Datasheet VRE3041LS, VRE3041LD, VRE3041KS, VRE3041KD, VRE3041JS Datasheet (THALER)

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Page 1

DESCRIPTION

FEATURES

The VRE3041 is a low cost, high precision 4.096V reference that operates from +10V. The device features a buried zener for low noise and excellent long term stability. Packaged in an 8 pin DIP and SMT, the device is ideal for high resolution data conversion systems.

The device provides ultrastable +4.096V output with ±0.4096 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 VRE3041 series the most accurate reference available.

For enhanced performance, the VRE3041 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.

VRE3041

TOP

VIEW

1 2 3 4

N/C +V

N/C GND

NOISE REDUCTION

OUT

TRIM

PIN CONFIGURATION

The VRE3041 is recommended for use as a reference for 14, 16, or 18 bit data converters which require an external precision reference. The device is also ideal for calibrating scale factor on high resolution data converters. The VRE3041 offers superior performance over monolithic references.

• 4.096 V Output ± 0.409 mV (.01%)

• Temperature Drift: 0.6 ppm/°C

• Low Noise: 3µV

p-p

(0.1Hz-10Hz)

• Low Thermal Hysteresis: 1 ppm Typ.

• ±15mA Output Source and Sink Current

• Excellent Line Regulation: 5 ppm/V Typ.

• Optional Noise Reduction and Voltage Trim

• Industry Standard Pinout

FIGURE 1

SELECTION GUIDE

Model

Temp.

Range °C

Temp.

Coeff.

ppm/°C

VRE3041A 0.410 0.6 0°C to +70°C VRE3041B 0.614 1.0 0°C to +70°C VRE3041C 0.820 2.0 0°C to +70°C VRE3041J 0.410 0.6 -40°C to +85°C VRE3041K 0.614 1.0 -40°C to +85°C VRE3041L 0.820 2.0 -40°C to +85°C

For package option add D for DIP or S for Surface Mount to end of model number.

Initial

Error

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

N/C

VRE3041DS REV. D JULY 2000

VRE3041 Low Cost Precision Reference

Page 2

ppm/

1khrs

6∆V

OUT/t

Long Term Stability

µVp-p2.40.1Hz<f<10Hz

Output Noise Voltage

µs2 To 0.01% of final valueT

Turn-On Settling Time

mV±4Figure 3∆V

OUT

Trim Adjustment Range

1.0 2.0VRE3041C/K

0.5 1.0VRE3041B/K

4.0952 4.096 4.0968VRE3041C/L

4.0954 4.096 4.0966VRE3041B/K V

4.0956 4.096 4.0964VRE3041A/J

OUT

Output Voltage (Note 1)

5 1010V ≤ V

≤ 18V

ppm/V

25 358V ≤ V

≤ 10V

∆V

OUT

∆V

Line Regulation

ppm/

mA8 12

8 12

Sourcing:

0mA ≤ I

OUT

≤ 15mA

Sinking:

-15mA ≤ I

OUT

≤0mA

∆V

OUT

∆I

OUT

Load Regulation

mA3.5 4.0I

Supply Current

µV

RMS

2 410Hz<f<1kHz

ppm1Note 4Temperature Hysterisis

ppm/°C

0.3 0.6VRE3041A/J

TCV

OUT

Output Voltage Temperature Coefficient (Note 2)

V8 36V

UNITSMIN TYP MAXSYMBOL CONDITIONS

Input Voltage

PARAMETER

ELECTRICAL SPECIFICATIONS

Vps =+10V, T = 25°C, Iout=0mA unless otherwise noted.

VRE3041DS REV. D JULY 2000

ABSOLUTE MAXIMUM RATINGS

Power Supply ………………………-0.3V to +40V Out Short Circuit to GND Duration (VIN< 12V)…...Continuous OUT, TRIM …………………………-0.3V to +12V Out Short Circuit to GND Duration (VIN< 40V)…….……5 sec NR……………………………………-0.3V to +6V Out Short Circuit to IN Duration (VIN< 12V)……...Continuous Operating Temp. (A,B,C)……………0 °C to 70°C Continuous Power Dissipation (TA= +70°C)………...300mW Operating Temp. (J,K,L)……………-40 °C to 85°C Storage Temperature………………………..…-65°C to 150°C

Lead Temperature (soldering,10 sec)…………………..250°C

Notes:

1) The specified values are without external trim.

2) The temperature coefficient is determined by the box method. See discussion on temperature performance.

3) Line and load regulation are measured with pulses and do not include voltage changes due to temperature.

4) Hysterisis measured over the operating temperature range.

Page 3

TYPICAL PERFORMANCE CURVES

Temperature (oC)

VRE3041A

OUT

vs. TEMPERATURE

SUPPLY CURRENT

VS. SUPPLY VOLTAGE

QUIESCENT CURRENT VS. TEMP

Temperature (oC)

OUTPUT IMPEDIANCE

VS. FREQUENCY

Temperature (oC)

VRE3041B

OUT

vs. TEMPERATUREV

OUT

vs. TEMPERATURE

Temperature (oC)

VRE3041C

Temperature (oC)

VRE3041J

OUT

vs. TEMPERATURE

Temperature (oC)

VRE3041K

OUT

vs. TEMPERATURE

Temperature (oC)

VRE3041L

OUT

vs. TEMPERATURE

Supply Voltage (V)

Supply Current (mA)

Frequency (Hz)

∆V

out

(mV)

∆V

out

(mV)

∆V

out

(mV)

∆V

out

(mV)

∆V

out

(mV)

∆V

out

(mV)

Quiescent Current (mA)

Output Impediance ( Ω)

VRE3041DS REV. D JULY 2000

-50

100

6.0

4.0

2.0

8.0

15255

5.0

4.0

3.0

6.0

102030400

-50

-25

100

2.0

1.5

1.0

0.5

-1.0

-0.5

-1.5

-2.0

Lower Limit

Upper Limit

-50

-25

100

2.0

1.5

1.0

0.5

-1.0

-0.5

-1.5

-2.0

Lower Limit

Upper Limit

304050

1.00

0.75

0.50

0.25 0

-0.50

-0.25

-0.75

-1.00

Lower Limit

Upper Limit

304050

1.00

0.75

0.50

0.25 0

-0.50

-0.25

-0.75

-1.00

Lower Limit

Upper Limit

Lower Limit

Upper Limit

-0.75

304050

1.00

0.75

0.50

0.25 0

-0.50

-0.25

-1.00

Lower Limit

Upper Limit

-50

-25

100

2.0

1.5

1.0

0.5

-1.0

-0.5

-1.5

-2.0

Lower Limit

Upper Limit

Page 4

TYPICAL PERFORMANCE CURVES

RIPPLE REJECTION

Vs. FREQUENCY(CNR=0µF)

OUTPUT NOISE-VOLTAGE DENSITY vs. FREQUENCY

VRE3041DS REV. D JULY 2000

JUNCTION TEMP. RISE VS.

OUTPUT CURRENT

Output Current (mA)

CHANGE IN OUTPUT VOLTAGE

VS. INPUT VOLTAGE

CHANGE IN OUTPUT VOLTAGE

VS. OUTPUT CURRENT

Vin(V)

Vout (ppm)

out

(mA)

Vout (µV)

Frequency (Hz)

10k

100

042

13915

-20

-10

Ripple Rejection (dB)

Junction Temperature

Rise Above Ambient (

Output Noise Density (nV/√Hz)

10214

-200

-400

1216640

-300

-100

100

200

300

400

TURN-ON AND TURN-OFF

TRANSIENT RESPONSE

1 µs/div

+10V

A: Vin, 10V/div B: Vout, 1V/div

10k

100

0.1Hz to 10Hz Noise

∆Vout, 1µV/Div

1 Sec/Div

Page 5

VRE3041DS REV. D JULY 2000

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 4.096V 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.

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.

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 VRE3041 series voltage references with the optional trim resistor for initial error and the optional capacitor for noise reduction.

BASIC CIRCUIT CONNECTION

Figure 3 shows the proper connection of the VRE3041 voltage reference with the optional trim resistor for initial error and optional capacitor for noise reduction.

To achieve the specified performance, pay careful attention to the layout. A low resistance star configuration will reduce voltage errors, noise pickup, and noise coupled from the power supply. Commons should be connected to a single point to minimize interconnect resistances.

Figure 3 External Connections

Figure 2 Functional Block Diagram

Noise ReductionNR8

Voltage reference outputOUT6

External trim input. Leave open if not used.

TRIM5

GroundGND4

Positive power supply input

Internally connected. Do not use

Vin

N.C.

1,3,7

PIN DESCRIPTION

+ V

OUT

+ V

VRE3041

10kΩ

1µF

Optional Noise

Reduction

Capacitor

Optional Fine Trim Adjustment

Page 6

VRE3041DS REV. D JULY 2000

TEMPERATURE PERFORMANCE

The VRE3041 is designed for applications where the initial error at room temperature and drift over temperature are important to the user. For many instrument manufacturers, a voltage reference with a temperature coefficient less than 1ppm/°C makes it possible to not have to perform a system temperature calibration, a slow and costly process.

Of the three TC specification methods (slope, butterfly, and box), the box method is used commonly used. A box is formed by the min/max limits for the nominal output voltage over the operating temperature range. The equation follows:

This method corresponds more accurately to the method of test and provides a closer estimate of actual error than the other methods. The box method guarantees limits for the temperature error but does not specify the exact shape and slope of the device under test.

A designer who needs a 14-bit accurate data acquisition system over the industrial temperature range (-40°C to +85°C), will need a voltage reference with a temperature coefficient (TC) of 1.0ppm/°C if the reference is allowed to contribute an error equivalent to 1LSB. For 1/2LSB equivalent error from the reference you would need a voltage reference with a temperature coefficient of

0.5ppm/°C. Figure 4 shows the required reference TC vs. delta T change from 25°C for resolution ranging from 8 bits to 20 bits.

THERMAL HYSTERISIS

A change in output voltage as a result of a temperature change. When references experience a temperature change and return to the initial temperature, they do not always have the same initial voltage. Thermal hysterisis is difficult to correct and is a major error source in systems that experience temperature changes greater than 25°C. Reference vendors are starting to include this important specification in their datasheets.

( )

minmaxnominal

minmax

10.. •



 





 



−•

−

TTV

0.01

0.1

100

1000

10000

1 10 100

20 BIT

18 BIT

16 BIT

14 BIT

12 BIT

10 BIT

8 BIT

ReferenceTC

(

ppm/°

Reference TC vs. ∆T change from 25°C for 1 LSB change

Page 7

VRE3041DS REV. D JULY 2000

MECHANICAL SPECIFICATIONS

INCHES MILLIMETER DIM MIN MAX MIN MAX DIM MIN MAX MIN MAX A .110 .120 2.794 3.048 D1 .372 .380 9.45 9.65 B .095 .105 2.413 2.667 E .425 .435 10.80 11.05 B1 .021 .027 0.533 0.686 E1 .397 .403 10.08 10.24 C .055 .065 1.397 1.651 E2 .264 .270 6.71 6.86 C1 .012 .020 0.305 0.508 P .085 .095 2.16 2.41 C2 .020 .040 0.508 1.016 S .045 .055 1.14 1.40 D .395 .405 10.03 10.29

INCHES MILLIMETER

E2 E1 E

C C2

Page 8

VRE3041DS REV. D JULY 2000

MECHANICAL SPECIFICATIONSMECHANICAL SPECIFICATIONS

E2 E1 E

INCHES MILLIMETER DIM MIN MAX MIN MAX DIM MIN MAX MIN MAX A .170 .180 4.318 4.572 E .425 .435 10.80 11.05 B .095 .105 2.413 2.667 E1 .397 .403 10.08 10.24 B1 .016 .020 0.406 0.508 E2 .264 .270 6.71 6.86 C .008 .011 0.203 0.279 G .290 .310 7.36 7.87 C1 .055 .065 1.397 1.651 L .175 .225 4.46 5.72 D .395 .405 10.03 10.29 P .085 .095 2.16 2.41 D1 .372 .380 9.45 9.65 S .045 .055 1.14 1.40

INCHES MILLIMETER