MAXIM MAX6220

19-1930; Rev 0; 4/01
Low-Noise, Precision, +2.5V/+4.096V/+5V
Voltage Reference
The MAX6220 is a low-noise, precision voltage reference with extremely low 20ppm/°C temperature coefficient over the automotive temperature range (-40°C to
+125°C) and excellent ±0.1% initial accuracy. This
device features buried-zener technology for low noise
performance. The load-regulation specification is guaranteed for source and sink currents up to 15mA.
Excellent line and load regulation and low output
impedance at high frequency make the MAX6220 ideal
for high-resolution data-conversion systems up to
16 bits. The MAX6220 is set for 2.5V, 4.096V, and
5.0V outputs.
Applications
Features
♦ Low 20ppm/°C Temperature Coefficient over
-40°C to +125°C Range
♦ Very Low 1.5µVp-p Noise (0.1Hz to 10Hz)
♦ ±0.1% Initial Accuracy
♦ ±15mA Output Source and Sink Current
♦ 8V to 40V Input Voltage Range
♦ Optional Noise Reduction and Voltage Trim
♦ Excellent Transient Response
♦ Low 20ppm/1000hr Long-Term Stability
♦ Stable for All Capacitive Loads
High-Accuracy Industrial and Process Control
ATE Equipment
Precision Current Sources
Ordering Information
PART
TEMP. RANGE
MAX6220ASA25 -40°C to +125°C
8 SO
2.5
MAX6220ASA41 -40°C to +125°C
8 SO
4.096
MAX6220ASA50 -40°C to +125°C
8 SO
5.0
Pin Configuration
Typical Operating Circuit
TOP VIEW
8V TO 40V INPUT
IN
OUT
REFERENCE OUT
I.C. 1
IN 2
2.2µF *
NR
MAX6220
OUPUT
PINVOLTAGE
PACKAGE
(V)
NR 3
TRIM
2.2µF *
MAX6220
GND 4
8
I.C.
7
I.C.
6
OUT
5
TRIM
GND
SOIC
*OPTIONAL (STABLE WITH ALL CAPACITIVE LOADS)
________________________________________________________________ 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
MAX6220
General Description
MAX6220
Low-Noise, Precision, +2.5V/+4.096V/+5V
Voltage Reference
ABSOLUTE MAXIMUM RATINGS
(Voltages Referenced to GND)
IN..............................................................................-0.3V to +42V
OUT, TRIM ...............................................................-0.3V to +12V
NR ..............................................................................-0.3V to +6V
OUT Short-Circuit to GND Duration (VIN ≤ 12V)..........Continuous
OUT Short-Circuit to GND Duration (VIN ≤ 42V) ........................5s
OUT Short-Circuit to IN Duration (VIN ≤ 12V) ..............Continuous
Continuous Power Dissipation (TA = +70°C)
8-Pin SO (derate 5.9mW/°C above +70°C) ....................471mW
Operating Temperature Range...........................-40°C to +125°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—(+2.5V)
(VIN = +10V, IOUT = 0mA, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
Input Voltage Range
Output Voltage
SYMBOL
TCVOUT
Line Regulation (Note 2)
∆VOUT/
∆VIN
Supply Current
Trim-Adjustment Range
Turn-On Settling Time
Output Noise Voltage
(Note 3)
∆VOUT/
∆IOUT
2
MIN
+25°C
2.497
∆VOUT
tON
eN
∆VOUT
TYP
MAX
UNITS
40
V
2.500
2.503
V
2
20
ppm/˚C
8
8V ≤ VIN ≥ 40V
Sourcing: 0mA ≤ IOUT ≤ 15mA
Sinking: -15mA ≤ IOUT ≤ 0mA
+25°C
2
7
45
+25°C
1
+25°C
1
6
To ±0.01% of final value
ppm/mA
30
1.8
2.9
3.3
(Figure 1)
ppm/V
6
15
+25°C
IIN
Temperature Hysteresis
Long-Term Stability
TA
VIN
VOUT
Output Voltage Temperature
Coefficient (Note 1)
Load Regulation (Note 2)
CONDITIONS
±15
±25
mA
mV
5
µs
0.1Hz ≤ f ≥ 10Hz
1.5
µVp-p
10Hz ≤ f ≥ 1kHz
1.3
(Note 4)
20
ppm
∆t = 1000hr
20
ppm
_______________________________________________________________________________________
2.8
µVRMS
Low-Noise, Precision, +2.5V/+4.096V/+5V
Voltage Reference
MAX6220
ELECTRICAL CHARACTERISTICS—(+4.096V)
(VIN = +10V, IOUT = 0mA, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
Input Voltage Range
Output Voltage
SYMBOL
CONDITIONS
Output VoltageTemperature
Coefficient (Note 1)
TCVOUT
Line Regulation (Note 2)
∆VOUT/
∆VIN
Supply Current
∆VOUT/
∆IOUT
+25°C
8V ≤ VIN ≥ 40V
Sourcing: 0mA ≤ IOUT ≤ 15mA
Sinking: -15mA ≤ IOUT ≤ 0mA
IIN
Trim-Adjustment Range
∆VOUT
Turn-On Settling Time
tON
Output Noise Voltage
(Note 3)
eN
Temperature Hysteresis
Long-Term Stability
∆VOUT
MIN
TYP
MAX
UNITS
40
V
4.096
4.100
V
2
20
ppm/°C
2
7
8
VOUT
Load Regulation (Note 2)
TA
VIN
4.092
+25°C
45
+25°C
1
6
15
+25°C
1
6
+25°C
1.9
3.1
To ±0.01% of final value
ppm/mA
30
3.5
(Figure 1)
ppm/V
±24
mA
±40
mV
5
µs
0.1Hz ≤ f ≥ 10Hz
2.4
10Hz ≤ f ≥ 1kHz
2.0
(Note 4)
20
ppm
∆t = 1000hr
20
ppm
µVp-p
4.0
µVRMS
_______________________________________________________________________________________
3
MAX6220
Low-Noise, Precision, +2.5V/+4.096V/+5V
Voltage Reference
ELECTRICAL CHARACTERISTICS—(+5.0V)
(VIN = +10V, IOUT = 0mA, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
Input Voltage Range
Output Voltage
SYMBOL
TCVOUT
Line Regulation (Note 2)
∆VOUT/
∆VIN
Load Regulation (Note 2)
∆VOUT/
∆IOUT
Trim-Adjustment Range
Turn-On Settling Time
Output Noise Voltage
(Note 3)
Note 1:
Note 2:
Note 3:
Note 4:
4
MIN
+25°C
4.995
∆VOUT
tON
eN
∆VOUT
TYP
MAX
40
V
5.000
5.005
V
2
20
ppm/°C
8
8V ≤ VIN ≥ 40V
Sourcing: 0mA ≤ IOUT ≤ 15mA
Sinking: -15mA ≤ IOUT ≤ 0mA
IIN
Temperature Hysteresis
Long-Term Stability
TA
VIN
VOUT
Output Voltage Temperature
Coefficient (Note 1)
Supply Current
CONDITIONS
+25°C
2
7
45
+25°C
1
To ±0.01% of final value
ppm/V
6
15
+25°C
1
6
+25°C
2.0
3.3
ppm/mA
30
3.7
(Figure 1)
UNITS
±30
±50
mA
mV
5
µs
0.1Hz ≤ f ≥ 10Hz
3.0
µVp-p
10Hz ≤ f ≥ 1kHz
2.5
(Note 4)
20
ppm
∆t = 1000hr
20
ppm
5.0
µVRMS
Temperature coefficient is measured by the box method; i.e., the maximum ∆VOUT is divided by ∆T x VOUT.
Line regulation (∆VOUT / (VOUT x ∆VIN)) and load regulation (∆VOUT / (VOUT x ∆IOUT)) are measured with pulses and do
not include output voltage changes due to die-temperature changes.
Noise specifications are guaranteed by design.
Temperature hysteresis is specified at TA = +25°C by measuring VOUT before and after changing temperature by +25°C.
_______________________________________________________________________________________
Low-Noise, Precision, +2.5V/+4.096V/+5V
Voltage Reference
0.5
100
0
0
-0.5
-100
-1.0
-200
0.5
125
0
0
-0.5
-1.5
-55 -35 -15
5
25
45
65
-1.0
-55 -35 -15
-300
85 105 125
5
25
45
200
0.4
160
0.3
120
0.2
80
0.1
40
0
-0.1
-40
-0.2
-80
-0.3
-120
-0.4
-55 -35 -15
-250
85 105 125
65
240
0.5
0
-125
5
25
45
-160
85 105 125
65
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
MAX6220_50
CHANGE IN OUTPUT VOLTAGE
vs. OUTPUT CURRENT
MAX6220_41
CHANGE IN OUTPUT VOLTAGE
vs. OUTPUT CURRENT
MAX6220_25
CHANGE IN OUTPUT VOLTAGE
vs. OUTPUT CURRENT
TA = +85°C
200
200
MAX6220 toc06
200
MAX6220 toc05
300
MAX6220 toc04
300
280
0.6
∆VOUT (ppm)
200
250
∆VOUT (mV)
1.0
MAX6220 toc03
0.7
375
1.0
∆VOUT (mV)
300
∆VOUT (ppm)
∆VOUT (mV)
1.5
MAX6220 toc02
1.5
400
∆VOUT (ppm)
MAX6220 toc01
2.0
MAX6220_25
NORMALIZED OUTPUT VOLTAGE
vs. TEMPERATURE
MAX6220_41
NORMALIZED OUTPUT VOLTAGE
vs. TEMPERATURE
MAX6220_50
NORMALIZED OUTPUT VOLTAGE
vs. TEMPERATURE
150
100
100
TA = +85°C
TA = -40°C
-100
50
TA = +25°C
∆VOUT (µV)
0
-100
-200
TA = +25°C
10
20
30
40
-250
-40 -30 -20
-10
0
10
20
30
40
-40 -30 -20
CHANGE IN OUTPUT VOLTAGE
vs. INPUT VOLTAGE
SUPPLY CURRENT vs. SUPPLY VOLTAGE
2.8
2.6
SUPPLY CURRENT (mA)
40
30
20
10
0
MAX6220_50
2.4
MAX6220_41
MAX6220_25
2.2
2.0
1.8
1.6
10
15
20
VIN (V)
25
30
35
40
40
3.0
2.5
MAX6220_50
MAX6220_41
2.0
MAX6220_25
1.0
1.0
5
30
SUPPLY CURRENT vs. TEMPERATURE
1.2
-20
20
1.5
1.4
-10
10
3.5
MAX6220 toc08
50
0
IOUT (mA)
3.0
MAX6220 toc07
60
0
-10
IOUT (mA)
SUPPLY CURRENT (mA)
0
TA = +85°C
-200
IOUT (mA)
∆VOUT (ppm)
-150
-300
-10
TA = +25°C
-200
-400
-40 -30 -20
TA = -40°C
-100
TA = -40°C
-300
0
-50
MAX6220 toc09
0
∆VOUT (µV)
∆VOUT (µV)
100
0
5
10
15
20
25
SUPPLY VOLTAGE (V)
30
35
40
-55 -35 -15
5
25 45
65
85 105 125
TEMPERATURE (°C)
_______________________________________________________________________________________
5
MAX6220
Typical Operating Characteristics
(VIN = +10V, IOUT = 0mA, TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
(VIN = +10V, IOUT = 0mA, TA = +25°C, unless otherwise noted.)
30
25
20
CNR = 1µF
15
10
70
CNR = 0µF
60
50
40
30
CNR = 1µF
20
10
100
1k
100
1k
30
CNR = 1µF
20
10
10k
100
MAX6220_50
0.1Hz TO 10Hz NOISE
MAX6220 toc15
VOUT, 1µV/div
VOUT, 0.5µV/div
VOUT, 1µV/div
1s/div
1s/div
RIPPLE REJECTION
vs. FREQUENCY (CNR = 1µF)
RIPPLE REJECTION (dB)
1
ISINK = 5mA
MAX6220_25
110
100
MAX6220_41
90
MAX6220_50
80
70
ISOURCE = 5mA
100k
MAX6220_25
MAX6220_41
90
85
MAX6220_50
80
75
70
65
60
1M
95
MAX6220 toc17
MAX6220 toc16
120
RIPPLE REJECTION
vs. FREQUENCY (CNR = 0µF)
RIPPLE REJECTION (dB)
OUTPUT IMPEDANCE vs. FREQUENCY
10
10k
COUT = CNR = 0µF
1s/div
100
1k
FREQUENCY (Hz)
COUT = CNR = 0µF
1k
10k
FREQUENCY (Hz)
40
MAX6220 toc14
COUT = CNR = 0µF
100
50
MAX6220_41
0.1Hz TO 10Hz NOISE
MAX6220 toc13
10
60
FREQUENCY (Hz)
MAX6220_25
0.1Hz TO 10Hz NOISE
0.01
CNR = 0µF
70
0
10
10k
FREQUENCY (Hz)
0.1
80
10
0
0
MAX6220 toc12
90
10
5
6
100
60
10
100
1k
FREQUENCY (Hz)
10k
10
100
1k
FREQUENCY (Hz)
_______________________________________________________________________________________
10k
MAX6220 toc18
35
80
OUTPUT NOISE DENSITY (nV√ Hz)
CNR = 0µF
90
MAX6220 toc11
OUTPUT NOISE DENSITY (nV/√ Hz)
45
OUTPUT NOISE DENSITY (nV/√ Hz)
MAX6220 toc10
50
40
MAX6220_50
OUTPUT NOISE-VOLTAGE
DENSITY vs. FREQUENCY
MAX6220_41
OUTPUT NOISE-VOLTAGE
DENSITY vs. FREQUENCY
MAX6220_25
OUTPUT NOISE-VOLTAGE
DENSITY vs. FREQUENCY
OUTPUT IMPEDANCE (Ω)
MAX6220
Low-Noise, Precision, +2.5V/+4.096V/+5V
Voltage Reference
Low-Noise, Precision, +2.5V/+4.096V/+5V
Voltage Reference
MAX6220_50
LOAD-TRANSIENT RESPONSE (SOURCING)
MAX6220_50
LOAD-TRANSIENT RESPONSE (SINKING)
MAX6220 toc19
MAX6220 toc20
0mA
10mA
A
A
-10mA
0mA
B
B
2µs/div
2µs/div
A: IOUT, 10mA/div (SOURCING)
B: VOUT, 500µV/div
A: IOUT, 10mA/div (SINKING)
B: VOUT, 500µV/div
MAX6220_25
TURN-ON AND TURN-OFF TRANSIENT RESPONSE
MAX6220_50
LOAD-TRANSIENT RESPONSE
MAX6220 toc22
MAX6220 toc21
+10mA
A
+10V
A
0
-10mA
B
B
VIN = 10V
COUT = CNR = 0µF
CIN = COUT = CNR = 0µF
1µs/div
1µs/div
A: VIN, 10V/div
B: VOUT, 1V/div
A: IOUT (±10mA SOURCE AND SINK), 20mA/div, AC COUPLED
B: VOUT, 20mV/div, AC COUPLED
MAX6220_41
TURN-ON AND TURN-OFF TRANSIENT RESPONSE
MAX6220_50
TURN-ON AND TURN-OFF TRANSIENT RESPONSE
MAX6220 toc22
MAX6220 toc24
+10V
A
+10V
A
0
B
0
B
CIN = COUT = CNR = 0µF
CIN = COUT = CNR = 0µF
1µs/div
A: VIN, 10V/div
B: VOUT, 1V/div
1µs/div
A: VIN, 10V/div
B: VOUT, 1V/div
_______________________________________________________________________________________
7
MAX6220
Typical Operating Characteristics (continued)
(VIN = +10V, IOUT = 0mA, TA = +25°C, unless otherwise noted.)
MAX6220
Low-Noise, Precision, +2.5V/+4.096V/+5V
Voltage Reference
_____________________Pin Description
PIN
NAME
1, 7, 8
I.C.
Internally Connected. Do not use.
2
IN
Positive Power-Supply Input
NR
Noise Reduction. Optional capacitor
connection for wideband noise
reduction. Leave open if not used
(Figure 2).
3
FUNCTION
4
GND
Ground
5
TRIM
External Trim Input. Allows ±1%
output adjustment (Figure 1).
Leave open if not used.
6
OUT
Voltage Reference Output
Detailed Description
Temperature Stability
The MAX6220 is a highly stable, low-noise voltage reference that uses a low-power temperature-compensation scheme to achieve laboratory-standard temperature stability. This produces a nearly flat temperature
curve, yet does not require the power associated with
heated references.
The output voltage can be trimmed 0.6% (min) by connecting a 10kΩ potentiometer between OUT and GND,
and connecting its tap to the TRIM pin (Figure 1). The
external trimming does not affect temperature stability.
Noise Reduction
To augment wideband noise reduction, add a 1µF
capacitor to the NR pin (Figure 2). Larger values do not
improve noise appreciably (see Typical Operating
Characteristics).
Noise in the power-supply input can affect output
noise, but can be reduced by adding an optional
bypass capacitor to the IN pin and GND.
Bypassing
The MAX6220 is stable with capacitive load values from
0µF to 100µF, for all values of load current. Adding an
output bypass capacitor can help reduce noise and
output glitching caused by load transients.
Applications Information
Negative Regulator
Figure 3 shows how both a +5V and -5V precision reference can be obtained from a single unregulated +5V
supply. The MAX865 generates approximately ±9V to
operate both the MAX6220 reference and the MAX480
inverting amplifier. The +5V is inverted by the MAX480.
Resistor R1 is optional, and may be used to trim the
±5V references. R2 and R4 should be matched, both in
absolute resistance and temperature coefficient. R3 is
optional, and is adjusted to set the -5V reference.
8V TO 40V INPUT
8V TO 40V INPUT
IN
IN
REFERENCE OUT
NR
MAX6220
2.2µF*
MAX6220
TRIM
GND
REFERENCE OUT
OUT
OUT
10kΩ
NR
1µF
TRIM
GND
*OPTIONAL
Figure 1. Output Voltage Adjustment
8
Figure 2. Noise-Reduction Capacitor
_______________________________________________________________________________________
Low-Noise, Precision, +2.5V/+4.096V/+5V
Voltage Reference
MAX6220
+5V INPUT
3.3µF
C1+
VCC
V+
IN
C1-
+REFERENCE OUT
OUT
R2
100kΩ
MAX865
3.3µF
C1
2.2µF
C2+
C2-
GND
MAX6220
V-
NR
TRIM
GND
C2
1µF
2.2µF
R1
10kΩ
C3
2.2µF
R3
1kΩ
MAX480
R4
100kΩ
-REFERENCE OUT
Figure 3. +5V and -5V References from a Single +5V Supply
Chip Information
TRANSISTOR COUNT: 435
_______________________________________________________________________________________
9
________________________________________________________Package Information
SOICN.EPS
MAX6220
Low-Noise, Precision, +2.5V/+4.096V/+5V
Voltage Reference
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.
10 __________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600
© 2001 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.