Texas Instruments LM385BDR-2-5, LM385BD-2-5, LM385BLP-2-5, LM385D-2-5, LM385LPR-2-5 Datasheet

V

CHIP FORM

0°C to 70°C

LM285-2.5, LM385-2.5, LM385B-2.5

MICROPOWER VOLTAGE REFERENCES

SLVS023E – JANUARY 1989 – REVISED JULY 1999

NC
NC
NC

D PACKAGE

(TOP VIEW)

1
2
3
4

8
7
6
5

CATHODE
NC
NC
NC

D

Operating Current Range ...20 µA to
20 mA

D

1.5% and 3% Initial Voltage Tolerance

D

Reference Impedance
– LM385...1 Ω Max at 25°C
– All Devices . . . 1.5 Ω Max Over Full

ANODE

T emperature Range

D

Very Low Power Consumption

D

Applications:

LP PACKAGE

(TOP VIEW)

– Portable Meter References
– Portable Test Instruments
– Battery-Operated Systems
– Current-Loop Instrumentation
– Panel Meters

D

Designed to be Interchangeable With
National LM285-2.5 and LM385-2.5

NC–No internal connection

ANODE
CATHODE

NC

description

These micropower two-terminal band-gap voltage references operate over a 20-µA to 20-mA current range and
feature exceptionally low dynamic impedance and good temperature stability . On-chip trimming provides tight
voltage tolerance. The band-gap reference for these devices has low noise and long-term stability.

The design makes these devices exceptionally tolerant of capacitive loading and thus, easier to use in most
reference applications. The wide dynamic operating temperature range accommodates varying current
supplies with excellent regulation.

The extremely low power drain of this series makes them useful for micropower circuitry. These voltage
references can make portable meters, regulators, or general-purpose analog circuitry with battery life
approaching shelf life. The wide operating current range allows them to replace older references with
tighter-tolerance parts.

The LM285-2.5 is characterized for operation from –40°C to 85°C. The LM385-2.5 and LM385B-2.5 are
characterized for operation from 0°C to 70°C.

AVAILABLE OPTIONS

T

A

°

°

–40°C to 85°C 1.5% LM285D-2.5 LM285LP-2.5

The D package is available taped and reeled. Add the suffix R to the device type (e.g., LM385DR-2-5). Chip
forms are tested at 25°C.
For ordering purposes, the decimal point in the part number must be replaced with a hyphen (i.e., show
the -2.5 suffix as “-2-5”).

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

Z

TOLERANCE

3% LM385D-2.5 LM385LP-2.5

1.5% LM385BD-2.5 LM385BLP-2.5

PACKAGED DEVICES

SMALL OUTLINE

(D)

PLASTIC

(LP)

(Y)

LM385Y-2.5

PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

Copyright  1999, Texas Instruments Incorporated

1

LM285-2.5, LM385-2.5, LM385B-2.5

Operating free-air temperature range, T

°C

MICROPOWER VOLTAGE REFERENCES

SLVS023E – JANUARY 1989 – REVISED JULY 1999

logic symbol

ANODE CATHODE

schematic

CATHODE

Q13

200 kΩ

50 kΩ

Q10

300 kΩ

Q9

7.5 kΩ

Q4 Q7

Q3

Q1

20 pF 20 pF

Q2

100 kΩ

NOTE A: All component values shown are nominal.

Q5

500 Ω 60 kΩ

600 kΩ

Q12

Q11

Q6 Q8

absolute maximum ratings over operating free-air temperature range

500 Ω

Q14

500 Ω

ANODE

†

Reverse current, IR 30 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Forward current, IF 10 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Package thermal impedance, θ

Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds 260°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Storage temperature range, T

†

Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

NOTES: 1. Maximum power dissipation is a function of T

temperature is PD = (T

2. The package thermal impedance is calculated in accordance with JESD 51, except for through-hole packages which use a trace
length of zero.

recommended operating conditions

Reference current, I

p

2

Z

p

J(max)

A

(see Notes 1 and 2): D package 97°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . .

JA

LP package 156°C/W. . . . . . . . . . . . . . . . . . . . . . . . .

–65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

stg

,

θ

– TA)/

J(max)

θ

. Operation at the absolute maximum TJ of 150°C can impact reliability.

JA

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

, and TA. The maximum allowable power dissipation at any allowable ambient

JA

MIN MAX UNIT

0.02 20 mA
LM285-2.5 –40 85
LM385-2.5, LM385B-2.5 0 70

°

PARAMETER

T

†

UNIT

Change in

Z

µ

∆V

mV

Z

µ

I

100 µA

Ω

PARAMETER

TEST CONDITIONS

UNIT

LM285-2.5, LM385-2.5, LM385B-2.5

MICROPOWER VOLTAGE REFERENCES

SLVS023E – JANUARY 1989 – REVISED JULY 1999

electrical characteristics at specified free-air temperature

TEST

CONDITIONS

Z

Reference
voltage

Average
temperature
coefficient of
reference

‡

voltage

reference
voltage with
current

Long-term
change in
reference
voltage

Minimum
reference
current

Reference
impedance

Broadband
noise voltage

V

Z

α

VZ

∆VZ/∆t

I

Z(min)

z

z

V

n

†

Full range is 0°C to 70°C for the LM385-2.5 and LM385B-2.5, and –40°C to 85°C for the LM285-2.5.

‡

The average temperature coefficient of reference voltage is defined as the total change in reference voltage divided by the specified temperature
range.

IZ = 20 µA
to 20 mA

IZ = 20 µA
to 20 mA

I

= 20 µA

to 1 mA
I

= 1 µA

to 20 mA

IZ = 100 µA 25°C ±20 ±20 ±20 ppm/khr

=

Z

IZ = 100 µA,
f = 10 Hz
to 10 kHz

A

25°C 2.462 2.5 2.538 2.425 2.5 2.575 2.462 2.5 2.538 V

25°C ±20 ±20 ±20 ppm/°C

25°C 1 2 2

Full range 1.5 2 2

25°C 10 20 20

Full range 30 30 30

Full range 8 20 8 20 8 20 µA

25°C 0.2 0.6 0.4 1 0.4 1

Full range 1.5 1.5 1.5

25°C 120 120 120 µV

LM285-2.5 LM385-2.5 LM385B-2.5

MIN TYP MAX MIN TYP MAX MIN TYP MAX

electrical characteristics at TA = 25°C

LM385Y-2.5

MIN TYP MAX

V

Z

α

VZ

∆VZ/∆t Long-term change in reference voltage IZ = 100 µA ±20 ppm/khr
z

z

V

n

‡

The average temperature coefficient of reference voltage is defined as the total change in reference voltage divided by the specified temperature
range.

Reference voltage IZ = 20 µA to 20 mA 2.462 2.5 2.575 V
Average temperature coefficient of reference voltage

Reference impedance IZ = 100 µA 0.4 1 Ω
Broadband noise voltage

‡

IZ = 20 µA to 20 mA ±20 ppm/°C

IZ = 100 µA,
f = 10 Hz to 10 kHz

120 µV

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

3

LM285-2.5, LM385-2.5, LM385B-2.5
MICROPOWER VOLTAGE REFERENCES

SLVS023E – JANUARY 1989 – REVISED JULY 1999

100

TA = –55°C to 125°C

AµI

10

1

– Reverse Current –

R

0.1
0 0.5 1 1.5

REVERSE CURRENT

vs

REVERSE VOLTAGE

2

VR – Reverse Voltage – V

Figure 1

TYPICAL CHARACTERISTICS

REFERENCE VOLTAGE CHANGE

16

TA = –55°C to 125°C

12

8

4

– Reference Voltage Change – mV

0

Z

∆V

2.5 3

– 4

0.01 0.1 1 10 100

†

vs

REVERSE CURRENT

IR – Reverse Current – mA

Figure 2

FORWARD VOLTAGE

vs

FORWARD CURRENT

1.6

1.4

1.2

0.8

0.6

– Forward Voltage – V

F

V

0.4

0.2

TA = 25°C

1

0

0.01 0.1 1 10 100
IF – Forward Current – mA

Figure 3

2.525

2.52

2.515

2.51

2.505

2.5

– Reference Voltage – V

2.495

Z

V

2.49

2.485

2.48
– 55 – 35 – 15 5

REFERENCE VOLTAGE

FREE-AIR TEMPERATURE

IZ = 20 µA to 20 mA

25

TA – Free-Air Temperature – °C

Figure 4

vs

45 65

105 12585

†

Data at high and low temperatures are applicable only within the rated operating free-air temperature ranges of the various devices.

4

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

LM285-2.5, LM385-2.5, LM385B-2.5

MICROPOWER VOLTAGE REFERENCES

SLVS023E – JANUARY 1989 – REVISED JULY 1999

TYPICAL CHARACTERISTICS

REFERENCE IMPEDANCE

vs

REFERENCE CURRENT

1000

f = 25 Hz
TA = MIN to MAX

Ω

100

10

– Reference Impedance –

1

z

z

0.1

0.01 0.1 1 10 100
Iz – Reference Current – mA

‡

Figure 5

†

REFERENCE IMPEDANCE

FREQUENCY

10 k

IZ = 100 µA
TA = 25°C

1 k

100

10

– Reference Impedance – Ω

z

z

1

0.1

0.01 0.1 1 10
f – Frequency – kHz

Figure 6

vs

1000100

NOISE VOLTAGE

vs

FREQUENCY

1400

IZ = 100 µA
TA = 25°C

1200

Hz

1000

nV/

800

600

– Noise Voltage –

400

n

V

200

0

10 100 1 k 10 k 100 k

f – Frequency – Hz

Figure 7

FILTERED RMS OUTPUT NOISE VOLTAGE

vs

FREQUENCY

120

100 µA

100

80

60

40

20

Filtered RMS Output Noise Voltage – Vµ

0

0.1 1 10

RC Low Pass

R

C

f – Frequency – kHz

Figure 8

TA = 25°C

100

†

Data at high and low temperatures are applicable only within the rated operating free-air temperature ranges of the various devices.

‡

For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

5

LM285-2.5, LM385-2.5, LM385B-2.5

ÎÎ

MICROPOWER VOLTAGE REFERENCES

SLVS023E – JANUARY 1989 – REVISED JULY 1999

TYPICAL CHARACTERISTICS

TRANSIENT RESPONSE

4

3

2

1

0

Input and Output Voltages – V

5

0

V

0 100 500 600

Output

24 kΩ

I

Input

t – Time – µs

Figure 9

†

V

O

†

Data at high and low temperatures are applicable only within the rated operating free-air temperature ranges of the various devices.

6

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

LM285-2.5, LM385-2.5, LM385B-2.5

MICROPOWER VOLTAGE REFERENCES

SLVS023E – JANUARY 1989 – REVISED JULY 1999

APPLICATION INFORMATION

IO ≈ 60 µA

+

Two Mercury

Cells

–

2.6 V

†

Adjust for 12.17 mV at 25°C across 412 Ω

3.3 kΩ

LM385-2.5

Figure 10. Thermocouple Cold-Junction Compensator

200 kΩ ±1%

Type K

V+

LM334

cw

20 kΩ

953 Ω
±1%

+

–

Meter

3.7 V ≤ V+ ≤ 30 V

R

V–

2.74 kΩ

V+

LM334

V–

412 Ω
±1%

†

2.00 kΩ ±1%

R

cw

500 Ω

2.5 V

LM385-2.5

Figure 11. Operation Over a Wide Supply Range

9 V

221 kΩ

LM385-2.5

Figure 12. Reference From a 9-V Battery

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

7

IMPORTANT NOTICE

T exas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue
any product or service without notice, and advise customers to obtain the latest version of relevant information
to verify, before placing orders, that information being relied on is current and complete. All products are sold
subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those
pertaining to warranty, patent infringement, and limitation of liability.

TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in
accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent
TI deems necessary to support this warranty . Specific testing of all parameters of each device is not necessarily
performed, except those mandated by government requirements.

CERTAIN APPLICA TIONS USING SEMICONDUCT OR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF
DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL
APPLICATIONS”). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, OR
WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEVICES OR SYSTEMS OR OTHER
CRITICAL APPLICA TIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERST OOD TO
BE FULLY AT THE CUSTOMER’S RISK.

In order to minimize risks associated with the customer’s applications, adequate design and operating
safeguards must be provided by the customer to minimize inherent or procedural hazards.

TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent
that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other
intellectual property right of TI covering or relating to any combination, machine, or process in which such
semiconductor products or services might be or are used. TI’s publication of information regarding any third
party’s products or services does not constitute TI’s approval, warranty or endorsement thereof.

Copyright  1999, Texas Instruments Incorporated