Maxim MAX5460 32-tap fleapot, 2-wire digital potentiometer Datasheet

19-1956; Rev 3; 11/05
32-Tap FleaPoT ™, 2-Wire Digital
Potentiometers
The MAX5460–MAX5468 linear-taper digital potentiometers perform the same function as a mechanical potentiometer or a variable resistor. These devices consist of a
fixed resistor and a wiper contact with 32-tap points that
are digitally controlled through a 2-wire serial interface.
The MAX5462/MAX5465/MAX5468 are configured as
potentiometers. The rest of the devices in this family are
configured as variable resistors. See Pin Configurations
for part functionality.
Three resistance values are available: 10kΩ (MAX5466/
MAX5467/MAX5468), 50kΩ (MAX5463/MAX5464/
MAX5465), and 100kΩ (MAX5460/MAX5461/MAX5462).
The MAX5460–MAX5465 (100kΩ and 50kΩ) are available in space-saving 5-pin and 6-pin SC70 packages.
The MAX5466/MAX5467/MAX5468 (10kΩ) are available
in 5-pin and 6-pin SOT23 packages.
Features
♦ Miniature SC70 and SOT23 Packages
♦ 0.3µA Ultra-Low Supply Current
♦ +2.7V to +5.5V Single-Supply Operation
♦ Glitchless Switching Between Resistor Taps
♦ Power-On Reset to Midscale
♦ 2-Wire Up/Down Serial Interface
♦ 10kΩ, 50kΩ, and 100kΩ Resistance Values
Ordering Information
Applications
LCD Screen Adjustment
PART
Volume Control
Mechanical Potentiometer Replacement
Gain Adjustment
Line Impedance Matching
FleaPoT is a trademark of Maxim Integrated Products Inc.
Functional Diagram appears at end of data sheet.
PINPACKAGE
TOP
MARK
R
(kΩ)
PKG
CODE
MAX5460EXK
5 SC70
ACA
100
X5-1
MAX5461EXT
6 SC70
AAP
100
X6S-1
MAX5462EXT
6 SC70
AAQ
100
X6S-1
MAX5463EXK
5 SC70
ACB
50
X5-1
MAX5464EXT
6 SC70
AAR
50
X6S-1
MAX5465EXT
6 SC70
AAS
50
X6S-1
MAX5466EUK
5 SOT23
ADQQ
10
U5-1
MAX5467EUT
6 SOT23
AARH
10
U6-1
MAX5468EUT
6 SOT23
AARI
10
U6-1
Note: All devices operate over the -40°C to +85°C temperature
range.
Pin Configurations
TOP VIEW
VDD 1
5
H
GND 2
U/D 3
MAX5460
MAX5463
MAX5466
SOT23, SC70
4
CS
VDD 1
6
H
VDD 1
6
H
GND 2
5
L
GND 2
5
W
4
CS
U/D 3
4
CS
U/D 3
MAX5461
MAX5464
MAX5467
SOT23, SC70
MAX5462
MAX5465
MAX5468
SOT23, SC70
________________________________________________________________ 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
MAX5460–MAX5468
General Description
MAX5460–MAX5468
32-Tap FleaPoT ™, 2-Wire Digital
Potentiometers
ABSOLUTE MAXIMUM RATINGS
VDD to GND ..............................................................-0.3V to +6V
All Other Pins to GND.................................-0.3V to (VDD + 0.3)V
Input and Output Latch-Up Immunity.............................±200mA
Maximum Continuous Current into H, L, and W
MAX5460/MAX5461/MAX5462 (100kΩ) .......................±0.6mA
MAX5463/MAX5464/MAX5465 (50kΩ) .........................±1.3mA
MAX5466/MAX5467/MAX5468 (10kΩ) .........................±1.3mA
Continuous Power Dissipation (TA = +70°C)
5-pin SC70 (derate 3.1mW/°C above TA = +70°C)..........247mW
5-pin SOT23 (derate 7.1mW/°C above TA = +70°C)........571mW
6-pin SC70 (derate 3.1mW/°C above TA = +70°C) ..........245mW
6-pin SOT23 (derate 8.7mW/°C above TA = +70°C).....695.7mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Soldering 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 = +2.7V to +5.5V, V H = V DD, V L = 0, T A = -40°C to +85°C. Typical values are at V DD = +2.7V, T A = +25°C, unless
otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DC PERFORMANCE
Resolution
32
End-to-End Resistance
End-to-End Resistance Tempco
Taps
MAX5460/MAX5461/MAX5462
75
100
125
MAX5463/MAX5464/MAX5465
37.5
50
62.5
MAX5466/MAX5467/MAX5468
7.5
10
12.5
TCR
35
Ratiometric Resistance Tempco
INL
Differential Nonlinearity
DNL
±0.5
ppm/°C
±1
±1
±0.1
Full-Scale Error
Zero-Scale Error
Wiper Resistance
ppm/°C
5
Integral Nonlinearity
LSB
LSB
LSB
1
RW
kΩ
MAX5462/MAX5465
600
1200
MAX5468
160
240
LSB
Ω
DIGITAL INPUTS
Input High Voltage
VIH
Input Low Voltage
VIL
0.7 x VDD
V
0.3 x VDD
V
TIMING CHARACTERISTICS (Figures 1, 2)
U/D Mode to CS Setup
tCU
25
ns
CS to U/D Step Setup
tCI
50
ns
CS to U/D Step Hold
tIC
25
ns
U/D Step Low Period
tIL
25
ns
U/D Step High Period
tIH
25
ns
Up/Down Toggle Rate (Note 1)
Output Settling Time (Note 2)
2
fTOGGLE
tSETTLE
1
100kΩ variable resistor configuration, CL = 10pF
100kΩ potentiometer configuration, CL = 10pF
1
0.25
_______________________________________________________________________________________
MHz
µs
32-Tap FleaPoT ™, 2-Wire Digital
Potentiometers
(V DD = +2.7V to +5.5V, V H = V DD, V L = 0, T A = -40°C to +85°C. Typical values are at V DD = +2.7V, T A = +25°C, unless
otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
5.5
V
POWER SUPPLIES
Supply Voltage
VDD
Active Supply Current (Note 3)
IDD
Standby Supply Current (Note 4)
ISD
2.7
VDD = +5V
25
µA
1
µA
0.3
Note 1: Up/Down Toggle Rate:
fTOGGLE =
1
t SETTLE
Note 2: Typical settling times are dependent on end-to-end resistance.
Note 3: Supply current taken while changing wiper tap, fTOGGLE = 1MHz.
Note 4: Supply current taken while wiper position is fixed.
Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
WIPER RESISTANCE vs. WIPER VOLTAGE
(MAX5466/MAX5467/MAX5468)
500
VDD = +5V
300
200
140
120
100
VDD = +5V
80
60
40
100
20
0
0
-0.05
50kΩ, 100kΩ
-0.10
-0.15
-0.20
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
-40
-15
10
35
60
WIPER VOLTAGE (V)
WIPER VOLTAGE (V)
TEMPERATURE (°C)
W-TO-L RESISTANCE
vs. TAP POSITION
SUPPLY CURRENT vs. TEMPERATURE
TAP-TO-TAP SWITCHING TRANSIENT
(MAX5460)
0.50
MAX5460 toc04
120
100
0.45
0.40
100kΩ
80
60
50kΩ
40
0.35
CURRENT (µA)
RESISTANCE (kΩ)
10kΩ
0
-0.25
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
MAX5460 toc05
0
0.05
MAX5460 toc03
VDD = +2.7V
160
0.10
VDD = +5V
85
MAX5460 toc06
400
MAX5460 toc02
VDD = +2.7V
180
WIPER RESISTANCE (Ω)
WIPER RESISTANCE (Ω)
600
200
MAX5460 toc01
700
END-TO-END RESISTANCE % CHANGE
vs. TEMPERATURE
END-TO-END RESISTANCE % CHNAGE
WIPER RESISTANCE vs. WIPER VOLTAGE
(MAX5460–MAX5465)
U/D
2V/div
0.30
0.25
0.20
0.15
VDD = +2.7V
0.10
20
10kΩ
0
OUTPUT
W
100mV/div
0.05
0.00
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31
TAP POSITION
-40
-15
10
35
60
85
200ns/div
TEMPERATURE (°C)
_______________________________________________________________________________________
3
MAX5460–MAX5468
ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
R-DNL ERROR vs. INPUT CODE (100kΩ)
0.06
0.02
0
R-INL (LSB)
0
-0.02
-0.04
R-DNL (LSB)
0.04
0.02
0.02
0
-0.02
-0.02
-0.04
-0.06
-0.08
-0.04
-0.06
-0.06
-0.10
-0.08
-0.08
-0.12
-0.10
-0.10
0
5
10
15
20
25
-0.14
0
30
5
10
15
20
25
0
30
0.10
0
-0.05
-0.10
0
-0.05
5
10
15
20
25
0.15
0.10
0.05
0
-0.05
-0.20
-0.10
-0.15
0
30
INPUT CODE (DECIMAL)
30
0.20
-0.15
-0.25
-0.10
25
0.25
R-INL (LSB)
R-DNL LSB
0.05
20
R-INL ERROR vs. INPUT CODE (10kΩ)
0.05
0.10
15
0.30
MAX5460 toc11
0.15
MAX5460 toc10
0.15
10
INPUT CODE (DECIMAL)
R-DNL ERROR vs. INPUT CODE (10kΩ)
R-INL ERROR vs. INPUT CODE (50kΩ)
0.20
0
5
INPUT CODE (DECIMAL)
INPUT CODE (DECIMAL)
MAX5460 toc12
R-DNL (LSB)
0.08
MAX5460 toc09
0.04
0.04
MAX5460 toc08
0.06
R-DNL ERROR vs. INPUT CODE (50kΩ)
R-INL ERROR vs. INPUT CODE (100kΩ)
0.10
MAX5460 toc07
0.08
R-INL LSB
MAX5460–MAX5468
32-Tap FleaPoT ™, 2-Wire Digital
Potentiometers
5
10
15
25
20
INPUT CODE (DECIMAL)
30
0
5
10
15
20
25
30
INPUT CODE (DECIMAL)
Pin Description
PIN
4
MAX5460
MAX5463
MAX5466
MAX5461
MAX5464
MAX5467
MAX5462
MAX5465
MAX5468
NAME
1
1
1
VDD
2
2
2
GND
Ground
FUNCTION
Power Supply
3
3
3
U/D
Up/Down Control Input. With CS low, a low-to-high
transition increments or decrements the wiper position.
4
4
4
CS
Chip Select Input. A high-to-low CS transition
determines the mode: increment if U/D is high, or
decrement if U/D is low.
5
6
6
H
High Terminal of Resistor
—
5
—
L
Low Terminal of Resistor
—
—
5
W
Wiper Terminal of Resistor
_______________________________________________________________________________________
32-Tap FleaPoT ™, 2-Wire Digital
Potentiometers
The MAX5460–MAX5468 consist of a fixed resistor and a
wiper contact with 32-tap points that are digitally controlled through a 2-wire serial interface. Three resistance
values are available: 10kΩ (MAX5466/MAX5467/
MAX5468), 50kΩ (MAX5463/MAX5464/MAX5465), and
100kΩ (MAX5460/MAX5461/MAX5462).
The MAX5462/MAX5465/MAX5468 are designed to operate as potentiometers. In this configuration, the low terminal of the resistor array is connected to ground (pin 2).
The MAX5461/MAX5464/MAX5467 perform as variable
resistors. In these devices, the wiper terminal and high
terminal of the resistor array are connected at pin 5.
The MAX5460/MAX5463/MAX5466 are similar variable
resistors, except the low terminal is connected to
ground (pin 2).
Digital Interface Operation
The MAX5460–MAX5468 have two modes of operation
when the serial interface is active: increment and
decrement mode. The serial interface is only active
when CS is low.
The CS and U/D inputs control the position of the wiper
along the resistor array. When CS transitions from high to
low, the part will go into increment mode if U/D is high,
and into decrement mode if U/D is low. Once the mode is
set, the device will remain in that mode until CS goes high
again. A low-to-high transition at the U/D pin will increment or decrement the wiper position depending on the
current mode (Figures 1 and 2).
When the CS input transitions to high (serial interface
inactive), the value of the counter is stored and the
wiper position is maintained.
Note that when the wiper reaches the maximum (or minimum) tap position, the wiper will not wrap around to the
minimum (or maximum) position.
CS
tCU
tIC
tIL
U/D
tIH
tCI
tSETTLE
tSETTLE
W
NOTE: "W" IS NOT A DIGITAL SIGNAL. IT REPRESENTS WIPER TRANSITIONS.
Figure 1. Serial Interface Timing Diagram, Increment Mode
CS
tIC
tCU
tIH
U/D
tIL
tCI
W
tSETTLE
tSETTLE
NOTE: "W" IS NOT A DIGITAL SIGNAL. IT REPRESENTS WIPER TRANSITIONS.
Figure 2. Serial Interface Timing Diagram, Decrement Mode
_______________________________________________________________________________________
5
MAX5460–MAX5468
Detailed Description
MAX5460–MAX5468
32-Tap FleaPoT ™, 2-Wire Digital
Potentiometers
Power-On Reset
All parts in this family feature power-on reset (POR) circuitry that sets the wiper position to midscale at powerup. By default, the chip is in the increment mode.
Applications Information
The MAX5460–MAX5468 are intended for circuits
requiring digitally controlled adjustable resistance,
such as LCD contrast control, where voltage biasing
adjusts the display contrast.
Controlling a Switch-Mode
LCD Bias Generator
Figure 3 shows an application where the variable resistor is used with a MAX1771 to make an adjustable positive LCD-bias circuit. The output of the MAX1771 is a
positive voltage that is digitally controlled through the
MAX5461/MAX5464/MAX5467. Similarly, Figure 4
shows the application of the variable resistor in a digitally controlled negative LCD-bias circuit along with the
MAX774/MAX775/MAX776.
VIN = 5V
Alternatively, use an op amp to provide buffering and
gain to the output of the MAX5462/MAX5465/MAX5468.
Connect the mechanical potentiometer to the positive
input of a noninverting op amp (Figure 5) to select a
portion of the input signal by digitally controlling the
wiper terminal. Figure 6 shows a similar circuit for the
MAX5461/MAX5464/MAX5467.
Adjustable Gain
Figure 7 shows how to use the variable resistor to digitally adjust the gain of a noninverting op amp configuration. Connect the MAX5461/MAX5464/MAX5467 in
series with a resistor to ground to form the adjustable
gain control of a noninverting amplifier. The MAX5460–
MAX5468 have a low 5ppm/°C ratiometric tempco that
allows for a very stable adjustable gain configuration
over temperature.
VIN
C1
68µF
C2
0.1µF
C1
150µF
2
L1
22µH
V+
5 REF
C3
0.1µF
Alternative Positive
LCD Bias Control
4 SHDN
MAX1771
EXT
6 AGND
CS
FB
1
VOUT = 12V
AT 0.5A
D1
1N5817-22
R2
3
V+
MAX5461
MAX5464
MAX5467
5
R3
0.07Ω
SHDN
CS 6
FB
N
MTD20N03HDL
RSENSE
40mΩ
1 OUT
2
C4
300µF
8
3
C2
0.1µF
EXT
7
Q1
Si9435
P
VOUT
MAX774
MAX775
MAX776
R2
RVAR
GND
7
C5
MAX5461
MAX5464
MAX5467
RVAR
R1
C3
0.1µF
R1
1N5822/
MBR340
L1
22µH
REF
GND
8
C4*
* MAX774 = 330µF, 10V
VREF = 1.5V
MAX775/MAX776 = 120µF, 20V
VOUT(MAX) R2
=
+1
R1
VREF
(
VOUT(MIN)
R2
=
R1 + RVAR(MAX)
VREF
Figure 3. Adjustable Positive LCD Bias
6
4
VOUT(MAX) R2 VOUT(MIN)
R2
=
,
=
R1
VREF
R1 + RVAR
VREF
)
+1
VREF - VFB
≥ 5µA (FOR 2% GAIN-SETTING ACCURACY)
R1 + RVAR
Figure 4. Adjustable Negative LCD Bias
_______________________________________________________________________________________
32-Tap FleaPoT ™, 2-Wire Digital
Potentiometers
MAX5460–MAX5468
+5V
+5V
H
H
30V
30V
W
VOUT
VOUT
L
L
MAX5461
MAX5464
MAX5467
MAX5462
MAX5465
MAX5468
Figure 6. Positive LCD Bias Control
Figure 5. Positive LCD Bias Control
VCC
VCC
VIN
VIN
VOUT
VOUT
H
W
H
L
L
MAX5461
MAX5464
MAX5467
MAX5462
MAX5465
MAX5468
a)
b)
Figure 7. Adjustable Gain Circuit
_______________________________________________________________________________________
7
32-Tap FleaPoT ™, 2-Wire Digital
Potentiometers
MAX5460–MAX5468
Functional Diagram
H
VDD
GND
CS
MAX5460–MAX5468
UP/DN
COUNTER
32-POSITION
DECODER
W
U/D
L
Chip Information
TRANSISTOR COUNT: 792
8
_______________________________________________________________________________________
32-Tap FleaPoT ™, 2-Wire Digital
Potentiometers
SC70, 5L.EPS
PACKAGE OUTLINE, 5L SC70
C
1
1
SOT-23 5L .EPS
21-0076
PACKAGE OUTLINE, SOT-23, 5L
21-0057
E
1
1
_______________________________________________________________________________________
9
MAX5460–MAX5468
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)
6LSOT.EPS
(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 OUTLINE, SOT 6L BODY
21-0058
G
1
1
SC70, 6L.EPS
MAX5460–MAX5468
32-Tap FleaPoT ™, 2-Wire Digital
Potentiometers
PACKAGE OUTLINE, 6L SC70
21-0077
C
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.
10 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2005 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products, Inc.
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