Datasheet

11
LT1790
1790fa
Line Regulation
Output Impedance vs Frequency
Power Supply Rejection Ratio
vs Frequency
INPUT VOLTAGE (V)
0
OUTPUT VOLTAGE (V)
1.255
1.265
1.275
1.285
16
17901.25. G07
1.245
1.235
1.250
1.260
1.270
1.280
1.240
1.230
1.225
4
8
12
218
6
10
14
20
T
A
= –55°C
T
A
= 25°C
T
A
= 125°C
FREQUENCY (Hz)
–60
POWER SUPPLY REJECTION RATIO (dB)
0
10
–70
–80
–10
–40
–20
–30
–50
100 10k 100k 1M
17901.25 G08
–90
1k
V
IN
= 3V
C
L
= 1µF
FREQUENCY (Hz)
1
OUTPUT IMPEDANCE (Ω)
10
100
100 10k 100k
17901.25 G09
0
1k
500
V
IN
= 3V
C
L
= 0.47µF
C
L
= 4.7µF
C
L
= 1µF
1.25V TYPICAL PERFOR A CE CHARACTERISTICS
UW
Each of the voltage options have similar performance curves. For the 3V, 3.3V and the 4.096V options,
the curves can be estimated based on the 2.5V and 5V curves.
–1.25V Characteristics
Long-Term Drift
(Data Points Reduced After 500 Hr)
Output Noise 0.1Hz to 10Hz
Output Voltage Noise Spectrum
OUTPUT TO GROUND VOLTAGE (V)
0
CURRENT IN R
L
(mA)
0.10
0.20
0.30
0.05
0.15
0.25
–2.0 –1.5 –1.0 –0.5
17091.25 G10
0–2.5
–V
EE
V
OUT
3V
R
L
5k
4
21
6
1µF
LT1790-1.25
R1 10k
T
A
= 25°C
T
A
= 125°C
T
A
= –55°C
HOURS
0
ppm
60
100
140
800
17901.25 G10
20
–20
40
80
120
0
–40
–60
200
400
600
1000
LT1790S6-1.25V
2 TYPICAL PARTS SOLDERED TO PCB
T
A
= 30°C
TIME (SEC)
0
OUTPUT NOISE (5µV/DIV)
8
17901.2 G12
246 107135 9
FREQUENCY (Hz)
10
2.0
NOISE VOLTAGE (µV/√Hz)
2.5
3.0
3.5
4.0
100 1k 10k
17901.25 G13
1.5
1.0
0.5
0
4.5
5.0
C
L
= 1µF
I
O
= 100µA
I
O
= 0µA
I
O
= 250µA
I
O
= 1mA
Integrated Noise 10Hz to 1kHz
FREQUENCY (Hz)
10
1
INTEGRATED NOISE (µV
RMS
)
10
100
100 1000
LT1790 G01