REF3220AIDBVTG4 [TI]
2.048V、4ppm/°C、100µA、6 引脚 SOT-23 串联（带隙）电压基准 | DBV | 6 | -40 to 125;
| 型号： | REF3220AIDBVTG4 |
| 厂家： | 
TEXAS INSTRUMENTS |
| 描述： | 2.048V、4ppm/°C、100µA、6 引脚 SOT-23 串联（带隙）电压基准 | DBV | 6 | -40 to 125 光电二极管 电源电路 参考电压源 |
| 文件： | 总14页 (文件大小：262K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
REF3212, REF3220
REF3225, REF3230
REF3233, REF3240
SBVS058 −JUNE 2005
4ppm/°C, 100µA, SOT23-6
SERIES VOLTAGE REFERENCE
FD EATURES
DESCRIPTION
The REF32xx is a very low drift, micropower, low-dropout,
precision voltage reference family available in the tiny
SOT23-6 package.
EXCELLENT SPECIFIED DRIFT
PERFORMANCE:
7ppm/°C (max) at 0°C to +125°C
20ppm/°C (max) at −40°C to +125°C
The small size and low power consumption (120µA max)
of the REF32xx make it ideal for portable and
battery-powered applications. This reference is stable with
any capacitive load.
D
D
D
D
D
MICROSIZE PACKAGE: SOT23-6
HIGH OUTPUT CURRENT: + 10mA
HIGH ACCURACY: 0.01%
The REF32xx can be operated from a supply as low as
5mV above the output voltage, under no load conditions.
All models are specified for the wide temperature range of
−40°C to +125°C.
LOW QUIESCENT CURRENT: 100µA
LOW DROPOUT: 5mV
AD PPLICATIONS
PORTABLE EQUIPMENT
AVAILABLE OUTPUT VOLTAGES
D
D
D
DATA ACQUISITION SYSTEMS
MEDICAL EQUIPMENT
TEST EQUIPMENT
PRODUCT
REF3212
REF3220
REF3225
REF3230
REF3233
REF3240
VOLTAGE
1.25V
2.048V
2.5V
3.0V
REF3212
REF3220
REF3225
REF3230
REF3233
REF3240
6
5
4
OUT_F
OUT_S
IN
GND_F
GND_S
ENABLE
1
2
3
3.3V
4.096V
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments
semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
ꢀꢁ ꢂ ꢃꢄ ꢅ ꢆꢇ ꢂꢈ ꢃ ꢉꢆꢉ ꢊꢋ ꢌꢍ ꢎ ꢏꢐ ꢑꢊꢍꢋ ꢊꢒ ꢓꢔ ꢎ ꢎ ꢕꢋꢑ ꢐꢒ ꢍꢌ ꢖꢔꢗ ꢘꢊꢓ ꢐꢑꢊ ꢍꢋ ꢙꢐ ꢑꢕꢚ ꢀꢎ ꢍꢙꢔ ꢓꢑꢒ
ꢓ ꢍꢋ ꢌꢍꢎ ꢏ ꢑꢍ ꢒ ꢖꢕ ꢓ ꢊ ꢌꢊ ꢓ ꢐ ꢑꢊ ꢍꢋꢒ ꢖ ꢕꢎ ꢑꢛꢕ ꢑꢕ ꢎ ꢏꢒ ꢍꢌ ꢆꢕꢜ ꢐꢒ ꢇꢋꢒ ꢑꢎ ꢔꢏ ꢕꢋꢑ ꢒ ꢒꢑ ꢐꢋꢙ ꢐꢎ ꢙ ꢝ ꢐꢎ ꢎ ꢐ ꢋꢑꢞꢚ
ꢀꢎ ꢍ ꢙꢔꢓ ꢑ ꢊꢍ ꢋ ꢖꢎ ꢍ ꢓ ꢕ ꢒ ꢒ ꢊꢋ ꢟ ꢙꢍ ꢕ ꢒ ꢋꢍꢑ ꢋꢕ ꢓꢕ ꢒꢒ ꢐꢎ ꢊꢘ ꢞ ꢊꢋꢓ ꢘꢔꢙ ꢕ ꢑꢕ ꢒꢑꢊ ꢋꢟ ꢍꢌ ꢐꢘ ꢘ ꢖꢐ ꢎ ꢐꢏ ꢕꢑꢕ ꢎ ꢒꢚ
Copyright 2005, Texas Instruments Incorporated
www.ti.com
ꢁꢠ ꢡꢢ ꢣ ꢤ ꢣ ꢥ ꢁ ꢠꢡ ꢢ ꢣꢣ ꢦ
ꢁ ꢠꢡ ꢢ ꢣꢣ ꢧ ꢥ ꢁ ꢠꢡ ꢢ ꢣꢢ ꢦ
ꢁ ꢠꢡ ꢢ ꢣꢢ ꢢ ꢥ ꢁ ꢠꢡ ꢢ ꢣꢨ ꢦ
SBVS058 −JUNE 2005
www.ti.com
This integrated circuit can be damaged by ESD. Texas
Instruments recommends that all integrated circuits be
(1)
ABSOLUTE MAXIMUM RATINGS
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +7.5V
Operating Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . −55°C to +135°C
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65°C to +150°C
Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +150°C
Lead Temperature (soldering, 10s) . . . . . . . . . . . . . . . . . . . . . . . . . . . +300°C
ESD Rating
handledwith 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.
Human Body Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4kV
Charged Device Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1kV
Machine Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400V
(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.
(1)
PACKAGE/ORDERING INFORMATION
PRODUCT
REF3212
REF3220
REF3225
REF3230
REF3233
REF3240
OUTPUT VOLTAGE
PACKAGE-LEAD
SOT23-6
PACKAGE DESIGNATOR
PACKAGE MARKING
1.25V
2.048V
2.5V
DBV
DBV
DBV
DBV
DBV
DBV
R32A
R32B
R32C
R32D
R32E
R32F
SOT23-6
SOT23-6
3.0V
SOT23-6
3.30V
4.096V
SOT23-6
SOT23-6
(1)
For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI website at www.ti.com.
PIN CONFIGURATION
Top View
SOT23
6
5
4
OUT_F
OUT_S
IN
GND_F
GND_S
1
2
ENABLE
3
NOTE: The location of pin 1 on the REF32xx is determined by orienting the package marking as shown in the diagram above.
2
ꢁꢠꢡ ꢢ ꢣ ꢤ ꢣ ꢥ ꢁ ꢠꢡ ꢢꢣ ꢣꢦ
ꢁꢠꢡ ꢢ ꢣ ꢣ ꢧ ꢥ ꢁ ꢠꢡ ꢢꢣ ꢢꢦ
ꢁꢠꢡ ꢢ ꢣ ꢢ ꢢ ꢥ ꢁ ꢠꢡ ꢢꢣ ꢨꢦ
SBVS058 −JUNE 2005
www.ti.com
ELECTRICAL CHARACTERISTICS
Boldface limits apply over the listed temperature range.
At TA = +25°C, ILOAD = 0mA, and VIN = 5V, unless otherwise noted.
REF32xx
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNIT
REF3212 (1.25V)
OUTPUT VOLTAGE, V
1.2475
−0.2
1.25
0.01
1.2525
0.2
V
OUT
OUT
OUT
OUT
OUT
OUT
Initial Accuracy
%
NOISE
Output Voltage Noise
Voltage Noise
f = 0.1Hz to 10Hz
f = 10Hz to 10kHz
17
24
µV
PP
µV
RMS
REF3220 (2.048V)
OUTPUT VOLTAGE, V
2.044
−0.2
2.048
0.01
2.052
0.2
V
Initial Accuracy
%
NOISE
Output Voltage Noise
Voltage Noise
f = 0.1Hz to 10Hz
f = 10Hz to 10kHz
27
39
µV
PP
µV
RMS
REF3225 (2.5V)
OUTPUT VOLTAGE, V
2.495
−0.2
2.50
0.01
2.505
0.2
V
Initial Accuracy
%
NOISE
Output Voltage Noise
Voltage Noise
f = 0.1Hz to 10Hz
f = 10Hz to 10kHz
33
48
µV
PP
µV
RMS
REF3230 (3V)
OUTPUT VOLTAGE, V
2.994
−0.2
3
3.006
0.2
V
Initial Accuracy
0.01
%
NOISE
Output Voltage Noise
Voltage Noise
f = 0.1Hz to 10Hz
f = 10Hz to 10kHz
39
57
µV
PP
µV
RMS
REF3233 (3.3V)
OUTPUT VOLTAGE, V
3.293
−0.2
3.3
3.307
0.2
V
Initial Accuracy
0.01
%
NOISE
Output Voltage Noise
Voltage Noise
f = 0.1Hz to 10Hz
f = 10Hz to 10kHz
43
63
µV
PP
µV
RMS
REF3240 (4.096V)
OUTPUT VOLTAGE, V
4.088
−0.2
4.096
0.01
4.104
0.2
V
Initial Accuracy
%
NOISE
Output Voltage Noise
Voltage Noise
f = 0.1Hz to 10Hz
f = 10Hz to 10kHz
53
78
µV
PP
µV
RMS
3
ꢁꢠ ꢡꢢ ꢣ ꢤ ꢣ ꢥ ꢁ ꢠꢡ ꢢ ꢣꢣ ꢦ
ꢁ ꢠꢡ ꢢ ꢣꢣ ꢧ ꢥ ꢁ ꢠꢡ ꢢ ꢣꢢ ꢦ
ꢁ ꢠꢡ ꢢ ꢣꢢ ꢢ ꢥ ꢁ ꢠꢡ ꢢ ꢣꢨ ꢦ
SBVS058 −JUNE 2005
www.ti.com
ELECTRICAL CHARACTERISTICS (continued)
Boldface limits apply over the listed temperature range.
At TA = +25°C, ILOAD = 0mA, and VIN = 5V, unless otherwise noted.
REF32xx
TYP
PARAMETER
CONDITIONS
MIN
MAX
UNIT
REF3212 / REF3220 / REF3225 / REF3230 / REF3233 / REF3240
OUTPUT VOLTAGE TEMP DRIFT
dVOUT/dT
0°C ≤ T ≤ +125°C
4
7
ppm/°C
ppm/°C
A
−40°C ≤ T ≤ +125°C
10.5
20
A
LONG-TERM STABILITY
LINE REGULATION
0 to 1000h
55
15
ppm
(1)
V
OUT
+ 0.05 ≤ V ≤ 5.5V
−65
+65
ppm/V
IN
LOAD REGULATION
Sourcing
dVOUT/dILOAD
(1)
(1)
0mA < I
< 10mA, V = V
+ 250mV
< 0mA, V = V + 100mV
OUT
−40
−60
3
40
60
µV/mA
µV/mA
LOAD
IN
OUT
Sinking
−10mA< I
20
LOAD
IN
(2)
THERMAL HYSTERESIS
First cycle
dT
100
25
ppm
ppm
Additional cycles
(1)
DROPOUT VOLTAGE
V
−V
0°C ≤ T ≤ +125°C
5
50
mV
A
IN OUT
(1)
OUTPUT CURRENT
I
V
IN
= V + 250mV
OUT
−10
10
mA
LOAD
SHORT-CIRCUIT CURRENT
I
SC
Sourcing
Sinking
50
40
mA
mA
TURN-ON SETTLING TIME
ENABLE/SHUTDOWN
to 0.1% at V = 5V with C = 0
60
µs
IN
L
V
Reference in Shutdown mode
Reference is active
0
0.7
V
V
L
V
H
0.75 × V
V
IN
IN
POWER SUPPLY
Voltage
I = 0
L
(1)
+ 0.05
V
V
OUT
5.5
120
135
1
V
IN
Current
I
ENABLE > 0.75 x V
100
115
0.1
µA
mA
µA
Q
IN
Over-temperature
Shutdown
0°C ≤ T ≤ +125°C
A
I
ENABLE < 0.7V
S
TEMPERATURE RANGE
Specified
−40
−55
−65
+125
+135
+150
°C
°C
°C
Operating
Storage
Thermal resistance, SOT23-6
θ
JA
200
°C/W
(1)
(2)
(3)
The minimum supply voltage for the REF3212 is 1.8V.
Thermal hysteresis procedure is explained in more detail in the Applications Information section.
Load regulation is using force and sense lines; see the Load Regulation section for more information.
4
ꢁꢠꢡ ꢢ ꢣ ꢤ ꢣ ꢥ ꢁ ꢠꢡ ꢢꢣ ꢣꢦ
ꢁꢠꢡ ꢢ ꢣ ꢣ ꢧ ꢥ ꢁ ꢠꢡ ꢢꢣ ꢢꢦ
ꢁꢠꢡ ꢢ ꢣ ꢢ ꢢ ꢥ ꢁ ꢠꢡ ꢢꢣ ꢨꢦ
SBVS058 −JUNE 2005
www.ti.com
TYPICAL CHARACTERISTICS
At T = +25°C, ILOAD = 0mA, V = +5V power supply, REF3225 is used for typical characteristics, unless otherwise noted.
A
IN
TEMPERATURE DRIFT
TEMPERATURE DRIFT
_
_
−
_
_
(0 C to +125 C)
( 40 C to +125 C)
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 1819 20
_
_
Drift (ppm/ C)
Drift (ppm/ C)
OUTPUT VOLTAGE ACCURACY
vs TEMPERATURE
DROPOUT VOLTAGE
vs LOAD CURRENT
0.12
0.08
0.04
0
160
140
120
100
80
_
+125 C
_
+25 C
−
_
40 C
60
−
−
−
0.04
0.08
0.12
40
20
0
−
−
−
−
−
5
15
10
0
5
10
15
50
25
0
+25
+50
+75
+100
+125
_
Temperature ( C)
Load Current (mA)
QUIESCENT CURRENT
vs TEMPERATURE
POWER−SUPPLY REJECTION RATIO
vs FREQUENCY
130
120
110
100
90
100
90
80
70
60
50
40
30
20
10
80
70
−
−
25
50
0
+25
+50
+75
+100 +125
1
10
100
1k
10k
100k
_
Temperature ( C)
Frequency (Hz)
5
ꢁꢠ ꢡꢢ ꢣ ꢤ ꢣ ꢥ ꢁ ꢠꢡ ꢢ ꢣꢣ ꢦ
ꢁ ꢠꢡ ꢢ ꢣꢣ ꢧ ꢥ ꢁ ꢠꢡ ꢢ ꢣꢢ ꢦ
ꢁ ꢠꢡ ꢢ ꢣꢢ ꢢ ꢥ ꢁ ꢠꢡ ꢢ ꢣꢨ ꢦ
SBVS058 −JUNE 2005
www.ti.com
TYPICAL CHARACTERISTICS (continued)
At T = +25°C, ILOAD = 0mA, V = +5V power supply, REF3225 is used for typical characteristics, unless otherwise noted.
A
IN
OUTPUT VOLTAGE vs INPUT VOLTAGE
(REF3212)
OUTPUT VOLTAGE
vs LOAD CURRENT
2.505
2.504
2.503
2.502
2.501
2.500
2.499
2.498
2.497
2.496
2.495
1.2525
1.2520
1.2515
1.2510
1.2505
1.2500
1.2495
1.2490
1.2485
1.2480
1.2475
_
+125 C
_
+125 C
_
+25 C
_
+25 C
−
_
40 C
−
_
40 C
−
−
−
5
1.5
2
2.5
3
3.5
4
4.5
5
15
10
0
5
10
15
Input Voltage (V)
Load Current (mA)
0.1Hz TO 10Hz
NOISE
OUTPUT VOLTAGE
INITIAL ACCURACY
400ms/div
Output Accuracy (%)
STEP RESPONSE
STEP RESPONSE
µ
CL = 0pF, 5V STARTUP
CL = 1 F
VIN
VIN
VOUT
VOUT
µ
100 s/div
µ
10 s/div
6
ꢁꢠꢡ ꢢ ꢣ ꢤ ꢣ ꢥ ꢁ ꢠꢡ ꢢꢣ ꢣꢦ
ꢁꢠꢡ ꢢ ꢣ ꢣ ꢧ ꢥ ꢁ ꢠꢡ ꢢꢣ ꢢꢦ
ꢁꢠꢡ ꢢ ꢣ ꢢ ꢢ ꢥ ꢁ ꢠꢡ ꢢꢣ ꢨꢦ
SBVS058 −JUNE 2005
www.ti.com
TYPICAL CHARACTERISTICS (continued)
At T = +25°C, ILOAD = 0mA, V = +5V power supply, REF3225 is used for typical characteristics, unless otherwise noted.
A
IN
LINE TRANSIENT
CL = 0pF
LINE TRANSIENT
µ
CL = 10 F
VIN
VIN
VOUT
VOUT
µ
µ
20 s/div
100 s/div
LOAD TRANSIENT
LOAD TRANSIENT
µ
CL = 0pF, 10mA OUTPUT PULSE
CL = 1 F, 10mA OUTPUT PULSE
ILOAD
ILOAD
+10mA
+10mA
+10mA
+10mA
−
−
10mA
10mA
VOUT
VOUT
µ
µ
40 s/div
40 s/div
LOAD TRANSIENT
LOAD TRANSIENT
µ
CL = 0pF, 1mA OUTPUT PULSE
CL = 1 F, 1mA OUTPUT PULSE
ILOAD
ILOAD
+1mA
+1mA
+1mA +1mA
−
1mA
−
1mA
VOUT
VOUT
µ
µ
40 s/div
40 s/div
7
ꢁꢠ ꢡꢢ ꢣ ꢤ ꢣ ꢥ ꢁ ꢠꢡ ꢢ ꢣꢣ ꢦ
ꢁ ꢠꢡ ꢢ ꢣꢣ ꢧ ꢥ ꢁ ꢠꢡ ꢢ ꢣꢢ ꢦ
ꢁ ꢠꢡ ꢢ ꢣꢢ ꢢ ꢥ ꢁ ꢠꢡ ꢢ ꢣꢨ ꢦ
SBVS058 −JUNE 2005
www.ti.com
TYPICAL CHARACTERISTICS (continued)
At T = +25°C, ILOAD = 0mA, V = +5V power supply, REF3225 is used for typical characteristics, unless otherwise noted.
IN
A
LONG−TERM STABILITY
(32 Units)
200
150
100
50
0
−
50
−
−
−
100
150
200
0
200
400
600
800
1000
1200
Time (Hours)
THEORY OF OPERATION
APPLICATION INFORMATION
The REF32xx is a family of CMOS, precision bandgap
voltage references. Figure 1 shows the basic bandgap
The REF32xx does not require a load capacitor and is
stable with any capacitive load. Figure 2 shows typical
connections required for operation of the REF32xx. A
supply bypass capacitor of 0.47µF is recommended.
topology. Transistors Q and Q are biased so that the
1
2
current density of Q is greater than that of Q . The
1
2
difference of the two base-emitter voltages (Vbe – Vbe )
1
2
has a positive temperature coefficient and is forced across
resistor R . This voltage is amplified and added to the
1
base-emitter voltage of Q , which has a negative
temperature coefficient. The resulting output voltage is
virtually independent of temperature.
2
+2.5V
1
2
3
6
5
4
µ
0.47 F
+5V
VBANDGAP
Figure 2. Typical Operating Connections for the
REF3225
R1
SUPPLY VOLTAGE
+
Vbe1
−
+
Vbe2
−
The REF32xx family of references features an extremely
low dropout voltage. With the exception of the REF3212,
which has a minimum supply requirement of 1.8V, these
references can be operated with a supply of only 5mV
above the output voltage in an unloaded condition. For
loaded conditions, a typical dropout voltage versus load is
shown in the Typical Characteristic curves.
Q1
I
N Q2
Figure 1. Simplified Schematic of Bandgap
Reference
8
ꢁꢠꢡ ꢢ ꢣ ꢤ ꢣ ꢥ ꢁ ꢠꢡ ꢢꢣ ꢣꢦ
ꢁꢠꢡ ꢢ ꢣ ꢣ ꢧ ꢥ ꢁ ꢠꢡ ꢢꢣ ꢢꢦ
ꢁꢠꢡ ꢢ ꢣ ꢢ ꢢ ꢥ ꢁ ꢠꢡ ꢢꢣ ꢨꢦ
SBVS058 −JUNE 2005
www.ti.com
The REF32xx also features a low quiescent current of
THERMAL HYSTERESIS
100µA, with
a maximum quiescent current over
Thermal hysteresis for the REF32xx 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. It can be
expressed as:
temperature of just 135µA. The quiescent current typically
changes less than 2µA over the entire supply range, as
shown in Figure 3.
Ť
Ť
VPRE * VPOST
6
+ ǒ
Where:
Ǔ
110
108
106
104
102
100
98
VHYST
10 (ppm)
VNOM
(1)
V
= thermal hysteresis (in units of ppm).
= the specified output voltage.
HYST
V
V
NOM
PRE
= output voltage measured at +25_C
pretemperature cycling.
96
V
= output voltage measured after the device
POST
has been cycled through the specified temperature
range of –40_C to +125_C and returned to +25_C.
94
1.5
2.0
2.5 3.0
3.5
4.0
4.5
5.0
5.5
6.0
Power Supply (V)
TEMPERATURE DRIFT
Figure 3. Supply Current vs Supply Voltage
The REF32xx is designed to exhibit minimal drift error,
which is defined as the change in output voltage over
varying temperature. The drift is calculated using the box
method, as described by the following equation:
Supply voltages below the specified levels can cause the
REF32xx to momentarily draw currents greater than the
typical quiescent current. This momentary current draw
can be prevented by using a power supply with a fast rising
edge and low output impedance.
VOUTMAX * VOUTMIN
6
Drift + ǒ
Ǔ
10 (ppm)
VOUT Temp Range
(2)
The REF32xx features a typical drift coefficient of 4ppm/°C
from 0_C to +125_C—the primary temperature range for
many applications. For the extended industrial
temperature range of –40_C to +125_C, the REF32xx
family drift increases to a typical value of 10.5ppm/°C.
SHUTDOWN
The REF32xx can be placed in a low-power mode by
pulling the ENABLE/SHUTDOWN pin low. When in
Shutdown mode, the output of the REF32xx becomes a
resistive load to ground. The value of the load depends on
the model, and ranges from approximately 100kΩ to
400kΩ.
NOISE PERFORMANCE
Typical 0.1Hz to 10Hz voltage noise can be seen in the
Typical Characteristic curve, 0.1 to 10Hz Voltage Noise.
The noise voltage of the REF32xx increases with output
voltage and operating temperature. Additional filtering can
be used to improve output noise levels, although care
should be taken to ensure the output impedance does not
degrade AC performance.
9
ꢁꢠ ꢡꢢ ꢣ ꢤ ꢣ ꢥ ꢁ ꢠꢡ ꢢ ꢣꢣ ꢦ
ꢁ ꢠꢡ ꢢ ꢣꢣ ꢧ ꢥ ꢁ ꢠꢡ ꢢ ꢣꢢ ꢦ
ꢁ ꢠꢡ ꢢ ꢣꢢ ꢢ ꢥ ꢁ ꢠꢡ ꢢ ꢣꢨ ꢦ
SBVS058 −JUNE 2005
www.ti.com
LONG-TERM STABILITY
APPLICATION CIRCUITS
Long-term stability refers to the change of the output
voltage of a reference over a period of months or years.
This effect lessens as time progresses, as is shown by the
long-term stability Typical Characteristic curves. The
typical drift value for the REF32xx is 55ppm from 0 to 1000
hours. This parameter is characterized by measuring 30
units at regular intervals for a period of 1000 hours.
NEGATIVE REFERENCE VOLTAGE
For applications requiring a negative and positive
reference voltage, the REF32xx and OPA735 can be used
to provide a dual-supply reference from a 5V supply.
Figure 5 shows the REF3225 used to provide a 2.5V
supply reference voltage. The low drift performance of the
REF32xx complements the low offset voltage and zero
drift of the OPA735 to provide an accurate solution for
split-supply applications. Care must be taken to match the
LOAD REGULATION
Load regulation is defined as the change in output voltage
as a result of changes in load current. The load regulation
of the REF32xx is measured using force and sense
contacts, as shown in Figure 4. The force and sense lines
can be used to effectively eliminate the impact of contact
and trace resistance, resulting in accurate voltage at the
load. By connecting the force and sense lines at the load,
the REF32xx compensates for the contact and trace
resistances because it measures and adjusts the voltage
actually delivered at the load.
temperature coefficients of R and R .
1
2
+5V
4
3
5
6
REF3225
+2.5V
2
1
R1
Ω
10k
R2
Ω
10k
+5V
Contact and Trace Resistance
−
2.5V
OPA735
−
5V
GND_F
GND_S
SHDN
OUT_F
OUT_S
IN
1
2
3
6
5
4
NOTE: Bypass capacitor is not shown.
REF32xx
Figure 5. REF3225 Combined with OPA735 to
Create Positive and Negative Reference Voltages
RLOAD
µ
0.47 F
+5V
DATA ACQUISITION
Data acquisition systems often require stable voltage
references to maintain accuracy. The REF32xx family
features stability and a wide range of voltages suitable for
most microcontrollers and data converters. Figure 6,
Figure 7, and Figure 8 show basic data acquisition
systems.
Figure 4. Accurate Load Regulation of REF32xx
10
ꢁꢠꢡ ꢢ ꢣ ꢤ ꢣ ꢥ ꢁ ꢠꢡ ꢢꢣ ꢣꢦ
ꢁꢠꢡ ꢢ ꢣ ꢣ ꢧ ꢥ ꢁ ꢠꢡ ꢢꢣ ꢢꢦ
ꢁꢠꢡ ꢢ ꢣ ꢢ ꢢ ꢥ ꢁ ꢠꢡ ꢢꢣ ꢨꢦ
SBVS058 −JUNE 2005
www.ti.com
5
6
3
4
REF3233
3.3V
VS
V+
Ω
5
µ
0.47 F
2
1
GND
ADS7822
VREF
+
VCC
µ
µ
1 F to 10 F
+
µ µ
1 F to 10 F
µ
0.1 F
Microcontroller
VIN
+In
CS
DOUT
−
In
GND
DCLOCK
Figure 6. Basic Data Acquisition System 1
2.5V Supply
2.5V
3
Ω
5
VIN
4
+
5
6
µ
µ
1 F to 10 F
VS
ADS8324
VREF
V
OUT = 1.25V
REF3212
VCC
+
µ
0.1 F
2
1
µ
µ
1 F to 10 F
GND
Microcontroller
+In
CS
DOUT
0V to 1.25V
−
In
DCLOCK
GND
Figure 7. Basic Data Acquisition System 2
+5V
2
1
3
4
REF3240
5
6
µ
µ
1 F
0.1 F
VOUT = 4.096V
Ω
Ω
10
1k
µ
22 F
+5V
Ω
1k
VREF
ADS8381
VIN
Ω
10
THS4031
6800pF
µ
0.22 F
Ω
500
−
5V
Figure 8. REF3240 Provides an Accurate Reference for Driving the ADS8381
11
PACKAGE OPTION ADDENDUM
www.ti.com
8-Jul-2005
PACKAGING INFORMATION
Orderable Device
REF3212AIDBVR
REF3212AIDBVT
REF3220AIDBVR
REF3220AIDBVT
REF3225AIDBVR
REF3225AIDBVT
REF3230AIDBVR
REF3230AIDBVT
REF3233AIDBVR
REF3233AIDBVT
REF3240AIDBVR
REF3240AIDBVT
Status (1)
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
Package Package
Pins Package Eco Plan (2) Lead/Ball Finish MSL Peak Temp (3)
Qty
Type
Drawing
SOT-23
DBV
6
6
6
6
6
6
6
6
6
6
6
6
3000 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
SOT-23
SOT-23
SOT-23
SOT-23
SOT-23
SOT-23
SOT-23
SOT-23
SOT-23
SOT-23
SOT-23
DBV
DBV
DBV
DBV
DBV
DBV
DBV
DBV
DBV
DBV
DBV
250 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
3000 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
250 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
3000 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
250 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
3000 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
250 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
3000 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
250 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
3000 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
250 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
(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)
Eco Plan
-
The planned eco-friendly classification: Pb-Free (RoHS) or Green (RoHS
&
no Sb/Br)
-
please check
http://www.ti.com/productcontent for the latest availability information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame
retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder
temperature.
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.
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 1
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications,
enhancements, improvements, and other changes to its products and services at any time and to discontinue
any product or service without notice. Customers should obtain the latest relevant information before placing
orders and should verify that such information is current and complete. All products are sold subject to TI’s terms
and conditions of sale supplied at the time of order acknowledgment.
TI warrants performance of its hardware products to the specifications applicable at the time of sale in
accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI
deems necessary to support this warranty. Except where mandated by government requirements, testing of all
parameters of each product is not necessarily performed.
TI assumes no liability for applications assistance or customer product design. Customers are responsible for
their products and applications using TI components. To minimize the risks associated with customer products
and applications, customers should provide adequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right,
copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process
in which TI products or services are used. Information published by TI regarding third-party products or services
does not constitute a license from TI to use such products or services or a warranty or endorsement thereof.
Use of such information may require a license from a third party under the patents or other intellectual property
of the third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of information in TI data books or data sheets is permissible only if reproduction is without
alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction
of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for
such altered documentation.
Resale of TI products or services with statements different from or beyond the parameters stated by TI for that
product or service voids all express and any implied warranties for the associated TI product or service and
is an unfair and deceptive business practice. TI is not responsible or liable for any such statements.
Following are URLs where you can obtain information on other Texas Instruments products and application
solutions:
Products
Applications
Audio
Amplifiers
amplifier.ti.com
www.ti.com/audio
Data Converters
dataconverter.ti.com
Automotive
www.ti.com/automotive
DSP
dsp.ti.com
Broadband
Digital Control
Military
www.ti.com/broadband
www.ti.com/digitalcontrol
www.ti.com/military
Interface
Logic
interface.ti.com
logic.ti.com
Power Mgmt
Microcontrollers
power.ti.com
Optical Networking
Security
www.ti.com/opticalnetwork
www.ti.com/security
www.ti.com/telephony
www.ti.com/video
microcontroller.ti.com
Telephony
Video & Imaging
Wireless
www.ti.com/wireless
Mailing Address:
Texas Instruments
Post Office Box 655303 Dallas, Texas 75265
Copyright 2005, Texas Instruments Incorporated
相关型号：
©2020 ICPDF网 联系我们和版权申明