LTC6652AHMS8-3.3#PBF

LTC6652

Precision Low Drift Low

Noise Buffered Reference

Features

Description

The LTC^®6652 family of precision, low drift, low noise

references is fully specified over the temperature range

of –40°C to 125°C. High order curvature compensation

allows these references to achieve a low drift of less than

5ppm/°Cwithapredictabletemperaturecharacteristicand

an output voltage accuracy of 0.05ꢀ. The performance

overtemperatureshouldappealtoautomotive,highperfor-

manceindustrialandotherhightemperatureapplications.

n

Low Drift:

A-Grade 5ppm/°C Max

B-Grade 10ppm/°C Max (MSOP8)

B-Grade 8ppm/°C Max (LS8)

High Accuracy:

n

A-Grade 0ꢀ05ꢁ Max

B-Grade 0ꢀ1ꢁ Max

n

Low Noise: 2ꢀ1ppm (0ꢀ1Hz to 10Hz)

P-P

100ꢁ Tested at –40°C, 25°C and 125°C

Sinks and Sources Current: 5mA

Low Power Shutdown: <2µA Maximum

Thermal Hysteresis (LS8): 45ppm (–40°C to 125°C)

Long-Term Drift (LS8): 20ppm/√kHr

Low Dropout: 300mV

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

3V, 3.3V, 4.096V, 5V

8-Lead MSOP and 5mm × 5mm Surface Mount

Hermetic Packages

The LTC6652 voltage references can be powered from

supply voltages up to 13.2V. They boast low noise, ex-

cellent load regulation, source and sink capability and

exceptional line rejection, making them a superior choice

for demanding precision applications. A shutdown mode

allows power consumption to be reduced when the refer-

ence is not needed. The optional output capacitor can be

left off when space constraints are critical.

n

The LTC6652 references are offered in an 8-lead MSOP

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

× 5mm surface mount hermetic package that provides

outstanding stability.

applications

n

Automotive Control and Monitoring

L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear

Technology Corporation. All other trademarks are the property of their respective owners.

n

High Temperature Industrial

n

High Resolution Data Acquisition Systems

Instrumentation and Process Control

Precision Regulators

Medical Equipment

n

typical application

Output Voltage Temperature Drift

0.050

Basic Connection

0.025

0

V

OUT

V

OUT

LTC6652-2.5

GND

2.8V ≤ V ≤ 13.2V

IN

2.5V

C

OUT

C

IN

SHDN

1µF

0.1µF

(OPTIONAL)

6652 TA01a

–0.025

–0.050

–40 –20

0

20 40 60 80 100 125

TEMPERATURE (°C)

6652 TA01b

6652fg

1

For more information www.linear.com/LTC6652

LTC6652

absolute MaxiMuM ratings

(Note 1)

Input Voltage

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

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

Lead Temperature Range (Soldering, 10 sec)

V to GND.......................................... –0.3V to 13.2V

IN

SHDN to GND ........................... –0.3V to (V + 0.3V)

IN

Output Voltage

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

V

.......................................... –0.3V to (V + 0.3V)

IN

OUT

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

pin conFiguration

TOP VIEW

GND*

TOP VIEW

8

DNC

1

2

3

7

6

5

GND*

DNC

1

2

3

4

8 GND*

7 GND*

V

IN

V

IN

V

OUT

SHDN

6 V

OUT

GND

5 GND*

SHDN

GND*

4

MS8 PACKAGE

8-LEAD PLASTIC MSOP

GND

LS8 PACKAGE

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

T

= 150°C, θ = 200°C/W

JA

DNC: DO NOT CONNECT

JMAX

*CONNECT THE PINS TO DEVICE GND (PIN 4)

T

= 150°C, θ = 120°C/W

JA

JMAX

DNC: DO NOT CONNECT

*CONNECT THE PINS TO DEVICE GND (PIN 4)

orDer inForMation

LEAD FREE FINISH

TAPE AND REEL

PART MARKING* PACKAGE DESCRIPTION

SPECIFIED TEMPERATURE RANGE

LTC6652AHMS8-1.25#PBF

LTC6652BHMS8-1.25#PBF

LTC6652AHMS8-2.048#PBF

LTC6652BHMS8-2.048#PBF

LTC6652AHMS8-2.5#PBF

LTC6652BHMS8-2.5#PBF

LTC6652AHMS8-3#PBF

LTC6652BHMS8-3#PBF

LTC6652AHMS8-3.3#PBF

LTC6652BHMS8-3.3#PBF

LTC6652AHMS8-4.096#PBF

LTC6652BHMS8-4.096#PBF

LTC6652AHMS8-5#PBF

LTC6652BHMS8-5#PBF

LTC6652AHMS8-1.25#TRPBF

LTC6652BHMS8-1.25#TRPBF

LTCVH

8-Lead Plastic MSOP

–40°C to 125°C

LTC6652AHMS8-2.048#TRPBF LTCVJ

LTC6652BHMS8-2.048#TRPBF LTCVJ

LTC6652AHMS8-2.5#TRPBF

LTC6652BHMS8-2.5#TRPBF

LTC6652AHMS8-3#TRPBF

LTC6652BHMS8-3#TRPBF

LTC6652AHMS8-3.3#TRPBF

LTC6652BHMS8-3.3#TRPBF

LTCQV

LTCVK

LTCVM

LTC6652AHMS8-4.096#TRPBF LTCVN

LTC6652BHMS8-4.096#TRPBF LTCVN

LTC6652AHMS8-5#TRPBF

LTC6652BHMS8-5#TRPBF

LTCVP

6652fg

2

For more information www.linear.com/LTC6652

LTC6652

orDer inForMation

LEAD FREE FINISH

PART MARKING*

PACKAGE DESCRIPTION

SPECIFIED TEMPERATURE RANGE

–40°C to 125°C

†

LTC6652AHLS8-2.5#PBF

LTC6652BHLS8-2.5#PBF

665225

8-Lead Ceramic LCC 5mm × 5mm

665225

–40°C to 125°C

†

LTC6652AHLS8-4.096#PBF

LTC6652BHLS8-4.096#PBF

524096

–40°C to 125°C

524096

–40°C to 125°C

†

LTC6652AHLS8-5#PBF

66525

–40°C to 125°C

†

LTC6652BHLS8-5#PBF

66525

–40°C to 125°C

Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.

For more information on lead free part marking, go to: http://www.linear.com/leadfree/

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

†

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

available options

OUTPUT VOLTAGE

INITIAL ACCURACY

TEMPERATURE COEFFICIENT

PART NUMBER**

1.250

0.05ꢀ

0.1ꢀ

5ppm/°C

10ppm/°C

LTC6652AHMS8-1.25

LTC6652BHMS8-1.25

2.048

2.500

0.05ꢀ

0.1ꢀ

5ppm/°C

LTC6652AHMS8-2.048

LTC6652BHMS8-2.048

10ppm/°C

0.05ꢀ

0.1ꢀ

0.05ꢀ

0.1ꢀ

5ppm/°C

10ppm/°C

5ppm/°C

8ppm/°C

LTC6652AHMS8-2.5

LTC6652BHMS8-2.5

LTC6652AHLS8-2.5

LTC6652BHLS8-2.5

3.000

3.300

4.096

0.05ꢀ

0.1ꢀ

5ppm/°C

LTC6652AHMS8-3

LTC6652BHMS8-3

10ppm/°C

0.05ꢀ

0.1ꢀ

5ppm/°C

10ppm/°C

LTC6652AHMS8-3.3

LTC6652BHMS8-3.3

0.05ꢀ

0.1ꢀ

0.05ꢀ

0.1ꢀ

5ppm/°C

10ppm/°C

5ppm/°C

8ppm/°C

LTC6652AHMS8-4.096

LTC6652BHMS8-4.096

LTC6652AHLS8-4.096

LTC6652BHLS8-4.096

5.000

0.05ꢀ

0.1ꢀ

0.05ꢀ

0.1ꢀ

5ppm/°C

10ppm/°C

5ppm/°C

8ppm/°C

LTC6652AHMS8-5

LTC6652BHMS8-5

LTC6652AHLS8-5

LTC6652BHLS8-5

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

electrical characteristics ^Thel denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at T_A= 25°C, V_IN= V_OUT+ 0ꢀ5V, unless otherwise notedꢀ

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Output Voltage

LTC6652A

LTC6652B

–0.05

–0.1

0.05

0.1

ꢀ

l

Output Voltage Temperature Coefficient

(Note 3)

LTC6652A

LTC6652BMS8

LTC6652BLS8

2

4

5

10

8

ppm/°C

Line Regulation

V

+ 0.5V ≤ V ≤ 13.2V, SHDN = V

IN

2

50

80

ppm/V

OUT

IN

l

6652fg

3

For more information www.linear.com/LTC6652

LTC6652

electrical characteristics ^Thel denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at T_A= 25°C, V_IN= V_OUT+ 0ꢀ5V, unless otherwise notedꢀ

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Load Regulation (Note 4)

I

= 5mA, LTC6652-1.25, LTC6652-2.048,

20

75

200

ppm/mA

SOURCE

l

LTC6652-2.5, LTC6652-3, LTC6652-3.3,

LTC6652-4.096, LTC6652-5

I

= 1mA, LTC6652-1.25, LTC6652-2.048

80

50

250

600

ppm/mA

SINK

l

I

= 5mA, LTC6652-2.5, LTC6652-3,

150

450

ppm/mA

SINK

LTC6652-3.3, LTC6652-4.096, LTC6652-5

I = 5mA, V Error ≤ 0.1ꢀ

SOURCE

Minimum Operating Voltage (Note 5)

OUT

l

LTC6652-1.25, LTC6652-2.048

LTC6652-2.5, LTC6652-3, LTC6652-3.3,

LTC6652-4.096, LTC6652-5

2.7

OUT

V

+ 0.3V

Output Short-Circuit Current

Short V

to GND

16

mA

OUT

to V

IN

l

Shutdown Pin (SHDN)

Logic High Input Voltage

Logic High Input Current

2

V

µA

0.1

1

l

Logic Low Input Voltage

Logic Low Input Current

0.8

1

V

µA

0.1

Supply Current

No Load

350

µA

l

560

2

Shutdown Current

SHDN Tied to GND

0.1

µA

Output Voltage Noise (Note 6)

0.1Hz ≤ f ≤ 10Hz

LTC6652-1.25

2.4

2.1

2.2

2.3

2.8

3

ppm

P-P

LTC6652-2.048, LTC6652-2.5, LTC6652-3

LTC6652-3.3

LTC6652-4.096

LTC6652-5

10Hz ≤ f ≤ 1kHz

ppm

RMS

Turn-On Time

0.1ꢀ Settling, C

= 0

100

µs

LOAD

Long-Term Drift of Output Voltage (Note 7) LTC6652MS8

LTC6652LS8

60

20

ppm/√kHr

Hysteresis (Note 8)

∆T = –40°C to 125°C, LTC6652MS8

∆T = –40°C to 85°C, LTC6652MS8

∆T = 0°C to 70°C, LTC6652MS8

∆T = –40°C to 125°C, LTC6652LS8

∆T = –40°C to 85°C, LTC6652LS8

∆T = 0°C to 70°C, LTC6652LS8

80

75

45

25

10

ppm

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 specified temperature range,

the output may shift due to hysteresis.

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 first 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 is roughly proportional to the square of the temperature change.

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.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 3: Temperature coefficient is measured by dividing the maximum

change in output voltage by the specified temperature range.

Note 4: 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 5: Excludes load regulation errors.

Note 6: Peak-to-peak noise is measured with a 3-pole highpass at 0.1Hz

and 4-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. 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 9: The stated temperature is typical for soldering of the leads during

manual rework. For detailed IR reflow recommendations, refer to the

Applications section.

6652fg

4

For more information www.linear.com/LTC6652

LTC6652

typical perForMance characteristics

Characteristic curves are similar for most

LTC6652sꢀ Curves from the LTC6652-1ꢀ25, LTC6652-2ꢀ5 and the LTC6652-5 represent the extremes and typical of the voltage optionsꢀ

Characteristic curves for other output voltages fall between these curves and can be estimated based on their outputꢀ

1ꢀ25V Output Voltage

Temperature Drift

1ꢀ25V Line Regulation

1ꢀ25V Load Regulation (Sourcing)

1.2506

1.2504

1.2502

1.2500

0

–50

1.2510

1.2505

1.2500

1.2495

1.2490

3 TYPICAL PARTS

–40°C

125°C

25°C

–100

–150

–200

–250

125°C

25°C

1.2498

1.2496

1.2494

–40°C

10

8

12

14

0

2

4

6

80

TEMPERATURE (°C)

1

10

–80

–40

0

40

120

160

0.1

INPUT VOLTAGE (V)

OUTPUT CURRENT (mA)

6652 G18

6652 G17

6652 G19

1ꢀ25V Low Frequency 0ꢀ1Hz to

10Hz Transient Noise

1ꢀ25V Output Voltage Noise

Spectrum

1ꢀ25V Load Regulation (Sinking)

400

350

300

250

200

150

100

50

400

300

200

100

0

125°C

25°C

–40°C

0

0.1

1

10

TIME (1 SECOND/DIV)

0.01

0.1

1

10

OUTPUT CURRENT (mA)

FREQUENCY (kHz)

6652 G22

6652 G20

6652 G21

1ꢀ25V Stability with Output

Capacitance

1ꢀ25 Sinking Current Without

Output Capacitor

1ꢀ25 Sinking Current with Output

Capacitor

10µF

1µF

1mA

0mA

1mA

0mA

I

OUT

0.1µF

10nF

V

REGION OF

MARGINAL

STABILITY

OUT

500mV/DIV

1nF

100pF

6652 G23

6652 G24

500µs/DIV

C

= 0µF

C

= 1µF

OUT

NO CAP

–5

–1

0

5

LOAD CURRENT (mA)

6652 G16

6652fg

5

For more information www.linear.com/LTC6652

LTC6652

typical perForMance characteristics

Characteristic curves are similar for most

LTC6652sꢀ Curves from the LTC6652-1ꢀ25, LTC6652-2ꢀ5 and the LTC6652-5 represent the extremes and typical of the voltage optionsꢀ

Characteristic curves for other output voltages fall between these curves and can be estimated based on their outputꢀ

2ꢀ5V Output Voltage

Temperature Drift

2ꢀ5V Line Regulation

2ꢀ5V Load Regulation (Sourcing)

0

–20

2.5010

2.5005

2.5000

2.4995

2.5010

2.5005

2.5000

2.4995

2.4990

2.4985

3 TYPICAL PARTS

–40°C

–40

–60

125°C

25°C

–80

125°C

–100

–120

–140

–160

–180

–200

–40°C

2.4990

2.4985

2.4980

0.1

1

10

8

12

14

50

0

2

4

6

10

–50 –25

0

25

75 100 125 150

OUTPUT CURRENT (mA)

INPUT VOLTAGE (V)

TEMPERATURE (°C)

6652 G03

6652 G02

6652 G01

2ꢀ5V Supply Current

vs Input Voltage

2ꢀ5V Shutdown Current

vs Input Voltage

2ꢀ5V Load Regulation (Sinking)

1000

900

800

700

600

500

400

300

200

100

0

700

600

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

500

400

125°C

25°C

125°C

25°C

200

100

0

–40°C

25°C

–40°C

0

4

6

8

10

12

14

0.1

1

10

2

0

4

6

8

10

12

14

2

INPUT VOLTAGE (V)

OUTPUT CURRENT (mA)

INPUT VOLTAGE (V)

6652 G05

6652 G04

6652 G06

2ꢀ5V Minimum V_IN-V_OUT

Differential (Sourcing)

2ꢀ5V Minimum V_OUT-V_IN

Differential (Sinking)

10

1

25°C

0.1

0.01

25°C

125°C, –40°C

125°C

–40°C

0.1

0.001

0.01

0.1

1

0.001

0.01

0.1

1

OUTPUT-INPUT VOLTAGE (V)

INPUT-OUTPUT VOLTAGE (V)

6652 G10

6652 G09

6652fg

6

For more information www.linear.com/LTC6652

LTC6652

typical perForMance characteristics

Characteristic curves are similar for most

LTC6652sꢀ Curves from the LTC6652-1ꢀ25, LTC6652-2ꢀ5 and the LTC6652-5 represent the extremes and typical of the voltage optionsꢀ

Characteristic curves for other output voltages fall between these curves and can be estimated based on their outputꢀ

2ꢀ5V Low Frequency 0ꢀ1Hz to

10Hz Transient Noise

2ꢀ5V Output Voltage Noise

Spectrum

600

500

400

300

200

100

0

TIME (1 SECOND/DIV)

0.01

0.1

1

10

FREQUENCY (kHz)

6652 G12

6652 G11

Stability with Output Capacitance

(LTC6652-2ꢀ5, LTC6652-3,

LTC6652-3ꢀ3, LTC6652-4ꢀ096,

LTC6652-5)

Typical V_OUTDistribution for

LTC6652-2ꢀ5

180

160

140

120

80

10µF

1µF

1004 UNITS

LTC6652A LIMITS

0.1µF

10nF

REGION OF

MARGINAL STABILITY

60

1nF

100pF

40

20

0

NO CAP

2.4985

2.4995

2.5005

2.5015

–5

0

5

OUTPUT VOLTAGE (V)

LOAD CURRENT (mA)

6652 G15

6652 G14

6652fg

7

For more information www.linear.com/LTC6652

LTC6652

typical perForMance characteristics

Characteristic curves are similar for most

LTC6652sꢀ Curves from the LTC6652-1ꢀ25, LTC6652-2ꢀ5 and the LTC6652-5 represent the extremes and typical of the voltage optionsꢀ

Characteristic curves for other output voltages fall between these curves and can be estimated based on their outputꢀ

5V Output Voltage

Temperature Drift

5V Supply Current

vs Input Voltage

5V Line Regulation

5.005

5.003

5.000

4.998

4.995

1000

900

800

700

600

500

400

300

200

100

0

5.002

5.001

5.000

4.999

4.998

3 TYPICAL PARTS

25°C

125°C

–40°C

125°C

25°C

–40°C

50

–50 –25

0

25

75 100 125 150

0

4

6

8

10

12

14

8

12

14

2

0

2

4

6

10

TEMPERATURE (°C)

INPUT VOLTAGE (V)

6652 G25

6652 G27

6652 G26

5V Shutdown Current

vs Input Voltage

5V Minimum V_INto V_OUT

Differential (Sourcing)

5V Low Frequency 0ꢀ1Hz to 10Hz

Transient Noise

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

10

1

125°C

25°C

0.1

0.01

–40°C

125°C

25°C

10

12

INPUT VOLTAGE (V)

0

4

6

8

14

0.001

0.01

0.1

1

TIME (1 SECOND/DIV)

2

INPUT-OUTPUT VOLTAGE (V)

6652 G31

6652 G29

6652 G30

5V Start-Up Response Without

Output Capacitor

5V Start-Up Response with Output

Capacitor

5V Output Voltage Noise Spectrum

1000

800

600

400

200

0

V

IN

2V/DIV

V

OUT

2V/DIV

OUT

2V/DIV

6652 G33

6652 G34

100µs/DIV

C

= 0µF

C

OUT

= 1µF

OUT

0.01

0.1

1

10

FREQUENCY (kHz)

6652 G32

6652fg

8

For more information www.linear.com/LTC6652

LTC6652

typical perForMance characteristics

Characteristic curves are similar for most

LTC6652sꢀ Curves from the LTC6652-1ꢀ25, LTC6652-2ꢀ5 and the LTC6652-5 represent the extremes and typical of the voltage optionsꢀ

Characteristic curves for other output voltages fall between these curves and can be estimated based on their outputꢀ

Power Supply Rejection Ratio

vs Frequency

SHDN Input Voltage Thresholds

Output Impedance vs Frequency

vs V_IN

100

0

–10

–20

–30

2.5

2.0

1.5

1.0

0.5

0

C

= 0µF

OUT

C

= 0µF

OUT

V

TH(UP)

10

1

C

= 1µF

OUT

–40

–50

V

TH(DN)

C

= 1µF

OUT

C

= 10µF

–60

–70

OUT

C

= 10µF

OUT

–80

–90

0.1

–100

8

12

14

0.01

0.1

1

10

100

1000

0.01

0.1

1

10

100

2

4

6

10

FREQUENCY (kHz)

V

(V)

IN

6652 G13

6652 G08

6652 G07

pin Functions

DNC (Pin 1): Do Not Connect.

GND (Pin 4): Device Ground.

(Pin 6): Output Voltage. An output capacitor is not

required.Forsomeapplications,acapacitorbetween0.1µF

to 10µF can be beneficial. See the graphs in the Typical

Performance Characteristics section for further details.

V (Pin 2): Power Supply. The minimum supply input is

V

IN

OUT

V

+300mVor2.7V;whicheverishigher.Themaximum

supply is 13.2V. Bypassing V with a 0.1µF capacitor to

GND will improve PSRR.

IN

SHDN (Pin 3): Shutdown Input. This active low input

GND (Pins 5,7,8): Internal Function. Ground these pins.

powers down the device to <2µA. For normal operation

tie this pin to V .

IN

6652fg

9

For more information www.linear.com/LTC6652

LTC6652

block DiagraM

V

IN

2

+

–

V

OUT

SHDN

BANDGAP

3

6

GND

4

6652 BD

applications inForMation

Bypass and Load Capacitors

The transient response for a 0.5V step on V with and

IN

without an output capacitor is shown in Figures 2 and 3,

The LTC6652 voltage references do not require an input

capacitor, but a 0.1µF capacitor located close to the part

improves power supply rejection.

respectively.

The LTC6652 references with an output of 2.5V and above

are guaranteed to source and sink 5mA. The 1.25V and

2.048V versions are guaranteed to source 5mA and sink

1mA. The test circuit for transient load step response is

shown in Figure 1. Figures 4 and 5 show a 5mA source

and sink load step response without a load capacitor,

respectively.

TheLTC6652voltagereferencesarestablewithorwithout

acapacitiveload. Forapplicationswhereanoutputcapaci-

tor is beneficial, a value of 0.1µF to 10µF is recommended

depending on load conditions. The Typical Performance

Characteristics section includes a plot illustrating a region

of marginal stability. Either no or low value capacitors for

anyloadcurrentareacceptable. Forloadsthatsinkcurrent

orlightloadsthatsourcecurrent,a0.1µFto10µFcapacitor

has stable operation. For heavier loads that source current

a 0.5µF to 10µF capacitor range is recommended.

Start-Up

The start-up characteristic of the LTC6652 is shown in

Figures 8 and 9. Note that the turn-on time is affected by

the value of the output capacitor.

100Ω

2, 3

6

V

IN

LTC6652-2.5

3V

C

IN

C

OUT

1µF

0.5V

V

GEN

0.1µF

4, 5, 7, 8

6652 F01

Figure 1ꢀ Transient Load Test Circuit

6652fg

10

For more information www.linear.com/LTC6652

LTC6652

applications inForMation

3.5V

5mA

0mA

V

IN

I

OUT

3V

V

OUT

500mV/DIV

V

OUT

200mV/DIV

6652 F05

6652 F02

C

= 0µF

250µs/DIV

C

= 0µF

500µs/DIV

OUT

Figure 2ꢀ Transient Response Without

Output Capacitor

Figure 5ꢀ LTC6652-2ꢀ5 Sinking Current

Without Output Capacitor

0mA

3.5V

I

OUT

V

IN

–5mA

3V

V

OUT

500mV/DIV

V

OUT

200mV/DIV

6652 F03

6652 F06

C

= 1µF

500µs/DIV

C

= 1µF

250µs/DIV

OUT

Figure 3ꢀ Transient Response with 1µF

Output Capacitor

Figure 6ꢀ LTC6652-2ꢀ5 Sourcing Current

with Output Capacitor

5mA

0mA

I

OUT

0mA

–5mA

V

OUT

V

OUT

50mV/DIV

200mV/DIV

6652 F07

6652 F04

C

= 1µF

250µs/DIV

C

= 0µF

250µs/DIV

OUT

Figure 4ꢀ LTC6652-2ꢀ5 Sourcing

Current Without Output Capacitor

Figure 7ꢀ LTC6652-2ꢀ5 Sinking Current

with Output Capacitor

6652fg

11

For more information www.linear.com/LTC6652

LTC6652

applications inForMation

2.8V ≤ V ≤ 13.2V

IN

V

IN

C1

1µF

R1

20k

2V/DIV

V

IN

LTC6652-2.5

SHDN

V

OUT

V

OUT

GND

1V/DIV

TO µC

6652 F10

C2

1µF

2N7002

6652 F08

C

= 0µF

100µs/DIV

OUT

Figure 8ꢀ Start-Up Response without

Output Capacitor

Figure 10ꢀ Open-Drain Shutdown Circuit

V

IN

2V/DIV

SHDN

1V/DIV

V

OUT

V

OUT

1V/DIV

6652 F09

6652 F11

C

= 1µF

100µs/DIV

I

= 5mA

1ms/DIV

OUT

LOAD

Figure 9ꢀ Start-Up Response with 1µF

Output Capacitor

Figure 11ꢀ Shutdown Response with

5mA Load

In Figure 8, ripple momentarily appears just after the

leading edge of powering on. This brief one time event is

caused by calibration circuitry during initialization. When

anoutputcapacitorisused, therippleisvirtuallyundetect-

able as shown in Figure 9.

an output impedance of 20k • 2.5 = 50kΩ. For normal

operation, SHDN should be greater than or equal to 2.0V.

For use with a microcontroller, use a pull-up resistor to

V

and an open-drain output driver as shown in Figure

IN

10. The LTC6652’s response into and out of shutdown

mode is shown in Figure 11.

Shutdown Mode

ThetripthresholdsonSHDNhavesomedependenceonthe

Shutdown mode is enabled by tying SHDN low which

places the part in a low power state (i.e., <2µA). In shut-

down mode, the output pin takes the value 20k • (rated

output voltage). For example, an LTC6652-2.5 will have

voltageappliedtoV asshownintheTypicalPerformance

IN

Characteristics section. Be careful to avoid leaving SHDN

ata voltage between the thresholds asthis willlikely cause

anincreaseinsupplycurrentduetoshoot-throughcurrent.

6652fg

12

For more information www.linear.com/LTC6652

LTC6652

applications inForMation

80

60

LTC6652-2.5 MS8 PACKAGE

LTC6652-2.5 LS8 PACKAGE

4 TYPICAL PARTS

A

3 TYPICAL PARTS

T

= 35°C

T

= 30°C

60

40

A

40

20

0

–20

–40

–20

–40

0

300

600

900

1200

1500

0

200

400

600

800

1000

HOURS

6652 F12a

6652 F12b

Figure 12aꢀ MS8 Long-Term Drift

Figure 12bꢀ LS8 Long-Term Drift

35

30

25

20

15

10

5

9

8

7

6

5

4

3

2

1

0

25°C TO 125°C TO 25°C 25°C TO –40°C TO 25°C

25°C TO 125°C TO 25°C 25°C TO –40°C TO 2

5°C

0

–250

–150

–50

50

150

–110 –80 –50 –20

0 20 50 80 110

DISTRIBUTION (ppm)

6652 F13a

6652 F13b

Figure 13aꢀ MS8 Hysteresis Plot

–40°C to 125°C

Figure 13bꢀ LS8 Hysteresis Plot

–40°C to 125°C

Long-Term Drift

Hysteresis

Long-termdriftcannotbeextrapolatedfromaccelerated

hightemperaturetestingꢀThiserroneoustechniquegives

drift numbers that are wildly optimisticꢀ The only way

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

thetimeintervalofinterestꢀTheLTC6652long-termdrift

data was collected on more than 100 parts that were sol-

dered into PC boards similar to a “real world” application.

The boards were then placed into a constant temperature

The hysteresis data shown in Figure 13 represents the

worst-case data collected on parts from –40°C to 125°C.

The output is capable of dissipating relatively high power,

i.e., for the LTC6652-2.5, P = 10.7V • 5.5mA = 58.85mW.

D

The thermal resistance of the MS8 package is 200°C/W

and this dissipation causes a 11.8°C internal rise. This

could increase the junction temperature above 125°C and

may cause the output to shift due to thermal hysteresis.

oven with T = 35°C, their outputs were scanned regularly

A

and measured with an 8.5 digit DVM. Long-term drift is

shown below in Figure 12.

6652fg

13

For more information www.linear.com/LTC6652

LTC6652

applications inForMation

PC Board Layout

expectedusingaconvectionreflowoven.Inourexperiment,

the serialized parts were run through the reflow process

twice. The results indicate that the standard deviation of

the output voltage increases with a slight positive mean

shift of 0.003ꢀ as shown in Figure 15. While there can

be up to 0.016ꢀ of output voltage shift, the overall drift

of the LTC6652 after IR reflow does not vary significantly.

The mechanical stress of soldering a surface mount volt-

age reference to a PC board can cause the output voltage

to shift and temperature coefficient to change. These two

changes are not correlated. For example, the voltage may

shift, but the temperature coefficient 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.

Power Dissipation

Power dissipation in the LTC6652 is dependent on V ,

IN

load current, and package. The LTC6652 package has

The capacitors should be mounted close to the package.

a thermal resistance, or θ , of 200°C/W. A curve that

JA

The GND and V

traces should be as short as possible

illustrates allowed power dissipation vs temperature for

OUT

to minimize I • R drops. Excessive trace resistance directly

this package is shown in Figure 16.

impacts load regulation.

The power dissipation of the LTC6652-2.5V as a function

of input voltage is shown in Figure 17. The top curve

showspowerdissipationwitha5mAloadandthebottom

curve shows power dissipation with no load.

IR Reflow Shift

Thedifferentexpansionandcontractionratesofthemateri-

als that make up the lead-free LTC6652 package cause the

outputvoltagetoshiftafterundergoingIRreflow.Lead-free

reflow profiles reach over 250°C, considerably more than

their leaded counterparts. The lead-free IR reflow profile

used to experimentally measure output voltage shift in the

LTC6652-2.5 is shown in Figure 14. Similar results can be

When operated within its specified limits of V = 13.2V

IN

andsourcing5mA,theLTC6652-2.5consumesjustunder

60mW at room temperature. At 125°C the quiescent cur-

rent will be slightly higher and the power consumption

increases to just over 60mW. The power-derating curve

in Figure 16 shows the LTC6652-2.5 can safely dissipate

125mW at 125°C about half the maximum power con-

sumption of the package.

300

380s

T

= 260°C

P

RAMP

DOWN

T

= 217°C

L

225

150

75

Humidity Sensitivity

T

= 200°C

S(MAX)

t

T

= 190°C

P

S

30s

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 volt-

age reference, usually on the order of 100ppm. The LS8

packageishermetic, soitisnotaffectedbyhumidity, and

is therefore more stable in environments where humidity

may be a concern.

T = 150°C

t

L

RAMP TO

150°C

130s

40s

120s

4

0

2

6

8

10

MINUTES

6652 F14

Figure 14ꢀ Lead-Free Reflow Profile

6652fg

14

For more information www.linear.com/LTC6652

LTC6652

applications inForMation

10

8

7

6

5

4

3

2

1

0

1X

3X

6

4

2

0

–0.014 –0.006

0.002

0.010

0.018

–0.1

–0.06 –0.02 0 0.02

0.06

0.1

OUTPUT VOLTAGE SHIFT DUE TO IR REFLOW (%)

6652 F15a

6652 F15b

Figure 15aꢀ MS8 Output Voltage

Shift Due to IR Reflow

Figure 15bꢀ LS8 Output Voltage

Shift Due to IR Reflow

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

0.06

T

= 25°C

A

0.05

0.04

0.03

0.02

0.01

0

5mA LOAD

NO LOAD

0

20

40

60

140

2

4

6

8

14

80 100 120

10

12

TEMPERATURE (°C)

V

(V)

IN

6652 F16

6652 F17

Figure 16ꢀ Maximum Recommended

Dissipation for LTC6652

Figure 17ꢀ Typical Power Dissipation

of the LTC6652

6652fg

15

For more information www.linear.com/LTC6652

LTC6652

typical applications

Extended Supply Range Reference

6V TO 160V

4V TO 30V

R1

330k

R2

4.7k

ON SEMI

MMBT5551

V

OUT

LTC6652-2.5

GND

V

OUT

IN

V

SHDN

IN

SHDN

C1

0.1µF

BZX84C18

C2

OPTIONAL

6652 TA02

V

LTC6652-2.5

GND

OUT

BZX84C18

C2

OPTIONAL

C1

0.1µF

6652 TA03

Negative Rail Circuit

Boosted Output Current

V

≥ 1.75V

2, 3

+

CC

V

≥ (V

+ 1.8V)

OUT

R1

220Ω

C1

1µF

C1

0.1µF

2N2905

V

SHDN

IN

6

LTC6652-2.5

V

OUT

V

OUT

LTC6652-2.5

GND

C2

1µF

4, 5, 7, 8

500Ω

≤ –3V

V

OUT

6652 TA04

–2.5V

1µF

6652 TA06

V

EE

6652fg

16

For more information www.linear.com/LTC6652

LTC6652

package Description

Please refer to http://wwwꢀlinearꢀcom/product/LTC6652#packaging for the most recent package drawingsꢀ

MS8 Package

8-Lead Plastic MSOP

(Reference LTC DWG # 05-08-1660 Rev G)

0.889 0.127

(.035 .005)

5.10

3.20 – 3.45

(.201)

(.12ꢀ – .13ꢀ)

MIN

3.00 0.102

(.118 .004)

(NOTE 3)

0.52

(.0205)

REF

0.ꢀ5

(.025ꢀ)

BSC

0.42 0.038

(.01ꢀ5 .0015)

TYP

8

7 ꢀ 5

RECOMMENDED SOLDER PAD LAYOUT

3.00 0.102

(.118 .004)

(NOTE 4)

4.90 0.152

(.193 .00ꢀ)

DETAIL “A”

0.254

(.010)

0° – ꢀ° TYP

GAUGE PLANE

1

2

3

4

0.53 0.152

(.021 .00ꢀ)

1.10

(.043)

MAX

0.8ꢀ

(.034)

REF

DETAIL “A”

0.18

(.007)

SEATING

PLANE

0.22 – 0.38

0.101ꢀ 0.0508

(.009 – .015)

(.004 .002)

0.ꢀ5

(.025ꢀ)

BSC

TYP

MSOP (MS8) 0213 REV G

NOTE:

1. DIMENSIONS IN MILLIMETER/(INCH)

2. DRAWING NOT TO SCALE

3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.

MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.00ꢀ") PER SIDE

4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.

INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.00ꢀ") PER SIDE

5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX

6652fg

17

For more information www.linear.com/LTC6652

LTC6652

package Description

Please refer to http://wwwꢀlinearꢀcom/product/LTC6652#packaging for the most recent package drawingsꢀ

LS8 Package

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

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

8

2.50 0.15

PACKAGE OUTLINE

7

1

0.5

2

3

6

2.54 0.15

1.4

1.50 0.15

XYY ZZ

ABCDEF

4

Q12345

0.70 0.05 × 8

COMPONENT

PIN “A1”

5.00 SQ 0.15

5.80 SQ 0.15

TRAY PIN 1

BEVEL

APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED

PACKAGE IN TRAY LOADING ORIENTATION

5.00 SQ 0.15

4.20 SQ 0.10

8

1.45 0.10

0.95 0.10

5.00 SQ 0.15

8

R0.20 REF

2.00 REF

PIN 1

1

2

1

2

7

6

7

6

TOP MARK

(SEE NOTE 5)

0.5

2.54 0.15

4.20 0.10

1.4

5

3

5

R0.20 REF

1.00 × 7 TYP

LS8 0113 REV B

4

0.70 TYP

0.10 TYP

0.64 × 8 TYP

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

6652fg

18

For more information www.linear.com/LTC6652

LTC6652

revision history ^{(Revision history begins at Rev C)}

REV

DATE

DESCRIPTION

PAGE NUMBER

C

11/09 Change to Typical Performance Characteristics.

Change to Typical Application.

6

14

D

8/12

Addition of 5mm × 5mm Hermetic LS8 Package.

Update to Electrical Characteristics to Include LS8 Package.

Addition of Long Term Drift, Hysteresis, IR Drift Plots for LS8 Package.

Addition of Humidity Sensitivity Information.

1, 2, 3, 12, 18

4

13, 15

14

E

F

1/13

7/15

Correction to pin labeling of LS8 Package

2

Order Information updated to include 4.096V and 5V options in LS8 package.

MS8 and LS8 package descriptions updated.

3

17, 18

3

G

10/15 Correction to the Electrical Characteristics Table: Output Voltage Temperature Coefficient for LTC6652BMS8

specification applies over the full operating temperature range.

6652fg

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 representa-

tion that the interconneFcotiornmoof irtseciinrcfouirtms aastdioenscrwibwedwh.leirneeinarw.cilol nmot/LinTfCrin6g6e5o2n existing patent rights.

19

LTC6652

typical application

Improved Reference Supply Rejection in a Data Converter Application

LTC1657

16

D/A

REF

DATA

VDAC

V

CC

GND

V

IN

R1

50k

V

OUT

LTC6652

REF

A/D

LTC1605

SHDN

V1

16

C1

0.1µF

V2

V3

V4

D

OUT

C2

C

OUT

10µF

1µF

GND

6652 TA05

relateD parts

PART NUMBER DESCRIPTION

COMMENTS

LT1460

LT1461

LT1790

LT6650

LT6660

LT6654

Micropower Series References

Micropower Series Low Dropout

Micropower Precision Series References

0.075% Max, 10ppm/°C Max, 20mA Output Current

0.04% Max, 3ppm/°C Max, 50mA Output Current

0.05% Max, 10ppm/°C Max, 60µA Supply, SOT23 Package

0.5% Max, 5.6µA Supply, SOT23 Package

Micropower Reference with Buffer Amplifier

Tiny Micropower Series Reference

0.2% Max, 20ppm/°C Max, 20mA Output Current, 2mm × 2mm DFN

Precision Wide Supply High Output Drive Low Noise Reference 0.05% Max, 10ppm/°C Max, 10mA Output Current,

1.6ppm Noise, SOT23 and LS8 Packages, –55°C to 125°C

P-P

LTC6655

Precision, Low Drift, Low Noise Reference

0.025% Max, 2ppm/°C Max, 5mA Output Current,

0.25ppm Noise, –40°C to 125°C

P-P

6652fg

LT 1015 REV G • PRINTED IN USA

LinearTechnology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

20

For more information www.linear.com/LTC6652

●

(408)432-1900 FAX: (408) 434-0507 www.linear.com/LTC6652

 LINEAR TECHNOLOGY CORPORATION 2007


型号：	LTC6652AHMS8-3.3#PBF
厂家：	Linear
描述：	LTC6652 - Precision Low Drift Low Noise Buffered Reference; Package: MSOP; Pins: 8; Temperature Range: -40°C to 125°C 光电二极管
文件：	总20页 (文件大小：544K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

LTC6652AHMS8-3.3#PBF [Linear]

相关型号：

LTC6652AHMS8-3.3#TRPBF

LTC6652AHMS8-3.3-PBF

LTC6652AHMS8-3.3-TRPBF

LTC6652AHMS8-4.096

LTC6652AHMS8-4.096#PBF

LTC6652AHMS8-4.096-PBF

LTC6652AHMS8-4.096-TRPBF

LTC6652AHMS8-5

LTC6652AHMS8-5#PBF

LTC6652AHMS8-5-PBF

LTC6652AHMS8-5-TRPBF

LTC6652BHLS8-4.096#PBF