SCHEMATIC DIAGRAM
PRECISION 2.5 VOLT MICROPOWER
VOLTAGE REFERENCE
ISSUE 5 FEBRUARY 1998
DEVICE DESCRIPTION
The ZR285 uses a bandgap circuit
d e s i g n t o a c h i e v e a p r e c i s i o n
micropower voltage reference of 2.5
volts. The device is available in small
outline surface mount packages, ideal
for applications where space saving is
important, as well as packages for
through hole requirements.
The ZR285 design provides a stable
voltage without an external capacitor
and is stable with capacitive loads. The
ZR285 is recommended for operation
between 20
A and 20mA and so is
ideally suited to low power and battery
powered applications.
Excellent performance is maintained to
an absolute maximum of 30mA,
however the rugged design and 20 volt
processing allows the reference to
w i t h s t a n d t r a ns i e nt e f f e c t s a n d
currents up to 200mA. Superior
switching capability allows the device
to reach stable operating conditions in
only a few microseconds.
FEATURES
Small outline SOT23 and SO8 packages
TO92 style packages
No stabilising capacitor required
Low knee current, 15
A typical
Typical T
C
30ppm/C
Typical slope resistance 0.4
3%, 2% and 1% tolerance
Industrial temperature range
Operating current 20
A to 20mA
APPLICATIONS
Battery powered and portable equipment.
Metering and measurement systems.
Instrumentation.
Test equipment.
Data acquisition systems.
Precision power supplies.
V
R
G
nd
ZR285-2.5
4-165
ABSOLUTE MAXIMUM RATING
Reverse Current
30mA
Forward Current
25mA
Operating Temperature
-40 to 85C
Storage Temperature
-55 to 125C
Power Dissipation (T
amb
=25C)
SO8
625mW
SOT23
330mW
E-Line,2 Pin(TO92)
500mW
E-Line,3 Pin(TO92)
500mW
ELECTRICAL CHARACTERISTICS
TEST CONDITIONS (Unless otherwise stated) T
amb
=25C
SYMBOL PARAMETER
CONDITIONS
LIMITS
TOL.
%
UNITS
MIN
TYP MAX
V
R
Reverse Breakdown Voltage
I
R
=150
A
2.475
2.45
2.425
2.5
2.5
2.5
2.525
2.55
2.575
1
2
3
V
I
MIN
Minimum Operating Current
13
20
A
I
R
Recommended Operating
Current
0.02
20
mA
T
C
Average Reverse Breakdown
Voltage Temp. Co.
I
R
= 1mA to
20mA
30
90
ppm/C
R
S
Slope Resistance
0.4
1
Z
R
Reverse Dynamic Impedance
I
R
= 1mA
f = 100Hz
I
AC
= 0.1 I
R
0.3
0.8
E
N
Wideband Noise Voltage
I
R
= 150
A
f = 10Hz to
10kHz
60
V (rms)
ZR285-2.5
R
ev
ers
e
C
ur
r
e
nt (
A
)
Reverse Characteristics
Reverse Voltage (V)
0
1.0
2.0
3.0
T
A
=25C
0
10
20
30
40
T
C
=
(
V
R
(
max
)
-
V
R
(
min
)
)
x 1000000
V
R
x
(
T
(
max
)
-
T
(
min
)
)
Note: V
R(max)
- V
R(min)
is the maximum
deviation in reference voltage measured
over the full operating temperature
range.
R
S
=
V
R
Change
(
I
R
(
min
)
to I
R
(
max
))
I
R
(
max
)
-
I
R
(
min
)
4-166
-40
-20
0
20
40
60
80
2.47
2.48
2.49
2.50
2.51
0.1
1
10
100
0.2
0.4
0.6
0.8
1.0
1.2
1.4
10
100
1K
10K
100K
1
10
100
1000
0
4
8
12
16
0
1
2
0
10
0
4
8
12
16
0
10
2
1
0
TYPICAL CHARACTERISTICS
Transient Response - Single pulse
Transient Response - Repetitive Test
Temperature (C)
Reference Current (mA)
Temperature Drift
Slope Resistance v Current
R
ef
erence v
ol
tage
(V)
S
l
ope resi
s
t
a
nce
(
)
Time (
s)
Slope Resistance v Frequency
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0.001
0.01
0.1
1
10
100
F
orw
ard V
ol
t
a
ge
(V)
Forward Characteristics
Forward Current (mA)
Time (
s)
S
l
ope resi
s
t
a
nce
(
)
V
I
N
(
V)
V
R
(
V)
Frequency (kHz)
V
I
N
(
V)
V
R
(V
)
I
R
=150
A to 5mA
I
R
=150
A
I
R
=1mA
I
R
=5mA
I
R
=5mA
I
R
=150
A
I
R
=5mA
I
R
=150
A
3
85C
25C
-40C
ZR285-2.5
4-167
ZR285-2.5
SO8 Package
Suffix N8
Top
View
SOT23 Package
Suffix F
Top
View
Pin 1 floating or connected to pin 2
E-Line, 3 pin,Rev Package Suffix R
Bottom View
Pin 3 floating or connected to pin 1
E-Line, 2 pin Package Suffix Y
Bottom
View
CONNECTION DIAGRAMS
Part No
Tol% Package
Partmark
ZR285F03
3
SOT23
28A
ZR285F02
2
SOT23
28B
ZR285F01
1
SOT23
28C
ZR285N803
3
SO8
ZR285803
ZR285N802
2
SO8
ZR285802
ZR285N801
1
SO8
ZR285801
ZR285R03
3
E-Line *
ZR28503
ZR285R02
2
E-Line *
ZR28502
Part No
Tol% Package
Partmark
ZR285R01
1
E-Line *
ZR28501
ZR285Y03
3
E-Line
ZR28503
ZR285Y02
2
E-Line
ZR28502
ZR285Y01
1
E-Line
ZR28501
* E-Line 3 pin Reversed
E-Line 2 pin
ORDERING INFORMATION
4-168
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