ANALOG DEVICES LTC 6652 BHMS Datasheet

LTC6652

V

ACCURACY (%)

0.050

Precision Low Drift Low

Noise Buffered Reference

Features

n

Low Drift:

A-Grade 5ppm/°C Max
B-Grade 10ppm/°C Max (MSOP8)
B-Grade 8ppm/°C Max (LS8)

n

High Accuracy:

A Grade ±0.05% Max
B-Grade ±0.1% Max

n

Low Noise: 2.1ppm

n

100% Tested at – 40°C, 25°C and 125°C

n

Sinks and Sources Current: ±5mA

n

Low Power Shutdown: <2µA Maximum

n

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

n

Long-Term Drift (LS8): 20ppm/√kHr

n

Low Dropout: 300mV

n

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

(0.1Hz to 10Hz)

P-P

3V, 3.3V, 4.096V, 5V

n

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

Hermetic Packages

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 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/°C with a predictable temperature characteristic and
an output voltage accuracy of ±0.05%. The performance
over temperature should appeal to automotive, high perfor­mance industrial and other high temperature applications.

The LTC6652 voltage references can be powered from
supply voltages up to 13.2V. They boast low noise, ex­cellent 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 refer­ence is not needed. The optional output capacitor can be
left off when space constraints are critical.

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.

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.

typical application

Basic Connection

V

2.8V ≤ VIN ≤ 13.2V

0.1µF

(OPTIONAL)

C

IN

IN

SHDN

LTC6652-2.5

GND

Output Voltage Temperature Drift

0.025

V

C

OUT

1µF
(OPTIONAL)

6652 TA01a

OUT

2.5V

OUT

–0.025

–0.050

0

–20 0 20 40

–40

TEMPERATURE (°C)

60 80 100 125

6652 TA01b

6652fe

1

V

OUT

For more information www.linear.com/6652

LTC6652

absolute MaxiMuM ratings

(Note 1)

Input Voltage

V

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

IN

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

+ 0.3V)

IN

Output Voltage

V

...........................................–0.3V to (V

OUT

+ 0.3V)

IN

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

pin conFiguration

TOP VIEW

1

DNC

2

V

IN

3

SHDN

4

GND

MS8 PACKAGE

8-LEAD PLASTIC MSOP

= 150°C, θJA = 200°C/W

T

JMAX

DNC: DO NOT CONNECT

*CONNECT THE PINS TO DEVICE GND (PIN 4)

8
7
6
5

GND*
GND*
V

OUT

GND*

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

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

Lead Temperature Range (Soldering, 10 sec)

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

TOP VIEW

GND*

8

1

DNC

2

V

IN

SHDN

3

GND

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

*CONNECT THE PINS TO DEVICE GND (PIN 4)

LS8 PACKAGE

= 150°C, θJA = 120°C/W

T

JMAX

DNC: DO NOT CONNECT

7

GND*

6

V

OUT

GND*

5

4

orDer inForMation

LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE

LTC6652AHMS8-1.25#PBF LTC6652AHMS8-1.25#TRPBF LTCVH 8-Lead Plastic MSOP –40°C to 125°C
LTC6652BHMS8-1.25#PBF LTC6652BHMS8-1.25#TRPBF LTCVH 8-Lead Plastic MSOP –40°C to 125°C
LTC6652AHMS8-2.048#PBF LTC6652AHMS8-2.048#TRPBF LTCVJ 8-Lead Plastic MSOP –40°C to 125°C
LTC6652BHMS8-2.048#PBF LTC6652BHMS8-2.048#TRPBF LTCVJ 8-Lead Plastic MSOP –40°C to 125°C
LTC6652AHMS8-2.5#PBF LTC6652AHMS8-2.5#TRPBF LTCQV 8-Lead Plastic MSOP –40°C to 125°C
LTC6652BHMS8-2.5#PBF LTC6652BHMS8-2.5#TRPBF LTCQV 8-Lead Plastic MSOP –40°C to 125°C
LTC6652AHMS8-3#PBF LTC6652AHMS8-3#TRPBF LTCVK 8-Lead Plastic MSOP –40°C to 125°C
LTC6652BHMS8-3#PBF LTC6652BHMS8-3#TRPBF LTCVK 8-Lead Plastic MSOP –40°C to 125°C
LTC6652AHMS8-3.3#PBF LTC6652AHMS8-3.3#TRPBF LTCVM 8-Lead Plastic MSOP –40°C to 125°C
LTC6652BHMS8-3.3#PBF LTC6652BHMS8-3.3#TRPBF LTCVM 8-Lead Plastic MSOP –40°C to 125°C
LTC6652AHMS8-4.096#PBF LTC6652AHMS8-4.096#TRPBF LTCVN 8-Lead Plastic MSOP –40°C to 125°C
LTC6652BHMS8-4.096#PBF LTC6652BHMS8-4.096#TRPBF LTCVN 8-Lead Plastic MSOP –40°C to 125°C
LTC6652AHMS8-5#PBF LTC6652AHMS8-5#TRPBF LTCVP 8-Lead Plastic MSOP –40°C to 125°C
LTC6652BHMS8-5#PBF LTC6652BHMS8-5#TRPBF LTCVP 8-Lead Plastic MSOP –40°C to 125°C

2

6652fe

For more information www.linear.com/6652

LTC6652

orDer inForMation

LEAD FREE FINISH PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE

†

LTC6652AHLS8-2.5#PBF
LTC6652BHLS8-2.5#PBF
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.

Consult LTC Marketing for information on non-standard lead based finish parts.
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/

665225 8-Lead Ceramic LCC 5mm × 5mm –40°C to 125°C

†

665225 8-Lead Ceramic LCC 5mm × 5mm –40°C to 125°C

available options

OUTPUT VOLTAGE INITIAL ACCURACY TEMPERATURE COEFFICIENT PART NUMBER**

1.250 0.05%

0.1%

2.048 0.05%

0.1%

2.500 0.05%

0.1%

0.05%

0.1%

3.000 0.05%

0.1%

3.300 0.05%

0.1%

4.096 0.05%

0.1%

5.000 0.05%

0.1%

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

5ppm/°C

10ppm/°C

5ppm/°C

10ppm/°C

5ppm/°C

10ppm/°C

5ppm/°C
8ppm/°C

5ppm/°C

10ppm/°C

5ppm/°C

10ppm/°C

5ppm/°C

10ppm/°C

5ppm/°C

10ppm/°C

LTC6652AHMS8-1.25
LTC6652BHMS8-1.25

LTC6652AHMS8-2.048
LTC6652BHMS8-2.048

LTC6652AHMS8-2.5
LTC6652BHMS8-2.5
LTC6652AHLS8-2.5
LTC6652BHLS8-2.5

LTC6652AHMS8-3
LTC6652BHMS8-3

LTC6652AHMS8-3.3
LTC6652BHMS8-3.3

LTC6652AHMS8-4.096
LTC6652BHMS8-4.096

LTC6652AHMS8-5
LTC6652BHMS8-5

electrical characteristics

The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C, VIN = V

PARAMETER CONDITIONS MIN TYP MAX UNITS

Output Voltage LTC6652A

Output Voltage Temperature Coefficient
(Note 3)

Line Regulation V

Load Regulation (Note 4) I

LTC6652B
LTC6652A

LTC6652BMS8
LTC6652BLS8

+ 0.5V ≤ VIN ≤ 13.2V, SHDN = V

OUT

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

SOURCE

LTC6652-2.5, LTC6652-3, LTC6652-3.3,
LTC6652-4.096, LTC6652-5

= 1mA, LTC6652-1.25, LTC6652-2.048

I

SINK

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

I

SINK

LTC6652-3.3, LTC6652-4.096, LTC6652-5

For more information www.linear.com/6652

+ 0.5V, unless otherwise noted.

OUT

–0.05

–0.1

l

l

IN

l

l

l

l

2

0.05

0.1

4
4

2 50

20 75

80 250

50 150

5

10

8

80

200

600

450

ppm/°C
ppm/°C
ppm/°C

ppm/V
ppm/V

ppm/mA
ppm/mA

ppm/mA
ppm/mA

ppm/mA
ppm/mA

6652fe

3

%
%

LTC6652

electrical characteristics

The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C, VIN = V

PARAMETER CONDITIONS MIN TYP MAX UNITS

Minimum Operating Voltage (Note 5) I

Output Short-Circuit Current Short V

Shutdown Pin (SHDN) Logic High Input Voltage

Supply Current No Load

Shutdown Current SHDN Tied to GND
Output Voltage Noise (Note 6) 0.1Hz ≤ f ≤ 10Hz

Turn-On Time 0.1% Settling, C
Long-Term Drift of Output Voltage (Note 7) LTC6652MS8

Hysteresis (Note 8) ∆T = –40°C to 125°C, LTC6652MS8

= 5mA, V

SOURCE

LTC6652-1.25, LTC6652-2.048
LTC6652-2.5, LTC6652-3, LTC6652-3.3,
LTC6652-4.096, LTC6652-5

to GND

OUT
OUT

to V

Short V

Logic High Input Current
Logic Low Input Voltage

Logic Low Input Current

LTC6652-1.25
LTC6652-2.048, LTC6652-2.5, LTC6652-3
LTC6652-3.3
LTC6652-4.096
LTC6652-5
10Hz ≤ f ≤ 1kHz

LTC6652LS8

∆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

Error ≤ 0.1%

OUT

IN

= 0 100 µs

LOAD

+ 0.5V, unless otherwise noted.

OUT

l
l

l
l

l
l

l

l

2.7
+ 0.3V

V

OUT

2

16
16

0.1

0.1

350

0.1 2 µA

2.4

2.1

2.2

2.3

2.8
3

60
20

80
75
45
45
25
10

1

0.8
1

560

mA
mA

ppm
ppm
ppm
ppm
ppm

ppm

RMS

ppm/√kHr
ppm/√kHr

ppm
ppm
ppm
ppm
ppm
ppm

µA

µA
µA

µA

P-P
P-P
P-P
P-P
P-P

V
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 specified temperature range,
the output may shift due to hysteresis.

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

6652fe

4

For more information www.linear.com/6652

LTC6652

NOISE VOLTAGE (nV/√Hz)

OUTPUT NOISE (1µV/DIV)

OUTPUT VOLTAGE (V)

REFERENCE VOLTAGE (V)

1.2510

OUTPUT VOLTAGE CHANGE (ppm)

OUTPUT VOLTAGE CHANGE (ppm)

typical perForMance characteristics

Characteristic curves are similar for most
LTC6652s. Curves from the LTC6652-1.25, LTC6652-2.5 and the LTC6652-5 represent the extremes and typical of the 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

1.2505

1.2500

1.2495

1.2490
–80

–40 0

40 160

TEMPERATURE (°C)

1.25V Load Regulation (Sinking)

400

350

300

250

200

150

100

50

0

0.1
OUTPUT CURRENT (mA)

–40°C

1 10

3 TYPICAL PARTS

80

120

6652 G17

125°C

25°C

6652 G20

1.25V Line Regulation

1.2506

1.2504

1.2502

1.2500

1.2498

1.2496

1.2494
0

2 4

6 10

INPUT VOLTAGE (V)

1.25V Low Frequency 0.1Hz to
10Hz Transient Noise

TIME (1 SECOND/DIV)

125°C

25°C

–40°C

8 12 14

6652 G18

6652 G21

1.25V Load Regulation (Sourcing)

0

–50

–100

–150

–200

–250

0.1
OUTPUT CURRENT (mA)

125°C

1

1.25V Output Voltage Noise
Spectrum

400

300

200

100

0

0.01

0.1 1 10
FREQUENCY (kHz)

–40°C

25°C

10

6652 G19

6652 G22

I

OUT

500mV/DIV

1.25 Sinking Current Without
Output Capacitor

1mA

0mA

V

OUT

C

= 0µF

OUT

500µs/DIV

6652 G23

1.25 Sinking Current with Output
Capacitor

1mA

I

OUT

0mA

V

OUT

500mV/DIV

C

= 1µF

OUT

For more information www.linear.com/6652

500µs/DIV

6652 G24

1.25V Stability with Output
Capacitance

10µF

1µF

0.1µF

10nF

1nF

OUTPUT CAPACITOR

100pF

NO CAP

–5 –1 0 5

LOAD CURRENT (mA)

REGION OF
MARGINAL

STABILITY

6652 G16

6652fe

5

LTC6652

typical perForMance characteristics

Characteristic curves are similar for most
LTC6652s. Curves from the LTC6652-1.25, LTC6652-2.5 and the LTC6652-5 represent the extremes and typical of the 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

2.5010

2.5005

2.5000

2.4995

REFERENCE VOLTAGE (V)

2.4990

2.4985
–50

–25 0

50

25 75 150

TEMPERATURE (°C)

2.5V Load Regulation (Sinking)

700

600

500

400

200

100

OUTPUT VOLTAGE CHANGE (ppm)

0

0.1
OUTPUT CURRENT (mA)

1 10

3 TYPICAL PARTS

100 125

125°C

25°C

–40°C

6652 G01

6652 G04

2.5V Line Regulation

2.5010

2.5005

2.5000

2.4995

2.4990

OUTPUT VOLTAGE (V)

2.4985

2.4980
0

2 4

2.5V Supply Current
vs Input Voltage

1000

900

800

700

600

500

400

300

SUPPLY CURRENT (µA)

200

100

0

0

2

8 12 14

6 10

INPUT VOLTAGE (V)

125°C

25°C

–40°C

8

6

4

INPUT VOLTAGE (V)

125°C

25°C

–40°C

10

12

6652 G02

6652 G05

14

2.5V Load Regulation (Sourcing)

0

–20

–40

–60

–80

–100

–120

–140

–160

OUTPUT VOLTAGE CHANGE (ppm)

–180

–200

0.1
OUTPUT CURRENT (mA)

1

2.5V Shutdown Current
vs Input Voltage

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

SUPPLY CURRENT (µA)

0.2

0.1

0

0

2

125°C

25°C

–40°C

8

6

4

INPUT VOLTAGE (V)

125°C

10

–40°C

25°C

12

10

6652 G03

14

6652 G06

6

2.5V Minimum V
Differential (Sourcing)

10

1

25°C

0.1

OUTPUT CURRENT (mA)

0.01

0.001

125°C, –40°C

0.01 0.1 1

INPUT-OUTPUT VOLTAGE (V)

IN-VOUT

6652 G09

For more information www.linear.com/6652

2.5V Minimum V
Differential (Sinking)

10

1

OUTPUT CURRENT (mA)

0.1

0.001

25°C

125°C

0.01 0.1 1

OUTPUT-INPUT VOLTAGE (V)

OUT-VIN

–40°C

6652 G10

6652fe

LTC6652

typical perForMance characteristics

Characteristic curves are similar for most
LTC6652s. Curves from the LTC6652-1.25, LTC6652-2.5 and the LTC6652-5 represent the extremes and typical of the voltage options.
Characteristic curves for other output voltages fall between these curves and can be estimated based on their output.

2.5V Low Frequency 0.1Hz to
10Hz Transient Noise

OUTPUT NOISE (1µV/DIV)

TIME (1 SECOND/DIV)

Typical V

Distribution for

OUT

LTC6652-2.5

180

1004 UNITS

160

140

120

80

60

NUMBER OF UNITS

40

20

0

2.4985

LTC6652A LIMITS

2.4995 2.5015
OUTPUT VOLTAGE (V)

2.5005

6652 G11

6652 G15

2.5V Output Voltage Noise
Spectrum

600

500

400

300

200

NOISE VOLTAGE (nV/√Hz)

100

0

0.01

0.1 1 10
FREQUENCY (kHz)

Stability with Output Capacitance
(LTC6652-2.5, LTC6652-3,
LTC6652-3.3, LTC6652-4.096,
LTC6652-5)

10µF

1µF

0.1µF

10nF

1nF

OUTPUT CAPACITOR

100pF

NO CAP

–5 0 5

REGION OF

MARGINAL STABILITY

LOAD CURRENT (mA)

6652 G12

6652 G14

For more information www.linear.com/6652

6652fe

7

LTC6652

NOISE VOLTAGE (nV/√Hz)

OUTPUT NOISE (5µV/DIV)

SUPPLY CURRENT (µA)

OUTPUT VOLTAGE (V)

5.002

REFERENCE VOLTAGE (V)

SUPPLY CURRENT (µA)

OUTPUT CURRENT (mA)

10

typical perForMance characteristics

Characteristic curves are similar for most
LTC6652s. Curves from the LTC6652-1.25, LTC6652-2.5 and the LTC6652-5 represent the extremes and typical of the 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

5.005

5.003

5.000

4.998

4.995
–50 25 75 150

–25 0

TEMPERATURE (°C)

3 TYPICAL PARTS

50

100 125

5V Shutdown Current
vs Input Voltage

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

0

2

6

4

INPUT VOLTAGE (V)

125°C

–40°C

25°C

8

10

12

6652 G25

6652 G29

5V Line Regulation

5.001

25°C

5.000

125°C

4.999

4.998
0

2 4

5V Minimum VIN to V

6 10

INPUT VOLTAGE (V)

–40°C

8 12 14

6652 G26

OUT

Differential (Sourcing)

1

25°C

0.1

–40°C

125°C

0.01

14

0.001

0.01 0.1 1

INPUT-OUTPUT VOLTAGE (V)

6652 G30

5V Supply Current
vs Input Voltage

1000

900

800

700

600

500

400

300

200

100

0

0

4

2

INPUT VOLTAGE (V)

125°C

25°C

–40°C

8

6

5V Low Frequency 0.1Hz to 10Hz
Transient Noise

TIME (1 SECOND/DIV)

12

14

6652 G27

6652 G31

10

1000

800

600

400

200

8

5V Output Voltage Noise Spectrum

0

0.01

0.1 1 10
FREQUENCY (kHz)

6652 G32

5V Start-Up Response Without
Output Capacitor

V

IN

2V/DIV

V

OUT

2V/DIV

= 0µF

C

OUT

For more information www.linear.com/6652

100µs/DIV

6652 G33

5V Start-Up Response with Output
Capacitor

V

IN

2V/DIV

V

OUT

2V/DIV

= 1µF

C

OUT

100µs/DIV

6652 G34

6652fe

LTC6652

typical perForMance characteristics

Characteristic curves are similar for most
LTC6652s. Curves from the LTC6652-1.25, LTC6652-2.5 and the LTC6652-5 represent the extremes and typical of the voltage options.
Characteristic curves for other output voltages fall between these curves and can be estimated based on their output.

Power Supply Rejection Ratio
vs Frequency

0

–10

–20

–30

–40
–50

–60

–70

–80

–90

POWER SUPPLY REJECTION RATIO (dB)

–100

0.01

0.1 1 10 100 1000

C

OUT

FREQUENCY (kHz)

= 0µF

C

OUT

C

OUT

= 10µF

= 1µF

6652 G07

Output Impedance vs Frequency

100

10

1

OUTPUT IMPEDANCE (Ω)

0.1

0.01 1 10 100

pin Functions

DNC (Pin 1): Do Not Connect.

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

V

IN

+ 300mV or 2.7V; whichever is higher. The maximum

V

OUT

supply is 13.2V. Bypassing V
GND will improve PSRR.

with a 0.1µF capacitor to

IN

C

OUT

C

0.1
FREQUENCY (kHz)

SHDN Input Voltage Thresholds
vs V

1.5

0.5

IN

V

TH(UP)

V

TH(DN)

0

2

4

8 12 14

6 10

VIN (V)

6652 G13

= 1µF

OUT

C

OUT

= 10µF

= 0µF

6652 G08

(V)

TRIP

V

2.5

2.0

1.0

GND (Pin 4): Device Ground.

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

V

OUT

required. For some applications, a capacitor between 0.1µF
to 10µF can be beneficial. See the graphs in the Typical
Performance Characteristics section for further details.

SHDN (Pin 3): Shutdown Input. This active low input
powers down the device to <2µA. For normal operation
tie this pin to V

IN

.

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

6652fe

For more information www.linear.com/6652

9

LTC6652

block DiagraM

V

IN

2

SHDN

3 6

GND

4

BANDGAP

applications inForMation

Bypass and Load Capacitors

The LTC6652 voltage references do not require an input
capacitor, but a 0.1µF capacitor located close to the part
improves power supply rejection.

The LTC6652 voltage references are stable with or without
a capacitive load. For applications where an output capaci­tor 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
any load current are acceptable. For loads that sink current
or light loads that source current, a 0.1µF to 10µF capacitor
has stable operation. For heavier loads that source current
a 0.5µF to 10µF capacitor range is recommended.

+

–

The transient response for a 0.5V step on V

6652 BD

V

OUT

with and

IN

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

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.

10

2, 3 6

V

IN

3V

C

IN

0.1µF

Figure 1. Transient Load Test Circuit

For more information www.linear.com/6652

LTC6652-2.5

4, 5, 7, 8

100Ω

C

OUT

1µF

V

6652 F01

GEN

0.5V

6652fe

applications inForMation

LTC6652

3.5V

V

IN

3V

V

OUT

500mV/DIV

C

OUT

= 0µF

500µs/DIV

6652 F02

Figure 2. Transient Response Without Output Capacitor

3.5V

V

IN

3V

V

OUT

500mV/DIV

5mA

I

OUT

0mA

V

OUT

200mV/DIV

0mA

I

OUT

–5mA

V

OUT

200mV/DIV

C

OUT

= 0µF

250µs/DIV

Figure 5. LTC6652-2.5 Sinking
Current Without Output Capacitor

6652 F05

C

= 1µF

OUT

500µs/DIV

6652 F03

Figure 3. Transient Response with 1µF Output Capacitor

0mA

I

OUT

–5mA

V

OUT

200mV/DIV

C

OUT

= 0µF

250µs/DIV

6652 F04

Figure 4. LTC6652-2.5 Sourcing
Current Without Output Capacitor

5mA

I

OUT

0mA

V

OUT

50mV/DIV

C

= 1µF

OUT

250µs/DIV

6652 F06

Figure 6. LTC6652-2.5 Sourcing Current
with Output Capacitor

C

= 1µF

OUT

250µs/DIV

6652 F07

Figure 7. LTC6652-2.5 Sinking
Current with Output Capacitor

For more information www.linear.com/6652

6652fe

11

LTC6652

applications inForMation

V

IN

2V/DIV

V

OUT

1V/DIV

C

= 0µF

OUT

100µs/DIV

6652 F08

Figure 8. Start-Up Response without Output Capacitor

V

IN

2V/DIV

V

OUT

1V/DIV

2.8V ≤ VIN ≤ 13.2V

Figure 10. Open-Drain Shutdown Circuit

SHDN

1V/DIV

V

OUT

1V/DIV

I

LOAD

TO µC

= 5mA

C1
1µF

R1
20k

SHDN

2N7002

1ms/DIV

V

IN

LTC6652-2.5

GND

V

6652 F10

OUT

6652 F11

C2
1µF

V

OUT

C

OUT

= 1µF

100µs/DIV

6652 F09

Figure 9. Start-Up Response with 1µF Output Capacitor

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
an output capacitor is used, the ripple is virtually undetect­able as shown in Figure 9.

Shutdown Mode

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

Figure 11. Shutdown Response with 5mA Load

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

and an open-drain output driver as shown in Figure

V

IN

10. The LTC6652’s response into and out of shutdown
mode is shown in Figure 11.

The trip thresholds on SHDN have some dependence on the
voltage applied to V

as shown in the Typical Performance

IN

Characteristics section. Be careful to avoid leaving SHDN
at a voltage between the thresholds as this will likely cause
an increase in supply current due to shoot-through current.

12

6652fe

For more information www.linear.com/6652

applications inForMation

LTC6652

80

LTC6652-2.5 MS8 PACKAGE
3 TYPICAL PARTS

= 35°C

T

60

A

40

20

ppm

0

–20

–40

0

300 600 1200 1500

900

HOURS

Figure 12a. MS8 Long-Term Drift

35

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

30

25

20

15

NUMBER OF UNITS

10

5

0
–250 –150 –50

DISTRIBUTION (ppm)

6652 F12a

15050

6652 F13a

80

LTC6652-2.5 LS8 PACKAGE
4 TYPICAL PARTS

= 30°C

T

60

A

40

20

ppm

0

–20

–40

0

200 400 800 1000

600

HOURS

Figure 12b. LS8 Long-Term Drift

9

25°C TO 125°C TO 25°C

8

7

6

5

4

3

NUMBER OF UNITS

2

1

0

–110 –80 –50 –20 0 5020 80

DISTRIBUTION (ppm)

25°C TO –40°C TO 25°C

6652 F12b

110

6652 F13b

Figure 13a. MS8 Hysteresis Plot –40°C to 125°C Figure 13b. LS8 Hysteresis Plot –40°C to 125°C

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 LTC6652 long-term drift

data was collected on more than 100 parts that were sol­dered into PC boards similar to a “real world” application.
The boards were then placed into a constant temperature
oven with 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.

For more information www.linear.com/6652

Hysteresis

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.

6652fe

13

LTC6652

300

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 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.

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

traces should be as short as possible

OUT

to minimize I • R drops. Excessive trace resistance directly

impacts load regulation.

IR Reflow Shift

The different expansion and contraction rates of the materi­als that make up the lead-free LTC6652 package cause the
output voltage to shift after undergoing IR reflow. 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

380s

TP = 260°C

225

TS = 190°C

T = 150°C

150

RAMP TO
150°C

75

0

0 2 4 6

Figure 14. Lead-Free Reflow Profile

T

S(MAX)

TL = 217°C

= 200°C

120s

MINUTES

t

30s

t

130s

40s

RAMP

DOWN

P

L

10

8

6652 F14

expected using a convection reflow oven. In our experiment,
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 0.003% as shown in Figure 15. While there can
be up to 0.016% of output voltage shift, the overall drift
of the LTC6652 after IR reflow does not vary significantly.

Power Dissipation

Power dissipation in the LTC6652 is dependent on V

IN

,
load current, and package. The LTC6652 package has
a thermal resistance, or θ

, of 200°C/W. A curve that

JA

illustrates allowed power dissipation vs temperature for
this package is shown in Figure 16.

The power dissipation of the LTC6652-2.5V as a function
of input voltage is shown in Figure 17. The top curve
shows power dissipation with a 5mA load and the bottom
curve shows power dissipation with no load.

When operated within its specified limits of V

= 13.2V

IN

and sourcing 5mA, the LTC6652-2.5 consumes just under
60mW at room temperature. At 125°C the quiescent cur­rent 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 con­sumption of the package.

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 hermetic, so it is not affected by humidity, and
is therefore more stable in environments where humidity
may be a concern.

14

6652fe

For more information www.linear.com/6652

applications inForMation

LTC6652

10

8

6

4

NUMBER OF UNITS

2

0

–0.014 –0.006

OUTPUT VOLTAGE SHIFT DUE TO IR REFLOW (%)

0.0180.0100.002

6652 F15a

Figure 15a. MS8 Output Voltage Shift Due to IR Reflow

0.7

0.6

0.5

0.4

0.3

DISSIPATION (W)

0.2

0.1

0

0

40

20

TEMPERATURE (°C)

60 140

80

100 120

6652 F16

7

1X
3X

6

5

4

3

NUMBER OF UNITS

2

1

0

–0.1 –0.02–0.06

OUTPUT VOLTAGE SHIFT DUE TO IR REFLOW (%)

0.060.020

0.1

6652 F15b

Figure 15b. LS8 Output Voltage Shift Due to IR Reflow

0.06
TA = 25°C

0.05

0.04

5mA LOAD

0.03

POWER (W)

0.02

0.01

0

2

4

NO LOAD

6

8 14

VIN (V)

10 12

6652 F17

Figure 16. Maximum Recommended Dissipation for LTC6652

For more information www.linear.com/6652

Figure 17. Typical Power Dissipation of the LTC6652

6652fe

15

LTC6652

VCC ≥ 1.75V

typical applications

Extended Supply Range Reference Extended Supply Range Reference

4V TO 30V

R1

BZX84C18

V

LTC6652-2.5

IN

SHDN

C1

0.1µF

Negative Rail Circuit

C1

0.1µF
6

LTC6652-2.5

VEE ≤ –3V

GND

2, 3

4, 5, 7, 8

500Ω

V

OUT

6652 TA02

1µF

6652 TA06

V

OUT

–2.5V

V

OUT

C2
OPTIONAL

R1
330k

V+ ≥ (V

R2

4.7k

BZX84C18

+ 1.8V)

OUT

6V TO 160V

ON SEMI
MMBT5551

V

SHDN

IN

GND

V

OUT

6652 TA03

LTC6652-2.5

C1

0.1µF

Boosted Output Current

C1
1µF

R1
220Ω

V

IN

LTC6652-2.5

GND

SHDN

6652 TA04

V

OUT

C2
OPTIONAL

2N2905

V

C2
1µF

OUT

V

OUT

16

6652fe

For more information www.linear.com/6652

package Description

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

MS8 Package

8-Lead Plastic MSOP

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

LTC6652

0.889 ± 0.127
(.035 ± .005)

5.23

(.206)

MIN

0.42 ± 0.038

(.0165 ± .0015)

TYP

RECOMMENDED SOLDER PAD LAYOUT

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 (.006") PER SIDE

4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE

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

3.20 – 3.45

(.126 – .136)

0.65

(.0256)

BSC

GAUGE PLANE

0.18

(.007)

0.254
(.010)

DETAIL “A”

DETAIL “A”

0° – 6° TYP

0.53 ± 0.152

(.021 ± .006)

SEATING

PLANE

3.00 ± 0.102
(.118 ± .004)

(NOTE 3)

4.90 ± 0.152

(.193 ± .006)

(.043)

0.22 – 0.38

(.009 – .015)

TYP

1.10

MAX

8

1 2

0.65

(.0256)

BSC

0.52

5

4

(.0205)

REF

3.00 ± 0.102
(.118 ± .004)

(NOTE 4)

0.86

(.034)

REF

0.1016 ± 0.0508
(.004 ± .002)

MSOP (MS8) 0307 REV F

7

6

3

For more information www.linear.com/6652

6652fe

17

LTC6652

LS8 Package

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

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

package Description

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

LS8 Package

8-Leadless Chip Carrier (5mm × 5mm)

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

8

2.50 ±0.15

1

2

3

4

5.00 SQ ±0.15

5.80 SQ ±0.15

APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED

5.00 SQ ±0.15

4.20 SQ ±0.10
8

1

PIN 1
TOP MARK
(SEE NOTE 5)

0.70 ±0.05

PACKAGE OUTLINE

7

6

2.54 ±0.15

5

1.50 ±0.15

7

1.45 ±0.10

0.95 ±0.10

2.00 REF

8

7

R0.20 REF

1

18

2

3

4

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

6

5

4.20 ±0.10

For more information www.linear.com/6652

R0.20 REF

6

5

4

0.10 TYP0.70 TYP

0.64 TYP

2

2.54 ±0.15

3

1.00 TYP

LS8 0609 REV Ø

6652fe

LTC6652

revision history

REV DATE DESCRIPTION PAGE NUMBER

C 11/09 Change to Typical Performance Characteristics.

Change to Typical Application.

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.

E 1/13 Correction to pin labeling of LS8 Package 2

(Revision history begins at Rev C)

6

14

1, 2, 3, 12, 18

4

13, 15

14

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa­tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.

For more information www.linear.com/6652

6652fe

19

LTC6652

typical application

Improved Reference Supply Rejection in a Data Converter Application

R1
50k

C1

0.1µF
C2

10µF

SHDN

GND

V

V

CC

IN

LTC6652

LTC1657

16

DATA

V

OUT

C

OUT

1µF

D/A

REFGND

V1
V2
V3
V4

VDAC

6652 TA05

REF

GND

A/D

LTC1605

16

D

OUT

relateD parts

PART NUMBER DESCRIPTION COMMENTS

LT1460 Micropower Series References 0.075% Max, 10ppm/°C Max, 20mA Output Current
LT1461 Micropower Series Low Dropout 0.04% Max, 3ppm/°C Max, 50mA Output Current
LT1790 Micropower Precision Series References 0.05% Max, 10ppm/°C Max, 60µA Supply, SOT23 Package
LT6650 Micropower Reference with Buffer Amplifier 0.5% Max, 5.6µA Supply, SOT23 Package
LT6660 Tiny Micropower Series Reference
LT6654 Precision Wide Supply High Output Drive Low Noise Reference 0.05% Max, 10ppm/°C Max, 10mA Output Current,

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

1.6ppm

Noise in SOT23 and LS8 Packages

P-P

20

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

[phone] ● FAX: [phone]

For more information www.linear.com/6652

●

www.linear.com/6652

6652fe

LT 0113 REV E • PRINTED IN USA

 LINEAR TECHNOLOGY CORPORATION 2007