ANALOG DEVICES LT 6654AHS6-2.5 Datasheet

LT6654

SOT-23 Precision Wide

Supply High Output Drive

Low Noise Reference

FEATURES

n

Low Drift:

A Grade: 10ppm/°C Max B Grade: 20ppm/°C Max

n

High Accuracy:

A Grade: ±0.05% Max B Grade: ±0.10% Max

n

Low Noise: 1.6ppm

n

Wide Supply Range to 36V

n

Low Thermal Hysteresis

n

Line Regulation (Up to 36V): 5ppm/V Max

n

Low Dropout Voltage: 100mV Max

n

Sinks and Sources ±10mA

n

Load Regulation at 10mA: 8ppm/mA Max

n

Easily Conﬁ gured for Negative Voltage Output

n

Fully Speciﬁ ed from –55°C to 125°C

n

Available Output Voltage Options: 1.25V, 2.048V, 2.5V,

(0.1Hz to 10Hz)

P-P

3V, 3.3V, 4.096V, 5V

n

Low Proﬁ le (1mm) ThinSOT™ Package

APPLICATIONS

n

Automotive Control and Monitoring

n

High Temperature Industrial

n

High Resolution Data Acquisition Systems

n

Instrumentation and Process Control

n

Precision Regulators

n

Medical Equipment

DESCRIPTION

The LT®6654 is a family of small precision voltage references that offers high accuracy, low noise, low drift, low dropout and low power. The LT6654 operates from voltages up to 36V and is fully speciﬁ ed from –55°C to 125°C. A buffered output ensures ±10mA of output drive with low output impedance and precise load regulation. These features, in combination, make the LT6654 ideal for portable equipment, industrial sensing and control, and automotive applications.

The LT6654 was designed with advanced manufacturing techniques and curvature compensation to provide 10ppm/°C temperature drift and 0.05% initial accuracy. Low thermal hysteresis ensures high accuracy and

1.6ppm Since the LT6654 can also sink current, it can operate as a low power negative voltage reference with the same precision as a positive reference.

The LT6654 is offered in a 6-lead SOT-23 package.

L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners.

noise minimizes measurement uncertainty.

P-P

TYPICAL APPLICATION

Basic Connection

+ 0.5V) < VIN < 36V

(V

OUT

46

C

IN

0.1µF

LT6654

12

CL 1µF

V

OUT

6654 TA01a

Output Voltage Temperature Drift

0.10 3 TYPICAL PARTS

LT6654-2.5

0.05

0.00

ACCURACY (%)

OUT

V

–0.05

–0.10

–60

TEMPERATURE (°C)

60

40200–40 –20

120

100

6654 TA01b

140

6654fa

80

1

LT6654

PIN CONFIGURATION ABSOLUTE MAXIMUM RATINGS

(Note 1)

Input Voltage VIN to GND ........................... –0.3V to 38V

Output Voltage V

.........................–0.3V to V

OUT

+ 0.3V

IN

Output Short-Circuit Duration ......................... Indeﬁ nite

Speciﬁ ed Temperature Range

H-Grade ............................................. –40°C to 125°C

MP-Grade ..........................................–55°C to 125°C

Operating Temperature Range................ –55°C to 125°C

Storage Temperature Range (Note 2) ..... –65°C to 150°C

GND*

GND DNC

*CONNECT PIN TO DEVICE GND (PIN 2)

TOP VIEW

1 2 3

S6 PACKAGE

6-LEAD PLASTIC TSOT-23

T

= 150°C, θJA = 192°C/W

JMAX

DNC: DO NOT CONNECT

6

V

OUT

5

DNC

4

V

IN

Lead Temperature (Soldering, 10 sec.)

(Note 9) ................................................................. 300°C

ORDER INFORMATION

Lead Free Finish

TAPE AND REEL (MINI) TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE

LT6654AHS6-1.25#TRMPBF LT6654AHS6-1.25#TRPBF LTFVD 6-Lead Plastic TSOT-23 –40°C to 125°C LT6654BHS6-1.25#TRMPBF LT6654BHS6-1.25#TRPBF LTFVD 6-Lead Plastic TSOT-23 –40°C to 125°C LT6654AMPS6-1.25#TRMPBF LT6654AMPS6-1.25#TRPBF LTFVD 6-Lead Plastic TSOT-23 –55°C to 125°C LT6654BMPS6-1.25#TRMPBF LT6654BMPS6-1.25#TRPBF LTFVD 6-Lead Plastic TSOT-23 –55°C to 125°C LT6654AHS6-2.048#TRMPBF LT6654AHS6-2.048#TRPBF LTFVF 6-Lead Plastic TSOT-23 –40°C to 125°C LT6654BHS6-2.048#TRMPBF LT6654BHS6-2.048#TRPBF LTFVF 6-Lead Plastic TSOT-23 –40°C to 125°C LT6654AMPS6-2.048#TRMPBF LT6654AMPS6-2.048#TRPBF LTFVF 6-Lead Plastic TSOT-23 –55°C to 125°C LT6654BMPS6-2.048#TRMPBF LT6654BMPS6-2.048#TRPBF LTFVF 6-Lead Plastic TSOT-23 –55°C to 125°C LT6654AHS6-2.5#TRMPBF LT6654AHS6-2.5#TRPBF LTFJY 6-Lead Plastic TSOT-23 –40°C to 125°C LT6654BHS6-2.5#TRMPBF LT6654BHS6-2.5#TRPBF LTFJY 6-Lead Plastic TSOT-23 –40°C to 125°C LT6654AMPS6-2.5#TRMPBF LT6654AMPS6-2.5#TRPBF LTFJY 6-Lead Plastic TSOT-23 –55°C to 125°C LT6654BMPS6-2.5#TRMPBF LT6654BMPS6-2.5#TRPBF LTFJY 6-Lead Plastic TSOT-23 –55°C to 125°C LT6654AHS6-3#TRMPBF LT6654AHS6-3#TRPBF LTFVG 6-Lead Plastic TSOT-23 –40°C to 125°C LT6654BHS6-3#TRMPBF LT6654BHS6-3#TRPBF LTFVG 6-Lead Plastic TSOT-23 –40°C to 125°C LT6654AMPS6-3#TRMPBF LT6654AMPS6-3#TRPBF LTFVG 6-Lead Plastic TSOT-23 –55°C to 125°C LT6654BMPS6-3#TRMPBF LT6654BMPS6-3#TRPBF LTFVG 6-Lead Plastic TSOT-23 –55°C to 125°C LT6654AHS6-3.3#TRMPBF LT6654AHS6-3.3#TRPBF LTFVH 6-Lead Plastic TSOT-23 –40°C to 125°C LT6654BHS6-3.3#TRMPBF LT6654BHS6-3.3#TRPBF LTFVH 6-Lead Plastic TSOT-23 –40°C to 125°C LT6654AMPS6-3.3#TRMPBF LT6654AMPS6-3.3#TRPBF LTFVH 6-Lead Plastic TSOT-23 –55°C to 125°C LT6654BMPS6-3.3#TRMPBF LT6654BMPS6-3.3#TRPBF LTFVH 6-Lead Plastic TSOT-23 –55°C to 125°C LT6654AHS6-4.096#TRMPBF LT6654AHS6-4.096#TRPBF LTFVJ 6-Lead Plastic TSOT-23 –40°C to 125°C LT6654BHS6-4.096#TRMPBF LT6654BHS6-4.096#TRPBF LTFVJ 6-Lead Plastic TSOT-23 –40°C to 125°C LT6654AMPS6-4.096#TRMPBF LT6654AMPS6-4.096#TRPBF LTFVJ 6-Lead Plastic TSOT-23 –55°C to 125°C LT6654BMPS6-4.096#TRMPBF LT6654BMPS6-4.096#TRPBF LTFVJ 6-Lead Plastic TSOT-23 –55°C to 125°C LT6654AHS6-5#TRMPBF LT6654AHS6-5#TRPBF LTFVK 6-Lead Plastic TSOT-23 –40°C to 125°C LT6654BHS6-5#TRMPBF LT6654BHS6-5#TRPBF LTFVK 6-Lead Plastic TSOT-23 –40°C to 125°C LT6654AMPS6-5#TRMPBF LT6654AMPS6-5#TRPBF LTFVK 6-Lead Plastic TSOT-23 –55°C to 125°C LT6654BMPS6-5#TRMPBF LT6654BMPS6-5#TRPBF LTFVK 6-Lead Plastic TSOT-23 –55°C to 125°C TRM = 500 pieces. *Temperature grades are identiﬁ ed by a label on the shipping container. Consult LTC Marketing for parts speciﬁ ed with wider operating temperature ranges.

Consult LTC Marketing for information on lead based ﬁ nish parts. For more information on lead free part marking, go to:

For more information on tape and reel speciﬁ cations, go to: http://www.linear.com/tapeandreel/

http://www.linear.com/leadfree/

6654fa

2

LT6654

AVAILABLE OPTIONS

OUTPUT VOLTAGE INITIAL ACCURACY TEMPERATURE COEFFICIENT ORDER PART NUMBER** SPECIFIED TEMPERATURE RANGE

1.25V 0.05%

0.1%

0.05%

0.1%

2.048V 0.05%

0.1%

0.05%

0.1%

2.5V 0.05%

0.1%

0.05%

0.1%

3V 0.05%

0.1%

0.05%

0.1%

3.3V 0.05%

0.1%

0.05%

0.1%

4.096V 0.05%

0.1%

0.05%

0.1%

5V 0.05%

0.1%

0.05%

0.1%

** See the Order Information section for complete part number listing.

10ppm/°C 20ppm/°C 10ppm/°C 20ppm/°C

LT6654AHS6-1.25

LT6654BHS6-1.25 LT6654AMPS6-1.25 LT6654BMPS6-1.25

LT6654AHS6-2.048

LT6654BHS6-2.048 LT6654AMPS6-2.048 LT6654BMPS6-2.048

LT6654AHS6-2.5

LT6654BHS6-2.5 LT6654AMPS6-2.5 LT6654BMPS6-2.5

LT6654AHS6-3

LT6654BHS6-3 LT6654AMPS6-3 LT6654BMPS6-3

LT6654AHS6-3.3 LT6654BHS6-3.3

LT6654AMPS6-3.3 LT6654BMPS6-3.3

LT6654AHS6-4.096

LT6654BHS6-4.096 LT6654AMPS6-4.096 LT6654BMPS6-4.096

LT6654AHS6-5

LT6654BHS6-5 LT6654AMPS6-5 LT6654BMPS6-5

–40°C to 125°C –40°C to 125°C –55°C to 125°C –55°C to 125°C

ELECTRICAL CHARACTERISTICS

The l denotes the speciﬁ cations which apply over the full operating temperature range, otherwise speciﬁ cations are at TA = 25°C, CL = 1μF and VIN = V

+ 0.5V, unless otherwise noted.

OUT

For LT6654-1.25, VIN = 2.4V, unless otherwise noted.

PARAMETER CONDITIONS MIN TYP MAX UNITS

Output Voltage Accuracy LT6654A

Output Voltage Temperature Coefﬁ cient (Note 3) LT6654A

Line Regulation V

Load Regulation (Note 4) I

LT6654B LT6654AH LT6654BH LT6654AMP LT6654BMP

LT6654B

+ 0.5V ≤ VIN ≤ 36V

OUT

LT6654-2.048, LT6654-2.5, LT6654-3, LT6654-3.3, LT6654-4.096, LT6654-5

2.4V ≤ V LT6654-1.25

OUT(SOURCE)

LT6654-2.048, LT6654-2.5, LT6654-3, LT6654-3.3, LT6654-4.096, LT6654-5 LT6654-1.25

≤ 36V

IN

= 10mA

–0.05 –0.10

l

–0.215

l

–0.43

l

–0.23

l

–0.46

l l

l

3

10

1.2 5

3

6

0.05

0.10

0.215

0.43

0.23

0.46 10

20

10

8 15 15 20

ppm/°C ppm/°C

ppm/V ppm/V

ppm/mA ppm/mA ppm/mA ppm/mA

6654fa

% % % % % %

3

LT6654

ELECTRICAL CHARACTERISTICS

The l denotes the speciﬁ cations which apply over the full operating temperature range, otherwise speciﬁ cations are at T

= 25°C, CL = 1μF and VIN = V

A

For LT6654-1.25, VIN = 2.4V, unless otherwise noted.

PARAMETER CONDITIONS MIN TYP MAX UNITS

Load Regulation (Note 4) I

LT6654-2.048, LT6654-2.5, LT6654-3, LT6654-3.3, LT6654-4.096, LT6654-5 LT6654-1.25

Dropout Voltage (Note 5) V

I LT6654-2.048, LT6654-2.5, LT6654-3, LT6654-3.3, LT6654-4.096, LT6654-5 I I

Minimum Input Voltage LT6654-1.25, ∆V

LT6654-1.25, ∆V

Supply Current No Load

Output Short-Circuit Current Short V

Short V

Output Voltage Noise (Note 6) 0.1Hz ≤ f ≤ 10Hz

LT6654-1.25 LT6654-2.048 LT6645-2.5 LT6645-3 LT6645-3.3 LT6645-4 LT6645-5

10Hz ≤ f ≤ 1kHz Turn-On Time 0.1% Settling, C Long-Term Drift of Output Voltage (Note 7) 60 ppm/√kHr Hysteresis (Note 8) ∆T = 0°C to 70°C

∆T = –40°C to 85°C

∆T = –40°C to 125°C

∆T = –55°C to 125°C

OUT(SINK)

– V

IN

OUT

OUT(SOURCE) OUT(SINK)

OUT OUT

= 10mA

, ∆V

= 0mA

to GND to V

= 0.1%

OUT

= 10mA

= –10mA

= 0.1%, I

OUT

= 0.1%, I

OUT

IN

= 1µF 150 µs

LOAD

= 0mA

OUT

= ±10mA

OUT

+ 0.5V, unless otherwise noted.

OUT

9

l

15

l

55 100

l

l l

1.5 1.6

l l

350

l

40 30

0.8

1.0

1.5

1.6

1.7

2.0

2.2

2.0

30 40 90

100

20 30 25 30

120

450

50

1.8

2.4

600

ppm/mA ppm/mA ppm/mA ppm/mA

mV mV

µA µA

mA mA

ppm

P-P

ppm

P-P

ppm

P-P

ppm

P-P

ppm

P-P

ppm

P-P

ppm

P-P

ppm

RMS

ppm ppm ppm ppm

V V V

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: If the parts are stored outside of the speciﬁ ed temperature range, the output may shift due to hysteresis.

Note 3: Temperature coefﬁ cient is measured by dividing the maximum change in output voltage by the speciﬁ ed temperature range.

Note 4: Load regulation is measured on a pulse basis from no load to the speciﬁ ed load current. Output changes due to die temperature change must be taken into account separately.

Note 5: Excludes load regulation errors. Note 6: Peak-to-peak noise is measured with a 1-pole highpass ﬁ lter at

0.1Hz and 2-pole lowpass ﬁ lter 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 on a spectrum analyzer in a shielded environment where the intrinsic noise of the instrument is removed to determine the actual noise of the device.

4

Note 7: Long-term stability 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 ﬁ rst thousand hours with a continuing trend toward reduced drift with time. Long-term stability will also be affected by differential stresses between the IC and the board material created during board assembly.

Note 8: Hysteresis in 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 the hot or cold temperature limit before successive measurements. Hysteresis measures the maximum output change for the averages of three hot or cold temperature cycles. For instruments that are stored at well controlled temperatures (within 20 or 30 degrees of operational temperature), it’s usually not a dominant error source.

Note 9: The stated temperature is typical for soldering of the leads during manual rework. For detailed IR reﬂ ow recommendations, refer to the Applications Information section.

6654fa

LT6654

The characteristic curves are similar across the

TYPICAL PERFORMANCE CHARACTERISTICS

LT6654 family. Curves from the LT6654-1.25, LT6654-2.5 and the LT6654-5 represent the full range of typical performance of all voltage options. Characteristic curves for other output voltages fall between these curves and can be estimated based on their output.

1.25V Output Voltage Temperature Drift 1.25V Turn-On Characteristics

1.2520 THREE TYPICAL PARTS

1.2515

1.2510

1.2505

1.2500

1.2495

REFERENCE VOLTAGE (V)

1.2490

1.2485

–60

–40 –20 0

20 40 60 80 140100 120

TEMPERATURE (°C)

6654 G01

V

1V/DIV

GND

V

OUT

0.5V/DIV

GND

IN

C

LOAD

= 1µF

20µs/DIV

6654 G02

1.25V Output Impedance vs Frequency

100

10

1

0.1

OUTPUT IMPEDANCE (Ω)

0.01

0.1

1 10 100

FREQUENCY (kHz)

1.25V Load Regulation (Sourcing) 1.25V Load Regulation (Sinking) 1.25V Output Noise 0.1Hz to 10Hz

30

20

10

0

–10

–20

–30

OUTPUT VOLTAGE CHANGE (ppm)

–40

–50

0.1

–55°C

125°C

1

OUTPUT CURRENT (mA)

–40°C

25°C

10

6654 G04

200

180

160

140

120

100

80

60

40

OUTPUT VOLTAGE CHANGE (ppm)

20

0

0.1

25°C

–55°C

1

OUTPUT CURRENT (mA)

125°C

OUTPUT NOISE (1µV/DIV)

–40°C

10

TIME (1s/DIV)

6654 G05

CL = 1µF

CL = 10µF

1000

6654 G03

109876543210

6654 G06

1.25V Minimum Input Voltage (Sourcing)

10

125°C

25°C

1

OUTPUT CURRENT (mA)

0.1 1 1.2 1.4 1.6 1.8 2 2.2

MINIMUM INPUT VOLTAGE (V)

–55°C

–40°C

6654 G07

2.4

1.25V Minimum Input Voltage (Sinking)

10

125°C

1

OUTPUT CURRENT (mA)

0.1 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7

MINIMUM INPUT VOLTAGE (V)

25°C

–40°C

–55°C

6654 G08

1.8

1.2V Output Voltage Noise Spectrum

400

350

300

250

200

150

NOISE VOLTAGE (nV√Hz)

100

50

0

0.01 0.1 1 10 FREQUENCY (kHz)

IO = 0µA

IO = 5mA

100

6654 G09

6654fa

5

LT6654

The characteristic curves are similar across the

TYPICAL PERFORMANCE CHARACTERISTICS

LT6654 family. Curves from the LT6654-1.25, LT6654-2.5 and the LT6654-5 represent the full range of typical performance of all voltage options. Characteristic curves for other output voltages fall between these curves and can be estimated based on their output.

2.5V Output Voltage Temperature Drift

2.502 THREE TYPICAL PARTS

2.501

2.500

OUTPUT VOLTAGE (V)

2.499

2.498

–60 –20 20 60 140100

TEMPERATURE (°C)

6654 G10

2.5V Supply Current vs Input Voltage 2.5V Line Regulation

600

500

400

300

200

INPUT CURRENT (µA)

100

0

0 5 10 15 20 25 30 35

–55°C

25°C

125°C

INPUT VOLTAGE (V)

–40°C

6654 G11

2.5050

2.5040

2.5030

2.5020

2.5010

2.5000

2.4990

2.4980

OUTPUT VOLTAGE (V)

2.4970

2.4960

2.4950

40

0 5 10 15 20 25 30 35

25°C

125°C

–55°C

INPUT VOLTAGE (V)

2.5V Load Regulation (Sourcing) 2.5V Load Regulation (Sinking) 2.5V Output Noise 0.1Hz to 10Hz

10

0

–10

–20

–30

OUTPUT VOLTAGE CHANGE (ppm)

–40

0.1 1

–40°C

125°C

OUTPUT CURRENT (mA)

–55°C

25°C

10

6654 G13

180

160

140

120

100

80

60

40

OUTPUT VOLTAGE CHANGE (ppm)

20

0

0.1 1

25°C

–40°C

OUTPUT CURRENT (mA)

125°C

–55°C

6654 G14

OUTPUT NOISE (1µV/DIV)

10

TIME (1s/DIV)

–40°C

40

6654 G12

6654 G15

2.5V Minimum V Differential (Sourcing)

10

–55°C

–40°C

1

OUTPUT CURRENT (mA)

0.1 0 200 300

INPUT-OUTPUT VOLTAGE (mV)

6

to V

IN

25°C

125°C

15010050 250

OUT

400

350

6654 G16

2.5V Minimum VIN to V Differential (Sinking)

10

125°C

1

OUTPUT CURRENT (mA)

0.1 –300 –100 0

INPUT-OUTPUT VOLTAGE (mV)

25°C

–150–200–250 –50

OUT

–40°C

–55°C

50

6654 G17

100

2.5V Output Voltage Noise Spectrum

400

350

300

250

200

150

NOISE VOLTAGE (nV√Hz)

100

50

0

0.01 0.1 1 10 FREQUENCY (kHz)

IO = 0µA

IO = 5mA

100

6654 G18

6654fa

LT6654

The characteristic curves are similar across the

TYPICAL PERFORMANCE CHARACTERISTICS

LT6654 family. Curves from the LT6654-1.25, LT6654-2.5 and the LT6654-5 represent the full range of typical performance of all voltage options. Characteristic curves for other output voltages fall between these curves and can be estimated based on their output.

2.5V Integrated Noise 10Hz to 10kHz

100

)

RMS

10

1

INTEGRATED NOISE (µV

0.1

0.01 0.1 1 FREQUENCY (kHz)

10

6654 G19

2.5V Power Supply Rejection Ratio vs Frequency

–20

–30

–40

–50

–60

–70

–80

–90

POWER SUPPLY REJECTION RATIO (dB)

–100

0.1 1 10 100 FREQUENCY (kHz)

2.5V Turn-On Characteristics 2.5V Line Transient Response

V

IN

0.5V/DIV

V

1V/DIV

GND

IN

3V/DC

CL = 1µF

CL = 10µF

6654 G20

1000

2.5V Output Impedance vs Frequency

100

10

1

OUTPUT IMPEDANCE (Ω)

0.1 1 10 100

CL = 10µF

FREQUENCY (kHz)

2.5V Load Transient Response (Sourcing)

I

OUT

0mA

5mA

CL = 1µF

1000

6654 G21

V

OUT

6654 G22

2mV/DIV/AC

2.5V/DC

C

LOAD

= 1µF

V

OUT

1V/DIV

GND

C

LOAD

= 1µF

20µs/DIV

2.5V Hysteresis Plot for – 40°C and 125°C 2.5V Long Term Drift

48

MAX AVG HOT CYCLE

44

25°C TO 125°C TO 25°C

40 36 32 28 24 20 16

NUMBER OF UNITS

12

8 4 0

–100–125

–150

MAX AVG COLD CYCLE 25°C TO –40°C TO 25°C

–50–75

–25 0 2 5 100125 15050 75

DISTRIBUTION (ppm)

6654 G25

150

TA = 35°C

120

90

60

30

0

–30

–60

–90

OUTPUT VOLTAGE CHANGE (ppm)

–120

–150

0 400 800 16001200

50µs/DIV

TIME (HOURS)

6654 G23

6654 G26

20mV/DIV/AC

2000

V

OUT

2.5V/DC

C

LOAD

= 1µF

50µs/DIV

2.5V Load Transient Response (Sinking)

I

OUT

5mA

0mA

V

OUT

2.5V/DC

C

LOAD

= 1µF

50µs/DIV

6654 G24

6654 G27

6654fa

7

LT6654

The characteristic curves are similar across the

TYPICAL PERFORMANCE CHARACTERISTICS

LT6654 family. Curves from the LT6654-1.25, LT6654-2.5 and the LT6654-5 represent the full range of typical performance of all voltage options. Characteristic curves for other output voltages fall between these curves and can be estimated based on their output.

5V Output Voltage Temperature Drift 5V Turn-On Characteristics

5.003 THREE TYPICAL PARTS

5.002

5.001

5.000

4.999

4.998

4.997

4.996

REFERENCE VOLTAGE (V)

4.995

4.994

4.993 –60 0 80604020–40 –20 120100

TEMPERATURE (°C)

140

6654 G28

V

2V/DIV

GND

V

OUT

2V/DIV

GND

IN

C

= 1µF

LOAD

50µs/DIV

6654 G29

5V Output Impedance vs Frequency

100

10

1

0.1

OUTPUT IMPEDANCE (Ω)

0.01

0.1 1 10 100 FREQUENCY (kHz)

5V Load Regulation (Sourcing) 5V Load Regulation (Sinking) 5V Output Noise 0.1Hz to 10Hz

50

40

30

20

10

0

OUTPUT VOLTAGE CHANGE (ppm)

–10

–20

0.1 1 OUTPUT CURRENT (mA)

–55°C

–40°C

125°C

25°C

10

6654 G31

220 200 180 160 140 120 100

80 60 40

OUTPUT VOLTAGE CHANGE (ppm)

20

0

0.1 1 OUTPUT CURRENT (mA)

–40°C

125°C

–55°C

25°C

6654 G32

OUTPUT NOISE (4µV/DIV)

10

TIME (1s/DIV)

CL = 1µF

CL = 10µF

1000

6654 G30

109876543210

6654 G33

5V Minimum VIN to V Differential (Sourcing)

10

–55°C

–40°C

1

OUTPUT CURRENT (mA)

0.1 0 50 100 150 200 250 300 350

INPUT-OUTPUT VOLTAGE (mV)

8

25°C

125°C

OUT

400

6654 G34

5V Minimum VIN to V

OUT

Differential (Sinking)

10

25°C

125°C

1

OUTPUT CURRENT (mA)

0.1 –300 –250 –200 –150 –100 –50 0 50

INPUT-OUTPUT VOLTAGE (mV)

–40°C

5V Output Voltage Noise Spectrum

600

550

–55°C

100

6654 G35

500 450 400 350 300 250 200

NOISE VOLTAGE (nV√Hz)

150 100

50

0

0.01 0.1 1 10 FREQUENCY (kHz)

IO = 0µA

IO = 5mA

100

6654 G36

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PIN FUNCTIONS

LT6654

GND (Pin 1): Internal Function. This pin must be tied to ground, near Pin 2.

GND (Pin 2): Primary Device Ground. DNC (Pin 3): Do Not Connect. Keep leakage current from

this pin to V

(Pin 4): Power Supply. Bypass VIN with a 0.1µF

V

IN

or GND to a minimum.

IN

capacitor to ground.

BLOCK DIAGRAM

V

IN

4

DNC

3

DNC

5

BANDGAP

DNC (Pin 5): Do Not Connect. Keep leakage current from this pin to V

(Pin 6): Output Voltage. An output capacitor of 1µF

V

OUT

or GND to a minimum.

IN

minimum is required for stable operation.

+

–

V

OUT

6

GND GND

2

1

6654 BD

6654fa

9

LT6654

APPLICATIONS INFORMATION

Bypass and Load Capacitors

The LT6654 voltage references should have an input bypass capacitor of 0.1µF or larger, however the bypassing on other components nearby is sufﬁ cient. In high voltage applications, V

> 30V, an output short-circuit to ground

IN

can create an input voltage transient that could exceed the maximum input voltage rating. To prevent this worst-case con di tio n, an R C in put li ne ﬁ lter of 10µs (i.e. 10Ω and 1µF) is recommended. These references also require an output capacitor for stabilit y. 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 ﬁ nal value.

V

IN

1V/DIV

GND

Figure 1 shows the turn-on time for the LT6654-2.5 with a

0.1µF input bypass and 1µF load capacitor. Figure 2 shows the output response to a 0.5V transient on V

with the

IN

same capacitors. The test circuit of Figure 3 is used to measure the stability

with various load currents. With R

= 1k, the 1V step pro-

L

duces 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.

V

IN

0.5V/DIV 3V/DC

V

OUT

1V/DIV

GND

6654 F01

C

LOAD

= 1µF

20µs/DIV

Figure 1. Turn-On Characteristics of LT6654-2.5

V

IN

3V

46

C

IN

0.1µF

Figure 3. Load Current Response Time Test Circuit

LT6654-2.5

1, 2

V

OUT

2mV/DIV/AC

2.5V/DC

6654 F02

C

LOAD

= 1µF

50µs/DIV

Figure 2. Output Response to 0.5V Ripple on V

1k

CL 1µF

V

GEN

1V

6654 F03

IN

10

6654fa

APPLICATIONS INFORMATION

I

OUT

–0.5mA

0.5mA

V

OUT

20mV/DIV/AC

2.5V/DC

C

LOAD

= 1µF

50µs/DIV

Figure 4. LT6654-2.5 Sourcing and Sinking 0.5mA

I

OUT

4mA

5mA

6654 F04

LT6654

Positive or Negative Operation

In addition to the series connection, as shown on the front page of this data sheet, the LT6654 can be operated as a negative voltage reference.

The circuit in Figure 7 shows an LT6654 conﬁ gured for negative operation. In this conﬁ guration, a positive voltage is required at V 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 stability during load transients. This connection maint ains the same accuracy and temperature coefﬁ cient of the positive connected LT6654.

6

(Pin 4) to bias the LT6654 internal

IN

R1

4.7k

4

LT6654-2.5

3V

0.1µF

V

OUT

10mV/DIV/AC

2.5V/DC

C

LOAD

= 1µF

50µs/DIV

Figure 5. LT6654-2.5 Sourcing 4mA to 5mA

I

OUT

–5mA

–4mA

V

OUT

0mV/DIV/AC

2.5V/DC

C

LOAD

= 1µF

50µs/DIV

6654 F05

6654 F06

R ≤

VEE – V

550µA + I

OUT

1, 2

V

EE

C1 1µF

V

OUT

= –2.5V

6654 F07

Figure 7. Using the LT6654-2.5 to Build a –2.5V Reference

Figure 6. LT6654-2.5 Sinking 4mA to 5mA

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11

LT6654

APPLICATIONS INFORMATION

Long-Term Drift

Long-term drif t cannot be extrapolated f rom accelerated high temperature testing. This erroneous technique 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 LT6654 drift data

was taken on 40 parts that were soldered into PC boards

80

40

0

–40

OUTPUT VOLTAGE CHANGE (ppm)

–80

0 200 400 800600

LONG TERM DRIFT: FIRST THOUSAND HOURS

TIME (HOURS)

1000

6654 F08a

similar to a real world application. The boards were then placed into a constant temperature oven with T

= 35°C,

A

their outputs scanned regularly and measured with an 8.5 digit DVM. Long-term drift curves are shown in Figure 8. Their drift is much smaller after the ﬁ rst thousand hours.

80

40

0

–40

OUTPUT VOLTAGE CHANGE (ppm)

–80

1000 1200 1400 18001600

LONG TERM DRIFT: SECOND THOUSAND HOURS (NORMALIZED TO THE FIRST THOUSAND HOURS)

TIME (HOURS)

2000

6654 F08b

Figure 8. LT6654-2.5 Long Term Drift

12

6654fa

TYPICAL APPLICATIONS

LT6654

Power Dissipation

The power dissipation in the LT6654 is dependent on V

IN

, load current and the package. The LT6654 package has a thermal resistance, or θ

, of 192°C/W. A curve that

JA

illustrates allowed power dissipation versus temperature for the 6-lead SOT-23 package is shown in Figure 9. The power dissipation of the LT6654-2.5 as a function of input voltage is shown in Figure 10. The top curve shows power dissipation with a 10mA load and the bottom curve shows power dissipation with no load. When operated within its speciﬁ ed limits of V

= 36V and sourcing 10mA, the

IN

LT6654-2.5 consumes about 335mW at room temperature. The power-derating curve in Figure 9 shows the LT6654-

2.5 can only safely dissipate 130mW at 125°C, which is less than its maximum power output. Care must be taken when designing the circuit so that the maximum junction temperature is not exceeded. For best performance, junction temperature should be kept below 125°C.

The LT6654 includes output current limit circuitry, as well as thermal limit circuitry, to protect the reference from damage in the event of excessive power dissipation. The LT6654 is protected from damage by a thermal shutdown circuit. However, changes in performance may occur as a result of operation at high temperature.

Hysteresis

The hysteresis data is shown in Figure 11. The LT6654 is capable of dissipating relatively high power. For example, with a 36V input voltage and 10mA load current applied to the LT6654-2.5, the power dissipation is P

= 33.5V

D

• 10mA = 335mW, which causes an increase in the die temperature of 64°C. This could increase the junction temperature above 125°C (T

is 150°C) and may cause

JMAX

the output to shift due to thermal hysteresis.

0.7

0.6

0.5

0.4

0.3

POWER (W)

0.2

0.1

0

20 40 60 80

TEMPERATURE (°C)

T = 150°C

= 192°C/W

e

JA

130mW

100 120 140

6654 F09

Figure 9. Maximum Allowed Power Dissipation of the LT6654

0.40

0.35

0.30

0.25

0.20

POWER (W)

0.15

0.10

0.05

0

10mA LOAD

51015

VIN (V)

20 25 30 35 40

335mW

NO LOAD

6654 F10

Figure 10. Typical Power Dissipation of the LT6654

50

MAX AVG HOT CYCLE

25°C TO 125°C TO 25°C

40

30

MAX AVG COLD CYCLE 25°C TO –40°C TO 25°C

20

NUMBER OF UNITS

10

0

–100

–50

–150

010015050

DISTRIBUTION (ppm)

6654 F11

Figure 11. Thermal Hysteresis –40°C to 125°C

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13

LT6654

APPLICATIONS INFORMATION

PC Board Layout

The mechanical stress of soldering a surface mount voltage reference to a PC board can cause the output voltage to shift and temperature coefﬁ cient to change. These two changes are not correlated. For example, the voltage may shift but the temperature coefﬁ cient may not.

To reduce the effects of stress-related shifts, mount the reference near the short edge of the PC board or in a corner. In addition, slots can be cut into the board on two sides of the device.

The capacitors should be mounted close to the LT6654. The GND and V

traces should be as short as possible

OUT

to minimize I • R drops, since high trace resistance directly impacts load regulation.

300

225

150

TEMPERATURE (°C)

75

= 190°C

T

S

T = 150°C

RAMP TO 150°C

T

S(MAX)

380s

= 217°C

T

L

= 200°C

120s

= 260°C

T

P

30s

t

130s

40s

RAMP DOWN

t

P

L

IR Reﬂ ow Shift

The different expansion and contraction rates of the materials that make up the LT6654 package may cause the output voltage to shift after undergoing IR reﬂ ow. Lead free solder reﬂ ow proﬁ les reach over 250°C, considerably more than with lead based solder. A typical lead free IR reﬂ ow proﬁ le is shown in Figure 12. Similar proﬁ les are found using a convection reﬂ ow oven. LT6654 devices run up to three times through this reﬂ ow process show that the standard deviation of the output voltage increases with a s l i g h t n e g a t i v e m e a n s h i f t o f 0 .0 0 3 % a s s h o w n i n F i g u r e 13 . While there can be up to 0.014% of output voltage shift, the overall drift of the LT6654 after IR reﬂ ow does not vary signiﬁ cantly.

14

260°C 3 CYCLES 260°C 1 CYCLE

12

10

8

6

NUMBER OF UNITS

4

2

14

0

2468

MINUTES

6654 F12

Figure 12. Lead Free Reﬂ ow Proﬁ le

10

0

–140

–120 –100 –80

CHANGE IN OUTPUT (ppm)

–60

–40 0–20

6654 F13

Figure 13. Output Voltage Shift Due to IR Reﬂ ow (%)

6654fa

TYPICAL APPLICATIONS

UP TO 160V

330k

MMBT5551

4.5V < V

Boosted Output Current ReferenceExtended Supply Range Reference

IN

< 36V

220

LT6654

4.7µF

2N2905

BZX84C12

0.1µF

LT6654-2.5

Boosted Output Current with Current Limit

< 36V

4.5V < V

IN

1

LED1*

220 4.7µF

2

LT6654-2.5

IN OUT

*

LED CANNOT BE OMMITTED THE LED CLAMPS THE VOLTAGE DROP ACROSS THE 220 AND LIMITS OUTPUT CURRENT

10

2N2905

1µF

6654 TA04

6654 TA02

I

OUT

UP TO 100mA

1µF

2.65V < V

IN

LT6654-2.5

OUT

6654 TA03

I

OUT

UP TO 300mA

1µF

Octal DAC Reference

LT6654-2.5

< 5V

IN

IN OUT

0.1µF 10µF

CS

SCK

SDI

CLEAR

V

REF

LTC2600

GND

V

IN

V

CC

DAC A

DAC B

DAC C

DAC D

DAC E

DAC F

DAC G

DAC H

6654 TA05

0.1µF

6654fa

15

LT6654

PACKAGE DESCRIPTION

S6 Package

6-Lead Plastic TSOT-23

(Reference LTC DWG # 05-08-1636)

0.62

MAX

3.85 MAX

2.62 REF

RECOMMENDED SOLDER PAD LAYOUT

PER IPC CALCULATOR

0.20 BSC

DATUM ‘A’

NOTE:

1. DIMENSIONS ARE IN MILLIMETERS

2. DRAWING NOT TO SCALE

3. DIMENSIONS ARE INCLUSIVE OF PLATING

4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR

5. MOLD FLASH SHALL NOT EXCEED 0.254mm

6. JEDEC PACKAGE REFERENCE IS MO-193

0.95 REF

1.22 REF

1.4 MIN

0.30 – 0.50 REF

2.80 BSC

0.09 – 0.20 (NOTE 3)

1.50 – 1.75 (NOTE 4)

1.00 MAX

0.95 BSC

0.80 – 0.90

2.90 BSC (NOTE 4)

PIN ONE ID

0.30 – 0.45 6 PLCS (NOTE 3)

0.01 – 0.10

1.90 BSC

S6 TSOT-23 0302 REV B

16

6654fa

LT6654

REVISION HISTORY

REV DATE DESCRIPTION PAGE NUMBER

A 12/10 Added voltage options (1.250V, 2.048V, 3.000V, 4.096V, 5.000V) reﬂ ected throughout the data sheet. 1-18

Information furnished by Linear Technology Corporation is believed to be accurate and reliable. Howev er, no resp onsib ilit y is ass umed fo r its us e. Line ar Techno logy C orpor atio n makes n o repr esen tat i o n t h a t t h e i n t e r c o n n e c t i o n o f i t s c i r c u i t s a s d e s c r i b e d h e r e i n w i l l n o t i n f r i n g e o n e x i s t i n g p a t e n t r i g h t s .

6654fa

17

LT6654

TYPICAL APPLICATION

4.6V < VS < 36V

16-Bit ADC Reference

LT6654-4.096

IN OUT

0.1µF

DIFFERENTIAL

10µF

+

< 2.048V

–

IN+

IN–

V

REF

GND

V

CC

SDO

LTC2480 TO MCU–2.048V < V

SDI

CS

SCK

f

O

6654 TA06

RELATED PARTS

PART NUMBER DESCRIPTION COMMENTS

LT1460 Micropower Series Reference 0.075% Max, 10ppm/°C Max Drift, 2.5V, 5V and 10V Versions, MSOP, PDIP, S0-8,

LT1461 Micropower Precision LDO Series Reference 3ppm/°C Max Drift, 0°C to 70°C, –40°C to 85°C, –40°C to 125°C Options in SO-8 LT1790 Micropower Precision Series References 0.05% Max, 10ppm/°C Max, 60µA Supply, SOT-23 Package LT6650 Micropower Reference with Buffer Ampliﬁ er 0.05% Max, 5.6µA Supply, SOT-23 Package LTC6652 Precision Low Drift Low Noise Buffered

Reference LT6660 Tiny Micropower Series Reference 0.2% Max, 20ppm/°C Max, 20mA Output Current, 2mm × 2mm DFN LTC6655 Precision Low Noise Reference 2ppm/°C Max, 650nV LT6656 800nA Precision Voltage Reference 800nA, 10ppm/°C Max, 0.05% Max, SOT-23 Package

SOT-23 and TO-92 Packages

0.5% Max, 5ppm/°C Max, 2.1ppm 25°C and 125°C

Noise (0.1Hz to 10Hz) 100% Tested at –40°C, 25°C and 125°C

P-P

Noise (0.1Hz to 10Hz) 100% Tested at –40°C,

P-P

18

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

(408) 432-1900 ● FAX: (408) 434-0507

●

www.linear.com

6654fa

LT 1210 REV A • PRINTED IN USA

ANALOG DEVICES LT 6654AHS6-2.5 Datasheet

Specifications and Main Features

Frequently Asked Questions

User Manual