LTM4650A datasheet(4/28 Pages) LINER

4 / 28 page

LTC7820

7820fc

For more information www.linear.com/LTC7820

Note 1: Stresses beyond those listed under Absolute Maximum Ratings

may cause permanent damage to the device. Exposure to any Absolute

Maximum Rating condition for extended periods may affect device

reliability and lifetime.

Note 2: The LTC7820 is tested under pulsed load conditions such that TJ

≈ TA. The LTC7820E is guaranteed to meet performance specifications

from 0°C to 85°C. Specifications over the –40°C to 125°C operating

junction temperature range are assured by design, characterization and

correlation with statistical process controls. The LTC7820I is guaranteed

over the –40°C to 125°C operating junction temperature range. Note that

the maximum ambient temperature consistent with these specifications

is determined by specific operating conditions in conjunction with board

layout, the rated package thermal impedance and other environmental

factors. TJ is calculated from the ambient temperature TA and power

dissipation PD according to the following formula:

TJ = TA + (PD • 43°C/W).

Note 3: All currents into device pins are positive; all currents out of device

pins are negative. All voltages are referenced to ground unless otherwise

specified.

Note 4: Delay times are measured using 50% levels with SW3 = VLOW =

6V, SW1 = 12V.

Note 5: The maximum output operating voltage for divider applications is

36V, the maximum input operating voltage for doubler applications is 36V.

Note 6: The maximum input operating voltage for divider applications is

72V, the maximum output operating voltage for doubler applications is 72V.

Note 7: When VCC > 15V, EXTVCC lower than VCC is recommended to

improve efficiency and reduce IC Temperature.

Note 8: All the voltage is referred to the GND pin unless otherwise

specified.

Note 9: EXTVCC is enabled only if VCC is higher than 7V.

Note 10: Guaranteed by design.

Note 11: This IC includes overtemperature protection that is intended

to protect the device during momentary overload conditions. Junction

temperature will exceed 125°C when overtemperature protection is active.

Continuous operation above the specified maximum junction temperature

may impair device reliability or permanently damage the device.

ELECTRICAL CHARACTERISTICS

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

VLOW

ISOURCEVLOW

Source Current to VLOW Pin from ISENSE+

ISENSE+ = VHIGH_SENSE = 24V,

VLOW_SENSE = 11V, VLOW = 12V, Timer = 1V

ISINKVLOW

Sink Current from VLOW Pin to GND

ISENSE+ = VHIGH_SENSE = 24V,

VLOW_SENSE = 13V, VLOW = 12V, Timer = 1V

Oscillator

Oscillator Frequency Range

100

1000

kHz

fNOM

Nominal Frequency

VFREQ = 1.02V

500

kHz

IFREQ

FREQ Setting Current

VFREQ = 1.02V (Note 3)

–9.5

–10

–10.5

µA

FAULTB and HYS_PRGM

RFAULT

FAULT Pull-Down Resistance

VFAULT = 0.5V

200

400

IFAULT_LEAK

FAULT Leakage Current

VFAULT = 80V

±2

µA

IHYS_PRGM

HYS_PRGM Setting Current

VHYS_PRGM = 1V (Note 3)

–9.3

–10

–10.7

µA

VVLOW_SENSE_FAULT VLOW_SENSE Voltage Trigger Fault

VVHIGH_SENSE = 24V, VHYS_PRGM = 0V

VVLOW_SENSE Ramp Up

VVLOW_SENSE Ramp Down

12.2

11.6

12.3

11.7

12.4

11.8

VVHIGH_SENSE = 24V, VHYS_PRGM = 5V

VVLOW_SENSE Ramp Up

VVLOW_SENSE Ramp Down

12.7

11.1

12.8

11.2

12.9

11.3

VVHIGH_SENSE = 24V, VHYS_PRGM = 2.4V

VVLOW_SENSE Ramp Up

VVLOW_SENSE Ramp Down

14.15

9.5

14.3

9.65

14.45

9.8

UV Comparator and PGOOD

VUVTH

UV Pin Comparator Threshold

UV Pin Voltage Rising

0.985

1.01

1.035

VUVHYS

Undervoltage Hysteresis

120

RPGOOD

PGOOD Pull-Down Resistance

VPGOOD = 0.5V

150

300

IPGOOD_LEAK

PGOOD Leakage Current

VPGOOD = 45V

±1

µA

Timer

ITIMER

Timer Pin Current

VTIMER < 0.5V or VTIMER > 1.2V (Note 3)

–3.5

µA

0.5V < VTIMER < 1.2V (Note 3)

–7

µA

The l denotes the specifications which apply over the specified operating

junction temperature range, otherwise specifications are at TA = 25°C (Note 2). VCC = 12V, VRUN = 5V, unless otherwise specified.

LTM4650A датащи(PDF) 4 Page - Linear Technology

LTM4650A датащи(HTML) 4 Page - Linear Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

датащи скачать

ссылки URL