Linear Technology LT1021 Datasheet

LT1021

Precision Reference

EATU

F

■

Pin Compatible with Most Bandgap Reference

RE

S

Applications, Including Ref 01, Ref 02, LM368,
MC1400 and MC1404 with Greatly Improved
Stability, Noise and Drift

■

Ultralow Drift: 5ppm/°C Max Slope

■

Trimmed Output Voltage

■

Operates in Series or Shunt Mode

■

Output Sinks and Sources in Series Mode

■

Very Low Noise: <1ppm

■

>100dB Ripple Rejection

■

Minimum Input/Output Differential of 1V

■

100% Noise Tested

U

O

PPLICATI

A

■

A/D and D/A Converters

■

Precision Regulators

■

Digital Voltmeters

■

Inertial Navigation Systems

■

Precision Scales

■

Portable Reference Standard

S

(0.1Hz to 10Hz)

P-P

DUESCRIPTIO

The LT®1021 is a precision reference with ultralow drift
and noise, extremely good long term stability and almost
total immunity to input voltage variations. The reference
output will both source and sink up to 10mA. Three
voltages are available: 5V, 7V and 10V. The 7V and 10V
units can be used as shunt regulators (two-terminal zeners)
with the same precision characteristics as the three­terminal connection. Special care has been taken to mini­mize thermal regulation effects and temperature
induced hysteresis.

The LT1021 references are based on a buried zener diode
structure that eliminates noise and stability problems
associated with surface breakdown devices. Further, a
subsurface zener exhibits better temperature drift and
time stability than even the best bandgap references.

Unique circuit design makes the LT1021 the first IC
reference to offer ultralow drift without the use of high
power on-chip heaters.

The LT1021-7 uses no resistive divider to set output
voltage, and therefore exhibits the best long term stability
and temperature hysteresis. The LT1021-5 and LT1021­10 are intended for systems requiring a precise 5V or 10V
reference with an initial tolerance as low as ±0.05%.

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

U

O

A

PPLICATITYPICAL

Typical Distribution of Temperature Drift

Basic Positive and Negative Connections

LT1021

IN

V

IN

OUT

GND

V

OUT

R1 =

NC

V

I

LOAD

OUT

LT1021

(7 AND 10 ONLY)
IN

GND

– (V–)

+ 1.5mA

–15V

(V

OUT

–V

OUT

R1

–

)

1021 TA01

24
21
18
15
12

UNITS (%)

9
6
3

– 0

–5

DISTRIBUTION
OF THREE RUNS

–3 –1 1 52–4 –2 0 4

OUTPUT DRIFT (ppm/°C)

3

1021 TA01

1

LT1021

A

W

O

LUTEXI T

S

A

WUW

ARB

U
G

I

(Note 1)

S

Input Voltage .......................................................... 40V

Input/Output Voltage Differential ............................ 35V

Output-to-Ground Voltage (Shunt Mode Current Limit)

LT1021-5............................................................. 10V

LT1021-7............................................................. 10V

LT1021-10........................................................... 16V

Trim Pin-to-Ground Voltage

Positive ............................................... Equal to V

OUT

Negative ........................................................... – 20V

PACKAGE

/

O

RDER I FOR ATIO

WU

U

ORDER PART

NUMBER

LT1021BCH-5

TOP VIEW

NC*

8

1

NC*

2

V

IN

3

NC*

H PACKAGE

8-LEAD TO-5 METAL CAN

CONNECTED INTERNALLY.

*

D0 NOT CONNECT EXTERNAL
CIRCUITRY TO THESE PINS

NO TRIM PIN ON LT1021-7.

**

DO NOT CONNECT EXTERNAL
CIRCUITRY TO PIN 5 ON LT1021-7

T

= 150°C, θJA = 150°C/W,θJC = 45°C/W

JMAX

7

5

4

GND

NC*

6

TRIM

V

OUT

**

LT1021BMH-5
LT1021CCH-5
LT1021CMH-5
LT1021DCH-5
LT1021DMH-5
LT1021BCH-7
LT1021BMH-7
LT1021DCH-7
LT1021DMH-7
LT1021BCH-10
LT1021BMH-10
LT1021CCH-10
LT1021CMH-10
LT1021DCH-10
LT1021DMH-10

Output Short-Circuit Duration

VIN = 35V......................................................... 10 sec

VIN ≤ 20V ................................................... Indefinite

Operating Temperature Range

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

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

Military ............................................ –55°C to 125°C

Storage Temperature Range ................ –65°C to 150°C

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

ORDER PART

NUMBER

LT1021BCN8-5

TOP VIEW

DNC*

1

V

2

IN

DNC*

3

GND

4

N8 PACKAGE
8-LEAD PDIP

CONNECTED INTERNALLY.

*

D0 NOT CONNECT EXTERNAL
CIRCUITRY TO THESE PINS

NO TRIM PIN ON LT1021-7.

**

DO NOT CONNECT EXTERNAL
CIRCUITRY TO PIN 5 ON LT1021-7

T

= 130°C, θJA = 130°C/W (N)

JMAX

= 130°C, θJA = 150°C/W (S)

T

JMAX

S8 PACKAGE

8-LEAD PLASTIC SO

8
7
6
5

DNC*
DNC*
V

0UT

TRIM**

LT1021CCN8-5
LT1021CIN8-5
LT1021DCN8-5
LT1021DIN8-5
LT1021DCS8-5
LT1021BCN8-7
LT1021DCN8-7
LT1021DCS8-7
LT1021BCN8-10
LT1021CCN8-10
LT1021CIN8-10
LT1021DCN8-10
LT1021DCS8-10
LT1021DIN8-10

S8 PART MARKING

2

021DC5
021DC7
021DC1

LT1021

LECTRICAL C CHARA TERIST

E

range, otherwise specifications are TA = 25°C. VIN = 10V, I

PARAMETER CONDITIONS MIN TYP MAX UNITS

Output Voltage (Note 2) LT1021C-5 4.9975 5.000 5.0025 V

Output Voltage Temperature Coefficient (Note 3) T

Line Regulation (Note 4) 7.2V ≤ VIN ≤ 10V 4 12 ppm/V

Load Regulation (Sourcing Current) 0 ≤ I

Load Regulation (Sinking Current) 0 ≤ I

Supply Current 0.8 1.2 mA

Output Voltage Noise (Note 6) 0.1Hz ≤ f ≤ 10Hz 3.0 µV

Long Term Stability of Output Voltage (Note 7) ∆t = 1000Hrs Noncumulative 15 ppm
Temperature Hysteresis of Output ∆T = ±25°C 10 ppm

ICS

LT1021B-5/LT1021D-5 4.9500 5.000 5.0500 V

≤ TJ ≤ T

MIN

LT1021B-5 ● 2 5 ppm/°C
LT1021C-5/LT1021D-5 ● 3 20 ppm/°C

10V ≤ V

OUT

(Note 4)

OUT

(Note 4)

10Hz ≤ f ≤ 1kHz 2.2 3.5 µV

The ● denotes specifications that apply over the full operating temperature

= 0, unless otherwise noted.

OUT

LT1021-5

MAX

● 20 ppm/V

≤ 40V 2 6 ppm/V

IN

≤ 10mA 10 20 ppm/mA

≤ 10mA 60 100 ppm/mA

● 10 ppm/V

● 35 ppm/mA

● 150 ppm/mA

● 1.5 mA

P-P

RMS

The ● denotes specifications that apply over the full operating temperature range, otherwise specifications are TA = 25°C.
VIN = 12V, I

PARAMETER CONDITIONS MIN TYP MAX UNITS

Output Voltage (Note 2) 6.95 7.00 7.05 V
Output Voltage Temperature Coefficient (Note 3) T

Line Regulation (Note 4) 8.5V ≤ VIN ≤ 12V 1.0 4 ppm/V

Load Regulation (Sourcing Current) 0 ≤ I

Load Regulation (Shunt Mode) 1.2mA ≤ I

Supply Current (Series Mode) 0.75 1.2 mA

Minimum Current (Shunt Mode) VIN is Open 0.7 1.0 mA

Output Voltage Noise (Note 6) 0.1Hz ≤ f ≤ 10Hz 4.0 µV

Long Term Stability of Output Voltage (Note 7) ∆t = 1000Hrs Noncumulative 7 ppm
Temperature Hysteresis of Output ∆T = ±25°C 3 ppm

= 0, unless otherwise noted.

OUT

LT1021-7

≤ TJ ≤ T

MIN

LT1021B-7 ● 2 5 ppm/°C
LT1021D-7

12V ≤ V

(Note 4)

(Notes 4, 5)

10Hz ≤ f ≤ 1kHz 2.5 4.0 µV

MAX

● 3 20 ppm/°C

● 2.0 8 ppm/V

≤ 40V 0.5 2 ppm/V

IN

≤ 10mA 12 25 ppm/mA

OUT

≤ 10mA 50 100 ppm/mA

SHUNT

● 1.0 4 ppm/V

● 40 ppm/mA

● 150 ppm/mA

● 1.5 mA

● 1.2 mA

P-P

RMS

3

LT1021

LECTRICAL C CHARA TERIST

E

range, otherwise specifications are TA = 25°C. VIN = 15V, I

PARAMETER CONDITIONS MIN TYP MAX UNITS

Output Voltage (Note 2) LT1021C-10 9.995 10.00 10.005 V

Output Voltage Temperature Coefficient (Note 3) T

Line Regulation (Note 4) 11.5V ≤ VIN ≤ 14.5V 1.0 4 ppm/V

Load Regulation (Sourcing Current) 0 ≤ I

Load Regulation (Shunt Mode) 1.7mA ≤ I

Supply Current (Series Mode) 1.2 1.7 mA

Minimum Current (Shunt Mode) VIN is Open 1.1 1.5 mA

Output Voltage Noise (Note 6) 0.1Hz ≤ f ≤ 10Hz 6.0 µV

Long Term Stability of Output Voltage (Note 7) ∆t = 1000Hrs Noncumulative 15 ppm
Temperature Hysteresis of Output ∆T = ±25°C 5 ppm

ICS

LT1021B-10/LT1021D-10 9.950 10.00 10.050 V

≤ TJ ≤ T

MIN

LT1021B-10 ● 2 5 ppm/°C
LT1021C-10/LT1021D-10 ● 5 20 ppm/°C

14.5V ≤ V

OUT

(Note 4)

(Notes 4, 5)

10Hz ≤ f ≤ 1kHz 3.5 6 µV

The ● denotes specifications that apply over the full operating temperature

= 0, unless otherwise noted.

OUT

LT1021-10

MAX

● 6 ppm/V

≤ 40V 0.5 2 ppm/V

IN

≤ 10mA 12 25 ppm/mA

≤ 10mA 50 100 ppm/mA

SHUNT

● 4 ppm/V

● 40 ppm/mA

● 150 ppm/mA

● 2.0 mA

● 1.7 mA

P-P

RMS

Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.

Note 2: Output voltage is measured immediately after turn-on. Changes
due to chip warm-up are typically less than 0.005%.

Note 3: Temperature coefficient is measured by dividing the change in
output voltage over the temperature range by the change in temperature.
Separate tests are done for hot and cold; T

Incremental slope is also measured at 25°C.
Note 4: Line and load regulation are measured on a pulse basis. Output

changes due to die temperature change must be taken into account
separately. Package thermal resistance is 150°C/W for TO-5 (H), 130°C/W
for N and 150°C/W for the SO-8.

to 25°C and 25°C to T

MIN

MAX

.

Note 5: Shunt mode regulation is measured with the input open. With the
input connected, shunt mode current can be reduced to 0mA. Load
regulation will remain the same.

Note 6: RMS noise is measured with a 2-pole highpass filter at 10Hz and a
2-pole lowpass filter at 1kHz. The resulting output is full-wave rectified and
then integrated for a fixed period, making the final reading an average as
opposed to RMS. Correction factors are used to convert from average to
RMS and correct for the non-ideal bandpass of the filters.

Peak-to-peak noise is measured with a single highpass filter at 0.1Hz and a
2-pole lowpass filter at 10Hz. The unit is enclosed in a still-air environment
to eliminate thermocouple effects on the leads. Test time is 10 seconds.

Note 7: Consult factory for units with long term stability data.

4

LPER

OUTPUT CURRENT (mA)

0

INPUT/OUTPUT VOLTAGE (V)

1.2

1.6

16

1021 G03

0.8

0.4

0

4

8

12

20

1.0

1.4

0.6

0.2

14

2

6

10

18

TJ = 125 °C

TJ = –55 °C

TJ = 25 °C

FREQUENCY (Hz)

100

NOISE VOLTAGE (nV/√Hz)

200

250

350

400

10 1k 10k

LT1021 G06

0

100

300

150

50

LT1021-10

LT1021-5

LT1021-7

Ripple Rejection

115

f = 150Hz

110

105

100

REJECTION (dB)

95

90

85

0

13
12
11
10

9
8
7
6

OUTPUT VOLTAGE (V)

5
4
3

10 20

515

INPUT VOLTAGE (V)

Start-Up (Series Mode)

VIN = 0V TO 12V

04

2

F

LT1021-10

LT1021-7

LT1021-5

6

TIME (µs)

R

O

LT1021-7

LT1021-10

LT1021-5

25

8

LT1021

UW

ATYPICA

30

10

35

LT1021 G01

12

LT1021 G04

40

14

CCHARA TERIST

E

C

Ripple Rejection

130

VIN = 15V

= 0

C

OUT

120
110

100

90
80

REJECTION (dB)

70
60
50

10

Start-Up (Shunt Mode)
LT1021-7, LT1021-10

11

10

9

8

7

OUTPUT VOLTAGE (V)

6

5

02

ICS

LT1021-7

LT1021-10

LT1021-5

100 1k 10k

FREQUENCY (Hz)

LT1021-10

+ 2V

V

OUT

0V

NC

LT1021-7

61012

48

TIME (µs)

LT1021 G02

1k

V

OUT

OUT

IN

GND

LT1021 G05

Minimum Input/Output Differential
LT1021-7, LT1021-10

Output Voltage Noise Spectrum

Output Voltage Noise

16

C

= 0

OUT

FILTER = 1 POLE

14

= 0.1Hz

f

LOW

12
10

8
6

RMS NOISE (µV)

4
2
0

10

LT1021-10

100 1k 10k

BANDWIDTH (Hz)

LT1021-7

LT1021-5

LT1021 G07

Output Voltage Temperature Drift
LT1021-5

5.006

5.004

5.002

5.000

4.998

OUTPUT VOLTAGE (V)

4.996

4.994
–50

0

–25

TEMPERATURE (°C)

50

25

Load Regulation LT1021-5

5

VIN = 8V

4
3
2
1

0
–1
–2

OUTPUT CHANGE (mV)

–3
–4

100

LT1021 G08

125

75

–5

–6–8 –4 0 4 8

–10

–2

SOURCING SINKING

OUTPUT CURRENT (mA)

2

6

10

LT1021 G09

5