VRE202M [CIRRUS]
Precision Voltage Reference; 精密电压基准
| 型号： | VRE202M |
| 厂家： | 
CIRRUS LOGIC |
| 描述： | Precision Voltage Reference |
| 文件： | 总4页 (文件大小：292K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
P r o d u c t I n n o v a t i o n F r o m
VRE202
Precision Voltage Reference
FEaTuRES
DESCRIPTION
VRE202 Series Precision Voltage References provide
ultrastable +2.5 V outputs with ±200 μV initial accuracy
and temperature coefficient as low as 0.6 ppm/°C over
the full military temperature range. This improvement
in accuracy is made possible by a unique, proprietary
multipoint laser compensation technique. Significant
improvements have been made in other performance
parameters as well, including initial accuracy, warm-
up drift, line regulation, and longterm stability, making
the VRE202 series the most accurate and stable 2.5 V
surface mount references available.
♦ Very High Accuracy: +2.5 V Output, ±200 µV
♦ Extremely Low Drift: 0.6 ppm/°C (25°C to
+85°C)
♦ Low Warm-up Drift: 1 ppm Typical
♦ Excellent Stability: 6 ppm/1000 Hrs. Typical
♦ Excellent Line Regulation: 6 ppm/V Typical
♦ Hermetic 20-Terminal Ceramic LCC
♦ Military Processing Option
aPPlICaTIONS
♦ Precision A/D and D/A Converters
♦ Transducer Excitation
♦ Accurate Comparator Threshold Reference
♦ High Resolution Servo Systems
♦ Digital Voltmeters
♦ High Precision Test and Measurement Instru-
ments
VRE202 devices are available in two operating tem-
perature ranges, -25°C to +85°C and -55°C to +125°C,
and two electrical performance grades. All devices
are packaged in 20-terminal ceramic LCC packages
for maximum long-term stability. “M” versions are
screened for high reliability and quality.
Figꢀre 1. BlOCK DIaGRaM
11
SElECTION GuIDE
Temperꢂtꢀre
Operꢂting Rꢂnge
Voꢁt Deviꢂtion
(MaX)
Modeꢁ
VRE202C
VRE202CA
Oꢀtpꢀt (V)
+2.5V
+2.5V
-25°C to +85°C
-25°C to +85°C
±200µV
±100µV
VRE202M
VRE202MA
+2.5V
+2.5V
-55°C to +125°C
-55°C to +125°C
±400µV
±200µV
20-terminꢂꢁ Cerꢂmic lCC
Package Style HD
Copyright © Cirrus Logic, Inc. 2009
(All Rights Reserved)
Jul 2009
APEX − VRE202DSREVH
http://www.cirrus.com
P r o d u c t I n n o v a t i o n F r o m
VRE202
1. CHARACꢀERiSꢀiCS AnD SPECifiCAꢀionS
ElECTRICal SPECIFICaTIONS
VPS =+15V, T = +25°C, RL = 10KΩ UꢀLESS OTHERWISE ꢀOTED.
Grꢂde
C
Ca
Pꢂrꢂmeter
Min
Typ
Mꢂx
Min
Typ
Mꢂx
units
aBSOluTE MaXIMuM RaTINGS
Power Supply
+13.5
-25
+22
+85
*
*
*
*
*
*
V
Operating Temperature
Storage Temperature
Short Circuit Protection
OuTPuT VOlTaGE
VRE202
ºC
ºC
-65
+150
Continuous
*
*
+2.5
V
OuTPuT VOlTaGE ERRORS
Initial Error
±300
±200
µV
ppm
Warmup Drift
2
1
TMIꢀ - TMAX
(ꢀote1)
200
100
µV
Long-Term Stability
ꢀoise (0.1 - 10Hz)
OuTPuT CuRRENT
Range
6
*
*
ppm/1000hrs.
µVpp
1.5
±10
*
mA
REGulaTION
Line
6
3
10
*
*
*
ppm/V
Load
ppm/mA
OuTPuT aDJuSTMENT
Range
10
*
*
mV
Temperature Coefficient
4
µV/ºC/mV
POWER SuPPlY CuRRENT (ꢀote 2)
VRE202 +PS
5
5
7
7
*
*
*
*
mA
mA
VRE202 -PS
ꢀOTES:
*
Same as C Models.
1. Using the box method, the specified value is the maximum deviation from the output voltage at 25°C
over the specified operating temperature range.
2. The specified values are unloaded.
2
VRE202DS
P r o d u c t I n n o v a t i o n F r o m
VRE202
2. TYPICal PERFORMaNCE CuRVES
VOUT vs. TEMPERATURE
VOUT vs. TEMPERATURE
Temperature oC
VRE202C
Temperature oC
VRE202CA
VOUT vs. TEMPERATURE
V
OUT vs. TEMPERATURE
Temperature oC
VRE202M
Temperature oC
VRE202MA
JUNCTION TEMP. RISE VS. OUTPUT CURRENT
PSRR VS. FREQUENCY
QUIESCENT CURRENT VS. TEMP
Temperature oC
Output Current (mA)
Frequency (Hz)
VRE202DS
3
P r o d u c t I n n o v a t i o n F r o m
VRE202
3. ꢀHEoRY of oPERAꢀion
The following discussion refers to the block diagram in Figure 1. A FET current source is used to bias a 6.3 V zener
diode. The zener voltage is divided by the resistor network R1 and R2. This voltage is then applied to the noninvert-
ing input of the operational amplifier which amplifies the voltage to produce a 2.5 V output. The gain is determined
by the resistor networks R3 and R4: G=1 + R4/R3. The 6.3 V zener diode is used because it is the most stable
diode over time and temperature.
The current source provides a closely regulated zener current, which determines the slope of the references’ volt-
age vs. temperature function. By trimming the zener current a lower drift over temperature can be achieved. But
since the voltage vs. temperature function is nonlinear this compensation technique is not well suited for wide tem-
perature ranges.
A nonlinear compensation network of thermistors and resistors is used in the VRE series voltage references. this
proprietary network eliminates most of the nonlinearity in the voltage vs. temperature function. Then by adjusting
the slope, a very stable voltage over wide temperature ranges is produced. This network is less than 2% of the
overall network resistance so it has a negligible effect on long term stability. By using highly stable resistors in our
network, a voltage reference is produced that also has very good long term stability.
4. aPPlICaTION INFORMaTION
The proper connection of the VRE202 series voltage references with the optional trim resistors is shown below. Pay
careful attention to the circuit layout to avoid noise pickup and voltage drops in the lines.
The VRE202 series voltage references have the ground terminal brought out on two pins (pin 9 and pin 10) which
are connected together internally. This allows the user to achieve greater accuracy when using a socket. Voltage
references have a voltage drop across their power supply ground pin due to quiescent current flowing through the
contact resistance. If the contact resistance was constant with time and temperature, this voltage drop could be
trimmed out. When the reference is plugged into a socket, this source of error can be as high as 20 ppm. By con-
necting pin 10 to the power supply ground and pin 9 to a high impedance ground point in the measurement circuit,
the error due to the contact resistance can be eliminated. If the unit is soldered into place, the contact resistance is
sufficiently small that it does not effect performance.
PIN CONFIGuRaTION
NC NC NC VOUT NC
EXTERNal CONNECTIONS
-15V
18 17 16 15 14
2
1
20
3
19
18
NC
NC
NC
13
12
11
10
9
19
20
1
4
5
6
7
8
NC
17
+15V
VRE202
NC
TRIM
GND
REF GND
16
15
14
TOP VIEW
NC
NC
2
VOUT = +2.5V
3
Δ
9
10 11 12
13
4
5
6
7
8
Ref. Gnd.
NC VIN NC NC NC
10KΩ
4
VRE202DS
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