Maxim MAX6126BASA50 Ultra-high-precision, ultra-low-noise, series voltage reference Datasheet

19-2647; Rev 2; 6/03
Ultra-High-Precision, Ultra-Low-Noise,
Series Voltage Reference
Features
♦ Ultra-Low 1.3µVP-P Noise (0.1Hz to 10Hz, 2.048V
Output)
♦ Ultra-Low 3ppm/°C (max) Temperature Coefficient
♦ ±0.02% (max) Initial Accuracy
♦ Wide (VOUT + 200mV) to 12.6V Supply Voltage
Range
♦ Low 200mV (max) Dropout Voltage
♦ 380µA Quiescent Supply Current
♦ 10mA Sink/Source-Current Capability
♦ Stable with CLOAD = 0.1µF to 10µF
♦ Low 20ppm/1000hr Long-Term Stability
♦ 0.025Ω (max) Load Regulation
♦ 20µV/V (max) Line Regulation
♦ Force and Sense Outputs for Remote Sensing
Pin Configuration
TOP VIEW
NR
1
IN
2
8
I.C.*
7
OUTF
3
6
OUTS
GNDS 4
5
I.C.*
MAX6126
GND
Applications
High-Resolution A/D and D/A Converters
ATE Equipment
SO/µMAX
High-Accuracy Reference Standard
*I.C. = INTERNALLY CONNECTED. DO NOT USE.
Precision Current Sources
Digital Voltmeters
High-Accuracy Industrial and Process Control
Ordering Information
PART
TEMP RANGE
PINPACKAGE
OUTPUT
VOLTAGE
(V)
MAXIMUM INITIAL
ACCURACY (%)
MAXIMUM TEMPCO
(-40°C to +85°C)
(ppm/°C)
TOP
MARK
—
MAX6126AASA21
-40°C to +125°C
8 SO
2.048
0.02
3
MAX6126BASA21
-40°C to +125°C
8 SO
2.048
0.06
5
—
MAX6126AAUA21
-40°C to +125°C
8 µMAX
2.048
0.06
3
6126A21
Ordering Information continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX6126
General Description
The MAX6126 is an ultra-low-noise, high-precision, lowdropout voltage reference. This family of voltage references feature curvature-correction circuitry and
high-stability, laser-trimmed, thin-film resistors that
result in 3ppm/°C (max) temperature coefficients and
an excellent ±0.02% (max) initial accuracy. The proprietary low-noise reference architecture produces a low
flicker noise of 1.3µVP-P and wideband noise as low as
60nV/√Hz (2.048V output) without the increased supply
current usually found in low-noise references. Improve
wideband noise to 35nV/√Hz and AC power-supply
rejection by adding a 0.1µF capacitor at the noise
reduction pin. The MAX6126 series mode reference
operates from a wide 2.7V to 12.6V supply voltage
range and load-regulation specifications are guaranteed to be less than 0.025Ω for sink and source currents up to 10mA. These devices are available over the
automotive temperature range of -40°C to +125°C.
The MAX6126 typically draws 380µA of supply current
and is available in 2.048V, 2.500V, 3.000V, 4.096V, and
5.000V output voltages. These devices also feature
dropout voltages as low as 200mV. Unlike conventional
shunt-mode (two-terminal) references that waste supply
current and require an external resistor, the MAX6126
offers supply current that is virtually independent of
supply voltage and does not require an external resistor. The MAX6126 is stable with 0.1µF to 10µF of load
capacitance.
The MAX6126 is available in the tiny 8-pin µMAX, as
well as 8-pin SO packages.
MAX6126
Ultra-High-Precision, Ultra-Low-Noise,
Series Voltage Reference
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND)
GNDS ....................................................................-0.3V to +0.3V
IN ........................................................................... -0.3V to +13V
OUTF, OUTS, NR........ -0.3V to the lesser of (VIN + 0.3V) or +6V
Output Short Circuit to GND or IN ..........................................60s
Continuous Power Dissipation (TA = +70°C)
8-Pin µMAX (derate 4.5mW/°C above +70°C) ............362mW
8-Pin SO (derate 5.88mW/°C above +70°C) ...............471mW
Operating Temperature Range ........................-40°C to +125°C
Junction Temperature .....................................................+150°C
Storage Temperature Range ............................-65°C to +150°C
Lead Temperature (soldering, 10s) ................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS—MAX6126_21 (VOUT = 2.048V)
(VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
A grade SO
-0.02
+0.02
B grade SO
-0.06
+0.06
A grade µMAX
-0.06
+0.06
B grade µMAX
-0.1
+0.1
UNITS
OUTPUT
Output Voltage
VOUT
TA = +25°C
Referred to
VOUT,
TA = +25°C
Output Voltage Accuracy
TA = -40°C
to +85°C
Output Voltage Temperature
Coefficient (Note 1)
TCVOUT
TA = -40°C
to +125°C
V
A grade SO
0.5
3
B grade SO
1
5
A grade µMAX
1
3
B grade µMAX
2
7
A grade SO
1
5
B grade SO
2
10
A grade µMAX
2
5
B grade µMAX
3
12
TA = +25°C
2
Line Regulation
∆VOUT/
∆VIN
2.7V ≤ VIN ≤
12.6V
Load Regulation
∆VOUT/
∆IOUT
Sourcing: 0 ≤ IOUT ≤ 10mA
0.7
25
Sinking: -10mA ≤ IOUT ≤ 0
1.3
25
Short to GND
160
Short to IN
20
SO
25
µMAX
80
OUT Short-Circuit Current
2
2.048
ISC
Thermal Hysteresis (Note 2)
∆VOUT/
cycle
Long-Term Stability
∆VOUT/
time
TA = -40°C to +125°C
1000hr at TA = +25°C
20
40
SO
20
µMAX
100
_______________________________________________________________________________________
%
ppm/°C
µV/V
µV/mA
mA
ppm
ppm/
1000hr
Ultra-High-Precision, Ultra-Low-Noise,
Series Voltage Reference
(VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DYNAMIC CHARACTERISTICS
Noise Voltage
eOUT
Turn-On Settling Time
Capacitive-Load Stability Range
tR
CLOAD
f = 0.1Hz to 10Hz
1.3
f = 1kHz, CNR = 0
60
f = 1kHz, CNR = 0.1µF
35
To VOUT = 0.01% of
final value
CNR = 0
0.8
CNR = 0.1µF
20
No sustained oscillations
µVP-P
nV/√Hz
ms
0.1 to 10
µF
INPUT
Supply Voltage Range
Quiescent Supply Current
VIN
IIN
Guaranteed by line-regulation test
2.7
TA = +25°C
12.6
380
TA = -40°C to +125°C
550
725
V
µA
ELECTRICAL CHARACTERISTICS—MAX6126_25 (VOUT = 2.500V)
(VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
OUTPUT
Output Voltage
VOUT
TA = +25°C
Referred to VOUT,
TA = +25°C
Output Voltage Accuracy
TA = -40°C to +85°C
Output Voltage Temperature
Coefficient (Note 1)
TCVOUT
TA = -40°C to
+125°C
Line Regulation
∆VOUT/
∆VIN
Load Regulation
∆VOUT/
∆IOUT
2.7V ≤ VIN ≤ 12.6V
2.500
V
A grade SO
-0.02
+0.02
B grade SO
-0.06
+0.06
A grade µMAX
-0.06
+0.06
B grade µMAX
-0.1
+0.1
A grade SO
0.5
3
B grade SO
1
5
A grade µMAX
1
3
B grade µMAX
2
7
A grade SO
1
5
B grade SO
2
10
A grade µMAX
2
5
B grade µMAX
3
12
TA = +25°C
3
20
TA = -40°C to +125°C
40
Sourcing: 0 ≤ IOUT ≤ 10mA
1
25
Sinking: -10mA ≤ IOUT ≤ 0
1.8
25
%
ppm/°C
µV/V
µV/mA
_______________________________________________________________________________________
3
MAX6126
ELECTRICAL CHARACTERISTICS—MAX6126_21 (VOUT = 2.048V) (continued)
MAX6126
Ultra-High-Precision, Ultra-Low-Noise,
Series Voltage Reference
ELECTRICAL CHARACTERISTICS—MAX6126_25 (VOUT = 2.500V) (continued)
(VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
Dropout Voltage (Note 3)
OUT Short-Circuit Current
SYMBOL
CONDITIONS
VIN - VOUT ∆VOUT = 0.1%
ISC
Thermal Hysteresis (Note 2)
∆VOUT/
cycle
Long-Term Stability
∆VOUT/
time
TYP
MAX
IOUT = 5mA
MIN
0.06
0.2
IOUT = 10mA
0.12
0.4
Short to GND
160
Short to IN
20
SO
35
µMAX
80
UNITS
V
mA
ppm
SO
20
µMAX
100
ppm/
1000hr
f = 0.1Hz to 10Hz
1.45
µVP-P
f = 1kHz, CNR = 0
75
f = 1kHz, CNR = 0.1µF
45
1000hr at TA = +25°C
DYNAMIC CHARACTERISTICS
Noise Voltage
Turn-On Settling Time
Capacitive-Load Stability Range
eOUT
tR
CLOAD
To VOUT = 0.01% of
final value
CNR = 0
1
CNR = 0.1µF
20
No sustained oscillations
nV/√Hz
ms
0.1 to 10
µF
INPUT
Supply Voltage Range
Quiescent Supply Current
VIN
IIN
Guaranteed by line-regulation test
2.7
TA = +25°C
12.6
380
TA = -40°C to +125°C
550
725
V
µA
ELECTRICAL CHARACTERISTICS—MAX6126_30 (VOUT = 3.000V)
(VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
OUTPUT
Output Voltage
VOUT
TA = +25°C
Referred to VOUT,
TA = +25°C
Output Voltage Accuracy
TA = -40°C to
+85°C
Output Voltage Temperature
Coefficient (Note 1)
TCVOUT
TA = -40°C to
+125°C
4
3.000
V
A grade SO
-0.02
+0.02
B grade SO
-0.06
+0.06
A grade µMAX
-0.06
+0.06
B grade µMAX
-0.1
+0.1
A grade SO
0.5
3
B grade SO
1
5
A grade µMAX
1
3
B grade µMAX
2
7
A grade SO
1
5
B grade SO
2
10
A grade µMAX
2
5
B grade µMAX
3
12
_______________________________________________________________________________________
%
ppm/°C
Ultra-High-Precision, Ultra-Low-Noise,
Series Voltage Reference
MAX6126
ELECTRICAL CHARACTERISTICS—MAX6126_30 (VOUT = 3.000V) (continued)
(VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
Line Regulation
∆VOUT/
∆VIN
Load Regulation
∆VOUT/
∆IOUT
Dropout Voltage (Note 3)
OUT Short-Circuit Current
CONDITIONS
3.2V ≤ VIN ≤ 12.6V
Thermal Hysteresis (Note 2)
∆VOUT/
cycle
Long-Term Stability
∆VOUT/
time
TYP
MAX
4
25
TA = -40°C to +125°C
50
Sourcing: 0 ≤ IOUT ≤ 10mA
1.5
30
Sinking: -10mA ≤ IOUT ≤ 0
2.8
30
VIN - VOUT ∆VOUT = 0.1%
ISC
MIN
TA = +25°C
IOUT = 5mA
0.06
0.2
IOUT = 10mA
0.11
0.4
Short to GND
160
Short to IN
20
SO
20
µMAX
80
UNITS
µV/V
µV/mA
V
mA
ppm
SO
20
µMAX
100
ppm/
1000hr
f = 0.1Hz to 10Hz
1.75
µVP-P
f = 1kHz, CNR = 0
90
f = 1kHz, CNR = 0.1µF
55
1000hr at TA = +25°C
DYNAMIC CHARACTERISTICS
Noise Voltage
eOUT
Capacitive-Load Stability Range
Turn-On Settling Time
CLOAD
tR
No sustained oscillations
To VOUT = 0.01%
of final value
nV/√Hz
0.1 to 10
CNR = 0
1.2
CNR = 0.1µF
20
µF
ms
INPUT
Supply Voltage Range
VIN
Quiescent Supply Current
IIN
Guaranteed by line-regulation test
3.2
TA = +25°C
12.6
380
TA = -40°C to +125°C
550
725
V
µA
ELECTRICAL CHARACTERISTICS—MAX6126_41 (VOUT = 4.096V)
(VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
OUTPUT
Output Voltage
VOUT
Output Voltage Accuracy
TA = +25°C
Referred to VOUT,
TA = +25°C
4.096
V
A grade SO
-0.02
+0.02
B grade SO
-0.06
+0.06
A grade µMAX
-0.06
+0.06
B grade µMAX
-0.1
+0.1
%
_______________________________________________________________________________________
5
MAX6126
Ultra-High-Precision, Ultra-Low-Noise,
Series Voltage Reference
ELECTRICAL CHARACTERISTICS—MAX6126_41 (VOUT = 4.096V) (continued)
(VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
TA = -40°C to
+85°C
Output Voltage Temperature
Coefficient (Note 1)
TCVOUT
TA = -40°C to
+125°C
Line Regulation
∆VOUT/
∆VIN
Load Regulation
∆VOUT/
∆IOUT
Dropout Voltage (Note 3)
OUT Short-Circuit Current
4.3V ≤ VIN ≤ 12.6V
Thermal Hysteresis (Note 2)
∆VOUT/
cycle
Long-Term Stability
∆VOUT/
time
TYP
MAX
A grade SO
0.5
3
B grade SO
1
5
A grade µMAX
1
3
B grade µMAX
2
7
A grade SO
1
5
B grade SO
2
10
A grade µMAX
2
5
B grade µMAX
3
12
4.5
30
TA = +25°C
TA = -40°C to +125°C
60
Sourcing: 0 ≤ IOUT ≤ 10mA
2
40
Sinking: -10mA ≤ IOUT ≤ 0
5
40
VIN - VOUT ∆VOUT = 0.1%
ISC
MIN
IOUT = 5mA
0.05
0.2
IOUT = 10mA
0.1
0.4
Short to GND
160
Short to IN
20
SO
20
µMAX
80
UNITS
ppm/°C
µV/V
µV/mA
V
mA
ppm
SO
20
µMAX
100
ppm/
1000hr
f = 0.1Hz to 10Hz
2.4
µVP-P
f = 1kHz, CNR = 0
120
f = 1kHz, CNR = 0.1µF
80
1000hr at TA = +25°C
DYNAMIC CHARACTERISTICS
Noise Voltage
Capacitive-Load Stability Range
Turn-On Settling Time
eOUT
CLOAD
tR
No sustained oscillations
To VOUT = 0.01% of
final value
nV/√Hz
0.1 to 10
CNR = 0
1.6
CNR = 0.1µF
20
µF
ms
INPUT
Supply Voltage Range
Quiescent Supply Current
6
VIN
IIN
Guaranteed by line-regulation test
TA = +25°C
4.3
12.6
380
TA = -40°C to +125°C
_______________________________________________________________________________________
550
725
V
µA
Ultra-High-Precision, Ultra-Low-Noise,
Series Voltage Reference
MAX6126
ELECTRICAL CHARACTERISTICS—MAX6126_50 (VOUT = 5.000V)
(VIN = 5.5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
OUTPUT
Output Voltage
VOUT
Output Voltage Accuracy
TA = +25°C
TA = +25°C
TA = -40°C to +85°C
Output Voltage Temperature
Coefficient (Note 1)
TCVOUT
TA = -40°C to
+125°C
Line Regulation
∆VOUT/
∆VIN
Load Regulation
∆VOUT/
∆IOUT
Dropout Voltage (Note 3)
OUT Short-Circuit Current
5.2V ≤ VIN ≤ 12.6V
Thermal Hysteresis (Note 2)
∆VOUT/
cycle
Long-Term Stability
∆VOUT/
time
V
A grade SO
-0.02
+0.02
B grade SO
-0.06
+0.06
A grade µMAX
-0.06
+0.06
B grade µMAX
-0.1
%
+0.1
A grade SO
0.5
3
B grade SO
1
5
A grade µMAX
1
3
B grade µMAX
2
7
A grade SO
1
5
B grade SO
2
10
A grade µMAX
2
5
B grade µMAX
3
12
TA = +25°C
3
40
TA = -40°C to +125°C
80
Sourcing: 0 ≤ IOUT ≤ 10mA
2.5
50
Sinking: -10mA ≤ IOUT ≤ 0
6.5
50
VIN - VOUT ∆VOUT = 0.1%
ISC
5.000
IOUT = 5mA
0.05
0.2
IOUT = 10mA
0.1
0.4
Short to GND
160
Short to IN
20
SO
15
µMAX
80
ppm/°C
µV/V
µV/mA
V
mA
ppm
SO
20
µMAX
100
ppm/
1000hr
f = 0.1Hz to 10Hz
2.85
µVP-P
f = 1kHz, CNR = 0
145
f = 1kHz, CNR = 0.1µF
95
1000hr at TA = +25°C
DYNAMIC CHARACTERISTICS
Noise Voltage
eOUT
Capacitive-Load Stability Range
CLOAD
No sustained oscillations
0.1 to 10
nV/√Hz
µF
_______________________________________________________________________________________
7
ELECTRICAL CHARACTERISTICS—MAX6126_50 (VOUT = 5.000V) (continued)
(VIN = 5.5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
Turn-On Settling Time
CONDITIONS
To VOUT = 0.01% of
final value
tR
MIN
TYP
CNR = 0
2
CNR = 0.1µF
20
MAX
UNITS
ms
INPUT
Supply Voltage Range
VIN
Quiescent Supply Current
Guaranteed by line-regulation test
5.2
12.6
TA = +25°C
IIN
380
V
550
TA = -40°C to +125°C
µA
725
Note 1: Temperature coefficient is measured by the “box” method, i.e., the maximum ∆VOUT / VOUT is divided by the maximum ∆T.
Note 2: Thermal hysteresis is defined as the change in +25°C output voltage before and after cycling the device from TMAX to TMIN.
Note 3: Dropout voltage is defined as the minimum differential voltage (VIN - VOUT) at which VOUT decreases by 0.1% from its
original value at VIN = 5.0V (VIN = 5.5V for VOUT = 5.0V).
Typical Operating Characteristics
(VIN = 5V for MAX6126_21/25/30/41, VIN = 5.5V for MAX6126_50, CLOAD = 0.1µF, IOUT = 0, TA = +25°C, unless otherwise specified.)
(Note 5)
OUTPUT VOLTAGE (V)
2.0485
2.0480
2.0475
2.0470
THREE TYPICAL PARTS
5.002
2.0485
OUTPUT VOLTAGE (V)
THREE TYPICAL PARTS
MAX6126 toc02
2.0490
MAX6126 toc01
2.0490
MAX6126A_50
OUTPUT VOLTAGE TEMPERATURE DRIFT
(VOUT = 5.000V) (SO)
2.0480
2.0475
MAX6126 toc03
MAX6126A_21
OUTPUT VOLTAGE TEMPERATURE DRIFT
(VOUT = 2.048V) (µMAX)
MAX6126A_21
OUTPUT VOLTAGE TEMPERATURE DRIFT
(VOUT = 2.048V) (SO)
OUTPUT VOLTAGE (V)
MAX6126
Ultra-High-Precision, Ultra-Low-Noise,
Series Voltage Reference
THREE TYPICAL PARTS
5.001
5.000
4.999
2.0465
2.0460
2.0470
-50
-25
0
25
50
75
TEMPERATURE (°C)
8
100
125
4.998
-50
-25
0
25
50
75
TEMPERATURE (°C)
100
125
-50
-25
0
25
50
75
TEMPERATURE (°C)
_______________________________________________________________________________________
100
125
Ultra-High-Precision, Ultra-Low-Noise,
Series Voltage Reference
5.000
4.999
MAX6126 toc05
5.001
TA = +25°C
2.0480
TA = +25°C
5.000
OUTPUT VOLTAGE (V)
5.001
MAX6126_50
LOAD REGULATION
2.0485
MAX6126 toc04
THREE TYPICAL PARTS
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
5.002
MAX6126_21
LOAD REGULATION
2.0475
TA = -40°C
2.0470
MAX6126 toc06
MAX6126A_50
OUTPUT VOLTAGE TEMPERATURE DRIFT
(VOUT = 5.000V) (µMAX)
2.0465
4.999
TA = -40°C
4.998
TA = +125°C
4.997
TA = +125°C
2.0460
4.998
0
25
50
75
-10
0
10
5
MAX6126_50
DROPOUT VOLTAGE
vs. SOURCE CURRENT
MAX6126_21
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
TA = +25°C
100
TA = -40°C
200
-20
-40
150
TA = +125°C
100
TA = +25°C
TA = -40°C
-100
0
3
6
9
12
15
0
-60
-80
50
0
0
MAX6126 toc09
250
MAX6126 toc07
TA = +125°C
0
-5
MAX6126_25
DROPOUT VOLTAGE
vs. SOURCE CURRENT
DROPOUT VOLTAGE (mV)
3
6
9
-120
0.001
15
12
0.01
0.1
1
10
100
1000
SOURCE CURRENT (mA)
SOURCE CURRENT (mA)
FREQUENCY (kHz)
MAX6126_50
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
MAX6126_21
SUPPLY CURRENT vs. INPUT VOLTAGE
MAX6126_50
SUPPLY CURRENT vs. INPUT VOLTAGE
-40
-60
-80
500
TA = +125°C
400
TA = +25°C
TA = -40°C
300
200
700
600
TA = +125°C
500
TA = +25°C
400
TA = -40°C
300
200
100
-100
800
SUPPLY CURRENT (µA)
SUPPLY CURRENT (µA)
-20
900
MAX6126 toc12
600
MAX6126 toc10
0
MAX6126 toc11
DROPOUT VOLTAGE (mV)
10
5
OUTPUT CURRENT (mA)
50
PSRR (dB)
0
OUTPUT CURRENT (mA)
250
150
-5
TEMPERATURE (°C)
300
200
4.996
-10
125
100
PSRR (dB)
-25
MAX6126 toc08
-50
100
-120
0.001
0
0.01
0.1
1
10
FREQUENCY (kHz)
100
1000
0
0
2
4
6
8
10
INPUT VOLTAGE (V)
12
14
0
2
4
6
8
10
12
14
INPUT VOLTAGE (V)
_______________________________________________________________________________________
9
MAX6126
Typical Operating Characteristics (continued)
(VIN = 5V for MAX6126_21/25/30/41, VIN = 5.5V for MAX6126_50, CLOAD = 0.1µF, IOUT = 0, TA = +25°C, unless otherwise specified.)
(Note 5)
MAX6126
Ultra-High-Precision, Ultra-Low-Noise,
Series Voltage Reference
Typical Operating Characteristics (continued)
(VIN = 5V for MAX6126_21/25/30/41, VIN = 5.5V for MAX6126_50, CLOAD = 0.1µF, IOUT = 0, TA = +25°C, unless otherwise specified.)
(Note 5)
MAX6126_21
OUTPUT NOISE (0.1Hz TO 10Hz)
MAX6126_50
OUTPUT NOISE (0.1Hz TO 10Hz)
MAX6126 toc13
MAX6126 toc14
VOUT = 2.048V
VOUT = 5V
0.4µV/div
1µV/div
1s/div
1s/div
MAX6126_21
LOAD TRANSIENT
MAX6126_21
LOAD TRANSIENT
MAX6126 toc16
MAX6126 toc15
10mA
1mA
IOUT
5mA/div
IOUT
500µA/div
0mA
-100µA
VOUT
AC-COUPLED
100mV/div
VOUT
AC-COUPLED
20mV/div
200µs/div
200µs/div
CLOAD = 0.1µF
VIN = 5V
CLOAD = 0.1µF
VIN = 5V
IOUT = 0 TO 10mA
VOUT = 2.048V
IOUT = -100µA TO 1mA
VOUT = 2.048V
MAX6126_21
LOAD TRANSIENT
MAX6126_21
LOAD TRANSIENT
MAX6126 toc18
MAX6126 toc17
10mA
-1mA
IOUT
5mA/div
IOUT
5mA/div
0mA
-10mA
VOUT
AC-COUPLED
20mV/div
VOUT
AC-COUPLED
100mV/div
1ms/div
400µs/div
CLOAD = 0.1µF
VIN = 5V
10
IOUT = -1mA TO -10mA
VOUT = 2.048V
CLOAD = 10µF
VIN = 5V
IOUT = 0 TO 10mA
VOUT = 2.048V
______________________________________________________________________________________
Ultra-High-Precision, Ultra-Low-Noise,
Series Voltage Reference
MAX6126_21
LOAD TRANSIENT
MAX6126_21
LOAD TRANSIENT
MAX6126 toc19
MAX6126 toc20
+1mA
IOUT
500µA/div
-1mA
IOUT
5mA/div
-100µA
-10mA
VOUT
AC-COUPLED
10mV/div
VOUT
AC-COUPLED
50mV/div
1ms/div
CLOAD = 10µF
VIN = 5V
400µs/div
CLOAD = 10µF
VIN = 5V
IOUT = -100µA TO 1mA
VOUT = 2.048V
IOUT = -1mA TO -10mA
VOUT = 2.048V
MAX6126_50
LINE TRANSIENT
MAX6126_21
LINE TRANSIENT
MAX6126 toc22
MAX6126 toc21
3.2V
5.7V
VIN
200mV/div
VIN
200mV/div
2.7V
5.2V
VOUT
AC-COUPLED
20mV/div
VOUT
AC-COUPLED
10mV/div
400µs/div
20µs/div
VOUT = 2.048V
VIN = 5.2V TO 5.7V
VOUT = 5V
CLOAD = 0.1µF
CLOAD = 0.1µF
MAX6126_50
TURN-ON TRANSIENT
MAX6126_21
TURN-ON TRANSIENT
MAX6126 toc24
MAX6126 toc23
5.5V
5.5V
VIN
2V/div
VIN
2V/div
GND
GND
VOUT
1V/div
VOUT
2V/div
GND
200µs/div
20µs/div
CLOAD = 0.1µF
VOUT = 2.048V
CLOAD = 0.1µF
VOUT = 5V
______________________________________________________________________________________
11
MAX6126
Typical Operating Characteristics (continued)
(VIN = 5V for MAX6126_21/25/30/41, VIN = 5.5V for MAX6126_50, CLOAD = 0.1µF, IOUT = 0, TA = +25°C, unless otherwise specified.)
(Note 5)
Typical Operating Characteristics (continued)
(VIN = 5V for MAX6126_21/25/30/41, VIN = 5.5V for MAX6126_50, CLOAD = 0.1µF, IOUT = 0, TA = +25°C, unless otherwise specified.)
(Note 5)
MAX6126 toc25
MAX6126 toc26
2.5006
5.5V
2.5004
VIN
2V/div
VIN
2V/div
2.5002
GND
GND
VOUT (V)
5.5V
TWO TYPICAL PARTS
VOUT = 2.5V
2.5000
2.4998
VOUT
2V/div
VOUT
1V/div
MAX6126 toc27
MAX6126B_25
LONG-TERM STABILITY vs. TIME (SO)
MAX6126_50
TURN-ON TRANSIENT
MAX6126_21
TURN-ON TRANSIENT
2.4996
GND
2.4994
0
400µs/div
200
400
CLOAD = 10µF
VOUT = 5V
CLOAD = 10µF
VOUT = 2.048V
MAX6126B_25
LONG-TERM STABILITY vs. TIME (µMAX)
TWO TYPICAL PARTS
VOUT = 5V
5.0004
1000
5.0010
MAX6126 toc29
5.0006
800
MAX6126B_50
LONG-TERM STABILITY vs. TIME (µMAX)
MAX6126B_50
LONG-TERM STABILITY vs. TIME (SO)
MAX6126 toc28
2.5010
600
TIME (hr)
MAX6126 toc30
40µs/div
TWO TYPICAL PARTS
VOUT = 5V
5.0005
2.5005
2.5000
VOUT (V)
VOUT (V)
5.0002
VOUT (V)
MAX6126
Ultra-High-Precision, Ultra-Low-Noise,
Series Voltage Reference
5.0000
5.0000
4.9998
4.9995
2.4995
4.9996
TWO TYPICAL PARTS
VOUT = 2.5V
2.4990
4.9990
4.9994
0
200
400
600
TIME (hr)
800
1000
0
200
400
600
800
1000
0
200
400
TIME (hr)
600
800
TIME (hr)
Note 5: Many of the MAX6126 Typical Operating Characteristics are extremely similar. The extremes of these characteristics are
found in the MAX6126_21 (2.048V output) and the MAX6126_50 (5.000V output). The Typical Operating Characteristics of
the remainder of the MAX6126 family typically lie between those two extremes and can be estimated based on their output
voltages.
12
______________________________________________________________________________________
1000
Ultra-High-Precision, Ultra-Low-Noise,
Series Voltage Reference
MAX6126
Pin Description
(VOUT + 200mV) TO 12.6V INPUT
PIN
NAME
FUNCTION
1
NR
Noise Reduction. Connect a 0.1µF
capacitor to improve wideband noise.
Leave unconnected if not used (see
Figure 1).
2
IN
Positive Power-Supply Input
3
GND
4
GNDS
Ground-Sense Connection. Connect to
ground connection at load.
5, 8
I.C.
Internally Connected. Do not connect
anything to these pins.
6
OUTS
Voltage Reference Sense Output
OUTF
Voltage Reference Force Output. Short
OUTF to OUTS as close to the load as
possible. Bypass OUTF with a
capacitor (0.1µF to 10µF) to GND.
7
IN
OUTF
MAX6126
REFERENCE
OUTPUT
OUTS
*
Ground
NR
0.1µF*
GND
GNDS
*OPTIONAL.
Figure 1. Noise-Reduction Capacitor
Detailed Description
Wideband Noise Reduction
To improve wideband noise and transient power-supply
noise, add a 0.1µF capacitor to NR (Figure 1). Larger
values do not improve noise appreciably. A 0.1µF NR
capacitor reduces the noise from 60nV/√Hz to
35nV/√Hz for the 2.048V output. Noise in the powersupply input can affect output noise, but can be
reduced by adding an optional bypass capacitor
between IN and GND, as shown in the Typical
Operating Circuit.
Output Bypassing
The MAX6126 requires an output capacitor between
0.1µF and 10µF. Locate the output capacitor as close
to OUTF as possible. For applications driving switching
capacitive loads or rapidly changing load currents, it is
advantageous to use a 10µF capacitor in parallel with a
0.1µF capacitor. Larger capacitor values reduce transients on the reference output.
Supply Current
The quiescent supply current of the series-mode
MAX6126 family is typically 380µA and is virtually independent of the supply voltage, with only a 2µA/V (max)
variation with supply voltage.
When the supply voltage is below the minimum specified input voltage during turn-on, the device can draw
up to 300µA beyond the nominal supply current. The
input voltage source must be capable of providing this
current to ensure reliable turn-on.
Thermal Hysteresis
Thermal hysteresis is the change of output voltage at
TA = +25°C before and after the device is cycled over
its entire operating temperature range. The typical thermal hysteresis value is 20ppm (SO package).
Turn-On Time
These devices typically turn on and settle to within
0.1% of their final value in 200µs to 2ms depending on
the device. The turn-on time can increase up to 4ms
with the device operating at the minimum dropout voltage and the maximum load. A noise reduction capacitor of 0.1µF increases the turn-on time to 20ms.
Output Force and Sense
The MAX6126 provides independent connections for the
power-circuit output (OUTF) supplying current into a
load, and for the circuit input regulating the voltage
applied to that load (OUTS). This configuration allows for
the cancellation of the voltage drop on the lines connecting the MAX6126 and the load. When using the Kelvin
connection made possible by the independent current
and voltage connections, take the power connection to
the load from OUTF, and bring a line from OUTS to join
the line from OUTF, at the point where the voltage accu-
______________________________________________________________________________________
13
MAX6126
Ultra-High-Precision, Ultra-Low-Noise,
Series Voltage Reference
racy is needed. The MAX6126 has the same type of
Kelvin connection to cancel drops in the ground return
line. Connect the load to ground and bring a connection
from GNDS to exactly the same point.
IN
ISOURCE
Applications Information
Precision Current Source
Figure 2 shows a typical circuit providing a precision
current source. The OUTF output provides the bias current for the bipolar transistor. OUTS and GNDS sense
the voltage across the resistor and adjust the current
sourced by OUTF accordingly. For even higher precision, use a MOSFET to eliminate base current errors.
MAX6126
OUTF
OUTS
GND
R
GNDS
High-Resolution DAC and Reference from
a Single Supply
Figure 3 shows a typical circuit providing the reference
for a high-resolution, 16-bit MAX541 D/A converter.
Temperature Coefficient vs. Operating
Temperature Range for a 1 LSB Maximum
Error
In a data converter application, the reference voltage of
the converter must stay within a certain limit to keep the
error in the data converter smaller than the resolution
limit through the operating temperature range. Figure 4
shows the maximum allowable reference voltage temperature coefficient to keep the conversion error to less
than 1 LSB, as a function of the operating temperature
range (TMAX - TMIN) with the converter resolution as a
parameter. The graph assumes the reference voltage
temperature coefficient as the only parameter affecting
accuracy.
In reality, the absolute static accuracy of a data converter is dependent on the combination of many parameters such as integral nonlinearity, differential
nonlinearity, offset error, gain error, as well as voltage
reference changes.
VOUT(NOMINAL) / R = ISOURCE
Figure 2. Precision Current Source
3V SUPPLY
VDD
IN
MAX6126
OUTF
REF
MAX541
DAC
OUT
ANALOG
OUTPUT
OUTS
GND
GNDS
GND
Figure 3. 14-Bit High-Resolution DAC and Positive Reference
from a Single 3V Supply
14
______________________________________________________________________________________
Ultra-High-Precision, Ultra-Low-Noise,
Series Voltage Reference
MAX6126
10,000
1000
100
TEMPERATURE
COEFFICIENT
(ppm/°C)
8 BIT
10
10 BIT
12 BIT
1
14 BIT
16 BIT
0.1
18 BIT
0.01
1
20 BIT
100
10
OPERATING TEMPERATURE RANGE (TMAX - TMIN) (°C)
Figure 4. Temperature Coefficient vs. Operating Temperature Range for a 1 LSB Maximum Error
Typical Operating Circuit
Chip Information
TRANSISTOR COUNT: 1171
PROCESS: BiCMOS
(VOUT + 200mV) TO 12.6V INPUT
IN
OUTF
MAX6126
REFERENCE
OUTPUT
OUTS
*
NR
LOAD
*
GND
GNDS
*OPTIONAL.
______________________________________________________________________________________
15
MAX6126
Ultra-High-Precision, Ultra-Low-Noise,
Series Voltage Reference
Ordering Information (continued)
PART
TEMP RANGE
PINPACKAGE
OUTPUT
VOLTAGE
(V)
MAXIMUM INITIAL
ACCURACY (%)
MAXIMUM TEMPCO
(-40°C to +85°C)
(ppm/°C)
TOP
MARK
MAX6126BAUA21
-40°C to +125°C
8 µMAX
2.048
0.1
7
6126B21
MAX6126AASA25
-40°C to +125°C
8 SO
2.500
0.02
3
—
MAX6126BASA25
-40°C to +125°C
8 SO
2.500
0.06
5
—
MAX6126AAUA25
-40°C to +125°C
8 µMAX
2.500
0.06
3
6126A25
MAX6126BAUA25
-40°C to +125°C
8 µMAX
2.500
0.1
7
6126B25
MAX6126AASA30
-40°C to +125°C
8 SO
3.000
0.02
3
—
MAX6126BASA30
-40°C to +125°C
8 SO
3.000
0.06
5
—
MAX6126AAUA30
-40°C to +125°C
8 µMAX
3.000
0.06
3
6126A30
MAX6126BAUA30
-40°C to +125°C
8 µMAX
3.000
0.1
7
6126B30
MAX6126AASA41
-40°C to +125°C
8 SO
4.096
0.02
3
—
MAX6126BASA41
-40°C to +125°C
8 SO
4.096
0.06
5
—
MAX6126AAUA41
-40°C to +125°C
8 µMAX
4.096
0.06
3
6126A41
MAX6126BAUA41
-40°C to +125°C
8 µMAX
4.096
0.1
7
6126B41
MAX6126AASA50
-40°C to +125°C
8 SO
5.000
0.02
3
—
MAX6126BASA50
-40°C to +125°C
8 SO
5.000
0.06
5
—
MAX6126AAUA50
-40°C to +125°C
8 µMAX
5.000
0.06
3
6126A50
MAX6126BAUA50
-40°C to +125°C
8 µMAX
5.000
0.1
7
6126B50
16
______________________________________________________________________________________
Ultra-High-Precision, Ultra-Low-Noise,
Series Voltage Reference
N
E
H
INCHES
MILLIMETERS
MAX
MIN
0.069
0.053
0.010
0.004
0.014
0.019
0.007
0.010
0.050 BSC
0.150
0.157
0.228
0.244
0.016
0.050
MAX
MIN
1.35
1.75
0.10
0.25
0.35
0.49
0.19
0.25
1.27 BSC
3.80
4.00
5.80
6.20
0.40
SOICN .EPS
DIM
A
A1
B
C
e
E
H
L
1.27
VARIATIONS:
1
INCHES
TOP VIEW
DIM
D
D
D
MIN
0.189
0.337
0.386
MAX
0.197
0.344
0.394
MILLIMETERS
MIN
4.80
8.55
9.80
MAX
5.00
8.75
10.00
N MS012
8
AA
14
AB
16
AC
D
A
B
e
C
0∞-8∞
A1
L
FRONT VIEW
SIDE VIEW
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, .150" SOIC
APPROVAL
DOCUMENT CONTROL NO.
21-0041
REV.
B
1
1
______________________________________________________________________________________
17
MAX6126
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.
4X S
8
8
INCHES
DIM
A
A1
A2
b
E
ÿ 0.50±0.1
H
c
D
e
E
H
0.6±0.1
L
1
1
α
0.6±0.1
S
BOTTOM VIEW
D
MIN
0.002
0.030
MAX
0.043
0.006
0.037
0.010
0.014
0.005
0.007
0.116
0.120
0.0256 BSC
0.116
0.120
0.188
0.198
0.016
0.026
0∞
6∞
0.0207 BSC
8LUMAXD.EPS
MAX6126
Ultra-High-Precision, Ultra-Low-Noise,
Series Voltage Reference
MILLIMETERS
MAX
MIN
0.05
0.75
1.10
0.15
0.95
0.25
0.36
0.13
0.18
2.95
3.05
0.65 BSC
2.95
3.05
4.78
5.03
0.41
0.66
0∞
6∞
0.5250 BSC
TOP VIEW
A1
A2
A
α
c
e
b
L
SIDE VIEW
FRONT VIEW
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, 8L uMAX/uSOP
APPROVAL
DOCUMENT CONTROL NO.
21-0036
REV.
J
1
1
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
18 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2003 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.