LTC1700_ 查看數據表（PDF） - Linear Technology

零件编号

产品描述 (功能)

生产厂家

LTC1700_

High Input Voltage, Current Mode Boost, Flyback and SEPIC Controller

Linear Technology 

LTC1871-7

ELECTRICAL CHARACTERISTICS

The q denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.

VIN = 8V, VRUN = 1.5V, RFREQ = 80k, VMODE/SYNC = 0V, unless otherwise specified.

SYMBOL PARAMETER

CONDITIONS

MIN TYP MAX UNITS

Oscillator

fOSC

Oscillator Frequency

Oscillator Frequency Range

RFREQ = 80k

250 300 350

kHz

50

1000

kHz

DMAX

fSYNC/fOSC

Maximum Duty Cycle

Recommended Maximum Synchronized

Frequency Ratio

fOSC = 300kHz (Note 6)

87

92

97

%

1.25 1.30

tSYNC(MIN) MODE/SYNC Minimum Input Pulse Width

tSYNC(MAX) MODE/SYNC Maximum Input Pulse Width

VIL(MODE) Low Level MODE/SYNC Input Voltage

VIH(MODE) High Level MODE/SYNC Input Voltage

RMODE/SYNC MODE/SYNC Input Pull-Down Resistance

VFREQ

Nominal FREQ Pin Voltage

Low Dropout Regulator

VSYNC = 0V to 5V

VSYNC = 0V to 5V

25

ns

0.8/fOSC

ns

0.3

V

1.2

V

50

kΩ

0.62

V

VINTVCC

UVLO

INTVCC Regulator Output Voltage

INTVCC Undervoltage Lockout Thresholds

∆VINTVCC

∆VIN1

∆VINTVCC

∆VIN2

VLDO(LOAD)

VDROPOUT

GATE Driver

INTVCC Regulator Line Regulation

INTVCC Regulator Line Regulation

INTVCC Load Regulation

INTVCC Regulator Dropout Voltage

VIN = 8V

Rising INTVCC

Falling INTVCC

UVLO Hysteresis

8V ≤ VIN ≤ 15V

15V ≤ VIN ≤ 30V

0 ≤ IINTVCC ≤ 20mA, VIN = 8V

VIN = 6V, INTVCC Load = 20mA

6.5

7

7.5

V

5.6

V

4.6

V

1.0

V

8

25

mV

70

200

mV

–2

– 0.2

%

280

mV

tr

GATE Driver Output Rise Time

tf

GATE Driver Output Fall Time

CL = 3300pF (Note 7)

CL = 3300pF (Note 7)

17

100

ns

8

100

ns

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

of the device may be impaired.

Note 2: The LTC1871-7E is guaranteed to meet performance specifications

from 0°C to 70°C. Specifications over the – 40°C to 85°C operating

temperature range are assured by design, characterization and correlation

with statistical process controls.

Note 3: TJ is calculated from the ambient temperature TA and power

dissipation PD according to the following formula:

TJ = TA + (PD • 120°C/W)

Note 4: The dynamic input supply current is higher due to power MOSFET

gate charging (QG • fOSC). See Applications Information.

Note 5: The LTC1871-7 is tested in a feedback loop that servos VFB to the

reference voltage with the ITH pin forced to a voltage between 0V and 1.4V

(the no load to full load operating voltage range for the ITH pin is 0.3V to

1.23V).

Note 6: In a synchronized application, the internal slope compensation

gain is increased by 25%. Synchronizing to a significantly higher ratio will

reduce the effective amount of slope compensation, which could result in

subharmonic oscillation for duty cycles greater than 50%.

Note 7: Rise and fall times are measured at 10% and 90% levels.

18717f

3

Share Link: