LT1790 Linear Technology, LT1790 Datasheet - Page 3

• Manufacturer Part Number: LT1790
• Description: 2.5V Micropower SOT-23 Low Dropout Reference
• Manufacturer: Linear Technology

ELECTRICAL CHARACTERISTICS
Note 5: Temperature coefficient is measured by dividing the change in
output voltage by the specified temperature range. Incremental slope is
also measured at 25 C.
Note 6: Load regulation is measured on a pulse basis from no load to the
specified load current. Output changes due to die temperature change
must be taken into account separately.
Note 7: Excludes load regulation errors.
Note 8: Peak-to-peak noise is measured with a single pole highpass filter
at 0.1Hz and a 2-pole lowpass filter at 10Hz. The unit is enclosed in a still
air environment to eliminate thermocouple effects on the leads. The test
time is 10 seconds. RMS noise is measured with a single pole highpass
filter at 10Hz and a 2-pole lowpass filter at 1kHz. The resulting output is
full-wave rectified and then integrated for a fixed period, making the final
reading an average as opposed to RMS. A correction factor of 1.1 is used
to convert from average to RMS and a second correction of 0.88 is used to
correct for the nonideal bandpass of the filters.
TYPICAL PERFOR A CE CHARACTERISTICS
2.508
2.506
2.504
2.502
2.500
2.498
2.496
2.494
–1
–2
–3
–4
–5
0
0.1
–50
Load Regulation (Sourcing)
Output Voltage Temperature Drift
FOUR TYPICAL PARTS
–30 –10
OUTPUT CURRENT (mA)
TEMPERATURE ( C)
T
10
T
A
A
= 125 C
= 25 C
30
1
50
70
T
A
W
90 110
= –55 C
1790 616
1790 G13
U
10
130
0.1
10
5
4
3
2
1
0
1
0.1
0
Load Regulation (Sinking)
Minimum Input-Output Voltage
Differential (Sourcing) Series Mode
T
A
= –55 C
0.1
INPUT-OUTPUT VOLTAGE (V)
OUTPUT CURRENT (mA)
T
0.2
A
= 125 C
0.3
1
Note 9: Long-term drift typically has a logarithmic characteristic and
therefore changes after 1000 hours tend to be smaller than before that
time. Total drift in the second thousand hours is normally less than one
third that to the first thousand hours with a continuing trend toward
reduced drift with time. Long-term drift is affected by differential stress
between the IC and the board material created during board assembly. See
Applications Information.
Note 10: Hysteresis in the output voltage is created by package stress that
differs depending on whether the IC was previously at a higher or lower
temperature. Output voltage is always measured at 25 C, but the IC is
cycled to 85 C or – 40 C before a successive measurements. Hysteresis is
roughly proportional to the square of the temperature change. Hysteresis
is not normally a problem for operational temperature excursions where
the instrument might be stored at high or low temperature. See
Applications Information.
T
A
= 25 C
T
T
A
A
0.4
= 125 C
= –55 C
T
A
= 25 C
0.5
1790 G14
1790 617
0.6
10
–30
–10
90
50
30
10
70
80
70
60
50
40
30
20
10
0
–50
Minimum Input-Output Voltage
Differential (Sinking) Series Mode
0
Supply Current vs Input Voltage
–30
–10
5
TEMPERATURE ( C)
INPUT VOLTAGE (V)
10
LT1790-2.5
30
T
T
T
10
A
A
A
50
= 25 C
= –55 C
= 125 C
70
5mA
15
1mA
90 110
100 A
1790 G15
1790 G18
3
130
20