2.5V LOW POWER
PRECISION REFERENCE SOURCE
ISSUE 1 - OCTOBER 1995
ZRT025
DEVICE DESCRIPTION
The ZRT025 is a monolithic integrated circuit
providing a precise stable reference voltage
of 2.5V at 500
A.
The circuit features a knee current of 150
A
and ope ra tion over a wide range of
temperatures and currents.
The ZRT025 is available in a 3-pin metal can
package for through hole applications as
well as SOT223 and SO8 packages for
surface mount applications. Each package
option offers a trim facility whereby the
output voltage can be adjusted as shown in
F i g . 1 . T h i s f a c i l i t y i s u s e d w h e n
compensating for system errors or setting
the reference output to a particular value.
When the trim facility is not used, the pin
should be left open circuit.
FEATURES
Trimmable output
Excellent temperature stability
Low output noise figure
Available in two temperature ranges
1 and 2% initial voltage tolerance
versions available
No external stabilising capacitor
required in most cases
Low slope resistance
No derating required at low
temperatures
TO18 package
SOT223 and SO8 small outline
packages
R
V
CC
V
R
G
nd
G
nd
R
T
=100k
(Optional trim facility)
R=V
CC
-V
R
I
R
This circuit will allow the reference to be
trimmed over a wide range. The device is
specified over a 5% trim range
.
SCHEMATIC DIAGRAM
4-279
ABSOLUTE MAXIMUM RATING
Reverse Current
75mA
Operating Temperature
A grade
-55C to 125C
C grade
0C to 70C
Storage Temperature
TO18
-55 C to 175 C
SO8, SOT223 -55 C to 125 C
Power Dissipation (T
amb
=25C)
TO18
300mW
SO8
625mW
SOT223
2W
Above 72C this figure should be linearly
derated to 25mA at 125C
ELECTRICAL CHARACTERISTICS
( at T
amb
=25C and Trim pin o/c unless otherwise stated)
SYMBOL
PARAMETER
MIN.
TYP.
MAX. UNITS
COMMENTS
V
R
Output voltage
1% tolerance (A1,C1)
2% tolerance (C2)
2.475
2.450
2.500
2.500
2.525
2.550
V
I
R
=500
A
V
TRIM
Output voltage adjustment
range
5
%
R
T
=100k
T
C
V
TRIM
Change in T
C
V
R
with output
adjustment
2.5
ppm/C/%
I
R
Operating current range
0.15
75
mA
t
on
t
off
Turn-on time
Turn-off time
10
0.3
s
R
L
=1k
e
np-p
Output voltage noise (over the
range 0.1 to 10Hz)
50
V
Peak to peak
measurement
R
S
Slope resistance
0.85
2.0
I
R
= 0.5mA to
5mA
See note (c)
ZRT025
TEMPERATURE DEPENDENT ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
INITIAL
VOLTAGE
TOLERANCE
%
GRADE A
-55C TO 125C
GRADE C
0C TO 70C
UNITS
TYP
MAX
TYP
MAX
V
R
Output voltage change
over relevant
temperature range
(See note (a))
1 & 2
6.8
22.5
2.7
8.8
mV
T
C
V
R
Output voltage
temperature coefficient
(See note (b))
1 & 2
15.0
50.0
15.0
50.0
ppm/C
4-280
TYPICAL CHARACTERISTICS
ZRT025
NOTES
(a) Output change with temperature
The absolute maximum difference between
the maximum output voltage and the
minimum output voltage over the specified
temperature range
V
R
= V
max
- V
min
(b) Output temperature coefficient (T
C
V
R
)
The ratio of the output change with
temperature to the specified temperature
range expressed in ppm/C
T
c
V
R
=
V
R
x
10
6
V
R
x
T
ppm
/
C
T= Full temperature range
(c) Slope
resistance
(R
S
)
The slope resistance is defined as :
R
S
=
change
in
V
R
specifiedcurrentrange
I = 5 - 0.5 = 4.5mA (typically)
(d) Line
regulation
The ratio of change in output voltage to the
change in input voltage producing it.
R
S
x 100
V
R
x
R
source
%
/
V
4-281
SO8 Package Suffix N8
Top
View
TO18 Package Suffix None
Bottom View
Case
is
internally
connected
to
pin
3
SOT223
Package
Suffix G
Top
View
Pin 4 floating or connected to pin 2
CONNECTION DIAGRAMS
Part No
Tol% Operating
Temp.(C)
Package
Partmark
ZRT025C2
2
0 to 70
TO18
ZRT025C2
ZRT025C1
1
0 to 70
TO18
ZRT025C1
ZRT025A1
1
-55 to 125
TO18
ZRT025A1
ZRT025GC2
2
0 to 70
SOT223
ZRT025C2
ZRT025GC1
1
0 to 70
SOT223
ZRT025C1
ZRT025GA1
1
-55 to 125
SOT223
ZRT025A1
ZRT025N8C2
2
0 to 70
SO8
ZRT025C2
ZRT025N8C1
1
0 to 70
SO8
ZRT025C1
ZRT025N8A1
1
-55 to 125
SO8
ZRT025A1
ORDERING INFORMATION
ZRT025
4-282
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