LTC1727/LTC1728

4

Rev. E

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ELECTRICAL CHARACTERISTICS

LTC1728-3.3 The l denotes specifications which apply over the full operating temperature range, otherwise specifications are at

TA = 25°C. VCC3 = 3.3V, VCC18 = 1.8V, VCCA = VCC3 unless otherwise noted.

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: All voltage values are with respect to GND.

Note 3: The LTC1727E/LTC1728E are guaranteed to meet specified

performance from 0°C to 70°C and are designed, characterized and

assured to meet the extended temperature limits of –40°C to 85°C

but are not tested at these temperatures.

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

VRT3

Reset Threshold VCC3

VCC3 Input Threshold

l

3.036

3.086

3.135

V

VRT18

Reset Threshold VCC18

VCC18 Input Threshold

l

1.656

1.683

1.710

V

VRTA

Reset Threshold VCCA

VCCA Input Threshold

l

0.985

1.000

1.015

V

VCCOP

VCC3, VCC18 Operating Voltage

RST in Correct Logic State

l

1

7

V

IVCC3

VCC3 Supply Current

VCC18 > VCC3

VCC18 < VCC3, VCC3 = 3.3V (Note 4)

l

l

1

10

2

20

µA

µA

IVCC18

VCC18 Supply Current

VCC18 < VCC3, VCC18 = 1.8V (Note 4)

l

1

2

µA

IVCCA

VCCA Input Current

VCCA = 1V

l

–15

0

15

nA

tRST

Reset Pulse Width

RST Low (Note 5)

l

140

200

280

ms

tUV

VCC Undervoltage Detect to RST

VCC18, VCC3 or VCCA Less Than Reset (Note 5)

Threshold VRT by More Than 1%

110

µs

VOL

Output Voltage Low, RST

ISINK = 2.5mA, VCC3 = 3.3V, VCC18 = 0V

ISINK = 100µA, VCC3 = 1V, VCC18 = 0V

ISINK = 100µA, VCC3 = 0V, VCC18 = 1V

ISINK = 100µA, VCC3 = 1V, VCC18 = 1V

l

l

l

l

0.15

0.05

0.05

0.05

0.4

0.3

0.3

0.3

V

V

V

V

VOH

Output Voltage High, RST

ISOURCE = 1µA (Note 6)

l

VCC3 – 1

V

Note 4: Both VCC3 and VCC5/VCC25/VCC18 can act as the supply depending

on which pin has the greatest potential.

Note 5: Measured from when input passes through the input threshold

(VRTX) until RST or COMPX passes through 1.5V.

Note 6: The output pins RST and COMPX have internal pull-ups to VCC3 of

typically 6µA. However, external pull-up resistors may be used when faster

rise times are required or for VOH voltages greater than VCC3.

Note 7: The VCC5 reset override voltage is valid for an operating range less

than approximately 4.15V. Above this point the override is turned off and

the VCC5 pin functions normally.