REF7025QFKHR [TI]
REF70 Ultra-High-Precision Voltage Reference with Low Noise and Low Drift;
| 型号： | REF7025QFKHR |
| 厂家： | 
TEXAS INSTRUMENTS |
| 描述： | REF70 Ultra-High-Precision Voltage Reference with Low Noise and Low Drift |
| 文件： | 总20页 (文件大小：985K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
REF70
SNAS781 – OCTOBER 2020
REF70 Ultra-High-Precision Voltage Reference with Low Noise and Low Drift
1 Features
3 Description
•
Low noise :
The REF70 device family offers a unique combination
of very low noise (0.22 ppmp-p), low thermal drift (2
ppm/°C), and high accuracy (±0.025%). These
characteristics of the REF70, when paired with high-
resolution data converters, enable various end
equipment to achieve their performance targets.
– 1/f Noise (0.1 Hz to 10 Hz): 0.22 ppmp-p
– 10 Hz to 1 kHz: 0.5 ppmrms
Low temperature drift coefficient :
– 2 ppm/°C (maximum for -40°C to 125°C)
High accuracy: ±0.025% (maximum)
Available in humidity resistance ceramic package
(LCCC)
Low dropout: 250 mV
Wide input voltage: 3 V to 18 V
Output current: ±10 mA
•
•
•
High initial accuracy with very low temperature and
long-term drift help reduce the need for frequent in
system calibration.
•
•
•
•
LCCC (FKH) package helps improve the long term
drift and thermal hysteresis performance further for
applications requiring a very stable reference.
Industry standard voltage options: 2.5 V, 3.0 V, 3.3
V, 4.096 V, 5.0 V
Operating temperature range: −40°C to +125°C
REF70 is specified for the wide temperature range of
−40°C to +125°C. The wide temperature range
enables the device to operate across various
applications. Contact the TI sales representative for
additional voltage and package options.
•
2 Applications
•
•
•
•
•
•
Precision data acquisition systems
Industrial instrumentation
Semiconductor test equipment
Power monitoring
PLC analog I/O modules
Field transmitters
Device Information
PART NAME(1)
REF7025
PACKAGE
BODY SIZE (NOM)
LCCC (8)
5.00 mm × 5.00 mm
REF7025
VSSOP (8)
3.00 mm x 3.00 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
2.501
2.50075
2.5005
2.50025
2.5
VIN
REF70
VIN
10µF
+
2.49975
2.4995
2.49925
2.499
AIN+
REFIN
ADS124S08
OUT
OPS2320
+
AIN-
-50
-25
0
25 50
Temperature (°C)
75
100
125
Output Voltage Vs Free-Air-Temperature
Simplified Schematic
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. ADVANCE INFORMATION for preproduction products; subject to change
without notice.
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Table of Contents
1 Features............................................................................1
2 Applications.....................................................................1
3 Description.......................................................................1
4 Revision History.............................................................. 2
5 Device Comparison Table...............................................3
6 Pin Configuration and Functions...................................3
7 Specifications.................................................................. 4
7.1 Absolute Maximum Ratings ....................................... 4
7.2 ESD Ratings .............................................................. 4
7.3 Recommended Operating Conditions ........................4
7.4 Thermal Information ...................................................4
7.5 REF7025 Electrical Characteristics ........................... 5
7.6 Typical Characteristics................................................6
8 Parameter Measurement Information............................9
8.1 Solder Heat Shift.........................................................9
8.2 Long-Term Stability................................................... 10
8.3 Thermal Hysteresis...................................................10
8.4 Power Dissipation..................................................... 10
8.5 Noise Performance................................................... 11
9 Detailed Description......................................................12
9.1 Overview...................................................................12
9.2 Functional Block Diagram.........................................12
9.3 Feature Description...................................................12
9.4 Device Functional Modes..........................................12
10 Application and Implementation................................13
10.1 Application Information........................................... 13
10.2 Typical Application: Basic Voltage Reference
Connection.................................................................. 13
11 Power Supply Recommendation................................15
12 Layout Guidelines....................................................... 15
13 Layout Example...........................................................16
14 Device and Documentation Support..........................17
14.1 Documentation Support.......................................... 17
14.2 Receiving Notification of Documentation Updates..17
14.3 Support Resources................................................. 17
14.4 Community Resources............................................17
14.5 Trademarks.............................................................17
14.6 Electrostatic Discharge Caution..............................17
14.7 Glossary..................................................................17
15 Mechanical, Packaging, and Orderable
Information.................................................................... 17
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
DATE
REVISION
NOTES
October 2020
*
Initial APL Release
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5 Device Comparison Table
PRODUCT
REF7025
REF7030
REF7033
REF7040
REF7050
VOUT
2.5 V
3.0 V
3.3 V
4.096 V
5.0 V
6 Pin Configuration and Functions
GND
8
OUTF
OUTS
GND
1
2
3
7
6
5
EN
VIN
GND
4
GND
Figure 6-1. FKH Package, 8-Pin LCCC, Top View
GND
1
2
8
7
EN
VIN
OUTF
3
4
6
5
GND
GND
OUTS
GND
Figure 6-2. DGK Package, 8-Pin VSSOP, Top View
Table 6-1. Pin Functions
PIN
FKH
TYPE
DESCRIPTION
NAME
EN
DGK
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
Input
Power
Ground
Ground
Ground
Input
Enable connection. Enables or disable the device.
VIN
Input supply voltage connection.
Ground connection.
GND
GND
GND
OUTS
OUTF
GND
Ground connection.
Ground connection
Reference voltage output sense connection.
Reference voltage output force connection.
Ground connection.
Output
Ground
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7 Specifications
7.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)(1)
MIN
-0.3
-0.3
-0.3
MAX
UNIT
V
Input voltage
VIN
EN
20
VIN + 0.3
6
Enable voltage
V
Output voltage
VOUT
ISC
V
Output short circuit current
Operating temperature range
Storage temperature range
40
mA
°C
°C
TA
-55
-65
150
Tstg
170
(1) Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may
degrade device reliability. These are stress ratings only, and functional operation of the device at these or any other conditions beyond
those specified is not implied. These are stress ratings only and functional operation of the device at these or any other conditions
beyond those specified in the Electrical Characteristics Table is not implied.
7.2 ESD Ratings
VALUE
UNIT
Human body model (HBM), per ANSI/ESDA/JEDEC JS-001,
all pins(1)
±TBD
V(ESD)
Electrostatic discharge
V
Charged device model (CDM), per JEDEC specification
JESD22-C101, all pins(2)
±TBD
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
7.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
MIN
NOM
MAX
UNIT
VOUT + VDO
VIN
Input voltage
18
V
(1)
EN
IL
Enable voltage
0
–10
–40
VIN
10
V
Output current
mA
°C
TA
Operating temperature
25
125
(1) Dropout voltage
7.4 Thermal Information
DEVICE
THERMAL METRIC(1)
FKH (CERAMIC)
DGK (MSOP)
8 PINS
201.2
UNIT
8 PINS
95.8
59.0
58.3
48.2
58.1
28.5
RθJA
Junction-to-ambient thermal resistance
Junction-to-case (top) thermal resistance
Junction-to-board thermal resistance
°C/W
°C/W
°C/W
°C/W
°C/W
°C/W
RθJC(top)
RθJB
85.7
122.9
ΨJT
Junction-to-top characterization parameter
Junction-to-board characterization parameter
Junction-to-case (bottom) thermal resistance
21.2
ΨJB
121.4
RθJC(bot)
N/A
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report.
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7.5 REF7025 Electrical Characteristics
Specifications are tested at TA = 25°C, IL = 0 mA, CIN = 0.1 µF, COUT = 10 µF, VIN = VOUT + 0.5V, OUTS
connected to OUTF, unless otherwise noted
PARAMETER
TEST CONDITION
MIN
TYP
MAX
UNIT
ACCURACY AND DRIFT
Output voltage accuracy TA = 25°C
–0.025
0.025
2
%
Output voltage
–40°C ≤ TA ≤ 125°C
ppm/℃
temperature coefficient
LINE AND LOAD REGULATION
VOUT + VDO ≤ VIN ≤ 18 V
4
5
40
ΔVO / ΔVIN Line regulation
ppm/V
VOUT + VDO ≤ VIN ≤ 18 V, –40°C ≤ TA ≤ 125°C
IL = 0 mA to 10mA, VIN = VOUT + VDO
100
IL = 0 mA to 10mA, VIN = VOUT + VDO, –40°C ≤
TA ≤ 125°C
15
15
ΔVO / ΔIL
Load regulation
ppm/mA
IL = 0 mA to –10mA, VIN = VOUT + VDO
10
IL = 0 mA to –10mA, VIN = VOUT + VDO, –40°C ≤
TA ≤ 125°C
NOISE
enp-p
en
Low frequency noise
Output voltage noise
ƒ = 0.1 Hz to 10 Hz
ƒ = 10 Hz to 1 kHz
0.22
0.5
ppmp-p
ppmrms
HYSTERESIS AND LONG-TERM STABILITY
Long-term stability
0 to 250h at 35°C - FKH package
16
60
ppm
ppm
25°C, –40°C, 125°C, 25°C (cycle 1) – FKH
package
Output voltage
hysteresis
25°C, –40°C, 125°C, 25°C (cycle 2) – FKH
package
60
TURN ON TIME
tON Turn-on time
CAPACITIVE LOAD
0.1% settling, COUT = 1µF
0.5
ms
Stable input capacitor
range
CIN
–40℃ ≤ TA ≤ 125℃
–40℃ ≤ TA ≤ 125℃
0.1
1
µF
µF
Stable output capacitor
range (1)
COUT
100
POWER SUPPLY
VIN Input voltage
3
18
6
V
TA = 25°C
4
5
mA
mA
uA
uA
V
Active mode
–40°C ≤ TA ≤ 125°C
6.5
10
12
IQ
Quiescent current
TA = 25°C
Shutdown mode
–40°C ≤ TA ≤ 125°C
Active mode (EN=1)
1.6
VEN
Enable pin voltage
Enable pin current
Shutdown mode (EN=0)
VIN = VEN = 18V
0.5
3
V
1
uA
uA
mV
mV
mA
IEN
VIN = VEN = 18V, –40°C ≤ TA ≤ 125°C
IL = 5mA, –40°C ≤ TA ≤ 125°C
IL = 10mA, –40°C ≤ TA ≤ 125°C
VOUT = 0V
5
250
500
VDO
ISC
Dropout voltage
Short circuit current
35
(1) ESR for the capacitor can range from 10mΩ to 400mΩ
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7.6 Typical Characteristics
at TA= 25°C, VIN= VEN= 5.5 V, IL= 0 mA, CL= 10 μF, CIN= 0.1 μF (unless otherwise noted)
2.501
40%
2.50075
2.5005
30%
2.50025
2.5
20%
2.49975
2.4995
10%
2.49925
2.499
-50
-25
0
25 50
Temperature (°C)
75
100
125
0
Figure 7-1. Output Voltage Vs Free-Air-
Temperature
Temperature Drift -40èC to 125èC (ppm/èC)
Figure 7-2. Temperature Drift Distribution (28
Units)
60
50
40
30
20
10
0
50%
40%
30%
20%
10%
0
-50
-25
0
25
50
75
100
125
Temperature (èC)
Figure 7-4. Line Regulation vs Temperature
Output Initial Accuracy (%)
Figure 7-3. Accuracy Distribution
50
40
30
20
10
0
20
15
10
5
0
-50
-25
0
25 50
Temperature (°C)
75
100
125
-50
-25
0
25 50
Temperature (°C)
75
100
125
Figure 7-5. Load Regulation (Sourcing) vs
Temperature
Figure 7-6. Load Regulation (Sinking) vs
Temperature
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10mA
10 mA/div
VIN
-10mA
-10mA
5 V/div
VOUT
100 mV/div
10 mV/div
100µs/div
200µs/div
Figure 7-7. Line Regulation Response
Figure 7-8. Load Transient Response (CL = 1 μF)
6
10mA
10 mA/div
5
4
3
2
1
0
-10mA
-10mA
10 mV/div
200µs/div
-50
-25
0
25 50
Temperature (°C)
75
100
125
Figure 7-9. Load Transient Response (CL = 10 μF)
Figure 7-10. Quiescent Current vs Temperature
2.4
2
1.5
VEN_HIGH
VEN_LOW
1.2
0.9
0.6
0.3
0
1.6
1.2
0.8
0.4
0
-50
-25
0
25 50
Temperature (°C)
75
100
125
0
4
8 12
Input Voltage (V)
16
20
Figure 7-11. Shutdown Current vs Temperature
Figure 7-12. Enable Threshold vs VIN
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0.25
-40
25
125
0.2
0.64
0.56
0.48
0.4
0.225
0.175
0.15
0.125
0.1
0.32
0.24
0.16
0.08
0
0.075
0.05
0.025
0
0
1
2
3
4
5
6
Load Current (mA)
7
8
9
10
Noise (ppmp-p
)
Figure 7-13. Dropout Voltage vs Load Current
Figure 7-14. 0.1-Hz to 10-Hz Voltage Noise
Distribution (300 units)
100
90
80
70
60
50
40
30
20
10
0
120
100
CL = 10 mF
80
60
40
20
0
10
100
1k
Frequency (Hz)
10k
100k
10
100
1k 10k
Frequency (Hz)
100k
1M
Figure 7-15. Noise Performance 10 Hz to 100 kHz
Figure 7-16. Power-Supply Rejection Ratio vs
Frequency
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8 Parameter Measurement Information
8.1 Solder Heat Shift
The materials used in the manufacture of the REF70 have differing coefficients of thermal expansion, resulting in
stress on the device die when the part is heated. Mechanical and thermal stress on the device die can cause the
output voltages to shift, degrading the initial accuracy specifications of the product. Reflow soldering is a
common cause of this error. In order to illustrate this effect, a total of 32 devices were soldered on two printed
circuit boards [16 devices on each printed circuit board (PCB)] using lead-free solder paste and the paste
manufacturer suggested reflow profile. The reflow profile is as shown in Figure 8-1. The printed circuit board is
comprised of FR4 material. The board thickness is 1.65 mm and the area is 114 mm × 152 mm.
300
250
200
150
100
50
0
0
50
100
150
200
250
300
350
400
Time (seconds)
C01
Figure 8-1. Reflow Profile
The reference output voltage is measured before and after the reflow process. Although all tested units exhibit
very low shifts (< TBD %), higher shifts are also possible depending on the size, thickness, and material of the
printed circuit board. An important note is that the histograms display the typical shift for exposure to a single
reflow profile. Exposure to multiple reflows, as is common on PCBs with surface-mount components on both
sides, causes additional shifts in the output bias voltage. If the PCB is exposed to multiple reflows, the device
must be soldered in the second pass to minimize its exposure to thermal stress.
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8.2 Long-Term Stability
One of the key parameters of the REF70 references is long-term stability. Typical characteristic expressed as:
curves shows the typical drift value for the REF70 VOUT FKH is 18 ppm from 0 to 250 hours. It is important to
understand that long-term stability is not ensured by design and that the output from the device may shift beyond
the typical 18 ppm specification at any time. For systems that require highly stable output voltages over long
periods of time, the designer should consider burning in the devices prior to use to minimize the amount of
output drift exhibited by the reference over time.
10
0
-10
-20
-30
-40
0
50
100
150
200
250
Time (Hr)
Figure 8-2. Long Term Stability FKH -250 hours (VOUT
)
8.3 Thermal Hysteresis
Thermal hysteresis is measured with the REF70 soldered to a PCB, similar to a real-world application. Thermal
hysteresis for the device is defined as the change in output voltage after operating the device at 25°C, cycling
the device through the specified temperature range, and returning to 25°C. The PCB was baked at 150°C for 30
minutes before thermal hysteresis was measured. Hysteresis can be expressed by Equation 1:
≈
∆
«
’
÷
◊
| VPRE - VPOST
VNOM
|
VHYST
=
ì106 ppm
(
)
(1)
where
•
•
•
•
VHYST = thermal hysteresis (in units of ppm)
VNOM = the specified output voltage
VPRE = output voltage measured at 25°C pre-temperature cycling
VPOST = output voltage measured after the device has cycled from 25°C through the specified temperature
range of –40°C to +125°C and returns to 25°C.
8.4 Power Dissipation
The REF70 voltage references are capable of source and sink up to 10 mA of load current across the rated input
voltage range. However, when used in applications subject to high ambient temperatures, the input voltage and
load current must be carefully monitored to ensure that the device does not exceeded its maximum power
dissipation rating. The maximum power dissipation of the device can be calculated with Equation 2:
TJ = TA +P ì RqJA
D
(2)
where
•
•
•
•
PD is the device power dissipation
TJ is the device junction temperature
TA is the ambient temperature
RθJA is the package (junction-to-air) thermal resistance
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Because of this relationship, acceptable load current in high temperature conditions may be less than the
maximum current-sourcing capability of the device. In no case should the device be operated outside of its
maximum power rating because doing so can result in premature failure or permanent damage to the device.
8.5 Noise Performance
Typical 1/f noise (0.1-Hz to 10-Hz) can be seen in Figure 8-3. Device noise increases with output voltage and
operating temperature. Typically 1/f noise is not practical to filter out which makes it a key parameter for ultra-low
noise measurements. Additional filtering can be used to improve broadband noise output noise levels, although
care must be taken to ensure the output impedance does not degrade ac performance.
Time 1s/div
Figure 8-3. 0.1-Hz to 10-Hz Voltage Noise
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9 Detailed Description
9.1 Overview
The REF70 is family of ultra low-noise, precision bandgap voltage references that are specifically designed for
excellent initial voltage accuracy and drift. The Section 9.2 is a simplified block diagram of the REF70 showing
basic band-gap topology.
9.2 Functional Block Diagram
VIN
Digital
Core
Bandgap
Core
+
Reference
Buffer
Å
VIN
OUTF
OUTS
REN
Enable
Controller
EN
GND
9.3 Feature Description
9.3.1 Low Temperature Drift
The REF70 is designed for minimal drift error, which is defined as the change in output voltage over
temperature. The drift is calculated using the box method, as described by Equation 3:
VREF(MAX) - VREF(MIN)
≈
∆
«
’
÷
◊
Drift =
ì 106
VREF ì Temperature Range
(3)
9.4 Device Functional Modes
9.4.1 EN Pin
The EN pin of the REF70 has an internal 16 MΩ pull-up resistor (REN) to VIN. This allows the EN pin of the
REF70 to be left floating. When the EN pin of the REF70 is pulled high, the device is in active mode. The device
must be in active mode for normal operation. The REF70 can be placed in a low-power mode by pulling the
ENABLE pin low. When in shutdown mode, the output of the device becomes high impedance and the quiescent
current of the device reduces to 10 µA in shutdown mode. The EN pin must not be pulled higher than VIN supply
voltage. See the Section 7.5 for logic high and logic low voltage levels.
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10 Application and Implementation
Note
Information in the following applications sections is not part of the TI component specification, and TI
does not warrant its accuracy or completeness. TI’s customers are responsible for determining
suitability of components for their purposes. Customers should validate and test their design
implementation to confirm system functionality.
10.1 Application Information
As this device has many applications and setups, there are many situations that this datasheet can not
characterize in detail. Basic applications include positive/negative voltage reference and data acquisition
systems. The table below shows the typical application of REF70 and its companion data converters.
Application
Data Converter
Precision Data Acquisition
Industrial Instrumentation
Semiconductor Test
ADS8900B, ADS1278, ADS1262, DAC80501, DAC8562
ADS127L01, ADS8699, ADS1256, ADS1251, DAC9881, DAC8811,
DAC1220, DAC80508
ADS8598H, ADS131M08, ADS8686S, ADS8881, DAC11001A,
DAC7744,
Power Monitoring, PLC Analog I/O
Field Transmitters
ADS131E04, ADS131A02,
ADS1247, ADS1220
10.2 Typical Application: Basic Voltage Reference Connection
The circuit shown in Figure 10-1 shows the basic configuration for the REF70 references. Connect bypass
capacitors according to the guidelines in Section 10.2.2.1.
VIN
REF70
VIN
10µF
+
AIN+
REFIN
OUT
ADS124S08
OPS2320
+
AIN-
Figure 10-1. Basic Reference Connection
10.2.1 Design Requirements
A detailed design procedure is based on a design example. For this design example, use the parameters listed
in Table 10-1 as the input parameters.
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Table 10-1. Design Example Parameters
DESIGN PARAMETER
VALUE
Input voltage VIN
5.5 V
2.5 V
10 µF
10 µF
Output voltage VOUT
REF7025 input capacitor
REF7025 output capacitor
10.2.2 Detailed Design Procedure
10.2.2.1 Input and Output Capacitors
A 1-μF to 10-μF electrolytic or ceramic capacitor can be connected to the input to improve transient response in
applications where the supply voltage may fluctuate. Connect an additional 0.1-μF ceramic capacitor in parallel
to reduce high frequency supply noise.
A low ESR capacitor of 1-μF to 100-μF must be connected to the output to improve stability and help filter out
high frequency noise. Best performance and stability is attained with low-ESR output capacitors (X5R, X7R, or
similar) with an ESR of 100 mΩ or less. For very low noise applications, special care must be taken with X7R
and other MLCC capacitors due to their piezoelectric effect. The inherit piezoelectric effect can cause a
mechanical vibration which appears as noise in the μV range which can dominate the noise of the REF70. It is
recommended to use film capacitors for noise sensitive applications.
10.2.2.2 4-Wire Kelvin Connections
Current flowing through a PCB trace produces an IR voltage drop, and with longer traces, this drop can reach
several millivolts or more, introducing a considerable error into the output voltage of the reference. A 1-inch long,
5-millimeter wide trace of 1-ounce copper has a resistance of approximately 100 mΩ at room temperature; at a
load current of 10 mA, this can introduce a full millivolt of error. In an ideal board layout, the reference must be
mounted as close as possible to the load to minimize the length of the output traces, and, therefore, the error
introduced by voltage drop. However, in applications where this is not possible or convenient, force and sense
connections (sometimes referred to as Kelvin sensing connections) are provided as a means of minimizing the
IR drop and improving accuracy.
Kelvin connections work by providing a set of high impedance voltage-sensing lines to the output and ground
nodes. Because very little current flows through these connections, the IR drop across their traces is negligible,
and the output and ground
It is always advantageous to use Kelvin connections whenever possible. However, in applications where the IR
drop is negligible or an extra set of traces cannot be routed to the load, the force and sense pins for both VOUT
and GND can simply be tied together, and the device can be used in the same fashion as a normal 3-terminal
reference.
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11 Power Supply Recommendation
The REF70 family of references features a low-dropout voltage. These references can be operated with a supply
of only 50 mV above the output voltage for 0-mA output current conditions. The dropout voltage will vary with the
output current so refer to the dropout voltage to see typical dropout voltage requirements. TI recommends a
supply bypass capacitor ranging between 0.1 µF to 10 µF.
During start-up the REF70 can experience moments of high input current due to the output capacitors. The input
current can momentarily rise to ISC
.
0.25
0.225
0.2
-40
25
125
0.175
0.15
0.125
0.1
0.075
0.05
0.025
0
0
1
2
3
4
5
6
Load Current (mA)
7
8
9
10
Figure 11-1. Dropout Voltage
12 Layout Guidelines
Figure 13-1 illustrates an example of a PCB layout for a data acquisition system using the REF70. Some key
considerations are:
•
•
•
•
Connect low-ESR, 0.1-μF ceramic bypass capacitors at VIN of the REF70.
Connect low-ESR, 1-uF to 100-uF capacitor at OUTF of the REF70.
Decouple other active devices in the system per the device specifications.
Using a solid ground plane helps distribute heat and reduces electromagnetic interference (EMI) noise
pickup.
•
•
Place the external components as close to the device as possible. This configuration prevents parasitic errors
(such as the Seebeck effect) from occurring.
Do not run sensitive analog traces in parallel with digital traces. Avoid crossing digital and analog traces if
possible, and only make perpendicular crossings when absolutely necessary.
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13 Layout Example
Analog GND
GND
8
OUTF
6 OUTS
GND
7
EN 1
VIN
GND 3
Input Voltage
VREF
C
C
2
5
4
GND
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Figure 13-1. Layout Example
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14 Device and Documentation Support
14.1 Documentation Support
14.1.1 Related Documentation
For related documentation see the following:
•
•
Voltage Reference Design Tips For Data Converters
Voltage Reference Selection Basics
14.2 Receiving Notification of Documentation Updates
To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper
right corner, click on Alert me to register and receive a weekly digest of any product information that has
changed. For change details, review the revision history included in any revised document.
14.3 Support Resources
TI E2E™ support forums are an engineer's go-to source for fast, verified answers and design help — straight
from the experts. Search existing answers or ask your own question to get the quick design help you need.
Linked content is provided "AS IS" by the respective contributors. They do not constitute TI specifications and do
not necessarily reflect TI's views; see TI's Terms of Use.
14.4 Community Resources
14.5 Trademarks
TI E2E™ is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
14.6 Electrostatic Discharge Caution
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled
with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may
be more susceptible to damage because very small parametric changes could cause the device not to meet its published
specifications.
14.7 Glossary
TI Glossary
This glossary lists and explains terms, acronyms, and definitions.
15 Mechanical, Packaging, and Orderable Information
The following pages include mechanical packaging and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
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PACKAGE OPTION ADDENDUM
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10-Dec-2020
PACKAGING INFORMATION
Orderable Device
Status Package Type Package Pins Package
Eco Plan
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
Samples
Drawing
Qty
(1)
(2)
(3)
(4/5)
(6)
PREF7025QFKHR
REF7025QFKHR
REF7025QFKHT
ACTIVE
LCCC
LCCC
LCCC
FKH
8
8
8
3000 RoHS (In work)
& Non-Green
Call TI
Call TI
Call TI
Call TI
-40 to 125
-40 to 125
-40 to 125
PREVIEW
PREVIEW
FKH
4000 RoHS (In work)
& Non-Green
Call TI
Call TI
FKH
250
RoHS (In work)
& Non-Green
(1) The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based
flame retardants must also meet the <=1000ppm threshold requirement.
(3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.
(5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation
of the previous line and the two combined represent the entire Device Marking for that device.
(6)
Lead finish/Ball material - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two
lines if the finish value exceeds the maximum column width.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
Addendum-Page 1
PACKAGE OPTION ADDENDUM
www.ti.com
10-Dec-2020
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
Addendum-Page 2
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