LTC7802EUFDM datasheet(5/34 Pages) AD

5 / 34 page

LTC7802

Rev. 0

For more information www.analog.com

ELECTRICAL CHARACTERISTICS

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 LTC7802 is tested under pulsed load conditions such that TJ ≈

TA. The LTC7802E is guaranteed to meet specifications from 0°C to 85°C

junction temperature. Specifications over the –40°C to 125°C operating

junction temperature range are assured by design, characterization and

correlation with statistical process controls. The LTC7802I is guaranteed

over the –40°C to 125°C operating junction temperature range, and the

LTC7802J/LTC7802H are guaranteed over the –40°C to 150°C operating

junction temperature range. High junction temperatures degrade operating

lifetimes; operating lifetime is derated for junction temperatures greater

than 125°C. 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. The junction temperature (TJ, in °C) is

calculated from the ambient temperature (TA, in °C) and power dissipation

(PD, in Watts) according to the formula: TJ = TA + (PD • θJA), where θJA (in

°C/W) is the package thermal impedance.

Note 3: When SENSE1– ≥ 3.2V or EXTVCC ≥ 4.8V, VIN supply current

is transferred to these pins to reduce the total input supply quiescent

current. SENSE1– bias current is reflected to the channel 1 input supply by

the formula IVIN1 = ISENSE1– • VOUT1/(VIN1 • η), where η is the efficiency.

EXTVCC bias current is similarly reflected to the input supply when biased

by an output. To minimize input supply current, select channel 1 to be the

lowest output voltage greater than 3.2V and connect EXTVCC to the lowest

output voltage greater than 4.8V

Note 4: The LTC7802 is tested in a feedback loop that servos VITH1,2 to a

specified voltage and measures the resultant VFB1,2. The specification at

85°C is not tested in production and is assured by design, characterization

and correlation to production testing at other temperatures (125°C for the

LTC7802E/LTC7802I, 150°C for the LTC7802J/LTC7802H).

Note 5: Dynamic supply current is higher due to the gate charge being

delivered at the switching frequency. See Applications Information.

Note 6: Rise and fall times are measured using 10% and 90% levels. Delay

times are measured using 50% levels.

Note 7: The minimum on-time condition is specified for an inductor

peak-to-peak ripple current >40% of IL(MAX) (See Minimum On-Time

Considerations in the Applications Information section).

Note 8: This IC includes overtemperature protection that is intended to

protect the device during momentary overload conditions. The maximum

rated junction temperature will be exceeded when this protection is active.

Continuous operation above the specified absolute maximum operating

junction temperature may impair device reliability or permanently damage

the device.

Note 9: Do not apply a voltage or current source to these pins. They must

be connected to capacitive loads only, otherwise permanent damage

may occur.

LTC7802EUFDM 数据表(PDF) 5 Page - Analog Devices

LTC7802EUFDM 数据表(HTML) 5 Page - Analog Devices

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 29 30 31 32 33 34

数据表下载