LT1461ACS8-2.5_技术文档

LT1461-2.5

Micropower Precision

Low Dropout Series

Voltage Reference

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FEATURES

DESCRIPTIO

The LT^®1461 is a low dropout micropower bandgap refer-

ence that combines very high accuracy and low drift with low

supply current and high output drive. This series reference

usesadvancedcurvaturecompensationtechniquestoobtain

low temperature coefficient and trimmed precision thin-film

resistorstoachievehighoutputaccuracy.TheLT1461draws

only35µAofsupplycurrent,makingitidealforlowpowerand

portable applications, however its high 50mA output drive

makes it suitable for higher power requirements, such as

precision regulators.

■

Trimmed to High Accuracy: 0.04% Max

■

Low Drift: 3ppm/

°

C Max

■

Low Supply Current: 50

µA Max

Temperature Coefficient Guaranteed to 125°C

High Output Current: 50mA Min

Low Dropout Voltage: 300mV Max

Excellent Thermal Regulation

Power Shutdown

Thermal Limiting

Operating Temperature Range: –40°C to 125°C

Available in SO-8 Package

In low power applications, a dropout voltage of less than

300mV ensures maximum battery life while maintaining full

reference performance. Line regulation is nearly immeasur-

able, while the exceedingly good load and thermal regulation

will not add significantly to system error budgets. The

shutdownfeaturecanbeusedtoswitchfullloadcurrentsand

can be used for system power down. Thermal shutdown

protects the part from overload conditions.

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APPLICATIO S

■

A/D and D/A Converters

■

Precision Regulators

■

Handheld Instruments

Power Supplies

■

, LTC and LT are registered trademarks of Linear Technology Corporation.

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TYPICAL APPLICATIO

Load Regulation, P_DISS= 200mW

Basic Connection

V

≥ 2.8V

2.5V

IN

LT1461-2.5

0mA

C

L

IN

2µF

1µF

I_OUT

1461 TA01

20mA

V_OUTLOAD REG

1mV/DIV

1461 TA02

10ms/DIV

1

LT1461-2.5

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ABSOLUTE MAXIMUM RATINGS

PACKAGE/ORDER INFORMATION

(Note 1)

Input Voltage ........................................................... 20V

Output Short-Circuit Duration......................... Indefinite

Operating Temperature Range

(Note 2) ........................................... –40°C to 125°C

Specified Temperature Range

Commercial ............................................ 0°C to 70°C

Industrial ........................................... –40°C to 85°C

High................................................. –40°C to 125°C

Storage Temperature Range (Note 3) ... –65°C to 150°C

Lead Temperature (Soldering, 10 sec).................. 300°C

ORDER PART

NUMBER

LT1461ACS8-2.5

LT1461BCS8-2.5

LT1461CCS8-2.5

LT1461AIS8-2.5

LT1461BIS8-2.5

LT1461CIS8-2.5

LT1461DHS8-2.5

TOP VIEW

DNC*

1

2

3

4

8

7

6

5

DNC*

V

IN

SHDN

GND

V

OUT

DNC*

S8 PACKAGE

8-LEAD PLASTIC SO

*DNC: DO NOT CONNECT

T_JMAX= 130°C, θ_JA= 190°C/ W

S8 PART MARKING

461A25

461B25

461C25

61AI25

61BI25

61CI25

61DH25

Consult factory for Military grade parts.

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AVAILABLE OPTIO S

INITIAL

MAXIMUM TEMPERATURE

GRADE

ACCURACY (%)

COEFFICIENT (ppm/°C)

LT1461ACS8-2.5/LT1461AIS8-2.5

LT1461BCS8-2.5/LT1461BIS8-2.5

LT1461CCS8-2.5/LT1461CIS8-2.5

LT1461DHS8-2.5, –40°C to 125°C

0.04%

3

7

0.06%

0.08%

12

20

0.15%

ELECTRICAL CHARACTERISTICS

The ● denotes specifications which apply over the specified temperature

range, otherwise specifications are at T_A= 25°C. V_IN– V_OUT= 0.5V, Pin 3 = 2.4V, C_L= 2µF, unless otherwise specified.

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Output Voltage (Note 4)

LT1461ACS8-2.5/LT1461AIS8-2.5

2.499

–0.04

2.500

2.501

0.04

V

%

LT1461BCS8-2.5/LT1461BIS8-2.5

LT1461CCS8-2.5/LT1461CIS8-2.5

LT1461DHS8-2.5

2.4985

–0.06

2.500

2.5015

0.06

V

%

2.498

–0.08

2.502

0.08

V

%

2.49625 2.500 2.50375

–0.15

V

%

0.15

Output Voltage Temperature Coefficient (Note 5)

LT1461ACS8-2.5/LT1461AIS8-2.5

LT1461BCS8-2.5/LT1461BIS8-2.5

LT1461CCS8-2.5/LT1461CIS8-2.5

LT1461DHS8-2.5

●

1

3

5

7

3

7

12

20

ppm/°C

2

LT1461-2.5

ELECTRICAL CHARACTERISTICS ^The● denotes specifications which apply over the specified temperature

range, otherwise specifications are at T_A= 25°C. V_IN– V_OUT= 0.5V, Pin 3 = 2.4V, C_L= 2µF, unless otherwise specified.

PARAMETER

CONDITIONS

(V + 0.5V) ≤ V ≤ 20V

MIN

TYP

MAX

UNITS

Line Regulation

2

8

12

ppm/V

OUT

IN

●

LT1461DHS8

= V + 2.5V

15

12

50

ppm/V

Load Regulation Sourcing (Note 6)

Dropout Voltage

V

IN

OUT

0 ≤ I

≤ 50mA

30

40

ppm/mA

OUT

●

LT1461DHS8, 0 ≤ I

≤ 10mA

50

ppm/mA

OUT

V

– V , V

Error = 0.1%

IN

OUT OUT

I

= 0mA

= 1mA

= 10mA

0.06

0.13

0.20

1.50

V

OUT

●

0.3

0.4

2.0

= 50mA, I and C Grades Only

Output Current

Shutdown Pin

Short V

to GND

100

mA

OUT

Logic High Input Voltage

Logic High Input Current, Pin 3 = 2.4V

●

2.4

V

µA

2

15

Logic Low Input Voltage

●

0.8

4

V

Logic Low Input Current, Pin 3 = 0.8V

0.5

35

µA

Supply Current

No Load

50

70

µA

●

Shutdown Current

R = 1k, Pin 3 = 0.8V

L

25

35

55

µA

Output Voltage Noise (Note 7)

0.1Hz ≤ f ≤ 10Hz

20

8

µV

P-P

ppm

10Hz ≤ f ≤ 1kHz

24

9.6

µV

RMS

ppm

Long-Term Drift of Output Voltage, SO-8 Package (Note 8)

Thermal Hysteresis (Note 9)

See Applications Information

60

ppm/√kHr

∆T = 0°C to 70°C

∆T = –40°C to 85°C

∆T = –40°C to 125°C

40

70

120

ppm

Note 1: Absolute Maximum Ratings are those values beyond which the life

of a device may be impaired.

Note 2: The LT1461 is guaranteed functional over the operating

temperature range of –40°C to 125°C.

Note 3: If the part is stored outside of the specified temperature range, the

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.

Note 8: Long-term drift typically has a logarithmic characteristic and

therefore, changes after 1000 hours tend to be much smaller than before

that time. Total drift in the second thousand hours is normally less than

one third that of the first thousand hours with a continuing trend toward

reduced drift with time. Long-term drift will also be affected by differential

stresses between the IC and the board material created during board

assembly.

output may shift due to hysteresis.

Note 4: ESD (Electrostatic Discharge) sensitive device. Extensive use of

ESD protection devices are used internal to the LT1461, however, high

electrostatic discharge can damage or degrade the device. Use proper ESD

handling precautions.

Note 5: Temperature coefficient is calculated from the minimum and

maximum output voltage measured at T , Room and T

as follows:

MIN

MAX

See the Applications Information section.

TC = (V

– V

)/(T

– T

)

OMAX

OMIN

MAX

MIN

Note 9: Hysteresis in output voltage is created by package stress that

depends 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 hot or cold before 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.

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: 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 sec. RMS noise is measured with a single pole highpass filter at

3

LT1461-2.5

TYPICAL PERFORMANCE CHARACTERISTICS

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Reference Voltage vs Temperature

Load Regulation

Line Regulation vs Temperature

2.5020

2.5015

2.5010

2.5005

2.5000

2.4995

2.4990

2.4985

2.4980

4

3

2

1

0

–1

–2

–3

–4

–5

–6

–7

–8

TEMPCO –60°C TO 120°C

3 TYPICAL PARTS

125°C

25°C

–55°C

SUPPLY ∆ = 15V

5V – 20V

0.1

1

10

100

20 40

TEMPERATURE (°C)

–40 –20

0

60 80 100 120

–60 –40 –20

0

20 40 60 80 100 120

TEMPERATURE (°C)

OUTPUT CURRENT (mA)

1461 G02

1461 G03

1461 G01

Minimum Input/Output Voltage

Differential vs Load Current

Supply Current vs Input Voltage

Supply Current vs Temperature

10

1000

100

10

50

40

30

20

10

0

V

= 5V

IN

I

S

I

S(SHDN)

1

25°C

125°C

25°C

–55°C

0.1

1

10

100

0

5

10

15

20

25

–40 –20

20

40

TEMPERATURE (°C)

60 80 100 120

0

OUTPUT CURRENT (mA)

INPUT VOLTAGE (V)

1461 G04

1461 G05

1461 G06

SHDN Pin Current

vs SHDN Input Voltage

Ripple Rejection Ratio

vs Frequency

Current Limit vs Temperature

140

120

100

80

200

180

160

140

120

100

80

100

90

80

70

125°C

25°C

60

50

–55°C

40

30

20

10

0

60

40

20

40

0

–50 –25

0

25

50

75 100 125

0

10

15

20

5

0.01

0.1

1

10

100

1000

TEMPERATURE (°C)

SHDN PIN INPUT VOLTAGE (V)

FREQUENCY (kHz)

1641 G01

1461 G07

1461 G08

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LT1461-2.5

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TYPICAL PERFORMANCE CHARACTERISTICS

Output Impedance vs Frequency

Turn-On Time

1000

100

10

C

= 2µF

V

IN

OUT

IN

20

10

0

20

10

0

C

= 1µF

OUT

2

1

0

2

1

0

V

OUT

C

= 1µF

C

= 1µF

IN

L

IN

L

= 2µF

R

=

∞

R

= 50Ω

L

1

0.01

0.1

1

10

TIME (100µs/DIV)

FREQUENCY (kHz)

1461 G11

1461 G12

1461 G10

Transient Response to 10mA

Load Step

Output Noise 0.1Hz ≤ f ≤ 10Hz

Line Transient Response

I_OUT

0mA

10mA/DIV

5V

4V

V_IN

V_OUT

50mV/DIV

V_OUT

50mV/DIV

1461 G13

1461 G14

C_L= 2µF

C_IN= 0.1µF

TIME (2SEC/DIV)

1461 G18

Long-Term Drift (Number of Data Points Reduced at 650 Hours)*

250

200

LT1461S8-2.5

3 TYPICAL PARTS SOLDERED ONTO PCB

T

= 30°C

A

150

100

50

0

–50

0

200

400

600

800

1000

1200

1400

1600

1800

2000

HOURS

1461 G15

*SEE APPLICATIONS INFORMATION FOR DETAILED EXPLANATION OF LONG-TERM DRIFT

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LT1461-2.5

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TYPICAL PERFORMANCE CHARACTERISTICS

0°C to 70°C Hysteresis

20

WORST-CASE HYSTERESIS

ON 35 UNITS

18

16

14

70°C TO 25°C

0°C TO 25°C

12

10

8

6

4

2

0

–100

–80

–60

–40

–20

0

20

40

60

80

100

HYSTERESIS (ppm)

1461 G16

–40°C to 85°C Hysteresis

20

18

16

14

12

10

8

WORST-CASE HYSTERESIS

ON 35 UNITS

85°C TO 25°C

–40°C TO 25°C

6

4

2

0

–100

–80

–60

–40 –20

0

20

40

60

80

100

HYSTERESIS (ppm)

1461 G17

–40°C to 125°C Hysteresis

16

14

12

10

8

WORST-CASE HYSTERESIS

ON 35 UNITS

125°C TO 25°C

–40°C TO 25°C

6

4

2

0

–200

–160

–120

–80

–40

0

40

80

120

160

200

HYSTERESIS (ppm)

1461 G19

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LT1461-2.5

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APPLICATIONS INFORMATION

Bypass and Load Capacitors

load current or input voltage changes, is not measurable.

This often overlooked parameter must be added to normal

line and load regulation errors. The load regulation photo,

on the first page of this data sheet, shows the output

response to 200mW of instantaneous power dissipation

and the reference shows no sign of thermal errors. The

reference has thermal shutdown and will turn off if the

junction temperature exceeds 150°C.

The LT1461 requires a capacitor on the input and on the

output for stability. The capacitor on the input is a supply

bypass capacitor and if the bypass capacitors from other

components are close (within 2 inches) they should be

sufficient. The output capacitor acts as frequency com-

pensation for the reference and cannot be omitted. For

light loads ≤1mA, a 1µF nonpolar output capacitor is

usually adequate, but for higher loads (up to 75mA), the

output capacitor should be 2µF or greater. Figures 1 and

2 show the transient response to a 1mA load step with a

1µF output capacitor and a 50mA load step with a 2µF

output capacitor.

Shutdown

The shutdown (Pin 3 low) serves to shut off load current

when the LT1461 is used as a regulator. The LT1461

operates normally with Pin 3 open or greater than or equal

to 2.4V. In shutdown, the reference draws a maximum

supply current of 35µA. Figure 3 shows the transient

response of shutdown while the part is delivering 25mA.

After shutdown, the reference powers up in about 200µs.

0mA

I_OUT

1mA/DIV

1mA

5V

V_OUT

20mV/DIV

PIN 3

0V

1461 F01

V_OUT

Figure 1. 1mA Load Step with C_L= 1µF

0V

1461 F03

Figure 3. Shutdown While Delivering 25mA, R_L= 100Ω

I_OUT

50mA/DIV

PC Board Layout

In 13- to 16-bit systems where initial accuracy and tem-

perature coefficient calibrations have been done, the me-

chanical and thermal stress on a PC board (in a card cage

forinstance)canshifttheoutputvoltageandmaskthetrue

temperature coefficient of a reference. In addition, the

mechanical stress of being soldered into a PC board can

cause the output voltage to shift from its ideal value.

Surface mount voltage references are the most suscep-

tible to PC board stress because of the small amount of

plastic used to hold the lead frame.

V_OUT

200mV/DIV

1461 F02

Figure 2. 50mA Load Step with C_L= 2µF

Precision Regulator

The LT1461 will deliver 50mA with V_IN= V_OUT+ 2.5V and

higher load current with higher V_IN. Load regulation is

typically 12ppm/mA, which means for a 50mA load step,

the output will change by only 1.5mV. Thermal regulation,

caused by die temperature gradients and created from

A simple way to improve the stress-related shifts is to

mount the reference near the short edge of the PC board,

or in a corner. The board edge acts as a stress boundary,

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LT1461-2.5

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APPLICATIONS INFORMATION

oraregionwheretheflexureoftheboardisminimum. The

package should always be mounted so that the leads

absorb the stress and not the package. The package is

generally aligned with the leads parallel to the long side of

the PC board as shown in Figure 5a.

This motion is repeated for a number of cycles and the

relative output deviation is noted. The result shown in

Figure 5a is for two LT1461S8-2.5s mounted vertically

andFigure5bisfortwoLT1461S8-2.5smountedhorizon-

tally. ThepartsorientedinFigure5aimpartlessstressinto

the package because stress is absorbed in the leads.

Figures5aand5bshowthedeviationtobebetween125µV

and 250µV and implies a 50ppm and 100ppm change

respectively. This corresponds to a 13- to 14-bit system

andisnotaproblemformost10-to12-bitsystemsunless

the system has a calibration. In this case, as with tempera-

ture hysteresis, this low level can be important and even

more careful techniques are required.

A qualitative technique to evaluate the effect of stress on

voltage references is to solder the part into a PC board and

deformtheboardafixedamountasshowninFigure4. The

flexure #1 represents no displacement, flexure #2 is

concave movement, flexure #3 is relaxation to no dis-

placement and finally, flexure #4 is a convex movement.

1

2

3

The most effective technique to improve PC board stress

is to cut slots in the board around the reference to serve as

a strain relief. These slots can be cut on three sides of the

reference and the leads can exit on the fourth side. This

“tongue” of PC board material can be oriented in the long

direction of the board to further reduce stress transferred

to the reference.

4

1461 F04

Figure 4. Flexure Numbers

2

1

LONG DIMENSION

0

SLOT

–1

0

40

10

20

FLEXURE NUMBER

30

–1

0

40

10

20

30

1461 F05a

FLEXURE NUMBER

1461 F06a

Figure 5a. Two Typical LT1461S8-2.5s,

Vertical Orientation Without Slots

Figure 6a. Same Two LT1461S8-2.5s in Figure 5a, but with Slots

2

1

2

1

LONG DIMENSION

0

SLOT

–1

0

40

10

20

30

–1

0

40

10

20

30

1461 F05b

FLEXURE NUMBER

1461 F06b

Figure 5b. Two Typical LT1461S8-2.5s,

Horizontal Orientation Without Slots

Figure 6b. Same Two LT1461S8-2.5s in Figure 5b, but with Slots

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LT1461-2.5

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APPLICATIONS INFORMATION

The results of slotting the PC boards of Figures 5a and

5b are shown in Figures 6a and 6b. In this example the

slots can improve the output shift from about 100ppm to

nearly zero.

The LT1461 long-term drift data was taken with parts that

were soldered onto PC boards similar to a “real world”

application. The boards were then placed into a constant

temperature oven with T_A= 30°C, their outputs were

scannedregularlyandmeasuredwithan8.5digitDVM. As

an additional accuracy check on the DVM, a Fluke 732A

laboratoryreferencewasalsoscanned.Figure7showsthe

long-term drift measurement system. The long-term drift

is the trend line that asymptotes to a value beyond 2000

hours. Note the slope in output shift between 0 hours and

1000 hours compared to the slope between 1000 hours

and 2000 hours. Long-term drift is affected by differential

stresses between the IC and the board material created

during board assembly.

Long-Term Drift

Long-term drift cannot be extrapolated from acceler-

atedhightemperaturetesting.Thiserroneoustechnique

gives drift numbers that are wildly optimistic. The only

way long-term drift can be determined is to measure it

over the time interval of interest. The erroneous tech-

nique uses the Arrhenius Equation to derive an accelera-

tion factor from elevated temperature readings. The

equation is:

E

1

A

PCB3

PCB2

–

A_F= e ^K

T1 T2

PCB1

8.5 DIGIT

DVM

COMPUTER

SCANNER

where: E_A= Activation Energy (Assume 0.7)

K = Boltzmann’s Constant

1461 F07

T2 = Test Condition in °Kelvin

T1 = Use Condition Temperature in °Kelvin

FLUKE

732A

LABORATORY

REFERENCE

To show how absurd this technique is, compare the

LT1461 data. Typical 1000 hour long-term drift at 30°C =

60ppm. The typical 1000 hour long-term drift at 130°C =

120ppm. From the Arrhenius Equation the acceleration

factor is:

Figure 7. Long-Term Drift Measurement Setup

0.7

1

403

Hysteresis

–

= 767

A_F= e^{0.0000863 303}

The hysteresis curves found in the Typical Performance

Characteristics represent the worst-case data taken on 35

typical parts after multiple temperature cycles. As ex-

pected, the parts that are cycled over the wider –40°C to

125°Ctemperaturerangehavemorehysteresisthanthose

cycled over lower ranges. Note that the hysteresis coming

from125°Cto25°Chasaninfluenceonthe–40°Cto25°C

hysteresis. The –40°C to 25°C hysteresis is different

depending on the part’s previous temperature. This is

because not all of the high temperature stress is relieved

during the 25°C measurement.

The erroneous projected long-term drift is:

120ppm/767 = 0.156ppm/1000 hr

For a 2.5V reference, this corresponds to a 0.39µV shift

after 1000 hours. This is pretty hard to determine (read

impossible) if the peak-to-peak output noise is larger than

this number. As a practical matter, one of the best labora-

tory references available is the Fluke 732A and its long-

term drift is 1.5µV/mo. This performance is only available

from the best subsurface zener references utilizing spe-

cialized heater techniques.

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LT1461-2.5

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APPLICATIONS INFORMATION

The typical performance hysteresis curves are for parts

mounted in a socket and represents the performance of

the parts alone. What is more interesting are parts IR sol-

dered onto a PC board. If the PC board is then temperature

cycled several times from –40°C to 85°C, the resulting

hysteresis curve is shown in Figure 8. This graph shows

the influence of the PC board stress on the reference.

The LT1461 is capable of dissipating high power, i.e.,

17.5V • 50mA = 875mW. The SO-8 package has a thermal

resistance of 190°C/W and this dissipation causes a

166°C internal rise producing a junction temperature of

T_J= 25°C + 166°C = 191°C. What will actually occur is the

thermal shutdown will limit the junction temperature to

around150°C. Thishightemperatureexcursionwillcause

the output to shift due to thermal hysteresis. Under these

conditions, a typical output shift is –135ppm, although

thisnumbercanbehigher.Thishighdissipationcancause

the 25°C output accuracy to exceed its specified limit. For

best accuracy and precision, the LT1461 junction tem-

perature should not exceed 125°C.

When the LT1461 is soldered onto a PC board, the output

shifts due to thermal hysteresis. Figure 9 shows the effect

of soldering 40 pieces onto a PC board using standard IR

reflow techniques. The average output voltage shift is

–110ppm. Remeasurement of these parts after 12 days

shows the outputs typically shift back 45ppm toward their

initial value. This second shift is due to the relaxation of

stress incurred during soldering.

12

WORST-CASE HYSTERESIS

ON 35 UNITS

11

10

85°C TO 25°C

–40°C TO 25°C

9

8

7

6

5

4

3

2

1

0

–200

–160

–120

–80

–40

0

40

80

120

160

200

HYSTERESIS (ppm)

1461 F08

Figure 8. –40°C to 85°C Hysteresis of 35 Parts Soldered Onto a PC Board

12

10

8

6

4

2

0

–300

–100

0

100

200

300

–200

OUTPUT VOLTAGE SHIFT (ppm)

1461 F09

Figure 9. Typical Distribution of Output Voltage Shift After Soldering Onto PC Board

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LT1461-2.5

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2

V

IN

V

6

OUT

SHDN

3

GND

4

1461 SS

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PACKAGE DESCRIPTION ^{Dimensions in inches (millimeters) unless otherwise noted.}

S8 Package

8-Lead Plastic Small Outline (Narrow 0.150)

(LTC DWG # 05-08-1610)

0.189 – 0.197*

(4.801 – 5.004)

7

5

8

6

0.150 – 0.157**

(3.810 – 3.988)

0.228 – 0.244

(5.791 – 6.197)

1

3

4

2

0.010 – 0.020

(0.254 – 0.508)

× 45°

0.053 – 0.069

(1.346 – 1.752)

0.004 – 0.010

(0.101 – 0.254)

0.008 – 0.010

(0.203 – 0.254)

0°– 8° TYP

0.016 – 0.050

(0.406 – 1.270)

0.050

(1.270)

BSC

0.014 – 0.019

(0.355 – 0.483)

TYP

*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH

SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE

**DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD

FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE

SO8 1298

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 represen-

tationthattheinterconnectionofitscircuitsasdescribedhereinwillnotinfringeonexistingpatentrights.

11

LT1461-2.5

TYPICAL APPLICATION

U

Low Power 16-Bit A/D

V

CC

35µA

200µA

1µF

V

CC

V

CC

F

O

LT1461-2.5

LTC2400

V

SCK

SD0

CS

OUT

REF

SPI

INTERFACE

1µF

INPUT

IN

0.1µF

GND

1461 TA03

NOISE PERFORMANCE*

V

= 0V, V

= 1.1ppm

= 2.25µV

= 16µV

IN

NOISE

RMS

RMS P-P

= V /2, V

= 1.6ppm

= 4µV

= 24µV

REF

NOISE

RMS

RMS P-P

= V , V

REF NOISE

= 2.5ppm

= 6.25µV

= 36µV

RMS P-P

RMS

*FOR 24-BIT PERFORMANCE USE LT1236 REFERENCE

RELATED PARTS

PART NUMBER

DESCRIPTION

COMMENTS

LT1019

Precision Reference

Bandgap, 0.05%, 5ppm/°C

LT1027

Precision 5V Reference

Lowest TC, High Accuracy, Low Noise, Zener Based

5V and 10V Zener-Based 5ppm/°C, SO-8 Package

0.15% Max, 6.5µA Supply Current

LT1236

LTC^®1798

Precision Reference

Micropower Low Dropout Reference

Micropower Precision Series Reference

Micropower Precision Shunt Voltage Reference

LT1460

Bandgap, 130µA Supply Current 10ppm/°C, Available in SOT-23

Bandgap 0.05%, 10ppm/°C, 10µA Supply Current

LT1634

146125f LT/TP 0100 4K • PRINTED IN USA

LINEAR TECHNOLOGY CORPORATION 1999

LinearTechnology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

12

●

(408)432-1900 FAX:(408)434-0507 www.linear-tech.com


型号：	LT1461ACS8-2.5
厂家：	Linear
描述：	Micropower Precision Low Dropout Series Voltage Reference 精密微功耗低压差系列基准电压源电源电路参考电压源光电二极管
文件：	总12页 (文件大小：209K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

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