PRECISION 2.5 VOLT MICROPOWER
VOLTAGE REFERENCE
ISSUE 2 - FEBRUARY 1998
DEVICE DESCRIPTION
The ZREF25 uses a bandgap circuit design to
achieve a precision micropower voltage
reference of 2.5 volts. The device is available
in a small outline surface mount package,
ideal for applications where space saving is
important as well as packages for through
hole requirements.
The ZREF25 design provides a stable voltage
without an external capacitor and is stable
with capacitive loads. The ZREF25 is
recommended for operation between 50µA
and 5mA and so is ideally suited to low
power and battery powered applications.
Excellent performance is maintained to an
absolute maximum of 25mA, however the
rugged design and 20 volt processing allows
the reference to withstand transient effects
and currents up to 200mA. Superior
switching capability allows the device to
reach stable operating conditions in only a
few microseconds.
ZREF25
FEATURES
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Small outline SO8 and TO92 style
packages.
No stabilising capacitor required
Typical T
C
30ppm/°C
Typical slope resistance 0.4Ω
2% and 1% tolerance
Industrial temperature range (Military
temperature range available on request)
Operating current 50µA to 5mA
Transient response, stable in less than 10µs
Alternative package options and
tolerances are available
APPLICATIONS
Battery powered and portable equipment.
Metering and measurement systems.
Instrumentation.
Test equipment.
Data acquisition systems.
Precision power supplies.
SCHEMATIC DIAGRAM
V
R
G
nd
4-271
ZREF25
ABSOLUTE MAXIMUM RATING
Reverse Current
Forward Current
Operating Temperature
Storage Temperature
25mA
25mA
-40 to 85°C
-55 to 125°C
Power Dissipation (T
amb
=25°C)
E-Line, 3 pin (TO92)
500mW
E-Line, 2 pin (TO92)
500mW
SO8
625mW
ELECTRICAL CHARACTERISTICS
TEST CONDITIONS (Unless otherwise stated) T
amb
=25°C
SYMBOL PARAMETER
CONDITIONS
MIN
V
R
I
MIN
I
R
T
C
†
R
S
§
Z
R
Reverse Breakdown Voltage
Minimum Operating Current
Recommended Operating
Current
Average Reverse Breakdown
Voltage Temp. Co.
I
R(min)
to
I
R(max)
Slope Resistance
Reverse Dynamic Impedance
I
R
= 1mA
f = 100Hz
I
AC
= 0.1 I
R
I
R
= 150µA
f = 10Hz to
10kHz
0.05
30
0.4
0.3
I
R
=150µA
LIMITS
TYP MAX
2.525 1
2.55
2
50
5
90
2
0.8
V
µA
mA
ppm/°C
Ω
Ω
TOL.
%
UNITS
2.475 2.5
2.45
2.5
25
E
N
Wideband Noise Voltage
45
µV(rms)
Reverse Current (µA)
†
(
V
R
(
max
)
−
V
R
(
min
)
)
x
1000000
T
C
=
V
R
x
(
T
(
max
)
−
T
(
min
)
)
60
50
40
30
20
10
0
0.2
0.6
1.0
1.4
1.8
2.2
2.6
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
)
5°C
=8
T
A
°C
25
°C
A
=
0
T
=-4
T
A
Reverse Voltage (V)
Reverse Characteristics
4-272
ADI Reference Circuit
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