Voltage Reference Selection Basics
Transcript of Voltage Reference Selection Basics
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Choosing the Best Shunt or Series Reference for Your Application
Voltage references are a key building block in data conversion systems. Understanding the
specications and how they contribute to error is necessary for selecting the right referenc
for the application.Figure 1 shows the application of a voltage reference in a simple analog
to-digital converter (ADC) and digital-to-analog converter (DAC). In each case, the refere
voltage (VREF ) acts as a very precise analog meter stick against which the incoming analog
signal is compared (as in an ADC) or the outgoing analog signal is generated (as for a DA
As such, a stable system reference is required for accurate and repeatable data conversion
and as the number of bits increases, less reference error can be tolerated. Monolithic
voltage references produce an output voltage which is substantially immune to variations
ambient temperature as well as loading, input supply, and time. While many ADCs and DA
incorporate an internal reference, beyond 8 to 10 bits it is rare to nd one with sufcient
precision as high-density CMOS technologies commonly used for data converters typical
produce low-quality references. In most cases, the internal reference can be overdriven
by an external one to improve performance. Terms such as high precision and ultra-
high precision are common in reference datasheets but do little to help designers in their
selection. This article seeks to provide an explanation of common reference specications
rank their relative importance and show how a designer can use them in some simple
calculations to narrow the search.
Overview Voltage references are key components
in data conversion systems which enable
the ADC and DAC to read accurate
values and are used in various sensing
applications. While they are simple parts
which often may only have two or threepins, there are numerous parameters that
affect the performance of a reference, and
careful consideration of all the parameters
are required to select the proper one.
This paper covers the differences between
the shunt and series architectures, explains
key parameters and special features, and
shows how to properly calculate the error
for a given reference in a given operatingcondition.
Voltage ReferenceSelection Basics
Mario EdnoProduct marketing engineer
W H I T E P A P E R
Figure 1. Simplied ADC/DAC Diagrams
+
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DECODER
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2 Texas Instruments
Figure 2 shows the two available voltage references topologies: series and shunt. A series reference prov
load current through a series transistor located between VIN and VREF (Q1), and is basically a high-precision,
low-current linear regulator. A shunt reference regulates VREF by shunting excess current to ground via a
parallel transistor (Q2). In general, series references require less power than shunt references because loa
current is provided as it is needed. The bias current of a shunt reference (IBIAS) is set by the value of RBand must be greater than or equal to the maximum load current plus the references minimum operating
current (the minimum bias current required for regulation). In applications where the maximum load
current is low (e.g. below 100 A to 200 A), the disparity in power consumption between series and sh
references shrinks. There is no inherent difference in accuracy between the two topologies and high- and
low-precision examples are available in both varieties.
The advantages and disadvantages of the two architectures are summarized inTable 1. Generally, shunt
references offer more exibility (VIN range, creation of negative or oating references) and better power
supply rejection at the expense of higher power consumption while series references typically dissipate l
power and can achieve better performance for extremely high-precision applications. The typical applica
diagram of data converters will often show a zener diode symbol representing the reference, indicating t
use of a shunt reference. This is merely a convention, and in nearly all cases a series reference could be
used as well.
Table 1. Series vs Shunt Architectures
Series Shunt
Number of Terminals 3 (VIN, VREF, GND) 2 (VREF, GND)
Current Requirements IQ + ILOAD (as needed) Min. operating current + ILOAD_MAX (continuous)
Advantages Low power dissipationShutdown/power-saving mode possible
No limit on maximum VINExcellent power supply rejectionCan be used to create negative reference voltagesCan be used to create oating references(cathode to a voltage other than GND)Inherent current sourcing and sinking
Disadvantages
Limited maximum VIN More sensitive to VIN supply (PSRR)May only be capable of sourcing current
Must idle at maximum load currentShutdown/power-saving mode not possible
Figure 2. Circuit Symbols and Simplied Schematics of Series and Shunt Architectures
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Texas Instruments
As with all ICs, voltage references have standardized parameters for determining the right part for a desi
The following are key specications in order of importance that are pertinent to all suppliers.
1. Temperature Coefcient
The variation in VREF over temperature is dened by its temperature coefcient (TC, also referred to as dri
which has units of parts-per-million per degree Celsius (ppm/C). It is convenient to represent the referenvoltage temperature dependence as a polynomial for the sake of discussion:
TC1 represents the rst-order (linear) temperature dependence, TC2 the second-order, and so on. Higher
than rst-order terms are usually lumped together and described as the curvature of the drift.
The majority of monolithic references are based on a bandgap reference. A bandgap reference is creat
when a specic Proportional To Absolute Temperature (PTAT) voltage is added to the Complementary To
Absolute Temperature (CTAT) base-to-emitter voltage of a bipolar transistor yielding a voltage at roughl
bandgap energy of silicon (~1.2V) where TC1 is nearly zero. Neither the PTAT nor CTAT voltage is perfe
linear leading to non-zero higher-order TC coefcients, with TC2 usually being dominant. References
designed for drifts less than 20 ppm/C generally require special circuitry to reduce TC2 (and possibly
higher-order terms), and their datasheets will often mention some form of curvature correction. Anothe
common type of reference is based on a buried-zener diode voltage plus a bipolar base-to-emitter voltag
produce a stable reference voltage on the order of 7V. The drift performance of buried-zener references is
par with that of bandgap references, although their noise performance is superior. Buried-zener reference
usually require large quiescent currents and must have an input supply greater than 7.2V, so they cannot used in low-voltage applications (VIN = 3.3V, 5V, etc.).
The temperature coefcient can be specied over several different temperature ranges, including the
commercial temperature range (0 to 70C), the industrial temperature range (-40 to 85C), and the extend
temperature range (-40 to 125C). There are several methods of dening TC, with the box method bein
used most often. The box method calculates TC using the difference in the maximum and minimum VREF
measurements over the entire temperature range whereas other methods use the values of VREF at the
endpoints of the temperature range (TMIN, TMAX ).
Voltage ReferenceSpecications
+
+
+
+= ...TTCTTC
C25
C25
C25T
TC 1| V(T) V3
3
2
21C25REFREF
Figure 3. Different Methods for TC Calculation
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4 Texas Instruments
Neither method is ideal. The weakness of the endpoints method is the failure to account for any curvatur
the drift (TC2, TC3, etc.). Calculating the
incremental TC from room temperature
to both the minimum and maximum
temperatures improves the situation asinformation on TC2 can be
garnered using three data points rather
than two. While the box method is more accurate than using endpoints, it may underestimate TC if the te
perature range of the application is smaller than the range over which the TC is specied.
2. Initial Accuracy
The initial accuracy of VREF indicates how close to the stated nominal voltage the reference voltage is
guaranteed to be at room temperature under stated bias conditions. It is typically specied as a percentag
and ranges from 0.01% to 1% (100-10,000 ppm). For example, a 2.5V reference with 0.1% initial accura
should be between 2.4975V and 2.5025V when measured at room temperature. The importance of initia
accuracy depends mainly on whether the data conversion system is calibrated. Buried-zener references h
very loose initial accuracy (5-10%) and will require some form of calibration.
3. 0.1-10 Hz Peak-to-Peak Noise
The internally-generated noise of a voltage reference causes a dynamic error that degrades the signal-to-
noise ratio (SNR) of a data converter, reducing the estimated number of bits of resolution (ENOB). Data
provide separate specications for low- and high-frequency noise. Broadband noise is typically speciedan rms value in microvolts over the 10 Hz to 10 kHz bandwidth. Broadband noise is the less troublesom
of the two as it can be reduced to some degree with a large VREF bypass capacitor. Broadband noise may
or may not be important in a given application depending on the bandwidth of the signal the designer in
interested in. Low-frequency VREF noise is specied over the 0.1 Hz to 10 Hz bandwidth as a peak-to-peak
value (in V or ppm). Filtering below 10 Hz is impractical, so the low-frequency noise contributes direc
the total reference error. Low-frequency noise is characterized using an active bandpass lter composed
a 1st-order high-pass lter at 0.1 Hz followed by an nth-order low-pass lter at 10 Hz. The order of the l
pass lter has a signicant effect on measured peak-to-peak value. Using a 2nd-order low pass at 10 Hz
reduce the peak-to-peak value by 50 to 60% compared to a 1st-order lter.
Some manufacturers use up to 8th-order lters, so a designer should read the datasheet notes
carefully when comparing references. From a design perspective, the 0.1 Hz to 10 Hz noise is mainly du
the icker (1/f ) noise of the devices and resistors in the bandgap cell, and therefore scales linearly with REF.
For example, a 5V reference will have twice the peak-to-peak noise voltage as the 2.5V option of the sam
part. Reducing the noise requires considerably higher current and larger devices in the bandgap cell, so v
=MINMAX25 CREF
TREF_MINTREF_MAX6BOX TT
1
| V
| V| V10TC
= MINMAX25 CREF
TMINREFTMAXREF6ENDPOINTS
TT
1
| V
| V| V10TC
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low noise references (
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should be placed as close to the load as the PCB layout will allow. References with pins for both forcing
sensing VREF provide some immunity to this problem. The impedance of the reference input is large enoug
(>10 k) on many data converters that load regulation error may not be signicant. Maximum load curr
information can be found in ADC/DAC datasheets specied as either a minimum reference pin resistanc
(RREF) or a maximum reference current (IREF). In situations where the reference is buffered with a hig
speed op amp, load regulation error can usually be ignored. The dual of load regulation for shunt referen
is the change in reverse breakdown voltage with current that species the change in VREF as a function of
the current shunted away from the load. It is calculated with the same equation as load regulation where
current is replaced with shunted current (ISHUNT). The amount of shunted current depends on both the
current and the input voltage so the change in reverse voltage with current specication also indicates
line sensitivity.
7. Line Regulation
Line regulation applies only to series voltage references and is the measure of the change in the referenc
voltage as a function of the input voltage. The importance of line regulation depends on the tolerance of
the input supply. In situations where the input voltage tolerance is within 10% or less, it may not contribu
signicantly to the total
error. The extension
of line regulation over
frequency is the Power Supply Rejection Ratio (PSRR). PSRR is rarely specied but typical curves are u
provided in the datasheet. As with line regulation, the importance of PSRR depends on specics of the in
supply. If VIN is noisy (generated with a switching regulator, sensitive to EMI, subject to large load transien
PSRR may be critical. The analogous specication for shunt references is the reverse dynamic impedanc
which indicates the sensitivity of VREF to an AC current. Noise on the supply powering a shunt reference
is converted to a noise current through RBIAS. Some shunt reference datasheets will specify the reverse
dynamic impedance at 60 Hz and 120 Hz, and nearly all will provide a plot of reverse dynamic impedan
versus frequency.
8. Special Features
In applications where power consumption is crucial, a series reference is usually the right choice. The
quiescent current of most series references ranges from 25 A to 200 A, although several are available
with IQ
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mode is not possible in shunt references. Additionally, series references can have dropout voltages less th
200 mV, allowing them to be used at lower input voltages. Shunt references can also be used at low
voltages, but the bias current may vary widely with changes in VIN due to the small RBIAS resistor required
References do not require many external passive components but proper selection can improve
performance. A bypass capacitor on VREF substantially improves PSRR (or reverse dynamic impedance in tcase of a shunt reference) at higher frequencies. It will also improve the load transient response, and redu
high-frequency noise. Generally speaking, the best performance is achieved with the largest bypass capa
allowed. The range of allowable bypass capacitors depends on the stability of the reference, which shoul
detailed along with ESR restrictions in the component selection section of the datasheet. When using a la
bypass capacitor (>1 F) it may be advantageous to bypass it with a smaller value, lower-ESR capacitor
reduce the effects of the ESR and ESL. The reverse dynamic impedance of a shunt reference varies inver
with the amount of current shunted. If noise immunity is more important than power consumption in a g
application, a smaller RBIAS may be used to increase ISHUNT.
Some series references have a TRIM / NOISE REDUCTION (NR) pin to further enhance performanc
using a series of resistors shown inFigure 4 , the TRIM/NR pin can be used to adjust output voltage by up
15 mV. The pin can also be used to create a low pass lter to decrease overall noise measured on VOUT by
using a capacitor as shown inFigure 5 . Note that increasing the capacitor size will continue to improve no
performance, but also increases startup time.
9. Other Considerations
Voltage references are becoming increasingly popular in the automotive space and as reliability becomes
more critical, the need for AEC-Q100 qualied parts increases as well. The AEC-Q100 qualication wascreated by the Automotive Electronics Council and requires specic quality and testing procedures to en
a devices performance. On top of the general qualication, there are also grades from 0-4 which indicate
temperature range of the qualied device. At the time of this article, the most common is grade 1 where t
operating temperature range of the device spans from -40 to 125C. It should be noted that many manu-
facturers offer voltage references in the extended temperature range of -40 to 125C and mention that the
device is suitable for automotive applications but this does not mean that the device is AEC-Q100 grad
1-qualied. Therefore, designers for automotive applications should be cautious of devices that state
DNC
TEMP VOUT
VIN
GND
DNC
NC
TRIM/NR
REF50xx
+V SUPPLY
10 k
1 k
470 k
DNC
TEMP VOUT
VIN
GND
DNC
NC
TRIM/NR
REF50xx
C11F
+VSUPPLY
Figure 4: V OUT Adjustment Using the TRIM/NR Pin Figure 5: Noise Reduction Using the TRIM/NR Pin
Texas Instruments
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suitability for automotive applications unless it is specically specied in the datasheet as AEC-Q100
qualied.
Due to the popularity of voltage references, many manufacturers have produced identical products a
sometimes even release them as the same part number as the original manufacturer for part recognition.
While the main performance characteristics are identical, there are times when there are subtle differencwhich could be of concern to a designer depending on their application. For example, the LM4040 offer
from Texas Instruments has a wideband noise value of 35 VRMS for a 2.5V output. The same part from
another supplier has a wideband noise value of 350 VRMS which is 10x the value even though the
initial accuracy and temperature coefcient are the same. Other differences that are prevalently found ar
operating temperature range and current consumption. A designer should be careful when considering
secondary or alternate parts with the same part number and should do a thorough comparison of the
performance to ensure that the key parameters are indeed the same.
Selecting the rightVoltage Reference
8 Texas Instruments
!"#$%&'%$'%()
T e m p c o ( p p m
/ o C )
LM4030
Initial Accuracy
REF1112
LM4050 / 51TL4050 / 51
LM4040/41
0.05% 0.1% 0.2% 0.5% 1.0% 2.0%
150
100
75
50
30
10
1.5%
TLV431
LMV431
LM1 / 2 / 385
LM431/ TL431
Shunt References
AECQ-100
Device Tempco (ppm/C) Initial Accuracy (%) Noise (V PP) VOUT (V) Iq (A) Package
LM4030 10 to 30 0.05 to 0.15 105 2.5, 4.096 120SOT23-3SOT23-5
REF1112 30 to 50 0.2 25 1.25 1.2 SOT23-3
LM1/2/385 30 to 150 1.0 to 2.0 50 Adj, 2.5 50SOT23-3TO-92SOIC-8
LM4050/51 50 0.1 to 0.5 48 Adj, 1.225, 2.0, 2.5, 4.096,
5.0, 8.2, 1039 SOT23-3
TL431 50 0.5 to 2.0 Adj, 2.5 4SOIC-8TO-92SC-70
LM4040/41 100 0.1 to 0.5 35 Adj, 1.225, 2.0, 2.5, 3.0,
4.096, 5.0, 8.2, 1065
SOT23-3SC-70TO-92
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Voltage reference selection begins with satisfying the application operating conditions, specically: nom
VREF, VIN range, current drive, power consumption, and package size. Beyond that, a reference is chosen ba
on the accuracy requirements of a given data converter application. The most convenient unit for
understanding how the reference error affects accuracy is in terms of the least signicant bit (LSB) of the
data converter. The LSB in units of parts-per-million is simply one million divided by two raised to the nu
of bits power.Table 2 provides the LSB values for
common resolutions.
ADCs / DACs have their own sources of error including
integral nonlinearity (INL), differential nonlinearity (DNL), and gain
and off set error. If we consider the case of the more common
unipolar data converter, voltage reference error is functionally
equivalent to a gain error. INL and DNL gauge the nonlinearity of
a data converter, on which the reference voltage has no effect.
The gain and off set errors can be understood conceptually
Bits LSB (ppm)
8 3906
10 977
12 244
14 61
16 15
Table 2. LSB Values in PPM forCommon Data Converter Resolution
Texas Instruments
Initial Accuracy
100
75
50
20
10
40
30
LM4128
REF30xx
LM4120 /21 /25
0.05% 0.1% 0.2% 0.5% 1.0% 2.0%
REF33xx REF32xx
REF31xxREF02
LM4132
REF50xxREF20xx REF102
LM4140
REF29xx
AECQ-100
T e m p c o ( p p m
/ o C )
Series References
Device Tempco (ppm/C) Initial Accuracy (%) Noise (V PP) VOUT(V) Iq (A) Package
REF50xx 3 to 8 0.05 to 0.1 6 to 302.0, 2.5, 3.0, 4.096, 4.5,
5.0, 101000
MSOP-8SO-8
LM4132 10 to 20 0.05 to 0.5 170 to 3501.8, 2.0, 2.5, 3.0, 3.3,
4.09560 (3)* SOT23-5
REF33xx 30 0.15 35 to 921.25, 1.8, 2.048, 2.5,
3.0, 3.38.5
SOT23-3SC-70UQFN-8
REF30xx 50 to 75 0.2 14 to 451.2, 2.0, 2.5, 3.0, 3.3,
4.09550 SOT23-3
LM4120/21 50 0.2 to 0.5 20 Adj, 1.2, 1.8, 2.0, 2.5, 3.0,
3.3, 4.095, 5.0275 (2)* SOT23-5
LM4128 75 to 100 0.1 to 1.0 170 to 3501.8, 2.0, 2.5, 3.0, 3.3,
4.095100 (7)* SOT23-5
* Shutdown current noted in parens
Bitof Number:NOB 21
10LSB(ppm)
NOB6
=
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by recognizing that ADCs / DACs have two reference voltages: VREF and GND in the case of a unipolar data
converter, and VREF and -VREF for bipolar data converters. The offset error is the deviation in the output (in
bits for an ADC and voltage for a DAC) from the ideal minus full-scale (MFS) value when a MFS input
applied. The MFS reference voltage is GND so VREF error has no effect. The gain error is the deviation
the ideal positive full-scale (PFS) output for a PFS input, minus the offset error. The PFS reference voltagis VREF, so any shift in the reference voltage equates to a gain error. As such, the reference error can cause
loss of dynamic range for input signals near PFS, which is also where it has the most pronounced effect
accuracy. The effect of reference error on a mid-scale (MS) input signal is half that for a PFS input, and i
negligible for inputs near MFS. For example, a worst-case reference error of 8 LSB would result in a los
3 bits of accuracy for a PFS input, 2 bits of lost accuracy at mid-scale, and no loss of accuracy at MFS. I
designer has no idea what kind of reference error they can live with, matching the worst-case reference e
to the maximum gain error is a reasonable starting point. In systems where error contributors are statistic
independent, and consequently add together as a root mean squared sum, balancing the error contributio
represents the optimal case. Otherwise, the error will tend to be dominated by one variable and the accur
of the other variable(s) is essentially wasted.
In calculating the total error in VREF it is helpful to separate the specications where a maximum value
is guaranteed (TC, initial accuracy, load regulation, line regulation) and those where only a typical value
provided (0.1 Hz to 10 Hz noise, thermal hysteresis, and long-term stability). Other than initial accuracy,
guaranteed specications are all linear coefcients and their contribution to the total error can be calcula
based on the operating ranges of the reference (temperature range, load current, and input voltage).
In calibrated systems, initial accuracy can be dropped from the equation. The above calculation repres
the worst case, and most of the time a reference will perform better than the guaranteed maximums (esp
cially when it comes to line and load regulation where the maximum may be more a function of the testi
system due to the very low signal-to-noise ratio of the measurement). It is worth noting that the statistica
methods through which the guaranteed maximum specications are calculated vary by manufacturer, so
comparing datasheets may not tell the full story. If the designer wants to estimate the average reference
10 Texas Instruments
1160 ppm50 ppm60 ppm550 ppm500 ppm)(0.05%|ERROR
50 ppm4.5V)(5.5V(50 ppm/V)|ERROR
60 ppm0 mA)(0.5 mA )(120 ppm/mA |ERROR
550 ppmC)0C(55C)(10 ppm/ |ERROR
Example using LM4132A 2.5V with 2.5V output
|ERROR|ERROR|ERROR |ERROR|ERROR
) V(VLINE_REG|ERROR
)I(ILOAD_REG|ERROR )T(TTC|ERROR
GUARANTEED
LINE
LOAD
oooTEMP
LINELOADTEMPCURACYINITIAL_ACGUARANTEED
IN_MININ_MAXLINE
LOAD_MINLOAD_MAXLOAD
MINMAXTEMP
=+++==
==
==
==
+++=
=
=
=
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Texas Instruments
1631 ppm 96 ppm 150 ppm225 ppm 1160 ppm |ERROR
96 ppm2.5V
240 10|ERROR
150 ppm(50 ppm)3|ERROR
225 ppm(75 ppm)3 |ERROR
|ERROR|ERROR|ERROR|ERROR|ERROR VREF
Peak toPeak 10 Hz0.110|ERROR
Stability)Term-Long(Typ.3|ERROR
)HysteresisThermal(Typ.3 |ERROR
TOT
PP6NOISELF_
LITYTERM_STABILONG
S_HYSTERESITHERMAL
LF_NOISELITYTERM_STABILONGS_HYSTERESITHERMALGUARANTEEDTOT
6NOISELF_
LITYTERM_STABILONG
S_HYSTERESITHERMAL
=+++=
=
=
=
=
+++=
=
V
Example using LM4132A 2.5V with 2.5V output
error, they can take the rms sum of the individual error sources rather than just adding them up. For
simplicity, one can convert from peak to peak to rms value by using the equation peak-to-peak = 6.6x rm
This is because 99.99% of the error will fall within 6.6 standard deviations of the total error distribution.
most cases, the TC error will be dominant, so TC error by itself gives a good indication of average
reference performance. Datasheets only provide typical values for thermal hysteresis and long-term stabi
but both are likely to vary a great deal unit to unit. The typical specication is not very helpful in estimat
worst-case error without knowing the standard deviation of the distribution. Many times this information
can be obtained by calling the manufacturer. Otherwise, a conservative, albeit crude, approach would be
multiply the typical specication by three or four to get a ballpark estimate of the worst-case shift. This i
assuming that the standard deviation of the distribution is on the order of the mean value and designing fa two or three standard deviation worst case. The loss of resolution due to noise is harder to predict and c
only really be known by testing a reference in the application.
Low-frequency noise should be very consistent on a unit-to-unit basis and no sand-bagging of the ty
value is required. Over a 10-second window, one can expect the VREF to shift by an amount equal to the
0.1 Hz to 10 Hz peak-to-peak specication.
Once the worst-case reference error in parts-per-million is estimated, it can be converted into LSB for
different data converter resolutions using the values inTable 2 . The worst-case accuracy loss at positive ful
scale and mid-scale can then be calculated taking the log base-2 of the number of LSB of error.
( )
(14 bit)bits 3.7 bit) (12 bits 1.7(10 bit)bit0 (MS) AccuracyLostCaseWorst
(14 bit)bits 4.7bit) (12bits 2.7(10 bit)bit80 (PFS) AccuracyLostCaseWorst
(LSB)|ERRORlog AccuracyLostCaseWorst
(14 bit)LSB 26.7 (12 bit)LSB 6.7(10 bit)1.7 LSB
LSBppm
ppm1631(LSB)|ERROR
TOTAL2
TOTAL
===
===
=
===
=
.
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SLPY00 2014 Texas Instruments Incorporated
WEBENCH is a registered trademark and the platform bar is a trademarksof Texas Instruments Incorporated. All other trademarks are the property oftheir respective owners.
12 Texas Instruments
If the average rather than the worst case is considered, the rms sum of reference error contributors can be
taken (replacing the maximums for the typicals).
Using the voltage reference specications to perform the above analysis, a designer should be able to pre
the typical and worst-case accuracy loss due to reference error in their data conversion system. Repeatin
this exercise for several different references should provide the designer with more insight into what
reference specications are most critical in their application. These often include operating temperature
range for temperature drift, initial accuracy if calibration is not possible, and low frequency noise which
cannot be ltered. Knowing which parameter is the dominant error factor helps to narrow down the refer
options signicantly and makes choosing the right reference easier.
1. Voltage Reference Selection BasicsPower Designer, issue #123by David Megaw2. For online resources for reference designs, technical documents, and selector wheel,
visit the Voltage Reference landing pageti.com/vref3. Try the interactive selection tool to help instantly choose the proper reference for an ADC from
the broad TI portfolio, see the WEBENCH Series Voltage Reference Selector Tool atti.com/webenchvref
About the author Mario Endo is a product marketing engineer for TIs Power Products group where he is responsible for
creating product awareness and identifying solutions for customer applications. Mario received his
Master of Science from Santa Clara University.
Resources
( )
(14 bit)bits2.6bit)(12bits0.6(10 bit)bit(MS) AccuracyLostTypical
(14 bit)bits3.6bit)(12bits1.6(10 bit)bit(PFS) AccuracyLostTypical
(LSB)|ERRORlog AccuracyLostTypical
(14 bit)LSB 12.5(12 bit)LSB 3(10 bit)0.8 LSB
LSBppm
ppm760(LSB)|ERROR
760 ppm 96) (50) (75)(60)(50)(500)(550) |ERROR
:)(Example
TOTAL2
RMS
2222222RMS
======
=
===
=
=++++++=
0
0
1.
(
5V LM4132A_2.
Conclusion
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TI warrants performance of its components to the specifications applicable at the time of sale, in accordance with the warranty in TIs termsand conditions of sale of semiconductor products. Testing and other quality control techniques are used to the extent TI deems necessaryto support this warranty. Except where mandated by applicable law, testing of all parameters of each component is not necessarilyperformed.
TI assumes no liability for applications assistance or the design of Buyers products. Buyers are responsible for their products andapplications using TI components. To minimize the risks associated with Buyers products and applications, Buyers should provideadequate design and operating safeguards.
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In some cases, TI components may be promoted specifically to facilitate safety-related applications. With such components, TIs goal is tohelp enable customers to design and create their own end-product solutions that meet applicable functional safety standards andrequirements. Nonetheless, such components are subject to these terms.
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TI has specifically designated certain components as meeting ISO/TS16949 requirements, mainly for automotive use. In any case of use of non-designated products, TI will not be responsible for any failure to meet ISO/TS16949.
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Amplifiers amplifier.ti.com Communications and Telecom www.ti.com/communications
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Power Mgmt power.ti.com Space, Avionics and Defense www.ti.com/space-avionics-defenseMicrocontrollers microcontroller.ti.com Video and Imaging www.ti.com/video
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Wireless Connectivity www.ti.com/wirelessconnectivity
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