LT6654BHS6-1.25#TRMPBF - Linear Technology Corporation

LT6654

6654fc

TYPICAL APPLICATION

DESCRIPTION

SOT-23 Precision Wide

Supply High Output Drive

Low Noise Reference

The LT

6654 is a family of small precision voltage ref-

erences 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 manufactur-

ing techniques and curvature compensation to provide

10ppm/°C temperature drift and 0.05% initial accuracy.

Low thermal hysteresis ensures high accuracy and

1.6ppmP-P noise minimizes measurement uncertainty.

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 references are offered in 6-lead SOT-23

package and an 8-lead LS8 package. The LS8 is a 5mm

× 5mm surface mount hermetic package that provides

outstanding stability.

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.

Basic Connection

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: 1.6ppmP-P (0.1Hz to 10Hz)

n Wide Supply Range to 36V

n Low Thermal Hysteresis: LS8 15ppm (–40°C to 125°C)

n Long Term Drift: (LS8) 15ppm/√kHr

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 Fully Speciﬁ ed from –55°C to 125°C

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

3V, 3.3V, 4.096V, 5V

n Low Proﬁ le (1mm) ThinSOT™ Package and 5mm ×

5mm Surface Mount Hermetic Package

FEATURES

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

Output Voltage Temperature Drift

LT6654

CIN

0.1µF

(VOUT + 0.5V) < VIN < 36V 46

12 CL

1µF

VOUT

6654 TA01a

TEMPERATURE (°C)

–60

–0.10

VOUT ACCURACY (%)

–0.05

0.05

0.00

0.10

40200–40 –20

6654 TA01b

140

100 120

60 80

3 TYPICAL PARTS

LT6654-2.5

LT6654

6654fc

PIN CONFIGURATION

ABSOLUTE MAXIMUM RATINGS

(Note 1)

TOP VIEW

S6 PACKAGE

6-LEAD PLASTIC TSOT-23

VOUT

DNC

VIN

GND*

GND

DNC

TJMAX = 150°C, θJA = 192°C/W

DNC: CONNECTED INTERNALLY

DO NOT CONNECT EXTERNAL

CIRCUITRY TO THESE PINS

*CONNECT PIN TO DEVICE GND (PIN 2)

DNC

GND*

GND

DNC

VOUT

GND*

VIN

TOP VIEW

LS8 PACKAGE

8-PIN LEADLESS CHIP CARRIER (5mm × 5mm)

TJMAX = 150°C, θJA = 125°C/W

DNC: CONNECTED INTERNALLY

DO NOT CONNECT EXTERNAL

CIRCUITRY TO THESE PINS

*CONNECT PIN TO DEVICE GND (PIN 3)

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

Output Voltage VOUT .........................–0.3V to VIN + 0.3V

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

Lead Temperature (Soldering, 10 sec.)

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

LT6654

6654fc

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

LEAD FREE FINISH PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE

LT6654AHLS8-2.5#PBF†665425 8-Lead Ceramic LCC (5mm × 5mm) –40°C to 125°C

LT6654BHLS8-2.5#PBF†665425 8-Lead Ceramic LCC (5mm × 5mm) –40°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: http://www.linear.com/leadfree/

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

†This product is only offered in trays. For more information go to: http://www.linear.com/packaging/

LT6654

6654fc

AVAILABLE OPTIONS

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

1.25V 0.05%

0.1%

0.05%

0.1%

10ppm/°C

20ppm/°C

10ppm/°C

20ppm/°C

LT6654AHS6-1.25

LT6654BHS6-1.25

LT6654AMPS6-1.25

LT6654BMPS6-1.25

–40°C to 125°C

–55°C to 125°C

2.048V 0.05%

0.1%

0.05%

0.1%

10ppm/°C

20ppm/°C

10ppm/°C

20ppm/°C

LT6654AHS6-2.048

LT6654BHS6-2.048

LT6654AMPS6-2.048

LT6654BMPS6-2.048

–40°C to 125°C

–55°C to 125°C

2.5V 0.05%

0.05%

0.1%

0.05%

0.1%

10ppm/°C

20ppm/°C

10ppm/°C

20ppm/°C

LT6654AHS6-2.5

LT6654AHLS8-2.5

LT6654BHS6-2.5

LT6654BHLS8-2.5

LT6654AMPS6-2.5

LT6654BMPS6-2.5

–40°C to 125°C

–55°C to 125°C

3V 0.05%

0.1%

0.05%

0.1%

10ppm/°C

20ppm/°C

10ppm/°C

20ppm/°C

LT6654AHS6-3

LT6654BHS6-3

LT6654AMPS6-3

LT6654BMPS6-3

–40°C to 125°C

–55°C to 125°C

3.3V 0.05%

0.1%

0.05%

0.1%

10ppm/°C

20ppm/°C

10ppm/°C

20ppm/°C

LT6654AHS6-3.3

LT6654BHS6-3.3

LT6654AMPS6-3.3

LT6654BMPS6-3.3

–40°C to 125°C

–55°C to 125°C

4.096V 0.05%

0.1%

0.05%

0.1%

10ppm/°C

20ppm/°C

10ppm/°C

20ppm/°C

LT6654AHS6-4.096

LT6654BHS6-4.096

LT6654AMPS6-4.096

LT6654BMPS6-4.096

–40°C to 125°C

–55°C to 125°C

5V 0.05%

0.1%

0.05%

0.1%

10ppm/°C

20ppm/°C

10ppm/°C

20ppm/°C

LT6654AHS6-5

LT6654BHS6-5

LT6654AMPS6-5

LT6654BMPS6-5

–40°C to 125°C

–55°C to 125°C

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

LT6654

6654fc

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 = VOUT + 0.5V, unless otherwise noted.

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

PARAMETER CONDITIONS MIN TYP MAX UNITS

Output Voltage Accuracy LT6654A

LT6654B

LT6654AH

LT6654BH

LT6654AMP

LT6654BMP

–0.05

–0.10

–0.215

–0.43

–0.23

–0.46

0.05

0.10

0.215

0.43

0.23

0.46

Output Voltage Temperature Coefﬁ cient (Note 3) LT6654A

LT6654B

ppm/°C

Line Regulation VOUT + 0.5V ≤ VIN ≤ 36V

LT6654-2.048, LT6654-2.5, LT6654-3,

LT6654-3.3, LT6654-4.096, LT6654-5 l

1.2 5

ppm/V

2.4V ≤ VIN ≤ 36V

LT6654-1.25 l

1.2 5

ppm/V

Load Regulation (Note 4) IOUT(SOURCE) = 10mA

LT6654-2.048, LT6654-2.5, LT6654-3,

LT6654-3.3, LT6654-4.096, LT6654-5

LT6654-1.25

LT6654LS8

ppm/mA

Load Regulation (Note 4) IOUT(SINK) = 10mA

LT6654-2.048, LT6654-2.5, LT6654-3,

LT6654-3.3, LT6654-4.096, LT6654-5

LT6654-1.25

LT6654LS8

ppm/mA

Dropout Voltage (Note 5) VIN – VOUT, ∆VOUT = 0.1%

OUT = 0mA

LT6654-2.048, LT6654-2.5, LT6654-3,

LT6654-3.3, LT6654-4.096, LT6654-5

OUT(SOURCE) = 10mA

OUT(SINK) = –10mA

55 100

120

450

Minimum Input Voltage LT6654-1.25, ∆VOUT = 0.1%, IOUT = 0mA

LT6654-1.25, ∆VOUT = 0.1%, IOUT = ±10mA

1.5 1.6

1.8

2.4

Supply Current No Load

350

600

µA

Output Short-Circuit Current Short VOUT to GND

Short VOUT to VIN

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

LT6654-1.25

LT6654-2.048

LT6654-2.5

LT6654-3

LT6654-3.3

LT6654-4.096

LT6654-5

10Hz ≤ f ≤ 1kHz

0.8

1.0

1.5

1.6

1.7

2.0

2.2

2.0

ppmP-P

ppmRMS

Turn-On Time 0.1% Settling, CLOAD = 1µF 150 µs

LT6654

6654fc

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.

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 is usually not a dominant error source. Typical

hysteresis is the worst-case of 25°C to cold to 25°C or 25°C to hot to

25°C, preconditioned by one thermal cycle.

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.

PARAMETER CONDITIONS MIN TYP MAX UNITS

Long-Term Drift of Output Voltage (Note 7) LT6654S6

LT6654LS8

ppm/√kHr

Hysteresis (Note 8) S6

∆T = 0°C to 70°C

∆T = –40°C to 85°C

∆T = –40°C to 125°C

∆T = –55°C to 125°C

LS8

∆T = 0°C to 70°C

∆T = –40°C to 85°C

∆T = –40°C to 125°C

∆T = –55°C to 125°C

ppm

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 = VOUT + 0.5V, unless otherwise noted.

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

ELECTRICAL CHARACTERISTICS

LT6654

6654fc

TYPICAL PERFORMANCE CHARACTERISTICS

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

1.25V Minimum Input Voltage

(Sourcing)

1.25V Minimum Input Voltage

(Sinking)

1.2V Output Voltage Noise

Spectrum

1.25V Output Voltage

Temperature Drift 1.25V Turn-On Characteristics

1.25V Output Impedance

vs Frequency

TEMPERATURE (°C)

–60

1.2485

1.2490

1.2495

REFERENCE VOLTAGE (V)

1.2500

1.2505

1.2510

1.2515

1.2520

–40 –20 0

6654 G01

20 40 60 80 140100 120

THREE TYPICAL PARTS

OUTPUT CURRENT (mA)

0.1

–50

–40

OUTPUT VOLTAGE CHANGE (ppm)

–30

–20

–10

6654 G04

–40°C

25°C

125°C

–55°C

OUTPUT CURRENT (mA)

0.1

OUTPUT VOLTAGE CHANGE (ppm)

100

140

160

180

120

200

6654 G05

125°C

–40°C

–55°C

25°C

OUTPUT NOISE (1µV/DIV)

TIME (1s/DIV)

6654 G06

109876543210

MINIMUM INPUT VOLTAGE (V)

1 1.2 1.4 1.6 1.8 2 2.2

0.1

OUTPUT CURRENT (mA)

6654 G07

2.4

25°C –40°C

–55°C

125°C

MINIMUM INPUT VOLTAGE (V)

1 1.1 1.2 1.3 1.4 1.5 1.6 1.7

0.1

OUTPUT CURRENT (mA)

6654 G08

1.8

–40°C

–55°C

125°C

25°C

FREQUENCY (kHz)

0.01 0.1 1 10

100

150

250

300

350

NOISE VOLTAGE (nV√Hz)

200

400

6654 G09

100

IO = 5mA

IO = 0µA

The characteristic curves are similar across the

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.

20µs/DIV

GND

VIN

1V/DIV

VOUT

0.5V/DIV

6654 G02

CLOAD = 1µF FREQUENCY (kHz)

0.1

0.01

OUTPUT IMPEDANCE (Ω)

0.1

100

1 10 100

6654 G03

1000

CL = 1µF

CL = 10µF

LT6654

6654fc

TYPICAL PERFORMANCE CHARACTERISTICS

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

2.5V Minimum VIN to VOUT

Differential (Sourcing)

2.5V Minimum VIN to VOUT

Differential (Sinking)

2.5V Output Voltage Noise

Spectrum

2.5V Output Voltage

Temperature Drift

2.5V Supply Current

vs Input Voltage 2.5V Line Regulation

TEMPERATURE (°C)

–60 –20 20 60 140100

2.498

2.499

2.500

2.501

OUTPUT VOLTAGE (V)

2.502

6654 G10

THREE TYPICAL PARTS

INPUT VOLTAGE (V)

0 5 10 15 20 25 30 35

INPUT CURRENT (µA)

300

600

500

400

100

200

6654 G11

–55°C

125°C

–40°C

25°C

INPUT VOLTAGE (V)

0 5 10 15 20 25 30 35

2.4950

2.4960

OUTPUT VOLTAGE (V)

2.5000

2.5050

2.5030

2.5010

2.5040

2.5020

2.4970

2.4980

2.4990

6654 G12

–40°C

–55°C

25°C

125°C

OUTPUT CURRENT (mA)

0.1 1

–40

–30

–20

–10

OUTPUT VOLTAGE CHANGE (ppm)

6654 G13

–55°C

25°C

125°C

–40°C

OUTPUT CURRENT (mA)

0.1 1

100

120

140

OUTPUT VOLTAGE CHANGE (ppm)

160

180

6654 G14

125°C

–55°C

–40°C

25°C

TIME (1s/DIV)

OUTPUT NOISE (1µV/DIV)

6654 G15

INPUT-OUTPUT VOLTAGE (mV)

0 200 300

0.1

OUTPUT CURRENT (mA)

6654 G16

400

15010050 250

350

25°C

–55°C

–40°C

125°C

INPUT-OUTPUT VOLTAGE (mV)

–300 –100 0

0.1

OUTPUT CURRENT (mA)

6654 G17

100

–150–200–250 –50

–40°C

25°C

–55°C

125°C

FREQUENCY (kHz)

0.01 0.1 1 10

100

150

250

300

350

NOISE VOLTAGE (nV√Hz)

200

400

6654 G18

100

IO = 5mA

IO = 0µA

The characteristic curves are similar across the

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.

LT6654

6654fc

TYPICAL PERFORMANCE CHARACTERISTICS

2.5V Turn-On Characteristics 2.5V Line Transient Response

2.5V Load Transient Response

(Sourcing)

2.5V Hysteresis Plot for –40°C

and 125°C (TSOT-23)

2.5V Hysteresis Plot for –40°C

and 125°C (LS8)

2.5V Long Term Drift (TSOT-23)

2.5V Integrated Noise

10Hz to 10kHz

2.5V Power Supply Rejection

Ratio vs Frequency

2.5V Output Impedance

vs Frequency

FREQUENCY (kHz)

0.01 0.1 1

0.1

INTEGRATED NOISE (µVRMS)

100

6654 G19

FREQUENCY (kHz)

0.1 1 10 100

–100

–90

–80

–70

–50

–40

–30

POWER SUPPLY REJECTION RATIO (dB)

–60

–20

6654 G20

1000

CL = 1µF

CL = 10µF

FREQUENCY (kHz)

1 10 100

0.1

OUTPUT IMPEDANCE (Ω)

100

6654 G21

1000

CL = 10µF

CL = 1µF

20µs/DIV

GND

VIN

1V/DIV

VOUT

1V/DIV

6654 G22

CLOAD = 1µF 50µs/DIV

VIN

0.5V/DIV

3V/DC

VOUT

2mV/DIV/AC

2.5V/DC

6654 G23

CLOAD = 1µF 50µs/DIV

IOUT

0mA

VOUT

20mV/DIV/AC

2.5V/DC

6654 G24

CLOAD = 1µF

5mA

DISTRIBUTION (ppm)

–150

NUMBER OF UNITS

–100–125

–50–75

6654 G25

–25 0 25 100 125 15050 75

MAX AVG HOT CYCLE

25°C TO 125°C TO 25°C

MAX AVG COLD CYCLE

25°C TO –40°C TO 25°C

TIME (HOURS)

0 400 800 16001200

–150

–120

–90

–60

–30

120

OUTPUT VOLTAGE CHANGE (ppm)

150

6654 G26

2000

TA = 35°C

The characteristic curves are similar across the

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.

DISTRIBUTION (ppm)

NUMBER OF UNITS

625°C TO –40°C TO 25°C

AND 25°C TO 125°C TO 25°C

–40 –30

–20 –10 0 10

6654 G37

20 30 40

LT6654

6654fc

TYPICAL PERFORMANCE CHARACTERISTICS

5V Load Regulation (Sourcing)

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

5V Minimum VIN to VOUT

Differential (Sourcing)

5V Output Voltage Temperature

Drift

5V Turn-On Characteristics 5V Output Impedance

vs Frequency

TEMPERATURE (°C)

–60 0 80604020–40 –20 120100

4.993

4.994

4.995

4.996

4.998

4.997

5.002

REFERENCE VOLTAGE (V)

5.003

5.000

4.999

5.001

6654 G28

140

THREE TYPICAL PARTS

50µs/DIV

GND

VOUT

2V/DIV

VIN

2V/DIV

6654 G29

CLOAD = 1µF

OUTPUT CURRENT (mA)

0.1 1

–20

OUTPUT VOLTAGE CHANGE (ppm)

6654 G31

–10

125°C

–40°C

25°C

–55°C

OUTPUT CURRENT (mA)

0.1 1

OUTPUT VOLTAGE CHANGE (ppm)

220

120

100

140

200

180

160

6654 G32

–55°C

25°C

–40°C

125°C

OUTPUT NOISE (4µV/DIV)

TIME (1s/DIV)

6654 G33

109876543210

INPUT-OUTPUT VOLTAGE (mV)

0 50 100 150 200 250 300 350

0.1

OUTPUT CURRENT (mA)

6654 G34

400

125°C

–40°C

–55°C 25°C

FREQUENCY (kHz)

0.1 1 10 100

0.01

0.1

OUTPUT IMPEDANCE (Ω)

100

6654 G30

1000

CL = 10µF

CL = 1µF

The characteristic curves are similar across the

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 Load Transient Response

(Sinking)

50µs/DIV

0mA

VOUT

20mV/DIV/AC

2.5V/DC

6654 G27

CLOAD = 1µF

IOUT

5mA

2.5V Long Term Drift (LS8)

TIME (HOURS)

PPM

150

–90

–60

–30

120

–150

–120

1000500

6654 G38

20001500

LT6654

6654fc

5V Minimum VIN to VOUT

Differential (Sinking)

5V Output Voltage Noise

Spectrum

INPUT-OUTPUT VOLTAGE (mV)

–300 –250 –200 –150 –100 –50 0 50

0.1

OUTPUT CURRENT (mA)

6654 G35

100

25°C

–55°C

–40°C

125°C

FREQUENCY (kHz)

0.01 0.1 1 10

100

150

250

300

350

NOISE VOLTAGE (nV√Hz)

200

450

500

550

400

600

6654 G36

100

IO = 5mA

IO = 0µA

The characteristic curves are similar across the

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.

PIN FUNCTIONS

DNC (Pins 1, 7): Do Not Connect. Keep leakage current

from this pin to VIN or GND to a minimum.

GND (Pin 2): Tie To Pin 3 For Proper Load Regulation.

GND (Pin 3): Primary Device Ground. This pin is the main

ground and should be connected in a star conﬁ guration

for best results. In a star conﬁ guration, this pin should

be connected to the ground plane and each additional

grou nd co nn ec tion sho uld be made wi th a si ngl e t race tha t

emanates from this ground connection. These additional

ground connections include Pin 2, Pin 4 of the LTC6654,

and the ground for the load and bypass capacitors.

GND (Pin 4): Internal Function. This pin must be tied to

GND, near pin 3.

VOUT (Pin 5): VOUT Pin. An output capacitor of 1µF or

greater is required for stable operation.

VOUT (Pin 6): VOUT Pin. Tie to pin 5 for proper load regu-

lation.

VIN (Pin 8): Power Supply. Bypass VIN with a 0.1µF, or

larger, capacitor to GND.

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 VIN or GND to a minimum.

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

capacitor to ground.

DNC (Pin 5): Do Not Connect. Keep leakage current from

this pin to VIN or GND to a minimum.

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

minimum is required for stable operation.

(LS8) (TSOT)

TYPICAL PERFORMANCE CHARACTERISTICS

LT6654

6654fc

BLOCK DIAGRAMS

–

+VOUT 6

6654 BD

BANDGAP

VIN

DNC

GND GND

–

+VOUT

VOUT

6654 BDa

BANDGAP

VIN

DNC

GND

SOT23

LS8

LT6654

6654fc

Bypass and Load Capacitors

The LT6654 voltage references should have an input by-

pass capacitor of 0.1µF or larger, however the bypassing

on other components nearby is sufﬁ cient. In high voltage

applications, VIN > 30V, an output short-circuit to ground

can create an input voltage transient that could exceed the

maximum input voltage rating. To prevent this worst-case

condition, an RC input line ﬁ lter of 10µs (i.e. 10Ω and 1µF)

is recommended. 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 ﬁ nal value.

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 VIN with the

same capacitors.

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

with various load currents. With RL = 1k, the 1V step pro-

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.

APPLICATIONS INFORMATION

Figure 1. Turn-On Characteristics of LT6654-2.5

LT6654-2.5

CIN

0.1µF

VIN

1, 2

1µF VGEN

6654 F03

Figure 2. Output Response to 0.5V Ripple on VIN

Figure 3. Load Current Response Time Test Circuit

20µs/DIV

GND

VIN

1V/DIV

VOUT

1V/DIV

6654 F01

CLOAD = 1µF

50µs/DIV

VIN

0.5V/DIV

3V/DC

VOUT

2mV/DIV/AC

2.5V/DC

6654 F02

CLOAD = 1µF

LT6654

6654fc

Figure 4. LT6654-2.5 Sourcing and Sinking 0.5mA

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

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

50µs/DIV

IOUT

–0.5mA

VOUT

20mV/DIV/AC

2.5V/DC

6654 F04

CLOAD = 1µF

0.5mA

APPLICATIONS INFORMATION

50µs/DIV

IOUT

4mA

VOUT

10mV/DIV/AC

2.5V/DC

6654 F05

CLOAD = 1µF

5mA

50µs/DIV

IOUT

–5mA

VOUT

0mV/DIV/AC

2.5V/DC

6654 F06

CLOAD = 1µF

–4mA

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 volt-

age is required at VIN (Pin 4) to bias the LT6654 internal

circuitry. This voltage must be current limited with R1 to

keep the output PNP transistor from turning on and driv-

ing the grounded output. C1 provides stability during load

transients. This connection maintains the same accuracy and

temperature coefﬁ cient of the positive connected LT6654.

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

LT6654-2.5

1, 2

VEE

VOUT = –2.5V

0.1µF

4.7k

6654 F07

1µF

VEE – VOUT

550µA + IOUT

R ≤

LT6654

6654fc

APPLICATIONS INFORMATION

similar to a real world application. The boards were then

placed into a constant temperature oven with TA = 35°C,

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.

Long-Term Drift

Long-term drift cannot be extrapolated from 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

Figure 8. LT6654-2.5 Long Term Drift

TIME (HOURS)

0 200 400 800600

–80

–40

OUTPUT VOLTAGE CHANGE (ppm)

6654 F08a

1000

LT6654-2.5 S6 PACKAGE

FIRST THOUSAND HOURS

TIME (HOURS)

1000 1200 1400 18001600

–80

–40

OUTPUT VOLTAGE CHANGE (ppm)

6654 F08b

2000

LT6654-2.5 S6 PACKAGE

SECOND THOUSAND HOURS

(NORMALIZED TO THE FIRST THOUSAND HOURS)

TIME (HOURS)

PPM

–40

–80 1000500

6654 G38

20001500

LT6654-2.5 LS8 PACKAGE

LT6654

6654fc

Figure 11a. LT6654 S6 Thermal Hysteresis –40°C to 125°C

Figure 11b. LT6654 LS8 Thermal Hysteresis –40°C to 125°C

DISTRIBUTION (ppm)

–150

NUMBER OF UNITS

–100

–50

6654 F11

010015050

MAX AVG HOT CYCLE

25°C TO 125°C TO 25°C

MAX AVG COLD CYCLE

25°C TO –40°C TO 25°C

APPLICATIONS INFORMATION

Figure 9. Maximum Allowed Power Dissipation of the LT6654

Figure 10. Typical Power Dissipation of the LT6654

TEMPERATURE (°C)

POWER (W)

0.1

0.2

0.6

0.5

0.4

0.3

0.7

20 40 60 80

6654 F09

100 120 140

T = 150°C

eJA = 192°C/W

130mW

VIN (V)

POWER (W)

0.05

0.25

0.20

0.15

0.10

0.40

0.35

0.30

51015

6654 F10

20 25 30 35 40

10mA LOAD

NO LOAD

335mW

Power Dissipation

The power dissipation in the LT6654 is dependent on VIN,

load current and the package. The LT6654 package has

a thermal resistance, or θJA, of 192°C/W. A curve that

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 VIN = 36V and sourcing 10mA, the

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, junc-

tion 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.

6654 F11b

DISTRIBUTION (ppm)

NUMBER OF UNITS

625°C TO –40°C TO 25°C

AND 25°C TO 125°C TO 25°C

–40 –30

–20 –10 0 10

20 30 40

LT6654

6654fc

APPLICATIONS INFORMATION

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 PD = 33.5V

• 10mA = 335mW, which causes an increase in the die

temperature of 64°C. This could increase the junction

temperature above 125°C (TJMAX is 150°C) and may cause

the output to shift due to thermal hysteresis.

PC Board Layout

The mechanical stress of soldering a surface mount volt-

age 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 VOUT traces should be as short as possible

to minimize I • R drops, since high trace resistance directly

impacts load regulation.

IR Reﬂ ow Shift

The different expansion and contraction rates of the ma-

terials 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.

Figure 12. Lead Free Reﬂ ow Proﬁ le

MINUTES

TEMPERATURE (°C)

RAMP

DOWN

30s

40s

130s

120s

150

225

300

2468

6654 F12

RAMP TO

150°C

380s TP = 260°C

TL = 217°C

TS(MAX) = 200°C

TS = 190°C

T = 150°C

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

CHANGE IN OUTPUT (ppm)

–140

NUMBER OF UNITS

–120 –100 –80

–60

6654 F13

–40 0–20

260°C 3 CYCLES

260°C 1 CYCLE

LT6654S6

Humidity Sensitivity

Plastic mould compounds absorb water. With changes in

relative humidity, plastic packaging materials change the

amount of pressure they apply to the die inside, which can

cause slight changes in the output of a voltage reference,

usually on the order of 100ppm. The LS8 package is her-

metic, so it is not affected by humidity, and is therefore

more stable in environments where humidity may be a

concern.

LT6654

6654fc

LT6654-2.5

2N2905

220

OUT

4.7µF

6654 TA03

1µF

IOUT

UP TO 300mA

4.5V < VIN < 36V

Boosted Output Current ReferenceExtended Supply Range Reference

Boosted Output Current with Current Limit

LED1*

*LED CANNOT BE OMMITTED

THE LED CLAMPS THE VOLTAGE

DROP ACROSS THE 220 AND

LIMITS OUTPUT CURRENT

6654 TA04

220 4.7µF

1µF

IOUT

UP TO 100mA

10

2N2905

4.5V < VIN < 36V

LT6654-2.5

IN OUT

Octal DAC Reference

TYPICAL APPLICATIONS

LT6654-2.5

BZX84C12

330k

UP TO 160V

MMBT5551

6654 TA02

1µF

0.1µF

2.65V < VIN < 5V

6654 TA05

0.1µF 10µF

VREF VCC

DAC E

DAC A

DAC B

DAC C

DAC D

DAC F

DAC G

GND DAC H

LTC2600

SCK

SDI

CLEAR

VIN

0.1µF

LT6654-2.5

IN OUT

LT6654

6654fc

PACKAGE DESCRIPTION

1.50 – 1.75

(NOTE 4)

2.80 BSC

0.30 – 0.45

6 PLCS (NOTE 3)

DATUM ‘A’

0.09 – 0.20

(NOTE 3) S6 TSOT-23 0302

2.90 BSC

(NOTE 4)

0.95 BSC

1.90 BSC

0.80 – 0.90

1.00 MAX 0.01 – 0.10

0.20 BSC

0.30 – 0.50 REF

PIN ONE ID

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

3.85 MAX

0.62

MAX

0.95

REF

RECOMMENDED SOLDER PAD LAYOUT

PER IPC CALCULATOR

1.4 MIN

2.62 REF

1.22 REF

S6 Package

6-Lead Plastic TSOT-23

(Reference LTC DWG # 05-08-1636)

Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.

LT6654

6654fc

PACKAGE DESCRIPTION

2.00 REF

R0.20 REF

4.20 ±0.10

4.20 SQ ±0.10

2.54 ±0.15

1.00 TYP

0.64 TYP

LS8 0609 REV Ø

R0.20 REF

0.95 ±0.10

1.45 ±0.10

0.10 TYP0.70 TYP

1.50 ±0.15

2.50 ±0.15

2.54 ±0.15

0.70 ±0.05

PACKAGE OUTLINE

5.00 SQ ±0.15

5.80 SQ ±0.15

APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED

NOTE:

1. ALL DIMENSIONS ARE IN MILLIMETERS

2. DRAWING NOT TO SCALE

3. DIMENSIONS PACKAGE DO NOT INCLUDE PLATING BURRS

PLATING BURRS, IF PRESENT, SHALL NOT EXCEED 0.30mm ON ANY SIDE

4. PLATING—ELECTO NICKEL MIN 1.25UM, ELECTRO GOLD MIN 0.30UM

5. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE

TOP AND BOTTOM OF PACKAGE

PIN 1

TOP MARK

(SEE NOTE 5)

LS8 Package

8-Pin Leadless Chip Carrier (5mm w 5mm)

(Reference LTC DWG # 05-08-1852 Rev Ø)

Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.

LT6654

6654fc

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.

However, no responsibilit y is assumed for its use. Linear Technology Corporation makes no representa-

t 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 .

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

B 3/11 Revised conditions for Output Voltage Noise in the Electrical Characteristics section. 4

C 8/12 Addition of LS8 Features and Order Information

Update to Electrical Characteristics to Include LS8 Package

Addition of Long Term Drift and Hysteresis Plots for LS8 Package

Addition of Humidity Sensitivity Information

Addition of LS8 Package Description

Addition of Related Parts

1,2,4

9, 15, 16

LT6654

6654fc

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

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

LT 0812 REV C • PRINTED IN USA

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SDO

SDI

GND SCK

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IN–

–

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VREF

4.6V < VS < 36V

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LTC2480 TO MCU–2.048V < VDIFFERENTIAL < 2.048V

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0.1µF 10µF