Document
PRECISION 2.45 VOLT VOLTAGE REFERENCE
ISSUE 3 — MARCH 1998
ZRA245
FEATURES
DEVICE DESCRIPTION
The ZRA245 uses a bandgap circuit design to achieve a precision voltage reference of 2.45 volts. The device is available in small outline surface mount packages, ideal for a p pl i c a t i on s whe re s pac e s av i ng i s important. The ZRA245 design provides a stable voltage without an external capacitor and is stable with capacitive loads. The ZRA245 is recommended for operation between 2mA and 120mA.
• • • • • • • • • • • • •
Small outline SOT23, SO8 and TO92 style package No stabilising capacitor required Typical TC 15ppm/°C Typical slope resistance 0.26Ω ± 3% , 2% and 1% tolerance Industrial temperature range Operating current 2mA to 120mA
APPLICATIONS Battery powered and portable equipment. Metering and measurement systems. Instrumentation. Test equipment. Data acquisition systems. Precision power supplies.
SCHEMATIC DIAGRAM
VR
1.25VREF
Gnd
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ZRA245
ABSOLUTE MAXIMUM RATING
Reverse Current Forward Current Operating Temperature Storage Temperature 200mA 25mA -40 to 85°C -55 to 125°C Power Dissipation (Tamb=25°C) SOT23 330mW E-Line, 3 pin (TO92) 500mW E-Line, 2 pin (TO92) 500mW SO8 625mW
ELECTRICAL CHARACTERISTICS TEST CONDITIONS (Unless otherwise stated) Tamb=25°C
SYMBOL PARAMETER CONDITIONS MIN VR Reverse Breakdown Voltage IR=5mA 2.43 2.40 2.38 LIMITS TYP MAX 2.45 2.47 2.45 2.50 2.45 2.52 2 2 120 1 2 3 V TOL. % UNITS
IMIN IR TC † RS § ZR
Minimum Operating Current Recommended Operating Current Average Reverse Breakdown Voltage Temp. Co. Slope Resistance Reverse Dynamic Impedance
mA mA
15 IR(min) to IR(max) IR = 5mA f = 100Hz IAC= 0.1 IR IR = 5mA f = 10Hz to 10kHz
50
ppm/°C Ω Ω
0.26 0.5 0.28 1
EN
Wideband Noise Voltage
65 µV(rms)
†
TC =
(VR(max)−VR(min)) x 1000000
VR x (T(max)−T(min))
Note: VR(max) - VR(min) is the maximum deviation in reference voltage measured over the full operating temperature range.
§
RS =
VR Change(IR (min) to IR (max)) IR (max) − IR (min)
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ZRA245
TYPICAL CHARACTERISTICS
1.6 1.4 1.2 1.0 0.8 0.6 0.4 1 2.46
Reference voltage (V)
10 100 1000
Forward Voltage (V)
2.45
2.44
2.43 -40
-20
0
20
40
60
80
Forward Current (mA)
Temperature (°C)
Forward Characteristics
Temperature Drift
100 0.6 TA=-40°C
IR=2mA
Slope resistance (Ω)
Slope resistance (Ω)
0.4 TA=25°C 0.2 TA=85°C
10
IR=5mA
IR=20mA
1
0 1 10 100
0.1 0.01 0.1 1 10 100
Reference Current (mA)
Frequency (KHz)
Slope Resistance v Current
Slope Resistance v Frequency
3.0
20mA 2mA
3K6 2mA
4.0 TA=25°C
VR - (V)
2.0
VIN
0.36K 20mA
1.0 0 10
VR
Reverse Current (mA)
2.0
VIN - (V)
0 0 5 10 15 20
0 0 1.0 2.0 3.0
Time (µs)
Reverse Voltage (V)
Transient Response
Reverse Characteristics
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ZRA245
CONNECTION DIAGRAMS
E-Line, 2 pin Package Suffix – Y E-Line, 3 pin,Rev Package Suffix – R
Bottom View
Bottom View – Pin 3 floating or connected to pin 1
E-Line, 3 pin Package Suffix – A
SO8 Package Suffix – N8
Bo.