VRE310BS [ETC]

VRE310

Low Cost

Precision Reference

THALER CORPORATION • 2015 N. FORBES BOULEVARD • TUCSON, AZ. 85745 • (520) 882-4000

FEATURES

•

10.000 V OUTPUT ± 1.000 mV (.01%)

•

TEMPERATURE DRIFT: 0.6 ppm/°C

•

LOW NOISE: 6

µ

V

p-p

(0.1-10Hz)

•

INDUSTRY STD PINOUT- 8 PIN DIP OR

SURFACE MOUNT PACKAGE

•EXCELLENT

LINE REGULATION: 6ppm/V Typ.

•

OUTPUT TRIM CAPABILITY

FIGURE 1

N/C

+V

IN

TEMP

GND

1

2

3

4

8

PIN CONFIGURATION

NOISE

REDUCTION

REF. GND

V

OUT

TRIM

VRE310

TOP

VIEW

7

6

5

DESCRIPTION

The VRE310 is a low cost, high precision 10.0V

reference. Packaged in the industry standard 8

pin DIP, the device is ideal for upgrading systems

that use lower performance references.

The device provides ultrastable +10.000V output

with ±1.000 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 VRE310 series the

most accurate reference available in the standard

8 pin DIP package.

For enhanced performance, the VRE310 has an

external trim option for users who want less than

0.01% initial error.

For ultra low noise

applications, an external capacitor can be

attached between the noise reduction pin and the

ground pin. A reference ground pin is provided to

eliminate socket contact resistance errors.

The VRE310 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 VRE310

offers superior performance over monolithic

references.

SELECTION GUIDE

Initial

Error

mV

1.0

1.6

2.0

1.0

1.6

2.0

Model

VRE310A

VRE310B

VRE310C

VRE310J

VRE310K

VRE310L

Temp.

Coeff.

ppm/°C

0.6

1.0

2.0

0.6

1.0

2.0

Temp.

Range

°C

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 package option add D for DIP or S for Surface Mount

to end of model number.

VRE310DS REV. D MAY 2001

ELECTRICAL SPECIFICATIONS

Vps =+15V, T = 25°C, RL = 10KΩ unless otherwise noted.

VRE310

B/K

MAX

MIN

TYP

MAX

MIN

MODEL

PARAMETER

ABSOLUTE RATINGS

Power Supply

Operating Temp. (

A,B,C

)

Operating Temp. (

J,K,L

)

Storage Temperature

Short Circuit Protection

OUTPUT VOLTAGE

VRE310

(1)

Temp. Sensor Voltage

OUTPUT VOLTAGE ERRORS

Initial Error

Warmup Drift

T

min

- T

max (3)

Long-Term Stability

Noise (.1-10Hz)

(4)

OUTPUT CURRENT

Range

REGULATION

Line

Load

OUTPUT ADJUSTMENT

Range

POWER SUPPLY CURRENTS

VRE310 +PS

NOTES:

*Same as A/J Models.

(5)

(2)

A/J

MIN

TYP

C/L

TYP

MAX

UNITS

+13.5

0

-40

-65

+22

+70

+85

+150

Continuous

+15

*

*

*

*

*

*

*

*

*

*

*

*

*

*

*

*

*

*

V

°C

°C

°C

*

*

10.000

630

*

*

*

*

V

mV

1.00

1

0.6

6

6

*

*

2

1.60

3

1.0

*

*

2.00

2.0

mV

ppm

ppm/°C

ppm/1000hrs

µVpp

±10

*

*

mA

3

3

10

*

*

*

*

*

*

ppm/V

ppm/mA

20

*

*

mV

5

7

*

*

*

*

mA

1. The temp. reference TC is 2.1mV/°C

2. The specified values are without external trim.

3. The temperature coefficient is determined by the box

method using the following formula:

V

max

- V

min

T.C. =

V

nominal

x (T

max

-T

min

)

x 10

6

4. The specified values are without the external

noise reduction capacitor.

5. The specified values are unloaded.

VRE310DS REV. D MAY 2001

TYPICAL PERFORMANCE CURVES

V

OUT

vs. TEMPERATURE

V

OUT

vs. TEMPERATURE

V

OUT

vs. TEMPERATURE

Temperature

o

C

VRE310A

Temperature

o

C

VRE310B

Temperature

o

C

VRE310C

V

OUT

vs. TEMPERATURE

V

OUT

vs. TEMPERATURE

V

OUT

vs. TEMPERATURE

Temperature

o

C

VRE310J

Temperature

o

C

VRE310K

Temperature

o

C

VRE310L

QUIESCENT CURRENT VS. TEMP

JUNCTION TEMP. RISE VS. OUTPUT CURRENT

PSRR VS. FREQUENCY

Temperature

o

C

Output Current (mA)

Frequency (Hz)

VRE310DS REV. D MAY 2001

DISCUSSION OF PERFORMANCE

THEORY OF OPERATION

The following discussion refers to the schematic in

figure 2 below. In operation, approximately 6.3 volts is

applied to the noninverting input of the op amp. The

voltage is amplified by the op amp to produce a 10.000V

output. The gain is determined by the networks R1 and

R2: G=1 + R2/R1. The 6.3V zener diode is used because

it is the most stable diode over time and temperature.

The zener operating current is derived from the

regulated output voltage through R3. This feedback

arrangement provides a closely regulated zener current.

This current 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 then adjusting

the slope, Thaler Corporation produces a very stable

voltage over wide temperature ranges.

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,

we produce a voltage reference that also has very good

long term stability

Figure 3 shows the proper connection of the VRE310

series voltage references with the optional trim resistor.

The VRE310 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.

VRE310

FIGURE 2

EXTERNAL CONNECTIONS

+ V

IN

2

8

V

TEMP OUT

3

6

+ V

OUT

10k

Ω

OPTIONAL

FINE TRIM

ADJUSTMENT

OPTIONAL

NOISE REDUCTION

CAPACITOR

VRE310

C

N

1µF

7

4

5

FIGURE 3

REF. GND

VRE310DS REV. D MAY 2001

FIGURE 3

MECHANICAL

D

D1

D2

INCHES

DIM

A

B

B1

MIN

.115

.098

.046

.107

.009

.052

.397

.372

MAX

.125

.102

.051

.113

.012

.058

.403

.380

MILLIMETER

MIN

2.92

2.48

1.14

2.71

0.22

1.32

10.0

9.44

MAX

3.17

2.59

1.29

2.89

0.30

1.47

10.2

9.65

DIM

D2

E

E1

E2

P

Q

S

INCHES

MIN

.018

.507

.397

.264

.085

.020

.045

MAX

.023

.513

.403

.270

.095

.030

.055

MILLIMETER

MIN

0.46

12.8

10.0

6.70

2.15

.508

1.14

MAX

0.58

13.0

10.2

6.85

2.41

.762

1.39

E2

E1

E

C

C1

C2

D

PIN 1 IDENTIFIER

D1

A

Q

BASE

SEATING

E1

P

C1

C2

C

B

B1

FIGURE 4

S

INCHES

DIM

A

B

B1

B2

C

D

D1

MIN

.115

.018

.046

.098

.009

.397

.372

MAX

.125

.022

.051

.102

.012

.403

.380

MILLIMETER

MIN

2.92

.457

1.14

2.48

0.22

10.0

9.44

MAX

3.17

.558

1.29

2.59

0.30

10.2

9.65

DIM

E

E1

G1

L

P

Q

S

INCHES

MIN

.397

.264

.290

.195

.085

.055

.045

MAX

.403

.270

.310

.215

.095

.065

.055

MILLIMETER

MIN

10.0

6.70

7.36

4.95

2.15

1.39

1.14

MAX

10.2

6.85

7.87

5.46

2.41

1.65

1.39

VRE310DS REV. D MAY 2001