

7.5

V

tIBL

Switch Current Limit Blanking Time

VSENSE Sense Voltage Shutdown Voltage

VC Pulled Low

VSENSEF Sense Voltage Fault Threshold

Slew Control for the Following Slew Tests See Test Circuit in Figure 1b

100

ns

q 86

103 120

mV

220 300

mV

VSLEWR Output Voltage Slew Rising Edge

VSLEWF Output Voltage Slew Falling Edge

VISLEWR Output Current Slew Rising Edge (CS pin V)

VISLEWF Output Current Slew Falling Edge (CS pin V)

Supply and Protection

RVSL = RCSL = 17k

RVSL = RCSL = 17k

RVSL = RCSL = 17k

RVSL = RCSL = 17k

26

V/µs

19

V/µs

2.1

V/µs

2.1

V/µs

VINMIN

IVIN

Minimum Input Voltage (Note 4)

Supply Current (Note 3)

VSHDN

∆VSHDN

ISHDN

V5

Shutdown Turn-On Threshold

Shutdown Turn-On Voltage Hysteresis

Shutdown Input Current Hysteresis

5V Reference Voltage

IV5SC

5V Reference Short-Circuit Current

VGCL = VIN

RVSL = RCSL = 17k

RVSL = RCSL = 17k

q

2.55

3.6

V

VIN = 12 q

VIN = 20

12

40

mA

35

55

mA

q 1.31 1.39 1.48

V

q 50

110 180

mV

q 10

24

35

µA

6.5V ≤ VIN ≤ 20V, IV5 = 5mA

6.5V ≤ VIN ≤ 20V, IV5 = – 5mA

VIN = 6.5V Source

VIN = 6.5V Sink

4.85

5

5.20

V

4.80

5

5.15

V

10

mA

– 10

mA

Note 1: Absolute Maximum Ratings are those values beyond which the

life of a device may be impaired.

Note 2: Supply current specification includes loads on each gate as in

Figure 1a. Actual supply currents vary with operating frequency, operating

voltages, V5 load, slew rates and type of external FET.

Note 3: The LT1738E is guaranteed to meet performance specifications

from 0°C to 70°C. Specifications from –40°C to 125°C are assured by

design, characterization and correlation with statistical process

controls.The LT1738I is guaranteed and tested to meet performance

specifications from – 40°C to 125°C.

Note 4: Output gate drive is enabled at this voltage. The GCL voltage will

also determine driver activity.

Note 5: Gate drive is ensured to be on when VIN is greater than max value.

1738fa

3

Share Link: