LINER LT1790AC

LT1790
Micropower SOT-23
Low Dropout Reference Family
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FEATURES
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DESCRIPTIO
High Accuracy:
A Grade—0.05% Max
B Grade—0.1% Max
Low Drift:
A Grade—10ppm/°C Max
B Grade—25ppm/°C Max
Low Profile (1mm) ThinSOTTM Package
Low Supply Current: 60µA Max
Sinks and Sources Current
Low Dropout Voltage
Guaranteed Operational –40°C to 125°C
Wide Supply Range to 18V
Available Output Voltage Options: 1.25V, 2.048V,
2.5V, 3V, 3.3V, 4.096V and 5V
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APPLICATIO S
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Handheld Instruments
Negative Voltage References
Industrial Control Systems
Data Acquisition Systems
Battery-Operated Equipment
The LT1790s are ideally suited for battery-operated systems because of their small size, low supply current and
reduced dropout voltage. These references provide supply
current and power dissipation advantages over shunt
references that must idle the entire load current to operate.
Since the LT1790 can also sink current, it can operate as
a micropower negative voltage reference with the same
performance as a positive reference.
, LTC and LT are registered trademarks of Linear Technology Corporation.
ThinSOT is a trademark of Linear Technology Corporation.
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The LT®1790 is a family of SOT-23 micropower low
dropout series references that combine high accuracy and
low drift with low power dissipation and small package
size. These micropower references use curvature compensation to obtain a low temperature coefficient and
trimmed precision thin-film resistors to achieve high
output accuracy. In addition, each LT1790 is post-package trimmed to greatly reduce the temperature coefficient
and increase the output accuracy. Output accuracy is
further assured by excellent line and load regulation.
Special care has been taken to minimize thermally induced
hysteresis.
TYPICAL APPLICATIO
Typical VOUT Distribution for LT1790-2.5
50
167 UNITS
45
Positive Connection for LT1790-2.5
0.1µF
LT1790-2.5
1, 2
6
VOUT = 2.5V
1µF
1790 TA01
NUMBER OF UNITS
2.6V ≤ VIN ≤ 18V
4
40
LT1790B LIMITS
35
LT1790A LIMITS
30
25
20
15
10
5
0
2.498
2.499 2.500
2.501
OUTPUT VOLTAGE (V)
2.502
1790 TA02
1790fa
1
LT1790
W W
W
AXI U
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ABSOLUTE
RATI GS
(Note 1)
Input Voltage .......................................................... 20V
Specified Temperature Range
Commercial ............................................ 0°C to 70°C
Industrial ............................................ – 40°C to 85°C
Output Short-Circuit Duration ......................... Indefinite
Operating Temperature Range
(Note 2) ........................................... – 40°C to 125°C
Storage Temperature Range
(Note 3) ........................................... – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
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PACKAGE/ORDER I FOR ATIO
ORDER
PART NUMBER
TOP VIEW
GND 1
6 VOUT
GND 2
5 DNC*
DNC* 3
4 VIN
S6 PACKAGE
6-LEAD PLASTIC SOT-23
TJMAX = 150°C, θJA = 230°C/W
*DNC: DO NOT CONNECT
LT1790ACS6-1.25
LT1790BCS6-1.25
LT1790ACS6-2.048
LT1790BCS6-2.048
LT1790ACS6-2.5
LT1790BCS6-2.5
LT1790ACS6-3
LT1790BCS6-3
LT1790ACS6-3.3
LT1790BCS6-3.3
LT1790ACS6-4.096
LT1790BCS6-4.096
LT1790ACS6-5
LT1790BCS6-5
OUTPUT
VOLTAGE
S6
PART MARKING*
1.250V
2.048V
2.500V
3.000V
3.300V
4.096V
5.000V
LTXT
LTXU
LTPZ
LTQA
LTXW
LTQB
LTQC
LT1790AIS6-1.25
LT1790BIS6-1.25
LT1790AIS6-2.048
LT1790BIS6-2.048
LT1790AIS6-2.5
LT1790BIS6-2.5
LT1790AIS6-3
LT1790BIS6-3
LT1790AIS6-3.3
LT1790BIS6-3.3
LT1790AIS6-4.096
LT1790BIS6-4.096
LT1790AIS6-5
LT1790BIS6-5
* The temperature grades and parametric grades are identified by a label on the shipping container. Consult LTC Marketing for parts specified with wider
operating temperature ranges.
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AVAILABLE OPTIO S
TEMPERATURE RANGE
0°C to 70°C
– 40°C to 85°C
OUTPUT
VOLTAGE
INITIAL
ACCURACY
TEMPERATURE
COEFFICEINT
ORDER PART NUMBER
ORDER PART NUMBER
1.250V
0.05%
0.1%
10ppm/°C
25ppm/°C
LT1790ACS6-1.25
LT1790BCS6-1.25
LT1790AIS6-1.25
LT1790BIS6-1.25
2.048V
0.05%
0.1%
10ppm/°C
25ppm/°C
LT1790ACS6-2.048
LT1790BCS6-2.048
LT1790AIS6-2.048
LT1790BIS6-2.048
2.500V
0.05%
0.1%
10ppm/°C
25ppm/°C
LT1790ACS6-2.5
LT1790BCS6-2.5
LT1790AIS6-2.5
LT1790BIS6-2.5
3.000V
0.05%
0.1%
10ppm/°C
25ppm/°C
LT1790ACS6-3
LT1790BCS6-3
LT1790AIS6-3
LT1790BIS6-3
3.300V
0.05%
0.1%
10ppm/°C
25ppm/°C
LT1790ACS6-3.3
LT1790BCS6-3.3
LT1790AIS6-3.3
LT1790BIS6-3.3
4.096V
0.05%
0.1%
10ppm/°C
25ppm/°C
LT1790ACS6-4.096
LT1790BCS6-4.096
LT1790AIS6-4.096
LT1790BIS6-4.096
5.000V
0.05%
0.1%
10ppm/°C
25ppm/°C
LT1790ACS6-5
LT1790BCS6-5
LT1790AIS6-5
LT1790BIS6-5
1790fa
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LT1790
1.25V ELECTRICAL CHARACTERISTICS
The ● denotes specifications that apply over the specified
temperature range, otherwise specifications are at TA = 25°C. CL = 1µF and VIN = 2.6V, unless otherwise noted.
PARAMETER
CONDITIONS
Output Voltage (Notes 3, 4)
Output Voltage Temperature Coefficient (Note 5)
Line Regulation
MIN
TYP
MAX
LT1790A
1.24937
–0.05
1.250
1.25062
0.05
V
%
LT1790B
1.24875
–0.10
1.250
1.25125
0.10
V
%
LT1790AC
●
●
1.24850
–0.120
1.250
1.25150
0.120
V
%
LT1790AI
●
●
1.24781
–0.175
1.250
1.25219
0.175
V
%
LT1790BC
●
●
1.24656
–0.275
1.250
1.25344
0.275
V
%
LT1790BI
●
●
1.24484
–0.4125
1.250
1.25516
0.4125
V
%
5
12
10
25
ppm/°C
ppm/°C
50
170
220
ppm/V
ppm/V
100
160
250
ppm/mA
ppm/mA
120
180
250
ppm/mA
ppm/mA
1.95
2.15
2.50
2.90
2.95
V
V
V
V
35
60
75
µA
µA
125
µA
TMIN ≤ TA ≤ TMAX
LT1790A
LT1790B
●
●
2.6V ≤ VIN ≤ 18V
●
Load Regulation (Note 6)
IOUT Source = 5mA, VIN = 2.8V
●
IOUT Sink = 1mA, VIN = 3.2V
●
Minimum Operating Voltage (Note 7)
VIN, ∆VOUT = 0.1%
IOUT = 0mA
IOUT Source = 5mA
IOUT Sink = 1mA
Supply Current
UNITS
●
●
●
No Load
●
Minimum Operating Current—
Negative Output (See Figure 7)
VOUT = – 1.25V, ±0.1%
100
Turn-On Time
CLOAD = 1µF
250
µs
Output Noise (Note 8)
0.1Hz ≤ f ≤ 10Hz
10Hz ≤ f ≤ 1kHz
10
14
µVP-P
µVRMS
50
ppm/√kHr
40
100
ppm
ppm
Long-Term Drift of Output Voltage (Note 9)
Hysteresis (Note 10)
∆T = 0°C to 70°C
∆T = – 40°C to 85°C
●
●
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LT1790
2.048V ELECTRICAL CHARACTERISTICS
The ● denotes specifications that apply over the specified
temperature range, otherwise specifications are at TA = 25°C. CL = 1µF and VIN = 2.8V, unless otherwise noted.
PARAMETER
CONDITIONS
MIN
TYP
MAX
Output Voltage (Notes 3, 4)
LT1790A
2.04697
–0.05
2.048
2.04902
0.05
V
%
LT1790B
2.04595
–0.10
2.048
2.05005
0.10
V
%
Output Voltage Temperature Coefficient (Note 5)
Line Regulation
LT1790AC
●
●
2.04554
–0.120
2.048
2.05046
0.120
V
%
LT1790AI
●
●
2.04442
–0.175
2.048
2.05158
0.175
V
%
LT1790BC
●
●
2.04237
–0.275
2.048
2.05363
0.275
V
%
LT1790BI
●
●
2.03955
–0.4125
2.048
2.05645
0.4125
V
%
5
12
10
25
ppm/°C
ppm/°C
50
170
220
ppm/V
ppm/V
120
200
280
ppm/mA
ppm/mA
130
260
450
ppm/mA
ppm/mA
50
100
500
750
450
mV
mV
mV
mV
35
60
75
µA
µA
125
µA
TMIN ≤ TA ≤ TMAX
LT1790A
LT1790B
●
●
2.8V ≤ VIN ≤ 18V
●
Load Regulation (Note 6)
IOUT Source = 5mA
●
IOUT Sink = 3mA
●
Dropout Voltage (Note 7)
VIN – VOUT, ∆VOUT = 0.1%
IOUT = 0mA
IOUT Source = 5mA
IOUT Sink = 3mA
Supply Current
UNITS
●
●
●
No Load
●
Minimum Operating Current—
Negative Output (See Figure 7)
VOUT = – 2.048V, 0.1%
100
Turn-On Time
CLOAD = 1µF
350
µs
Output Noise (Note 8)
0.1Hz ≤ f ≤ 10Hz
10Hz ≤ f ≤ 1kHz
22
41
µVP-P
µVRMS
50
ppm/√kHr
40
100
ppm
ppm
Long-Term Drift of Output Voltage (Note 9)
Hysteresis (Note 10)
∆T = 0°C to 70°C
∆T = – 40°C to 85°C
●
●
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LT1790
2.5V ELECTRICAL CHARACTERISTICS
The ● denotes specifications that apply over the specified
temperature range, otherwise specifications are at TA = 25°C. CL = 1µF and VIN = 3V, unless otherwise noted.
PARAMETER
CONDITIONS
MIN
TYP
MAX
Output Voltage (Notes 3, 4)
LT1790A
2.49875
–0.05
2.5
2.50125
0.05
V
%
LT1790B
2.4975
–0.10
2.5
2.5025
0.10
V
%
Output Voltage Temperature Coefficient (Note 5)
Line Regulation
LT1790AC
●
●
2.4970
–0.120
2.5
2.5030
0.120
V
%
LT1790AI
●
●
2.49563
–0.175
2.5
2.50438
0.175
V
%
LT1790BC
●
●
2.49313
–0.275
2.5
2.50688
0.275
V
%
LT1790BI
●
●
2.48969
–0.4125
2.5
2.51031
0.4125
V
%
5
12
10
25
ppm/°C
ppm/°C
50
170
220
ppm/V
ppm/V
80
160
250
ppm/mA
ppm/mA
70
110
300
ppm/mA
ppm/mA
50
100
120
450
250
mV
mV
mV
mV
35
60
80
µA
µA
125
µA
TMIN ≤ TA ≤ TMAX
LT1790A
LT1790B
●
●
3V ≤ VIN ≤ 18V
●
Load Regulation (Note 6)
IOUT Source = 5mA
●
IOUT Sink = 3mA
●
Dropout Voltage (Note 7)
VIN – VOUT, ∆VOUT = 0.1%
IOUT = 0mA
IOUT Source = 5mA
IOUT Sink = 3mA
Supply Current
UNITS
●
●
●
No Load
●
Minimum Operating Current—
Negative Output (See Figure 7)
VOUT = – 2.5V, 0.1%
100
Turn-On Time
CLOAD = 1µF
700
µs
Output Noise (Note 8)
0.1Hz ≤ f ≤ 10Hz
10Hz ≤ f ≤ 1kHz
32
48
µVP-P
µVRMS
50
ppm/√kHr
40
100
ppm
ppm
Long-Term Drift of Output Voltage (Note 9)
Hysteresis (Note 10)
∆T = 0°C to 70°C
∆T = – 40°C to 85°C
●
●
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LT1790
3V ELECTRICAL CHARACTERISTICS
The ● denotes specifications that apply over the specified temperature
range, otherwise specifications are at TA = 25°C. CL = 1µF and VIN = 3.5V, unless otherwise noted.
PARAMETER
CONDITIONS
MIN
TYP
MAX
Output Voltage (Notes 3, 4)
LT1790A
2.9985
–0.05
3
3.0015
0.05
V
%
LT1790B
2.9970
–0.10
3
3.003
0.10
V
%
Output Voltage Temperature Coefficient (Note 5)
Line Regulation
LT1790AC
●
●
2.99640
–0.120
3
3.00360
0.120
V
%
LT1790AI
●
●
2.99475
–0.175
3
3.00525
0.175
V
%
LT1790BC
●
●
2.99175
–0.275
3
3.00825
0.275
V
%
LT1790BI
●
●
2.98763
–0.4125
3
3.01238
0.4125
V
%
5
12
10
25
ppm/°C
ppm/°C
50
170
220
ppm/V
ppm/V
80
160
250
ppm/mA
ppm/mA
70
110
300
ppm/mA
ppm/mA
50
100
120
450
250
mV
mV
mV
mV
35
60
80
µA
µA
125
µA
TMIN ≤ TA ≤ TMAX
LT1790A
LT1790B
●
●
3.5V ≤ VIN ≤ 18V
●
Load Regulation (Note 6)
IOUT Source = 5mA
●
IOUT Sink = 3mA
●
Dropout Voltage (Note 7)
VIN – VOUT, ∆VOUT = 0.1%
IOUT = 0mA
IOUT Source = 5mA
IOUT Sink = 3mA
Supply Current
UNITS
●
●
●
No Load
●
Minimum Operating Current—
Negative Output (See Figure 7)
VOUT = – 3V, 0.1%
100
Turn-On Time
CLOAD = 1µF
700
µs
Output Noise (Note 8)
0.1Hz ≤ f ≤ 10Hz
10Hz ≤ f ≤ 1kHz
50
56
µVP-P
µVRMS
50
ppm/√kHr
40
100
ppm
ppm
Long-Term Drift of Output Voltage (Note 9)
Hysteresis (Note 10)
∆T = 0°C to 70°C
∆T = – 40°C to 85°C
●
●
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LT1790
3.3V ELECTRICAL CHARACTERISTICS
The ● denotes specifications that apply over the specified
temperature range, otherwise specifications are at TA = 25°C. CL = 1µF and VIN = 3.8V, unless otherwise noted.
PARAMETER
CONDITIONS
MIN
TYP
MAX
Output Voltage (Notes 3, 4)
LT1790A
3.29835
–0.05
3.3
3.30165
0.05
V
%
LT1790B
3.2967
–0.10
3.3
3.3033
0.10
V
%
Output Voltage Temperature Coefficient (Note 5)
Line Regulation
LT1790AC
●
●
3.29604
–0.120
3.3
3.30396
0.120
V
%
LT1790AI
●
●
3.29423
–0.175
3.3
3.30578
0.175
V
%
LT1790BC
●
●
3.29093
–0.275
3.3
3.30908
0.275
V
%
LT1790BI
●
●
3.28639
–0.4125
3.3
3.31361
0.4125
V
%
5
12
10
25
ppm/°C
ppm/°C
50
170
220
ppm/V
ppm/V
80
160
250
ppm/mA
ppm/mA
70
110
300
ppm/mA
ppm/mA
50
100
120
450
250
mV
mV
mV
mV
35
60
80
µA
µA
125
µA
TMIN ≤ TA ≤ TMAX
LT1790A
LT1790B
●
●
3.8V ≤ VIN ≤ 18V
●
Load Regulation (Note 6)
IOUT Source = 5mA
●
IOUT Sink = 3mA
●
Dropout Voltage (Note 7)
VIN – VOUT, ∆VOUT = 0.1%
IOUT = 0mA
IOUT Source = 5mA
IOUT Sink = 3mA
Supply Current
UNITS
●
●
●
No Load
●
Minimum Operating Current—
Negative Output (See Figure 7)
VOUT = – 3.3V, 0.1%
100
Turn-On Time
CLOAD = 1µF
700
µs
Output Noise (Note 8)
0.1Hz ≤ f ≤ 10Hz
10Hz ≤ f ≤ 1kHz
50
67
µVP-P
µVRMS
50
ppm/√kHr
40
100
ppm
ppm
Long-Term Drift of Output Voltage (Note 9)
Hysteresis (Note 10)
∆T = 0°C to 70°C
∆T = – 40°C to 85°C
●
●
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LT1790
4.096V ELECTRICAL CHARACTERISTICS
The ● denotes specifications that apply over the specified
temperature range, otherwise specifications are at TA = 25°C. CL = 1µF and VIN = 4.6V, unless otherwise noted.
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Output Voltage (Notes 3, 4)
LT1790A
4.094
–0.05
4.096
4.098
0.05
V
%
LT1790B
4.092
–0.10
4.096
4.10
0.10
V
%
Output Voltage Temperature Coefficient (Note 5)
Line Regulation
LT1790AC
●
●
4.09108
–0.120
4.096
4.10092
0.120
V
%
LT1790AI
●
●
4.08883
–0.175
4.096
4.10317
0.175
V
%
LT1790BC
●
●
4.08474
–0.275
4.096
4.10726
0.275
V
%
LT1790BI
●
●
4.07910
–0.4125
4.096
4.11290
0.4125
V
%
5
12
10
25
ppm/°C
ppm/°C
50
170
220
ppm/V
ppm/V
80
160
250
ppm/mA
ppm/mA
70
110
300
ppm/mA
ppm/mA
50
100
120
450
250
mV
mV
mV
mV
35
60
80
µA
µA
125
µA
TMIN ≤ TA ≤ TMAX
LT1790A
LT1790B
●
●
4.6V ≤ VIN ≤ 18V
●
Load Regulation (Note 6)
IOUT Source = 5mA
●
IOUT Sink = 3mA
●
Dropout Voltage (Note 7)
VIN – VOUT, ∆VOUT = 0.1%
IOUT = 0mA
IOUT Source = 5mA
IOUT Sink = 3mA
Supply Current
●
●
●
No Load
●
Minimum Operating Current—
Negative Output (See Figure 7)
VOUT = – 4.096V, 0.1%
100
Turn-On Time
CLOAD = 1µF
700
µs
Output Noise (Note 8)
0.1Hz ≤ f ≤ 10Hz
10Hz ≤ f ≤ 1kHz
60
89
µVP-P
µVRMS
50
ppm/√kHr
40
100
ppm
ppm
Long-Term Drift of Output Voltage (Note 9)
Hysteresis (Note 10)
∆T = 0°C to 70°C
∆T = – 40°C to 85°C
●
●
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8
LT1790
5V ELECTRICAL CHARACTERISTICS
The ● denotes specifications that apply over the specified temperature
range, otherwise specifications are at TA = 25°C. CL = 1µF and VIN = 5.5V, unless otherwise noted.
PARAMETER
CONDITIONS
Output Voltage (Notes 3, 4)
Output Voltage Temperature Coefficient (Note 5)
Line Regulation
MIN
TYP
MAX
LT1790A
4.9975
–0.05
5
5.0025
0.05
V
%
LT1790B
4.995
–0.10
5
5.005
0.10
V
%
LT1790AC
●
●
4.99400
–0.120
5
5.00600
0.120
V
%
LT1790AI
●
●
4.99125
–0.175
5
5.00875
0.175
V
%
LT1790BC
●
●
4.98625
–0.275
5
5.01375
0.275
V
%
LT1790BI
●
●
4.97938
–0.4125
5
5.02063
0.4125
V
%
5
12
10
25
ppm/°C
ppm/°C
50
170
220
ppm/V
ppm/V
80
160
250
ppm/mA
ppm/mA
70
110
300
ppm/mA
ppm/mA
50
100
120
450
250
mV
mV
mV
mV
35
60
80
µA
µA
125
µA
TMIN ≤ TA ≤ TMAX
LT1790A
LT1790B
●
●
5.5V ≤ VIN ≤ 18V
●
Load Regulation (Note 6)
IOUT Source = 5mA
●
IOUT Sink = 3mA
●
Dropout Voltage (Note 7)
VIN – VOUT, ∆VOUT = 0.1%
IOUT = 0mA
IOUT Source = 5mA
IOUT Sink = 3mA
Supply Current
UNITS
●
●
●
No Load
●
Minimum Operating Current—
Negative Output (See Figure 7)
VOUT = – 5V, 0.1%
100
Turn-On Time
CLOAD = 1µF
700
µs
Output Noise (Note 8)
0.1Hz ≤ f ≤ 10Hz
10Hz ≤ f ≤ 1kHz
80
118
µVP-P
µVRMS
50
ppm/√kHr
40
100
ppm
ppm
Long-Term Drift of Output Voltage (Note 9)
Hysteresis (Note 10)
∆T = 0°C to 70°C
∆T = – 40°C to 85°C
Note 1: Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired.
Note 2: The LT1790 is guaranteed functional over the operating
temperature range of – 40°C to 125°C. The LT1790-1.25 at 125°C is
typically less than 2% above the nominal voltage. The other voltage
options are typically less than 0.25% above their nominal voltage.
Note 3: If the part is stored outside of the specified temperature range, the
output voltage may shift due to hysteresis.
Note 4: ESD (Electrostatic Discharge) sensitive device. Extensive use of
ESD protection devices are used internal to the LT1790, however, high
electrostatic discharge can damage or degrade the device. Use proper ESD
handling precautions.
●
●
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. Integrated RMS noise is measured from 10Hz to 1kHz
with the HP3561A analyzer.
1790fa
9
LT1790
ELECTRICAL CHARACTERISTICS
Note 9: Long-term drift typically has a logarithmic characteristic and
therefore changes after 1000 hours tend to be smaller than before that
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 a problem for operational temperature excursions where the
instrument might be stored at high or low temperature. See Applications
Information.
U W
1.25V TYPICAL PERFOR A CE CHARACTERISTICS
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.
Minimum Input-Output Voltage
Differential (Sourcing)
Output Voltage Temperature Drift
1.253
Minimum Input-Output Voltage
Differential (Sinking)
1.0
10
FOUR TYPICAL PARTS
0.9
1.251
1.250
1.249
TA = 125°C
VOLTAGE DIFFERENTIAL (V)
OUTPUT CURRENT (mA)
OUTPUT VOLTAGE (V)
1.252
TA = –55°C
1
TA = 25°C
1.248
0.8
100µA
0.7
5mA
1mA
0.6
0.5
0.4
0.3
0.2
0.1
1.247
–50 –30 –10 10 30 50 70
TEMPERATURE (°C)
90
0.1
110
0
0.5
1
1.5
2
INPUT-OUTPUT VOLTAGE (V)
17901.25 G02
17091.25 G01
Load Regulation (Sourcing)
–600
–800
–1000
TA = 25°C
TA = 125°C
–1200
–1400
–1600
100
1800
90
1600
80
1400
1200
1000
1
OUTPUT CURRENT (mA)
10
17901.25 G04
TA = –55°C
800
600
400
200
–1800
–2000
0.1
Supply Current vs Input Voltage
2000
SUPPLY CURRENT (µA)
TA = –55°C
–200
–400
17091.25 G03
Load Regulation (Sinking)
OUTPUT VOLTAGE CHANGE (ppm)
OUTPUT VOLTAGE CHANGE (ppm)
0
0
–50 –30 –10 10 30 50 70 90 110 130
TEMPERATURE (°C)
2.5
0
0.1
TA = 125°C
TA = –55°C
TA = 25°C
70
60
50
TA = 125°C
40
30
20
TA = 25°C
1
OUTPUT CURRENT (mA)
10
10
17901.25 G05
0
0
5
15
10
INPUT VOLTAGE (V)
20
17901.25 G06
1790fa
10
LT1790
U W
1.25V TYPICAL PERFOR A CE CHARACTERISTICS
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.
Power Supply Rejection Ratio
vs Frequency
Line Regulation
500
–10
100
TA = 125°C
1.270
1.265
1.260
1.255
TA = 25°C
1.250
TA = –55°C
1.245
1.240
1.235
1.230
1.225
4
2
0
–20
–30
–40
–50
–60
–70
1k
10k
100k
FREQUENCY (Hz)
0.30
0.20
0.15
6
2
80
VOUT
RL
5k
1M
LT1790S6-1.25V
120 2 TYPICAL PARTS SOLDERED TO PCB
TA = 30°C
100
3V
1µF
60
ppm
CURRENT IN RL (mA)
1
CL = 1µF
1
0
100
1k
10k
FREQUENCY (Hz)
100k
17901.25 G09
Output Noise 0.1Hz to 10Hz
140
R1 10k
LT1790-1.25
CL = 4.7µF
Long-Term Drift
(Data Points Reduced After 500 Hr)
– 1.25V Characteristics
0.25
10
17901.25 G08
17901.25. G07
4
CL = 0.47µF
–80
–90
100
6 8 10 12 14 16 18 20
INPUT VOLTAGE (V)
VIN = 3V
OUTPUT NOISE (5µV/DIV)
OUTPUT VOLTAGE (V)
1.275
VIN = 3V
0 CL = 1µF
OUTPUT IMPEDANCE (Ω)
POWER SUPPLY REJECTION RATIO (dB)
1.285
1.280
Output Impedance vs Frequency
10
–VEE
40
20
0.10
0
TA = 25°C
TA = 125°C
TA = –55°C
0.05
–20
–40
–2.0
–1.5
–1.0
–0.5
OUTPUT TO GROUND VOLTAGE (V)
–60
0
200
0
600
400
HOURS
800
17091.25 G10
CL = 1µF
3.5
3.0
2.5
IO = 100µA
IO = 0µA
1.5
IO = 250µA
1.0
0.5
IO = 1mA
0
10
1
2
3
4 5 6
TIME (SEC)
7
8
9
10
17901.2 G12
Integrated Noise 10Hz to 1kHz
4.0
2.0
0
100
INTEGRATED NOISE (µVRMS)
4.5
1000
17901.25 G10
Output Voltage Noise Spectrum
5.0
NOISE VOLTAGE (µV/√Hz)
0
–2.5
100
1k
FREQUENCY (Hz)
10k
17901.25 G13
10
1
10
100
FREQUENCY (Hz)
1000
LT1790 G01
1790fa
11
LT1790
U W
2.048V TYPICAL PERFOR A CE CHARACTERISTICS
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.
Minimum Input-Output Voltage
Differential (Sourcing)
Output Voltage Temperature Drift
2.056
130
10
TA = 25°C
OUTPUT CURRENT (mA)
2.054
2.052
2.050
2.048
2.046
TA = 125°C
110
VOLTAGE DIFFERENTIAL (mV)
FOUR TYPICAL PARTS
OUTPUT VOLTAGE (V)
Minimum Input-Output Voltage
Differential (Sinking)
TA = –55°C
1
90
70
5mA
50
1mA
30
10
2.044
–30
2.042
–50 –30 –10 10 30 50 70 90 110 130
TEMPERATURE (°C)
0
0.1
0.2 0.3 0.4 0.5
0.6
INPUT-OUTPUT VOLTAGE (V)
–600
TA = 125°C
–800
–1000
–1200
–1400
–1600
80
1800
70
1400
1200
TA = –40°C
1000
800
600
TA = 125°C
400
TA = 25°C
200
1
OUTPUT CURRENT (mA)
0
0.1
10
1
OUTPUT CURRENT (mA)
17902.048 G04
TA = 125°C
2.050
TA = 25°C
TA = –55°C
2.046
2.044
2.042
2
4
6 8 10 12 14 16 18 20
INPUT VOLTAGE (V)
17902.048 G07
TA = 25°C
40
30
TA = 125°C
20
10
0
10
0
10
5
10
20
15
INPUT VOLTAGE (V)
17902.048 G06
Output Impedance vs Frequency
1000
CL = 1µF
0
OUTPUT IMPEDANCE (Ω)
POWER SUPPLY REJECTION RATIO (dB)
20
0
50
Power Supply Rejection Ratio
vs Frequency
2.054
2.048
60
17902.048 G05
Line Regulation
2.052
TA = –55°C
1600
–1800
–2000
0.1
Supply Current vs Input Voltage
2000
SUPPLY CURRENT (µA)
OUTPUT VOLTAGE CHANGE (ppm)
OUTPUT VOLTAGE CHANGE (ppm)
TA = 25°C
–400
17902.048 G03
Load Regulation (Sinking)
TA = –55°C
–200
0.7
17902.048 G02
Load Regulation (Sourcing)
0
–50
–50 –30 –10 10 30 50 70 90 110 130
TEMPERATURE (°C)
0.1
17902.048 G01
OUTPUT VOLTAGE (V)
100µA
–10
–10
–20
–30
–40
–50
CL = 0.47µF
100
10
CL = 4.7µF
CL = 1µF
–60
–70
–80
100
1k
10k
100k
FREQUENCY (Hz)
1M
17902.048 G08
1
10k
100k
1M
FREQUENCY (Hz)
10M
17902.048 G09
1790fa
12
LT1790
U W
2.048V TYPICAL PERFOR A CE CHARACTERISTICS
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.
– 2.048V Characteristics
Long-Term Drift
0.30
100
TA = 30°C
80 2 TYPICAL PARTS SOLDERED TO PCB
R1 10k
3V
4
0.25
LT1790-2.048
CURRENT IN RL (mA)
1
0.20
40
VOUT
RL
5k
1µF
20
ppm
0.15
60
6
2
–VEE
0
–20
0.10
TA = 125°C
TA = 25°C
TA = –55°C
0.05
–40
–60
–80
0
–4 –3.5 –3 –2.5 –2 –1.5 –1 –0.5
OUTPUT TO GROUND VOLTAGE (V)
–100
0
200
0
600
400
HOURS
17092.048 G10
800
1000
17901.048 G11
Output Noise 0.1Hz to 10Hz
Output Voltage Noise Spectrum
10
CL = 1µF
NOISE VOLTAGE (µV/√Hz)
OUTPUT NOISE (10µV/DIV)
9
8
7
6
5
IO = 100µA
4
IO = 0µA
3
IO = 250µA
2
1
IO = 1mA
0
1
2
3
4 5 6
TIME (SEC)
7
8
9
100
1k
FREQUENCY (Hz)
10
10
10k
17902.048 G13
17902.048 G12
Integrated Noise 10Hz to 1kHz
100
INTEGRATED NOISE (µVRMS)
0
10
1
10
100
FREQUENCY (Hz)
1000
LT1790 G02
1790fa
13
LT1790
U W
2.5V TYPICAL PERFOR A CE CHARACTERISTICS
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.
Minimum Input-Output Voltage
Differential (Sourcing)
Output Voltage Temperature Drift
2.508
Minimum Input-Output Voltage
Differential (Sinking)
90
10
FOUR TYPICAL PARTS
2.504
2.502
2.500
2.498
TA = –55°C
VOLTAGE DIFFERENTIAL (mV)
OUTPUT CURRENT (mA)
OUTPUT VOLTAGE (V)
2.506
TA = 125°C
TA = 25°C
1
2.496
2.494
–50 –30 –10 10 30 50 70 90 110 130
TEMPERATURE (°C)
0.1
0.2
0.3
0.4
0.5
INPUT-OUTPUT VOLTAGE (V)
Load Regulation (Sourcing)
TA = –55°C
–600
TA = 125°C
–800
–1000
–1200
–1400
–1600
1800
70
1400
1200
1000
800
TA = –55°C
600
400
TA = 125°C
0
0.1
10
POWER SUPPLY REJECTION RATIO (dB)
20
TA = 125°C
OUTPUT VOLTAGE (V)
2.505
TA = 25°C
2.500
TA = –55°C
2.490
2.489
4
TA = 25°C
40
30
TA = 125°C
20
10
TA = 25°C
1
OUTPUT CURRENT (mA)
0
10
6 8 10 12 14 16 18 20
INPUT VOLTAGE (V)
17902.5 G07
0
10
5
10
20
15
INPUT VOLTAGE (V)
17902.5 G06
Output Impedance vs Frequency
1000
CL = 1µF
CL = 0.47µF
0
OUTPUT IMPEDANCE (Ω)
2.515
2
50
Power Supply Rejection Ratio
vs Frequency
2.510
TA = –55°C
60
17902.5 G05
Line Regulation
0
Supply Current vs Input Voltage
1600
17902.5 G04
2.495
17902.5 G03
80
200
1
OUTPUT CURRENT (mA)
1mA
5mA
–10
2000
–1800
–2000
0.1
0.6
SUPPLY CURRENT (µA)
OUTPUT VOLTAGE CHANGE (ppm)
OUTPUT VOLTAGE CHANGE (ppm)
TA = 25°C
100µA
10
Load Regulation (Sinking)
0
–400
30
17902.5 G02
17902.5 G01
–200
50
–30
–50 –30 –10 10 30 50 70 90 110 130
TEMPERATURE (°C)
0.1
0
70
–10
–20
–30
–40
–50
CL = 1µF
100
CL = 4.7µF
10
–60
–70
–80
100
1k
10k
100k
FREQUENCY (Hz)
1M
17902.5 G08
1
100
1k
10k
FREQUENCY (Hz)
100k
17902.5 G09
1790fa
14
LT1790
U W
2.5V TYPICAL PERFOR A CE CHARACTERISTICS
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.
Long-Term Drift
(Data Points Reduced After 500 Hr)
– 2.5V Characteristics
140
0.30
TA = 30°C
120 2 TYPICAL PARTS SOLDERED TO PCB
R1 10k
3V
4
LT1790-2.5
100
6
1, 2
0.20
1µF
60
ppm
0.15
80
VOUT
RL
5k
–VEE
40
20
0.10
0
TA = 25°C
TA = 125°C
TA = –55°C
0.05
–20
–40
0
–4.0 –3.5 –3.0 –2.5 –2.0 –1.5 –1.0 –0.5
OUTPUT TO GROUND VOLTAGE (V)
–60
0
200
0
600
400
HOURS
800
1000
17902.5 G11
17902.5 G10
Output Noise 0.1Hz to 10Hz
Output Voltage Noise Spectrum
10
NOISE VOLTAGE (µV/√Hz)
OUTPUT NOISE (10µV/DIV)
CL = 1µF
8
IO = 0µA
6
IO = 250µA
4
IO = 1mA
2
0
0
1
2
3
4 5 6
TIME (SEC)
7
8
9
10
100
1k
FREQUENCY (Hz)
10
10k
1790 G05
17901.5 G12
Integrated Noise 10Hz to 1kHz
100
INTEGRATED NOISE (µVRMS)
CURRENT IN RL (mA)
0.25
10
1
10
100
FREQUENCY (Hz)
1000
LT1790 G03
1790fa
15
LT1790
U W
5V TYPICAL PERFOR A CE CHARACTERISTICS
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.
Minimum Input-Output Voltage
Differential (Sourcing)
Output Voltage Temperature Drift
5.025
Minimum Input-Output Voltage
Differential (Sinking)
90
10
FOUR TYPICAL PARTS
5.015
5.010
5.005
5.000
4.995
VOLTAGE DIFFERENTIAL (mV)
70
OUTPUT CURRENT (mA)
OUTPUT VOLTAGE (V)
5.020
TA = –55°C
TA = 125°C
TA = 25°C
1
4.985
–50 –30 –10 10 30 50 70 90 110 130
TEMPERATURE (°C)
1mA
10
–10
5mA
0
0.1
0.2
0.3
0.4
0.5
INPUT-OUTPUT VOLTAGE (V)
TA = 25°C
–600
TA = 125°C
–800
–1000
–1200
–1400
–1600
80
1800
70
1400
1200
1000
TA = –40°C
800
600
400
0
0.1
10
20
TA = 25°C
TA = –55°C
4.96
4.94
4.92
2
4
20
10
1
OUTPUT CURRENT (mA)
0
10
6 8 10 12 14 16 18 20
INPUT VOLTAGE (V)
17905 G07
0
10
5
10
20
15
INPUT VOLTAGE (V)
17905 G06
Output Impedance vs Frequency
1000
CL = 1µF
0
OUTPUT IMPEDANCE (Ω)
POWER SUPPLY REJECTION RATIO (dB)
TA = 125°C
5.02
TA = 125°C
30
Power Supply Rejection Ratio
vs Frequency
5.04
0
40
17905 G05
Line Regulation
4.98
TA = 25°C
50
TA = 25°C
17905 G04
5.00
60
TA = 125°C
200
1
OUTPUT CURRENT (mA)
TA = –55°C
1600
–1800
–2000
0.1
Supply Current vs Input Voltage
2000
SUPPLY CURRENT (µA)
OUTPUT VOLTAGE CHANGE (ppm)
–400
17905 G03
Load Regulation (Sinking)
TA = –55°C
–200
0.6
17905 G02
Load Regulation (Sourcing)
0
–50
–50 –30 –10 10 30 50 70 90 110 130
TEMPERATURE (°C)
0.1
17905 G01
OUTPUT VOLTAGE CHANGE (ppm)
100µA
30
–30
4.990
OUTPUT VOLTAGE (V)
50
–10
–20
–30
–40
–50
CL = 0.47µF
100
CL = 1µF
CL = 4.7µF
10
–60
–70
–80
100
1k
10k
100k
FREQUENCY (Hz)
1M
17905 G08
1
100
1k
10k
FREQUENCY (Hz)
100k
17905 G09
1790fa
16
LT1790
U W
5V TYPICAL PERFOR A CE CHARACTERISTICS
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.
– 5V Characteristics
Long-Term Drift
0.30
100
TA = 30°C
80 2 TYPICAL PARTS SOLDERED TO PCB
R1 10k
5.5V
4
0.25
LT1790-5
CURRENT IN RL (mA)
1
0.20
40
VOUT
RL
5k
1µF
20
ppm
0.15
60
6
2
–VEE
0
–20
0.10
–40
TA = 125°C
TA = 25°C
0.05
TA = –55°C
0
–10 –9 –8 –7 –6 –5 –4 –3 –2 –1
OUTPUT TO GROUND VOLTAGE (V)
–60
–80
–100
0
200
0
600
400
HOURS
800
17905 G10
1000
17905 G11
Output Noise 0.1Hz to 10Hz
Output Voltage Noise Spectrum
NOISE VOLTAGE (µV/√Hz)
OUTPUT NOISE (20µV/DIV)
10
CL = 1µF
8
IO = 0µA
6
IO = 250µA
4
IO = 1mA
2
1
2
3
4 5 6
TIME (SEC)
7
8
9
0
10
100
1k
FREQUENCY (Hz)
10
10k
1790 G05
17905 G12
Intergrated Noise 10Hz to 1kHz
1000
INTEGRATED NOISE (µVRMS)
0
100
10
1
10
100
FREQUENCY (Hz)
1000
1790 G04
1790fa
17
LT1790
U
U
W
U
APPLICATIONS INFORMATION
Bypass and Load Capacitors
The LT1790 voltage references should have an input
bypass capacitor of 0.1µF or larger, however the bypassing of other local devices may serve as the required
component. These references also require an output capacitor for stability. The optimum output capacitance for
most applications is 1µF, although larger values work as
well. This capacitor affects the turn-on and settling time
for the output to reach its final value.
All LT1790 voltages perform virtually the same, so the
LT1790-2.5 is used as an example.
VOUT
2V
The test circuit of Figure 3 is used to measure the stability
of various load currents. With RL = 1k, the 1V step
produces a current step of 1mA. Figure 4 shows the
response to a ±0.5mA load. Figure 5 is the output response to a sourcing step from 4mA to 5mA, and Figure␣ 6
is the output response of a sinking step from – 4mA to
– 5mA.
VGEN
3V
VIN
3V
Figure 1 shows the turn-on time for the LT1790-2.5 with
a 1µF input bypass and 1µF load capacitor. Figure 2 shows
the output response to a 0.5V transient on VIN with the
same capacitors.
2V
1V
VOUT
(AC COUPLED)
0V
1790 F04
1790 F01
Figure 4. LT1790-2.5 Sourcing and Sinking 0.5mA
Figure 1. Turn-On Characteristics of LT1790-2.5
VIN
3V
VOUT
2V
1V
VOUT
(AC Coupled)
0V
VGEN
–2V
–3V
1790 F05
1790 F02
Figure 5. LT1790-2.5 Sourcing 4mA to 5mA
Figure 2. Output Response to 0.5V Ripple on VIN
VIN
3V
4
CIN
0.1µF
LT1790-2.5
1, 2
1k
6
CL
1µF
VGEN
1V
1790 F03
Figure 3. Response Time Test Circuit
1790fa
18
LT1790
U
W
U
U
APPLICATIONS INFORMATION
stability during load transients. This connection maintains nearly the same accuracy and temperature coefficient of the positive connected LT1790.
VGEN
8V
6V
Long-Term Drift
VOUT
(AC Coupled)
4V
2V
0V
1790 F06
Figure 6. LT1790-2.5 Sinking – 4mA to – 5mA
Positive or Negative Operation
Series operation is ideal for extending battery life. If an
LT1790 is operated in series mode it does not require an
external current setting resistor. The specifications guarantee that the LT1790 family operates to 18V. When the
circuitry being regulated does not demand current, the
series connected LT1790 consumes only a few hundred
µW, yet the same connection can sink or source 5mA of
load current when demanded. A typical series connection
is shown on the front page of this data sheet.
The circuit in Figure 7 shows the connection for a – 2.5V
reference, although any LT1790 voltage option can be
configured this way to make a negative reference. The
LT1790 can be used as very stable negative references,
however, they require a positive voltage applied to Pin 4
to bias internal circuitry. This voltage must be current
limited with R1 to keep the output PNP transistor from
turning on and driving the grounded output. C1 provides
R1
10k
3V
4
6
LT1790-2.5
C1
0.1µF
1, 2
VOUT = –2.5V
V – VOUT
RL = EE
125µA
CL
1µF
VEE
1790 F07
Figure 7. Using the LT1790-2.5 to Build a –2.5V Reference
Long-term drift cannot be extrapolated from accelerated high temperature testing. This erroneous technique gives drift numbers that are widely optimistic. The
only way long-term drift can be determined is to measure it over the time interval of interest. The LT1790S6
drift data was taken on over 100 parts that were soldered
into PC boards similar to a “real world” application. The
boards were then placed into a constant temperature oven
with TA = 30°C, their outputs scanned regularly and
measured with an 8.5 digit DVM. Long-term drift curves
are shown in the Typical Performance Characteristics.
Hysteresis
Hysteresis data shown in Figures 8 and 9 represent the
worst-case data taken on parts from 0°C to 70°C and from
– 40°C to 85°C. Units were cycled several times over these
temperature ranges and the largest change is shown. As
expected, the parts cycled over the higher temperature
range have higher hysteresis than those cycled over the
lower range.
When an LT1790 is IR reflow soldered onto a PC board, the
output shift is typically just 150ppm (0.015%).
Higher Input Voltage
The circuit in Figure 10 shows an easy way to increase the
input voltage range of the LT1790. The zener diode can be
anywhere from 6V to 18V. For equal power sharing between R1 and the zener (at 30V), the 18V option is better.
The circuit can tolerate much higher voltages for short
periods and is suitable for transient protection.
Assuming 80µA max supply current for the LT1790, a
25µA load, 120mV max dropout and a 4V to 30V input
specification, the largest that R1 can be is (4V – 3.3V –
120mV)/(80µA + 25µA) = 5.5k. Furthermore, assuming
220mW of dissipation in the 18V SOT-23 zener, this gives
a max current of (220mW)/(18V) = 12.2mA. So the
smallest that R1 should be is (30V – 18V)/12.2mA = 1k,
rated at 150mW.
1790fa
19
LT1790
U
W
U
U
APPLICATIONS INFORMATION
16
8
14
7
0°C TO 25°C
12
NUMBER OF UNITS
NUMBER OF UNITS
6
5
70°C TO 25°C
4
3
10
4
1
2
0
–80 –70 –60 –50 –40 –30 –20 –10 0
DISTRIBUTION (ppm)
10
20
30
40
50
–240
–200
–160
–120
–80
–40
DISTRIBUTION (ppm)
0
40
80
1790 F09
1790 F08
Figure 8. Worst-Case 0°C to 70°C Hysteresis on 30 Units
–40°C TO 25°C
6
2
0
85°C TO 25°C
8
Figure 9. Worst-Case –40°C to 85°C Hysteresis on 30 Units
the transition region. The no load standing current is only
120µA, yet the output can deliver over 300mA.
4V TO 30V
R1
VOUT
LT1790-3.3
BZX84C18
C1
0.1µF
1µF
1790 F10
Figure 10. Extended Supply Range Reference
With R1 = 1k, and assuming a 450mV worst-case dropout,
the LT1790 can deliver a minimum current of (4V – 3.3V–
450mV)/(1k) = 250µA. In Figure 10, R1 and C1 provide
filtering of the zener noise when the zener is in its noisy V-I
knee.
There are other variations for higher voltage operation that
use a pass transistor shown in Figures 11 and 12. These
circuits allow the input voltage to be as high as 160V while
maintaining low supply current.
More Output Current
The circuit in Figure 13 is a compact, high output current,
low dropout precision supply. The circuit uses the SOT-23
LT1782 and the ThinSOT LT1790. Resistive divider R1 and
R2 set a voltage 22mV below VS. For under 1mA of output
current, the LT1790 supplies the load. Above 1mA of load
current, the (+) input of the LT1782 is pulled below the
22mV divider reference and the output FET turns on to
supply the load current. Capacitor C1 stops oscillations in
Noise
An estimate of the total integrated noise from 10Hz to 1kHz
can be made by multiplying the flat band spot noise by
√BW. For example, from the Typical Performance Curves,
the LT1790-1.25 noise spectrum shows the average spot
noise to be about 450nV/√Hz. The square root of the
bandwidth is √990 = 31.4. The total noise 10Hz to 1kHz
noise is (450nV)(31.4) = 14.1µV. This agrees well with the
measured noise.
This estimate may not be as good with higher voltage
options, there are several reasons for this. Higher voltage
options have higher noise and they have higher variability
due to process variations. 10Hz to 1kHz noise may vary by
2dB on the LT1790-5 and 1dB on the LT1790-2.5.
Measured noise may also vary because of peaking in the
noise spectrum. This effect can be seen in the range of
1kHz to 10kHz with all voltage options sourcing different
load currents. From the Typical Performance Curves the
10Hz to 1kHz noise spectrum of the LT1790-5 is shown to
be 3µV/√Hz at low frequency. The estimated noise is
(3µV)(31.4) = 93.4µV. The actual integrated 10Hz to 1kHz
noise measures 118.3µV. The peaking shown causes this
larger number. Peaking is a function of output capacitor as
well as load current and process variations.
1790fa
20
LT1790
U
U
W
U
APPLICATIONS INFORMATION
R1
330k
VS
6V TO 160V
R2
4.7k
ON SEMI
MMBT5551
BZX84C12
C1
0.1µF
R1
330k
ON SEMI
MMBT5551
LT1790
VOUT
C1
0.1µF
VS
6.5V TO 160V
BAV99
C2
1µF
VOUT
LT1790
C2
1µF
1790 F11
1790 F12
Figure 11. Extended Supply Range Reference
VS
2.8V TO 3.3V
NO LOAD
SUPPLY CURRENT
120µA
R1
680Ω
5%
R3
22Ω
5%
Figure 12. Extended Supply Range Reference
R4
1k
5%
+
LT1782
–
R2
100k
5%
VISHAY SILICONIX
Si3445DV
C1
0.1µF
LT1790-2.5
C2
1µF
17909 F13
VOUT = 2.5V
ILOAD = 0mA to 300mA
NOTE: NOT CURRENT LIMITED
Figure 13. Compact, High Output Current, Low Dropout, Precison 2.5V Supply
1790fa
21
LT1790
W
W
SI PLIFIED SCHE ATIC
4 VIN
6 VOUT
1, 2 GND
1790 SS
1790fa
22
LT1790
U
PACKAGE DESCRIPTIO
S6 Package
6-Lead Plastic SOT-23
(Reference LTC DWG # 05-08-1636)
2.80 – 3.10
(.110 – .118)
(NOTE 3)
SOT-23
(Original)
SOT-23
(ThinSOT)
A
.90 – 1.45
(.035 – .057)
1.00 MAX
(.039 MAX)
A1
.00 – 0.15
(.00 – .006)
.01 – .10
(.0004 – .004)
A2
.90 – 1.30
(.035 – .051)
.80 – .90
(.031 – .035)
L
.35 – .55
(.014 – .021)
.30 – .50 REF
(.012 – .019 REF)
2.60 – 3.00
(.102 – .118)
1.50 – 1.75
(.059 – .069)
(NOTE 3)
PIN ONE ID
.95
(.037)
REF
.25 – .50
(.010 – .020)
(6PLCS, NOTE 2)
.20
(.008)
A
DATUM ‘A’
L
NOTE:
1. CONTROLLING DIMENSION: MILLIMETERS
MILLIMETERS
2. DIMENSIONS ARE IN
(INCHES)
.09 – .20
(.004 – .008)
(NOTE 2)
A2
1.90
(.074)
REF
A1
S6 SOT-23 0401
3. DRAWING NOT TO SCALE
4. DIMENSIONS ARE INCLUSIVE OF PLATING
5. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
6. MOLD FLASH SHALL NOT EXCEED .254mm
7. PACKAGE EIAJ REFERENCE IS:
SC-74A (EIAJ) FOR ORIGINAL
JEDEC MO-193 FOR THIN
1790fa
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
23
LT1790
U
TYPICAL APPLICATIO
– 2.5V Negative 50mA Series Reference
No Load Supply Current
ICC = 1.6mA
IEE = 440µA
VCC = 5V
2k
4
VZ = 5.1V
LT1790-2.5
6
1, 2
5.1k
–2.5V
50mA
VEE = –5V
MPS2907A
1µF
1790 TA03
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LT1019
Precision Reference
Low Noise Bandgap, 0.05%, 5ppm/°C
LTC 1798
Micropower Low Dropout Reference
0.15% Max, 6.5µA Supply Current
LT1460
Micropower Precison Series Reference
Bandgap, 130µA Supply Current, 10ppm/°C, Available in SOT-23
LT1461
Micropower Precision Low Dropout Reference
Bandgap 0.04%, 3ppm/°C, 50µA Max Supply Current
®
1790fa
24
Linear Technology Corporation
LT/CPI 0202 1.5K REV A • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
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 LINEAR TECHNOLOGY CORPORATION 2000