19-2229; Rev 1; 7/03
Digitally Programmable Precision
Voltage Divider for PGAs
General Description
The MAX5420 and MAX5421 are digitally programmable
precision voltage dividers optimized for use in digitally pro-
grammable gain amplifier configurations. The MAX5420/
MAX5421 operate from a single +5V supply or dual ±5V
supply, and consume only 3µA supply current. These
devices consist of a digitally selectable resistor array that
provides four precision noninverting gains of 1, 2, 4, and 8
for PGAs. The MAX5420 and MAX5421 achieve a resistor
ratio accuracy of 0.025% (MAX542_A), 0.09% (MAX542_B),
and 0.5% (MAX542_C). The MAX5421 includes an on-chip
matching resistor for op amp bias-current compensation.
The MAX5420 and MAX5421 are available in 8-pin and
10-pin µMAX packages. The devices are specified over
the extended temperature range (-40°C to +85°C).
Features
o
Four Precision Divider Ratios For Noninverting
Gains of 1, 2, 4, and 8 in PGAs
o
0.025%, 0.09%, or 0.5% Ratio Accuracy
Guaranteed Over -40°C to +85°C
o
On-Chip Matching Resistor for Op Amp Bias-
Current Compensation (MAX5421)
o
5V Single or ±5V Dual Supply Operation
o
Low 3µA Supply Current
o
CMOS/TTL Logic Compatible 2-Wire Parallel
Interface
o
Small 8-Pin and 10-Pin µMAX Packages
MAX5420/MAX5421
Applications
General-Purpose Programmable Noninverting
Amplifiers
Programmable Instrumentation Amplifiers
Ordering Information
PART
TEMP
RANGE
-40°C to +85°C
PIN-
PACKAGE
8 µMAX
8 µMAX
8 µMAX
10 µMAX
10 µMAX
10 µMAX
GAIN
ACCURACY
0.025%
0.09%
0.5%
0.025%
0.09%
0.5%
MAX5420AEUA
-40°C to +85°C
MAX5420BEUA
MAX5420CEUA -40°C to +85°C
MAX5421AEUB
-40°C to +85°C
MAX5421BEUB
-40°C to +85°C
MAX5421CEUB -40°C to +85°C
Functional Diagram
TOP VIEW
V
DD
1
2
Pin Configurations
8
7
H
W
L
D1
V
DD
MAX5420
MAX5421
D0
DECODER
D1
MATCH_H
MATCH_L
H
V
SS
GND
MAX5420
3
6
5
W
D0
4
µMAX-8
V
DD
1
10
H
9
W
L
MATCH_H
MATCH_L
V
SS
GND L
MAX5421 ONLY
V
SS
GND
D0
D1
2
3
4
5
MAX5421
8
7
6
µMAX-10
________________________________________________________________
Maxim Integrated Products
1
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.
Digitally Programmable Precision
Voltage Divider for PGAs
MAX5420/MAX5421
ABSOLUTE MAXIMUM RATINGS
V
DD
to GND ..............................................................-0.3V to +6V
V
SS
to GND...............................................................+0.3V to -6V
D0, D1 to GND ...........................................-0.3V to (V
DD
+ 0.3V)
H, L, W, MATCH_ to GND ................(V
SS
- 0.3V) to (V
DD
+ 0.3V)
Input and Output Latchup Immunity.................................±50mA
Continuous Power Dissipation (T
A
= +70°C)
8-Pin µMAX (derate 4.1mW/°C above +70°C) .............333mW
10-Pin µMAX (derate 5.6mW/°C above +70°C) ...........444mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-60°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
(V
DD
= +5V ±5%, V
SS
= -5V ±5% or V
SS
= GND, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
Divider Ratio Accuracy
H-to-L Resistance
Input Resistance at H
Input Resistance at W
Capacitance at H, L, W,
MATCH_H, MATCH_L
Matching Resistor
DYNAMIC PERFORMANCE
Switching Time
DIGITAL INPUTS
Input High Voltage
Input Low Voltage
Input Leakage Current
Input Capacitance
V
IH
V
IL
D1, D0 = V
DD
or GND
5
2.4
0.8
±1
V
µA
pF
t
S
V
DD
= +5V, V
SS
= -5V, digital input 0 to +3V,
V
W
settles to 0.02% of final value with 2pF
capacitive load. Circuit of Figure 2.
0.5
µs
R
HL
R
H
R
W
Ratio = 1
Ratio = 2, 4, 8
C
ANALOG
Ratio = 1
Ratio = 2, 4, 8
V
SS
= -5V
V
SS
= 0
V
SS
= -5V
V
SS
= 0
SYMBOL
MAX542_A
MAX542_B
MAX542_C
(Figure 1)
15
15
300
500
8
5
300
500
8
CONDITIONS
MIN
TYP
MAX
±0.025
±0.09
±0.5
kΩ
kΩ
Ω
kΩ
pF
Ω
kΩ
%
UNITS
MAX5421
2
_______________________________________________________________________________________
Digitally Programmable Precision
Voltage Divider for PGAs
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +5V ±5%, V
SS
= -5V ±5% or V
SS
= GND, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
POWER SUPPLIES
Positive Supply Voltage
Negative Supply Voltage
Positive Supply Current
Negative Supply Current
W, H, L, MATCH_L, MATCH_H
Voltage Range
V
DD
V
SS
I
DD
I
SS
D1, D0 = V
DD
or GND
D1, D0 = 3V
D1, D0 = V
DD
or GND
D1, D0 = 3V
V
SS
4.75
0
3
15
3
15
5.25
-5.25
7
25
7
25
V
DD
V
µA
µA
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX5420/MAX5421
Typical Operating Characteristics
(V
DD
= +5V, V
SS
= -5V, or V
SS
= GND, T
A
= +25°C, unless otherwise noted.) (Note 1)
MAX542_A DIVIDER RATIO ACCURACY
vs. TEMPERATURE
MAX5420/21 toc01
MAX542_A DIVIDER RATIO ACCURACY
vs. TEMPERATURE
MAX5420/21 toc02
MAX542_A DIVIDER RATIO ACCURACY
vs. TEMPERATURE
V
H
= +5V
V
L
= -5V
RATIO = 4
MAX5420/21 toc03
0.0010
V
H
= +5V
V
L
= -5V
RATIO = 1
RATIO ACCURACY (%)
0.0007
0.0050
V
H
= +5V
V
L
= -5V
RATIO = 2
0.005
0.0046
RATIO ACCURACY (%)
0.004
RATIO ACCURACY (%)
0.0042
0.003
0.0038
0.002
0.0004
0.0034
0.001
0.0001
-40
-15
10
35
60
85
TEMPERATURE (°C)
0.0030
-40
-15
10
35
60
85
TEMPERATURE (°C)
0
-40
-15
10
35
60
85
TEMPERATURE (°C)
_______________________________________________________________________________________
3
Digitally Programmable Precision
Voltage Divider for PGAs
MAX5420/MAX5421
Typical Operating Characteristics (continued)
(V
DD
= +5V, V
SS
= -5V, or V
SS
= GND, T
A
= +25°C, unless otherwise noted.) (Note 1)
MAX542_A DIVIDER RATIO ACCURACY
vs. TEMPERATURE
MAX5420/21 toc04
MAX542_B DIVIDER RATIO ACCURACY
vs. TEMPERATURE
MAX5420/21 toc05
MAX542_B DIVIDER RATIO ACCURACY
vs. TEMPERATURE
V
H
= +5V
V
L
= -5V
RATIO = 2
RATIO ACCURACY (%)
-0.0225
MAX5420/21 toc06
0.007
0.006
RATIO ACCURACY (%)
0.005
0.004
0.003
0.002
0.001
0
-40
-15
10
35
60
V
H
= +5V
V
L
= -5V
RATIO = 8
0.0020
V
H
= +5V
V
L
= -5V
RATIO = 1
RATIO ACCURACY (%)
0.0015
-0.0200
0.0010
-0.0250
0.0005
-0.0275
0
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
-0.0300
-40
-15
10
35
60
85
TEMPERATURE (°C)
MAX542_B DIVIDER RATIO ACCURACY
vs. TEMPERATURE
MAX5420/21 toc07
MAX542_B DIVIDER RATIO ACCURACY
vs. TEMPERATURE
V
H
= +5V
V
L
= -5V
RATIO = 8
RATIO ACCURACY (%)
-0.055
MAX5420/21 toc08
MAX542_A RATIO ACCURACY
vs. POSITIVE SUPPLY VOLTAGE
RATIO = 4
RATIO ACCURACY (%)
MAX5420/21 toc09
-0.030
V
H
= +5V
V
L
= -5V
RATIO = 4
RATIO ACCURACY (%)
-0.035
-0.050
0.01
RATIO = 2
0.001
RATIO = 8
-0.040
-0.060
-0.045
-0.065
RATIO = 1
V
H
= +3V, V
L
= 0
-0.050
-40
-15
10
35
60
85
TEMPERATURE (°C)
-0.070
-40
-15
10
35
60
85
TEMPERATURE (°C)
0.0001
4.75
5.00
POSITIVE SUPPLY VOLTAGE (V)
5.25
MAX542_B RATIO ACCURACY
vs. POSITIVE SUPPLY VOLTAGE
MAX5420/21 toc10
MAX542_A RATIO ACCURACY
vs. NEGATIVE SUPPLY VOLTAGE
MAX5420/21 toc11
MAX542_B RATIO ACCURACY
vs. NEGATIVE SUPPLY VOLTAGE
RATIO = 4
MAX5420/21 toc12
0.1
RATIO = 4
0.01
RATIO = 8
0.1
RATIO ACCURACY (%)
RATIO ACCURACY (%)
0.01
RATIO = 8
0.001
RATIO = 2
RATIO ACCURACY (%)
RATIO = 2
0.01
RATIO = 8
V
H
= 5V, V
L
= 0
0.001
RATIO = 4
0.001
RATIO = 2
RATIO = 1
0.0001
V
H
= +3V, V
L
= 0
4.75
5.00
POSITIVE SUPPLY VOLTAGE (V)
RATIO = 1
5.25
V
H
= 5V, V
L
= 0
0.0001
-5.25
-4.00
-2.75
-1.50
-0.25
0.0001
-5.25
-4.00
RATIO = 1
-2.75
-1.50
-0.25
NEGATIVE SUPPLY VOLTAGE (V)
NEGATIVE SUPPLY VOLTAGE (V)
4
_______________________________________________________________________________________
Digitally Programmable Precision
Voltage Divider for PGAs
MAX5420/MAX5421
Typical Operating Characteristics (continued)
(V
DD
= +5V, V
SS
= -5V, or V
SS
= GND, T
A
= +25°C, unless otherwise noted.) (Note 1)
SWITCHING TIME
(RATIO 1-TO-2)
MAX5420/21 toc13
SWITCHING TIME
(RATIO 2-TO-4)
MAX5420/21 toc14
D0, 5V/div
0
D1, 5V/div
0
V
W
2V/div
V
W
1V/div
100ns/div
V
H
= +5V, V
L
= -5V
100ns/div
V
H
= +5V, V
L
= -5V
SWITCHING TIME
(RATIO 4-TO-8)
MAX5420/21 toc15
SUPPLY CURRENT
vs. TEMPERATURE
D1, D0 = GND or V
DD
5V
D0, 5V/div
0
4
SUPPLY CURRENT (µA)
MAX5420/21 toc16
5
3
V
W
500mV/div
2
1
0
100ns/div
V
H
= +5V, V
L
= -5V
-40
-15
10
35
60
85
TEMPERATURE (°C)
Note 1:
For MAX542_C accuracy
Typical Operating Characteristics,
refer to MAX542_B accuracy
Typical Operating Characteristics.
_______________________________________________________________________________________
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