VRE302-6LS [ETC]
Analog IC ; 模拟IC\n
| 型号： | VRE302-6LS |
| 厂家： | 
ETC |
| 描述： | Analog IC
|
| 文件： | 总5页 (文件大小：435K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
VRE302
Low Cost
Precision Reference
THALER CORPORATION • 2015 N. FORBES BOULEVARD • TUCSON, AZ. 85745 • (520) 882-4000
FEATURES
• 2.500 V OUTPUT ± 0.250 mV (.01%)
PIN CONFIGURATION
• TEMPERATURE DRIFT: 0.6 ppm/°C
8
7
6
1
2
3
N.C.
+VIN
NOISE
REF. GND
VOUT
• LOW NOISE: 1.5µV p-p (0.1-10Hz)
VRE302
• INDUSTRY STD PINOUT- 8 PIN DIP OR
TOP
TEMP
SURFACE MOUNT PACKAGE
VIEW
4
5
GND
TRIM
•EXCELLENT LINE REGULATION: 6ppm/V Typ.
• OUTPUT TRIM CAPABILITY
FIGURE 1
DESCRIPTION
The VRE302 is a low cost, high precision 2.5V
reference. Packaged in the industry standard 8
pin DIP, the device is ideal for upgrading systems
that use lower performance references.
The VRE302 is recommended for use as a
reference for 14, 16, or 18 bit D/A converters
which require an external precision reference.
The device is also ideal for calibrating scale factor
on high resolution A/D converters. The VRE302
offers superior performance over monolithic
references.
The device provides ultrastable +2.500V output
with ±0.2500 mV (.01%) initial accuracy and a
temperature coefficient of 0.6 ppm/°C.
This
improvement in accuracy is made possible by a
unique, patented multipoint laser compensation
technique developed by Thaler Corporation.
Significant improvements have been made in
other performance parameters as well, including
initial accuracy, warm-up drift, line regulation, and
long-term stability, making the VRE302 series the
most accurate reference available in the standard
8 pin DIP package.
SELECTION GUIDE
Temp.
Range
°C
Temp.
Coeff.
Initial
Error
mV
Model
ppm/°C
VRE302A
VRE302B
VRE302C
VRE302J
VRE302K
VRE302L
0.25
0.40
0.50
0.25
0.40
0.50
0.6
1.0
2.0
0.6
1.0
2.0
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
For enhanced performance, the VRE302 has an
external trim option for users who want less than
0.01% initial error. A reference ground pin is
provided to eliminate socket contact resistance
errors.
For package option add D for DIP or S for Surface Mount
to end of model number.
VRE302DS REV. F MAY 2001
ELECTRICAL SPECIFICATIONS
VRE302
Vps =+15V, T = 25°C, RL = 10KΩ unless otherwise noted.
MODEL
A/J
B/K
C/L
PARAMETER
ABSOLUTE RATINGS
MIN
TYP
MAX
MIN
TYP
MAX
MIN
TYP
MAX
UNITS
Power Supply
+13.5 +15
+22
+70
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
V
Operating Temp. (A,B,C)
Operating Temp. (J,K,L)
Storage Temperature
Short Circuit Protection
0
°C
°C
°C
-40
-65
+85
+150
Continuous
OUTPUT VOLTAGE
VRE302
2.500
630
*
*
*
*
V
(1)
Temp. Sensor Voltage
mV
OUTPUT VOLTAGE ERRORS
(2)
Initial Error
0.25
0.6
0.40
1.0
0.50
2.0
mV
ppm
Warmup Drift
1
2
3
(3)
Tmin - Tmax
ppm/°C
ppm/1000hrs
µVpp
Long-Term Stability
6
*
*
*
*
(4)
Noise (.1-10Hz)
1.5
OUTPUT CURRENT
Range
±10
*
*
mA
REGULATION
Line
6
3
10
*
*
*
*
*
*
*
*
ppm/V
Load
ppm/mA
OUTPUT ADJUSTMENT
Range
10
5
*
*
*
*
mV
mA
(5)
POWER SUPPLY CURRENTS
VRE302 +PS
7
4. The specified values are without the external
noise reduction capacitor.
NOTES: *Same as A/J Models.
1. The temp. reference TC is 2.1mV/ °C
2. The specified values are without external trim.
5. The specified values are unloaded.
3. The temperature coefficient is determined by the box
method using the following formula:
Vmax - Vmin
T.C. =
x 106
Vnominal x (Tmax-Tmin
)
VRE302DS REV. F MAY 2001
TYPICAL PERFORMANCE CURVES
VOUT vs. TEMPERATURE
VOUT vs. TEMPERATURE
VOUT vs. TEMPERATURE
Temperature oC
VRE302A
Temperature oC
VRE302B
Temperature oC
VRE302C
VOUT vs. TEMPERATURE
VOUT vs. TEMPERATURE
VOUT vs. TEMPERATURE
Temperature oC
VRE302K
Temperature oC
VRE302J
Temperature oC
VRE302L
POSITIVE OUTPUT (TYP)
JUNCTION TEMP. RISE VS. OUTPUT CURRENT
QUIESCENT CURRENT VS. TEMP
PSRR VS. FREQUENCY
Temperature oC
Output Current (mA)
Frequency
(Hz)
VRE302DS REV. F MAY 2001
DISCUSSION OF PERFORMANCE
THEORY OF OPERATION
The following discussion refers to the schematic in
figure 2 below. A FET current source is used to bias a
6.3V zener diode. The zener voltage is divided by the
resistor network R1 and R2. This voltage is then applied
to the noninverting input of the operational amplifier which
amplifies the voltage to produce a 2.500V output. The
gain is determined by the resistor networks R3 and R4:
G=1 + R4/R3. The 6.3V zener diode is used because it is
the most stable diode over time and temperature.
This network is less than 2% of the overall network
resistance so it has a negligible effect on long term
stability.
Figure 3 shows the proper connection of the VRE302
series voltage references with the optional trim resistor for
initial error. The VRE302 reference has the ground
terminal brought out on two pins (pin 4 and pin 7) 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 20ppm. By
connecting pin 4 to the power supply ground and pin 7 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. Pay careful attention to the circuit layout to
avoid noise pickup and voltage drops in the lines.
The current source provides a closely regulated zener
current, which determines the slope of the references’
voltage 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
temperature ranges.
Thaler Corporation has developed
a
nonlinear
compensation network of thermistors and resistors that is
used in the VRE series voltage references. This
proprietary network eliminates most of the nonlinearity in
the voltage vs. temperature function. By adjusting the
slope, Thaler Corporation produces a very stable voltage
over wide temperature ranges.
VRE302
FIGURE 2
EXTERNAL CONNECTIONS
+ VIN
V TEMP OUT
2
3
8
+ VOUT
6
VRE302
OPTIONAL
CN
OPTIONAL
FINE TRIM
10kΩ
5
NOISE REDUCTION
CAPACITOR
1µF
ADJUSTMENT
4
7
REF. GND
FIGURE 3
VRE302DS REV. F MAY 2001
MECHANICAL
FIGURE 3
D
D1
INCHES
MILLIMETER
INCHES
MILLIMETER
D2
DIM MIN
MAX MIN MAX
DIM
D2
E
MIN
.018
.507
.397
.264
.085
.020
.045
MAX MIN MAX
.023 0.46 0.58
.513 12.8 13.0
.403 10.0 10.2
.270 6.70 6.85
.095 2.15 2.41
.030 .508 .762
.055 1.14 1.39
A
.115 .125 2.92 3.17
.098 .102 2.48 2.59
.046 .051 1.14 1.29
.107 .113 2.71 2.89
.009 .012 0.22 0.30
.052 .058 1.32 1.47
.397 .403 10.0 10.2
.372 .380 9.44 9.65
B
B1
C
E1
E2
P
E1
E2
E
C1
C2
D
Q
S
D1
PIN 1 IDENTIFIER
E1
Q
A
P
BASE
SEATING
C1
C2
B
C
S
B1
FIGURE 4
INCHES
MILLIMETER
MAX
INCHES
MILLIMETER
DIM MIN MAX MIN
DIM
E
MIN
.397
.264
.290
.195
.085
.055
.045
MAX MIN
MAX
10.2
6.85
7.87
5.46
2.41
1.65
1.39
A
.115 .125 2.92 3.17
.018 .022 .457 .558
.046 .051 1.14 1.29
.098 .102 2.48 2.59
.009 .012 0.22 0.30
.397 .403 10.0 10.2
.372 .380 9.44 9.65
.403 10.0
.270 6.70
.310 7.36
.215 4.95
.095 2.15
.065 1.39
.055 1.14
B
E1
G1
L
B1
B2
C
P
D
Q
D 1
S
VRE302DS REV. F MAY 2001
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