MAXIM MAX5431BEUB

19-2222; Rev 0; 10/01
±15V Digitally Programmable
Precision Voltage-Dividers for PGAs
The MAX5430/MAX5431 are available in space-saving
8-pin SOT23 and 10-pin µMAX packages, and specified over the extended temperature range of (-40°C to
+85°C).
Features
♦ Four Noninverting PGA Gain Configurations:
AV = 1, 2, 4, and 8
♦ Precision 0.025% Ratio Accuracy
♦ On-Chip Matching Resistor for Op Amp BiasCurrent Compensation (MAX5431)
♦ Single-Supply +12V to +15V, or Dual-Supply ±12V
to ±15V Operation
♦ Low 35µA Supply Current
♦ CMOS/TTL Logic Compatible 2-Wire Parallel
Interface
♦ Space-Saving 8-Pin SOT23 and 10-Pin µMAX
Packages
♦ 3V Logic Compatibility
Ordering Information
Applications
General-Purpose Programmable Noninverting
Amplifier
Programmable Instrumentation Amplifier
TEMP.
RANGE
PART
PINGAIN
PACKAGE ACCURACY
*MAX5430AEKA -40°C to +85°C
8 SOT23
0.025%
*MAX5430BEKA -40°C to +85°C
8 SOT23
0.09%
*MAX5430CEKA -40°C to +85°C
8 SOT23
0.5%
MAX5431AEUB -40°C to +85°C
10 µMAX
0.025%
MAX5431BEUB -40°C to +85°C
10 µMAX
0.09%
MAX5431CEUB -40°C to +85°C
10 µMAX
0.5%
*Future product—contact factory for availability.
Pin Configurations
Functional Diagram
VDD
H
TOP VIEW
MAX5430*
MAX5431
10 D0
VDD 1
W
D0
MATCH_H 2
MAX5431
GND 3
DECODER
9 D1
8 W
D1
H 4
7 VSS
MATCH_H
L 5
6 MATCH_L
MATCH_L
µMAX
VSS GND L
MAX5431 ONLY
Pin Configurations 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
MAX5430/MAX5431
General Description
The MAX5430/MAX5431 are digitally programmable high
precision resistor arrays for PGAs. The MAX5430/
MAX5431 operate from a single +15V supply or dual ±15V
supplies, and consume only 35µA supply current. These
devices are intended for programmable-gain amplifier
(PGA) applications and consist of fixed resistor dividers,
digitally controlled contacts with four precision, noninverting gains of 1, 2, 4, and 8 with ratio accuracy of 0.025%
(MAX5430A/MAX5431A), 0.09% (MAX5430B/MAX5431B),
or 0.5% (MAX5430C/MAX5431C). The MAX5431 includes
an on-chip matching resistor for op amp input bias-current
compensation.
MAX5430/MAX5431
±15V Digitally Programmable
Precision Voltage-Dividers for PGAs
ABSOLUTE MAXIMUM RATINGS
VDD to GND ............................................................-0.3V to +17V
VSS to GND.............................................................-17V to +0.3V
D0, D1 to GND .........................................................-0.3V to +6V
H, L, W, MATCH_ to GND ................(VSS - 0.3V) to (VDD + 0.3V)
Current Into Any Signal Pin...............................................±50mA
Continuous Power Dissipation (TA = +70°C)
8-Pin SOT23 (derate 8.9mW/°C above +70°C)............714mW
10-Pin µMAX (derate 10.3mW/°C above +70°C) .........825mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range ...............................-60°C to 150°C
Junction Temperature ........................................................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
(VDD = +15V, VSS = -15V, GND = 0, TA = TMIN to TMAX. Typical values are at TA = +25°C, unless otherwise noted)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DC PERFORMANCE
Divider Ratio Accuracy
(Note 1)
VH = +5V, VL = -5V
Resistance between H and L
(Figure 1)
RHL
Capacitance at Analog Pins
CANALOG
Matching Resistor
MAX5431 only
MAX543_A
0.025
MAX543_B
0.09
MAX543_C
0.5
Ratio = 1
Ratio = 2, 4, 8
%
57
kΩ
2
pF
0.5
14
kΩ
DIGITAL INPUTS
Input High Voltage
VIH
Input Low Voltage
VIL
Input Leakage Current
Input Capacitance
2.4
V
VD__ = 5V or GND
CIN
5
ISS
1
0.8
V
±1
µA
pF
POWER REQUIREMENTS
Negative Supply Current
35
25
µA
Positive Supply Current
IDD
60
µA
Positive Power Supply Voltage
VDD
10.8
15.75
V
Negative Power Supply Voltage
VSS
-15.75
0
V
W, H, L, MATCH_H, MATCH _L
Voltage Range
VANALOG
VSS
VDD
V
DYNAMIC PERFORMANCE
Switching Time
tD2W, tH2W
0.3
Note 1: Gain accuracy is measured without load at pin W.
2
_______________________________________________________________________________________
µs
±15V Digitally Programmable
Precision Voltage-Dividers for PGAs
MAX5431A DIVIDER RATIO ACCURACY
vs. TEMPERATURE (RATIO = 2)
0.0005
0
-0.0005
-0.0010
0.006
0.004
0.002
0
-0.002
-0.004
-0.006
-0.0150
-0.008
-0.0020
-0.010
35
50
65
MAX5431A DIVIDER RATIO ACCURACY
vs. TEMPERATURE (RATIO = 8)
35
50
65
0.004
0.002
0
-0.002
-0.004
-0.006
-40 -25 -10
0.001
0
-0.001
-0.002
-0.003
-0.010
-0.005
65
5
20
35
50
65
-0.002
-0.004
-0.006
-0.008
0.004
0.002
0
-0.002
-0.004
-0.006
-40 -25 -10
0.008
0.006
0.004
0.002
0
-0.002
-0.004
-0.006
-0.010
65
80
-40 -25 -10
5
20
35
TEMPERATURE (°C)
5
20
35
50
65
80
TEMPERATURE (°C)
-0.008
-0.010
5 20 35 50
TEMPERATURE (°C)
0.006
80
0.010
DIVIDER RATIO ACCURACY (%)
0
80
0.008
MAX5431A DIVIDER RATIO ACCURACY
vs. POSITIVE SUPPLY (VSS = -15V)
MAX5431B DIVIDER RATIO ACCURACY
vs. TEMPERATURE (RATIO = 8)
MAX5430 toc07
0.002
65
0.010
TEMPERATURE (°C)
MAX5431B DIVIDER RATIO ACCURACY
vs.TEMPERATURE (RATIO = 4)
50
-0.010
-40 -25 -10
80
35
-0.008
MAX5430 toc08
50
20
MAX5431B DIVIDER RATIO ACCURACY
vs. TEMPERATURE (RATIO = 2)
0.002
-0.004
5
TEMPERATURE (°C)
0.003
-0.008
-40 -25 -10
-0.006
80
0.004
TEMPERATURE (°C)
DIVIDER RATIO ACCURACY (%)
20
MAX5430 toc05
0.006
35
5
0.005
DIVIDER RATIO ACCURACY (%)
DIVIDER RATIO ACCURACY (%)
0.008
20
-0.004
MAX5431B DIVIDER RATIO ACCURACY
vs. TEMPERATURE (RATIO = 1)
MAX5430 toc04
0.010
5
0
-0.002
TEMPERATURE (°C)
TEMPERATURE (°C)
-40 -25 -10
0.002
-0.010
-40 -25 -10
80
0.004
MAX5430 toc06
20
0.006
-0.008
DIVIDER RATIO ACCURACY (%)
5
0.008
50
65
80
0.0030
RATIO 1
0.0025
DIVIDER RATIO ACCURACY (%)
-40 -25 -10
0.010
MAX5430 toc03
0.008
MAX5430 toc09
0.0010
MAX5430 toc02
0.0015
0.010
DIVIDER RATIO ACCURACY (%)
MAX5430 toc01
DIVIDER RATIO ACCURACY (%)
0.0020
MAX5431A DIVIDER RATIO ACCURACY
vs. TEMPERATURE (RATIO = 4)
DIVIDER RATIO ACCURACY (%)
MAX5431A DIVIDER RATIO ACCURACY
vs. TEMPERATURE (RATIO = 1)
0.0020
0.0015
0.0010
0.0005
0
RATIO 8
RATIO 4
-0.0005
-0.0010
0.0015
-0.0020
-0.0025
-0.0030
RATIO 2
11
12
13
14
15
POSITIVE SUPPLY (V)
_______________________________________________________________________________________
3
MAX5430/MAX5431
Typical Operating Characteristics
(VDD = +15V, VSS = -15V or VSS = GND, TA = +25°C, unless otherwise noted.) (Note 2)
Typical Operating Characteristics (continued)
(VDD = +15V, VSS = -15V or VSS = GND, TA = +25°C, unless otherwise noted.) (Note 2)
RATIO 1
0.002
RATIO 2
0
-0.002
RATIO 8
0.004
-0.006
RATIO 4
-0.008
0.0010
RATIO 8
0.0005
RATIO 1
0
-0.005
RATIO 2
-0.0010
RATIO 4
-0.0015
-0.010
12
13
14
15
12
13
14
0.0010
RATIO 8
0.0005
0
RATIO 2
-0.0010
-0.0015
-0.0020
-9
-6
NEGATIVE SUPPLY (V)
-3
0
MAX5430 toc12
-0.006
RATIO 2
RATIO 4
11
0.004
0.002
RATIO 1
0
-0.002
RATIO 8
RATIO 2
0.004
12
13
14
15
POSITIVE SUPPLY CURRENT
vs. TEMPERATURE
MAX5430 toc14
0.006
-0.006
RATIO 4
-0.010
-12
RATIO 8
0.004
POSITIVE SUPPLY (V)
0.008
-0.008
-15
-0.002
15
0.010
DIVIDER RATIO ACCURACY (%)
0.0015
RATIO 1
0
MAX5431B DIVIDER RATIO ACCURACY
vs. NEGATIVE SUPPLY
MAX5430 toc13
0.0020
RATIO 4
0.002
POSITIVE SUPPLY (V)
MAX5431A DIVIDER RATIO ACCURACY
vs. NEGATIVE SUPPLY
-0.0005
0.004
-0.010
11
POSITIVE SUPPLY (V)
RATIO 1
0.006
-0.008
-0.0020
11
0.008
30
D0, D1 = +5V
POSITIVE SUPPLY CURRENT (µA)
0.004
0.0015
0.010
DIVIDER RATIO ACCURACY (%)
0.006
0.0020
MAX5430 toc11
DIVIDER RATIO ACCURACY (%)
0.008
DIVIDER RATIO ACCURACY (%)
MAX5430 toc10
0.010
MAX5431B DIVIDER RATIO ACCURACY
vs. POSITIVE SUPPLY (VSS = 0V)
MAX5431A DIVIDER RATIO ACCURACY
vs. POSITIVE SUPPLY (VSS = 0V)
25
MAX5430 toc15
MAX5431B DIVIDER RATIO ACCURACY
vs. POSITIVE SUPPLY (VSS = -15V)
DIVIDER RATIO ACCURACY (%)
MAX5430/MAX5431
±15V Digitally Programmable
Precision Voltage-Dividers for PGAs
20
15
10
D0, D1 = 0V
5
0
-15
-12
-9
-6
NEGATIVE SUPPLY (V)
-3
0
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE ( C)
Note 2: For MAX543_C accuracy Typical Operating Characteristics, refer to MAX543_B accuracy Typical Operating Characteristics.
4
_______________________________________________________________________________________
±15V Digitally Programmable
Precision Voltage-Dividers for PGAs
PIN
NAME
FUNCTION
MAX5431
MAX5430
4
6
H
High Terminal of Resistor-Divider
8
3
W
Wiper Terminal of Resistor-Divider
5
5
L
Low Terminal of Resistor-Divider
7
4
VSS
2
—
MATCH_H
Negative Power Supply
Matching Resistor High Terminal
6
—
MATCH_L
Matching Resistor Low Terminal
3
7
GND
9
2
D1
Second Bit Digital Input (MSB) (Table 1)
10
1
D0
First Bit Digital Input (LSB) (Table 1)
1
8
VDD
Ground
Positive Power Supply
applications (see Functional Diagram and Figure 1). The
MAX5430/MAX5431 achieve ratio accuracies of 0.025%
(MAX5430A/MAX5431A), 0.09% (MAX5430B/MAX5431B)
or 0.5% (MAX5430C/MAX5431C).
The end-to-end resistance from H to L is 57kΩ. The
impedance seen at W is designed to be the same 14kΩ
for gain settings 2, 4, and 8, ensuring excellent op-amp
input resistance balance, regardless of gain setting
(MAX5431 only). In a gain of +1 configuration, H is internally connected to W with a typical resistance of 500Ω.
H
RATIO = 1
R2B
R3B
R1B
RATIO = 2
Matching Resistor (MAX5431)
RATIO = 4
RATIO = 8
W
R3A
R2A
R1A
(
RATIO = 1+
R_B
R_A
)
The MAX5431 includes a matching resistor to compensate for the offset voltage due to the input bias current
of the op amp. The resistance from MATCH_H to
MATCH_L is a fixed matching resistor, the equal to the
resistance seen at W for gains of 2, 4, and 8. In the
gain of 1, an internal switch short circuits MATCH_H
and MATCH_L. This internal switch matches the impedance of the switch between H and W.
Table 1. Logic Control Truth Table
DIGITAL INPUTS
L
Figure 1. Simplified Functional Diagram
Detailed Description
The MAX5430/MAX5431 are digitally programmable precision resistor arrays. These devices have fixed resistor
dividers with digitally controlled contacts, providing four
precision noninverting gains of 1, 2, 4, and 8 for PGA
GAIN
D1
D0
0
0
1
0
1
2
1
0
4
1
1
8
_______________________________________________________________________________________
5
MAX5430/MAX5431
Pin Description
MAX5430/MAX5431
±15V Digitally Programmable
Precision Voltage-Dividers for PGAs
Digital Interface Operation
The MAX5430/MAX5431 feature a simple two-bit parallel programming interface. D1 and D0 program the gain
setting according to the Logic Control Truth Table (see
Table 1). The digital interface is CMOS/TTL logic compatible.
+15V
Applications Information
+15V
VDD
Programmable-Gain Amplifier
The MAX5430/MAX5431 are ideally suited for high-precision PGA applications. The typical application circuit
of Figure 2 uses the MAX5431 with matching resistor to
compensate for voltage offset due to op amp input bias
currents. Use the MAX5430 with an ultra-low input bias
current op amp (see Figure 3).
W
H
MAX5430
L
VSS
GND
Power Supplies and Bypassing
The MAX5430/MAX5431 operate from dual ±15V supplies or a single +15V supply. For dual supplies,
bypass VDD and VSS with 0.1µF ceramic capacitors to
GND. For single supply, connect V SS to GND and
bypass VDD with a 0.1µF ceramic capacitor to GND.
Figure 3. Programmable-Gain Amplifier Using the MAX5430
Functional Diagram
VDD
H
Switching Time and Layout Concerns
The switching time of the MAX5430/MAX5431 depends
on the capacitive loading at W. For best performance,
reduce parasitic board capacitance by minimizing the
circuit board trace from W to the op amp inverting input,
and choose an op amp with low input capacitance.
MAX5430*
MAX5431
W
D0
DECODER
D1
MATCH_H
MATCH_L
VSS GND L
MAX5431 ONLY
+15V
+15V
VDD
MATCH_H
MATCH_L
Pin Configurations (continued)
TOP VIEW
MAX5431
W
D1 2
H
VSS
L
8 VDD
D0 1
MAX5430
7
GND
W 3
6
H
VSS 4
5
L
GND
SOT23
Figure 2. MAX5431 Typical Application Circuit
Chip Information
TRANSISTOR COUNT: 121
PROCESS: CMOS
6
_______________________________________________________________________________________
±15V Digitally Programmable
Precision Voltage-Dividers for PGAs
SOT23, 8L.EPS
10LUMAX.EPS
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 7
© 2001 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
MAX5430/MAX5431
Package Information