LM285-1.2, LM385-1.2, LM385B-1.2
MICROPOWER VOLTAGE REFERENCES
SLVS075C – APRIL 1989 – REVISED JULY 1999
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
D
Operating Current Range
– LM285 . . . 10 µA to 20 mA
– LM385 . . . 15 µA to 20 mA
– LM385B ...15 µA to 20 mA
D
1% and 2% Initial Voltage Tolerance
D
Reference Impedance
– LM385...1 Ω Max at 25°C
– All Devices . . . 1.5 Ω Max Over Full
T emperature Range
D
Very Low Power Consumption
D
Applications:
– Portable Meter References
– Portable Test Instruments
– Battery-Operated Systems
– Current-Loop Instrumentation
– Panel Meters
D
Designed to be Interchangeable With
National LM285-1.2 and LM385-1.2
description
These micropower, two-terminal, band-gap voltage references operate over a 10-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 be used to 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 LM285-1.2 is characterized for operation from –40°C to 85°C. The LM385-1.2 and LM385B-1.2 are
characterized for operation from 0°C to 70°C.
AVAILABLE OPTIONS
Z
TOLERANCE
SMALL OUTLINE
(D)
PLASTIC
(LP)
2% LM385D-1.2 LM385LP-1.2
1% LM385BD-1.2 LM385BLP-1.2
LM385Y-1.2
–40°C to 85°C 1% LM285D-1.2 LM285LP-1.2
The D package is available taped and reeled. Add the suffix R to the device type (e.g., LM385DR-1-2).
The chip form is tested at TA = 25°C.
†
For ordering purposes, the decimal point in the part number must be replaced with a hyphen (i.e., show
the -1.2 suffix as “-1-2”).
Copyright 1999, Texas Instruments Incorporated
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.
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.
1
2
3
4
8
7
6
5
NC
NC
NC
ANODE
CATHODE
NC
NC
NC
D PACKAGE
(TOP VIEW)
NC–No internal connection
LP PACKAGE
(TOP VIEW)
ANODE
CATHODE
NC
LM285-1.2, LM385-1.2, LM385B-1.2
MICROPOWER VOLTAGE REFERENCES
SLVS075C – APRIL 1989 – REVISED JULY 1999
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
symbol
ANODE
CATHODE
schematic
CATHODE
Q13
Q12
Q7
Q4
600 kΩ
7.5 kΩ
ANODE
200 kΩ
50 kΩ
300 kΩ
Q14
20 pF20 pF
Q11
Q10
Q9
Q5
Q3
Q1
Q2
Q8Q6
60 kΩ500 Ω100 kΩ
NOTE A: Component values shown are nominal.
absolute maximum ratings over operating free-air temperature range
†
Reverse current, IR 30 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Forward current, IF 10 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Package thermal impedance, θJA (see Notes 1 and 2): D package 197°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . .
LP package 156°C/W. . . . . . . . . . . . . . . . . . . . . . . . . .
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds 260°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range, T
stg
–65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
†
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
J(max)
,
θ
JA
, and TA. The maximum allowable power dissipation at any allowable ambient
temperature is PD = (T
J(max)
– TA)/
θ
JA
. Operation at the absolute maximum TJ of 150°C can impact reliability.
2. The package thermal impedance is calculated in accordance with JESD51, except for through-hole packages which use a trace
length of zero.
recommended operating conditions
MIN MAX UNIT
Reference current, I
Z
0.01 20 mA
Operating free-air temperature range, T
A
LM385-1.2, LM385B-1.2 0 70
LM285-1.2, LM385-1.2, LM385B-1.2
MICROPOWER VOLTAGE REFERENCES
SLVS075C – APRIL 1989 – REVISED JULY 1999
3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
electrical characteristics at specified free-air temperature
LM285-1.2 LM385-1.2 LM385B-1.2
MIN TYP MAX MIN TYP MAX MIN TYP MAX
V
Z
Reference
voltage
IZ = I(min)
to 20 mA
‡
25°C 1.223 1.235 1.247 1.21 1.235 1.26 1.223 1.235 1.247 V
α
VZ
Average
temperature
coefficient of
reference
voltage
§
IZ = I(min)
to 20 mA
‡
25°C ±20 ±20 ±20 ppm/°C
to 1 mA
‡
Full range 1.5 1.5 1.5
to 20 mA
Full range 30 30 30
∆VZ/∆t
Long-term
change in
reference
voltage
IZ = 100 µA 25°C ±20 ±20 ±20 ppm/khr
IZ(min)
Minimum
reference
current
Full range 8 10 8 15 8 15 µA
f = 25 Hz
Full range 1.5 1.5 1.5
V
n
Broadband
noise voltage
IZ = 100 µA,
f = 10 Hz to
10 kHz
25°C 60 60 60 µV
†
Full range is –40°C to 85°C for the LM285-1.2, and 0°C to 70°C for the LM385-1.2 and LM385B-1.2.
‡
I(min) = 10 µA for the LM285-1.2 and 15 µA for the LM385-1.2 and LM385B-1.2.
§
The average temperature coefficient of reference voltage is defined as the total change in reference voltage divided by the specified temperature
range.
electrical characteristics, TA = 25°C
V
Z
Reference voltage
IZ = 15 µA to 20 mA
1.21 1.235 1.26 V
α
VZ
Average temperature coefficient of reference voltage
§
IZ = 15 µA to 20 mA
±20 ppm/°C
∆VZChange in reference voltage with current
∆VZ/∆t Long-term change in reference voltage IZ = 100 µA ±20 ppm/khr
IZ(min) Minimum reference current 8 15 µA
z
z
Reference impedance IZ = 100 µA 0.4 1 Ω
V
n
Broadband noise voltage
IZ = 100 µA,
f = 10 Hz to 10 kHz
60 µV
§
The average temperature coefficient of reference voltage is defined as the total change in reference voltage divided by the specified temperature
range.