MAX5394 Single, 256-Tap Volatile, SPI, Low-Voltage

MAX5394
Single, 256-Tap Volatile, SPI, Low-Voltage Linear
Taper Digital Potentiometer
General Description
Features
The MAX5394 single, 256-tap volatile, low-voltage
linear taper digital potentiometer offers three end-toend resistance values of 10kΩ, 50kΩ, and 100kΩ.
Potentiometer terminals are independent of supply for
voltages up to 5.25V with single-supply operation from
1.7V to 5.5V (charge pump enabled). User-controlled
shutdown modes allow the H, W, or L terminal to be
opened with the wiper position set to zero-code, midcode,
full-code, or the value contained in the wiper register. Ultralow-quiescent supply current (< 1μA) can be achieved
for supply voltages between 2.6V and 5.5V by disabling
the internal charge pump and not allowing potentiometer
terminals to exceed the supply voltage by more than
0.3V. The MAX5394 provides a low 50ppm/°C end-to-end
temperature coefficient and features a SPI serial interface.
●● Single Linear Taper 256-Tap Positions
●● 10kΩ, 50kΩ, and 100kΩ End-to-End Resistance
●● 1.7V to 5.5V Extended Single Supply
●● 0 to 5.25V H, W, L Operating Voltage Independent of
VDD
●● 1μA (typ) Supply Current in Low-Power Mode
●● ±1.0 LSB INL, ±0.5 LSB DNL (max) Wiper Accuracy
●● Power-On Sets Wiper to Midscale
●● 50ppm/°C End-to-End Temperature Coefficient
●● 5ppm/°C Ratiometric Temperature Coefficient
●● -40°C to +125°C Operating Temperature Range
●● 2mm x 2mm, 8-Pin TDFN Package
The small package size, low operating supply voltage,
low supply current, and automotive temperature range
of the MAX5394 make the device uniquely suited for the
portable consumer market and battery-backup industrial
applications.
●● SPI-Compatible Serial Interface
Applications
●●
●●
●●
●●
The MAX5394 is available in a lead-free, 8-pin TDFN
(2mm x 2mm) package. The device operates over the
-40°C to +125°C automotive temperature range.
Portable Electronics
System Calibration
Battery-Powered Systems
Mechanical Potentiometer Replacement
Ordering Information appears at end of data sheet.
Typical Operating Circuit
VDD
1.7V TO 5.5V
(CHARGE PUMP ENABLED) H
+5V
VS
MAX5394
CS
DIN
SCLK
MAX4250
W
SPI
INTERFACE
GND
VO
L
R1
VO / VS = 1 + RMAX5394 /R1
For related parts and recommended products to use with this part, refer to www.maximintegrated.com/MAX5394.related.
19-6392; Rev 2; 10/14
MAX5394
Single, 256-Tap Volatile, SPI, Low-Voltage Linear
Taper Digital Potentiometer
Absolute Maximum Ratings
(All voltages referenced to GND.)
VDD......................................................................... -0.3V to +6V
H, W, L (charge pump enabled)........................... -0.3V to +5.5V
H, W, L (charge pump disabled).................-0.3V to the lower of
(VDD + 0.3V) or +6V
All Other Pins.......................................................... -0.3V to +6V
Continuous Current into H, W, and L
MAX5394L.........................................................................5mA
MAX5394M........................................................................2mA
MAX5394N........................................................................1mA
Maximum Current into Any Input.........................................50mA
Continuous Power Dissipation (TA = +70°C)
TDFN (derate 11.9mW/°C above +70°C)................. 953.5mW
Operating Temperature Range.......................... -40°C to +125°C
Storage Temperature Range............................. -65°C to +150°C
Junction Temperature.......................................................+150°C
Lead Temperature (soldering, 10s)..................................+300°C
Soldering Temperature (reflow)........................................+260°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.
Package Thermal Characteristics (Note 1)
TDFN
Junction-to-Ambient Thermal Resistance (θJA)........83.9°C/W
Junction-to-Case Thermal Resistance (θJC).............37.0°C/W
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.
Electrical Characteristics
(VDD = 1.7V to 5.5V, VH = VDD, VL = GND, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VDD = 1.8V,
TA = +25°C.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
RESOLUTION
256-Tap Family
N
256
Tap
DC PERFORMANCE (VOLTAGE-DIVIDER MODE)
Integral Nonlinearity (Note 3)
INL
Differential Nonlinearity
DNL
Ratiometric Resistor Tempco
-1.0
(Note 3)
-0.5
(DVW/VW)/DT, VH = VDD, VL = GND, no load
Charge pump enabled, 1.7V < VDD < 5.5V
Full-Scale Error (Code FFh)
Charge pump disabled,
2.6V < VDD < 5.5VS
Charge pump disabled,
2.6V < VDD < 5.5V
+0.5
5
LSB
LSB
ppm/°C
-0.5
MAX5394M
MAX5394N
-0.5
MAX5394L
-1.0
Charge pump enabled, 1.7V < VDD < 5.5V
Zero-Scale Error (Code 00h)
+1.0
LSB
+0.5
MAX5394M
MAX5394N
+0.5
MAX5394L
+1.0
LSB
DC PERFORMANCE (VARIABLE RESISTOR MODE)
Charge pump enabled, 1.7V < VDD < 5.5V
Integral Nonlinearity (Note 4)
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R-INL
Charge pump disabled,
2.6V < VDD < 5.5V
-1.0
+1.0
MAX5394M
MAX5394N
-1.0
+1.0
MAX5394L
-1.5
+1.5
LSB
Maxim Integrated │ 2
MAX5394
Single, 256-Tap Volatile, SPI, Low-Voltage Linear
Taper Digital Potentiometer
Electrical Characteristics (continued)
(VDD = 1.7V to 5.5V, VH = VDD, VL = GND, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VDD = 1.8V,
TA = +25°C.) (Note 2)
PARAMETER
Differential Nonlinearity
Wiper Resistance (Note 5)
SYMBOL
R-DNL
RWL
CONDITIONS
(Note 4)
MIN
TYP
-0.5
Charge pump enabled, 1.7V < VDD < 5.5V
25
Charge pump disabled, 2.6V < VDD < 5.5V
MAX
UNITS
+0.5
LSB
50
200
Ω
DC PERFORMANCE (RESISTOR CHARACTERISTICS)
Terminal Capacitance
CH, CL
Measured to GND
10
pF
Wiper Capacitance
CW
Measured to GND
20
pF
End-to-End Resistor Tempco
TCR
No load
50
ppm/°C
End-to-End Resistor
Tolerance
Wiper not connected
-25
+25
%
AC PERFORMANCE
-3dB Bandwidth
Total Harmonic Distortion
Plus Noise
Wiper Settling Time
Charge-Pump Feedthrough
at W
BW
Code = 80h, 10pF load,
VDD = 1.8V
THD+N
(Note 6)
tS
(Note 7)
10kΩ
1600
50kΩ
340
100kΩ
165
kHz
0.035
10kΩ
190
50kΩ
400
100kΩ
664
VRW
%
ns
600
nVRMS
POWER SUPPLIES
Supply Voltage Range
VDD
Terminal Voltage Range
(H, W, L to GND)
1.7
5.5
Charge pump enabled, 1.7V < VDD < 5.5V
0
5.25
Charge pump disabled, 2.6V < VDD < 5.5V
0
VDD
Charge pump disabled, 2.6V < VDD < 5.5V
Supply Current (Note 8)
IVDD
Charge pump enabled,
1.7V < VDD < 5.5V
V
V
1
VDD = 5.5V
25
VDD = 1.7V
20
µA
DIGITAL INPUTS
Minimum Input High Voltage
VIH
Maximum Input Low Voltage
VIL
Input Leakage Current
Input Capacitance
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2.6V < VDD < 5.5V
70
1.7V < VDD < 2.6V
80
% x VDD
2.6V < VDD < 5.5V
30
1.7V < VDD < 2.6V
20
-1
+1
5
% x VDD
µA
pF
Maxim Integrated │ 3
MAX5394
Single, 256-Tap Volatile, SPI, Low-Voltage Linear
Taper Digital Potentiometer
Electrical Characteristics (continued)
(VDD = 1.7V to 5.5V, VH = VDD, VL = GND, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VDD = 1.8V,
TA = +25°C.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
TIMING CHARACTERISTICS (Note 9)
SCLK Frequency
fSCLK
SCLK Period
tSCLK
SCLK Pulse-Width High
tCH
SCLK Pulse-Width Low
tCL
2.6V < VDD < 5.5V
50
1.7V < VDD < 2.6V
25
2.6V < VDD < 5.5V
20
1.7V < VDD < 2.6V
40
MHz
ns
8
ns
8
ns
2.6V < VDD < 5.5V
8
1.7V < VDD < 2.6V
16
CS Fall to SCLK Fall Setup
Time
tCSS0
To 1st SCLK falling
edge (FE)
CS Fall to SCLK Fall Hold
Time
tCSH0
Applies to inactive FE preceding 1st FE
0
ns
CS Rise to SCLK Fall Hold
Time
tCSH1
Applies to 16th FE
0
ns
CS Rise to SCLK Fall
tCSA
Applies to 16th FE,
aborted sequence
SCLK Fall to CS Fall
tCSF
Applies to 16th FE
100
ns
CS Pulse-Width High
tCSPW
20
ns
tDS
5
ns
tDH
4.5
ns
tCSPW
20
ns
DIN to SCLK Fall Setup Time
DIN to SCLK Fall Hold Time
CS Pulse-Width High
2.6V < VDD < 5.5V
12
1.7V < VDD < 2.6V
16
ns
ns
Note 2: All devices are production tested at TA = +25°C and are guaranteed by design and characterization for TA = -40°C to
+125°C.
Note 3: DNL and INL are measured with the potentiometer configured as a voltage-divider with VH = 5.25 (QP enabled) or VDD
(QP disabled) and VL = GND. The wiper terminal is unloaded and measured with an ideal voltmeter.
Note 4: R-DNL and R-INL are measured with the potentiometer configured as a variable resistor (Figure 1). H is unconnected and
L = GND.
For charge pump enabled, VDD = 1.7V to 5.5V, the wiper terminal is driven with a source current of 400μA for the 10kΩ
configuration, 80μA for the 50kΩ configuration, and 40μA for the 100kΩ configuration.
For charge pump disabled and VDD = 5.5V, the wiper terminal is driven with a source current of 400μA for the 10kΩ
configuration, 80μA for the 50kΩ configuration, and 40μA for the 100kΩ configuration.
For charge pump disabled and VDD = +2.6V, the wiper terminal is driven with a source current of 200μA for the 10kΩ
configuration, 40μA for the 50kΩ configuration, and 20μA for the 100kΩ configuration.
Note 5: The wiper resistance is the maximum value measured by injecting the currents given in Note 4 into W with L = GND.
RW = (VW - VH)/IW.
Note 6: Measured at W with H driven with a 1kHz, 0V to VDD amplitude tone and VL = GND. Wiper at midscale with a 10pF load.
Note 7: Wiper-settling time is the worst-case 0-to-50% rise time, measured between tap 0 and tap 127. H = VDD, L = GND, and the
wiper terminal is loaded with 10pF capacitance to ground.
Note 8: Digital inputs at VDD or GND.
Note 9: Digital timing is guaranteed by design and characterization, and is not production tested.
www.maximintegrated.com
Maxim Integrated │ 4
MAX5394
Single, 256-Tap Volatile, SPI, Low-Voltage Linear
Taper Digital Potentiometer
H
N.C.
W
W
L
L
Figure 1. Voltage-Divider and Variable Resistor Configurations
DIN15
DIN
DIN14
DIN13
SCLK
tCSH0
2
tCSS0
DIN11
tDH
tDS
1
DIN12
3
4
5
tCH
DIN10
DIN9
DIN8
7
8
DIN2
DIN1
DIN0
DIN15
tCP
6
tCL
14
15
tCSA
16
1
tCSH1
CS
tCSPW
tCSF
Figure 2. SPI Timing Diagram
www.maximintegrated.com
Maxim Integrated │ 5
MAX5394
Single, 256-Tap Volatile, SPI, Low-Voltage Linear
Taper Digital Potentiometer
Typical Operating Characteristics
(VDD = 1.8V, TA = +25°C, unless otherwise noted.)
25
20
15
10
5
-40 -25 -10 5 20 35 50 65 80 95 110 125
4
MAX5394 toc03
15
TA = -40°C
10
5
0
5
5
4
3
2
1.70
2.65
3.60
4.55
5.50
40
35
30
25
20
15
10
5
0
0
96
128 160 192 224 256
100
MAX5394 toc06
45
1
64
MAX5394 toc05
50
90
W-TO-L RESISTANCE (kΩ)
6
80
70
60
50
40
30
20
10
0
32
64
96
0
128 160 192 224 256
0
32
64
96
128 160 192 224 256
WIPER RESISTANCE
vs. WIPER VOLTAGE
WIPER RESISTANCE
vs. WIPER VOLTAGE
END-TO-END RESISTANCE PERCENTAGE
CHANGE vs. TEMPERATURE
35
WIPER RESISTANCE (Ω)
VDD = 5V, QP OFF
40
VDD = 1.8V, QP ON
30
25
20
15
10
5
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
WIPER VOLTAGE (V)
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0
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
WIPER VOLTAGE (V)
0.8
MAX5394 toc08
TAP POSITION
END-TO-END RESISTANCE PERCENTAGE CHANGE (%)
TAP POSITION
MAX5394 toc07b
TAP POSITION
VDD = 2.6V, QP OFF
0
20
RESISTANCE (W-TO-L)
vs. TAP POSITION (100kΩ)
MAX5394 toc07a
W-TO-L RESISTANCE (kΩ)
WIPER RESISTANCE (Ω)
3
25
RESISTANCE (W-TO-L)
vs. TAP POSITION (50kΩ)
7
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
2
TA = +25°C
30
RESISTANCE (W-TO-L)
vs. TAP POSITION (10kΩ)
8
32
1
0
VDD = 1.8V
(LOW-HIGH)
TA = +125°C
INPUT VOLTAGE (V)
9
0
VDD = 3.3V
(HIGH-LOW)
VDD = 1.8V
(HIGH-LOW)
35
DIGITAL INPUT VOLTAGE (V)
MAX5394 toc04
10
VDD = 5V
(HIGH-LOW)
SUPPLY CURRENT vs. INPUT VOLTAGE
TEMPERATURE (°C)
W-TO-L RESISTANCE (kΩ)
0
VDD = 5V
(LOW-HIGH)
VDD = 3.3V
(LOW-HIGH)
40
SUPPLY CURRENT (μA)
SUPPLY CURRENT (µA)
30
2600
2400
2200
2000
1800
1600
1400
1200
1000
800
600
400
200
0
MAX5394 toc02
VDD = 1.8V
35
SUPPLY CURRENT (μA)
MAX5394 toc01
40
SUPPLY CURRENT
vs. DIGITAL INPUT VOLTAGE
SUPPLY CURRENT vs. TEMPERATURE
0.6
100kΩ
0.4
0.2
0
-0.2
50kΩ
10kΩ
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
Maxim Integrated │ 6
MAX5394
Single, 256-Tap Volatile, SPI, Low-Voltage Linear
Taper Digital Potentiometer
Typical Operating Characteristics (continued)
(VDD = 1.8V, TA = +25°C, unless otherwise noted.)
TAP-TO-TAP SWITCHING TRANSIENT
(CODE 127 TO 128 10kΩ)
TAP-TO-TAP SWITCHING TRANSIENT
(CODE 127 TO 128 50kΩ)
MAX5394 toc09
MAX5394 toc10
VW-L
10mV/div
VW-L
10mV/div
VSCLK
2V/div
VSCLK
2V/div
200ns/div
200ns/div
TAP-TO-TAP SWITCHING TRANSIENT
(CODE 127 TO 128 100kΩ)
POWER-ON TRANSIENT (10kΩ)
MAX5394 toc11
MAX5394 toc12a
VW-L
1V/div
VW-L
10mV/div
VDD
1V/div
VSCLK
2V/div
200ns/div
10µs/div
POWER-ON TRANSIENT (50kΩ)
POWER-ON TRANSIENT (100kΩ)
MAX5394 toc12b
MAX5394 toc12c
VW-L
1V/div
VW-L
1V/div
VDD
1V/div
VDD
1V/div
10µs/div
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10µs/div
Maxim Integrated │ 7
MAX5394
Single, 256-Tap Volatile, SPI, Low-Voltage Linear
Taper Digital Potentiometer
Typical Operating Characteristics (continued)
(VDD = 1.8V, TA = +25°C, unless otherwise noted.)
0
-10
0
VDD = 5V
GAIN (dB)
GAIN (dB)
GAIN (dB)
0
MIDSCALE FREQUENCY
RESPONSE (100kΩ)
10
MAX5394 toc14
10
MAX5394 toc13
10
MIDSCALE FREQUENCY
RESPONSE (50kΩ)
MAX5394 toc15
MIDSCALE FREQUENCY
RESPONSE (10kΩ)
-10
VDD = 5V
-10
VDD = 5V
1k
10k
100k
1M
-30
0.01k
10M
0.1k
1k
FREQUENCY (Hz)
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY
0.16
0.12
0.10
10kΩ
0.08
50kΩ
100k
1M
10M
0.5
50kΩ 100kΩ
0.3
500
400
0.1
0
-0.1
-0.2
-0.3
0.02
100
-0.4
1
10
100
0.50
0.75
1.00
VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON
VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF
VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF
0.4
1.75
0.3
-0.5
2.00
0.5
0.3
0.1
INL (LSB)
0.2
0.1
0
-0.1
0
-0.2
-0.2
-0.3
-0.3
-0.3
-0.4
-0.4
-0.4
32
64
96
128 160 192 224 256
TAP POSITION
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-0.5
0
32
128 160 192 224 256
-0.1
-0.2
0
96
64
96
128 160 192 224 256
TAP POSITION
VDD = 2.6V,
VH = 2.6V,
CHARGE
PUMP OFF
0.4
0.1
-0.5
64
VARIABLE-RESISTOR INL
vs. TAP POSITION (10kΩ)
0.2
-0.1
32
VARIABLE-RESISTOR DNL
vs. TAP POSITION (100kΩ)
0.2
0
0
TAP POSITION
VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON
VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF
VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF
0.4
DNL (LSB)
DNL (LSB)
0.3
0.5
MAX5394 toc18b
0.5
1.50
FREQUENCY (MHz)
FREQUENCY (kHz)
VARIABLE-RESISTOR DNL
vs. TAP POSITION (50kΩ)
1.25
MAX5394 toc18c
0.1
10M
0.2
10kΩ
600
200
0.01
1M
VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON
VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF
VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF
0.4
700
0
100k
VARIABLE-RESISTOR DNL
vs. TAP POSITION (10kΩ)
800
100kΩ
10k
CHARGE-PUMP FEEDTHROUGH AT W
300
0
1k
FREQUENCY (Hz)
0.04
0.06
0.1k
VDD = 1.8V
FREQUENCY (Hz)
900
VOLTAGE (nVRMS)
0.14
10k
-30
0.01k
DNL (LSB)
0.18
THD+N (%)
1000
MAX5394 toc16
0.20
VIN = 1VP-P
CW = 10pF
VDD = 1.8V
MAX5394 toc18a
0.1k
-20
VIN = 1VP-P
CW = 10pF
MAX5394 toc19a
-30
0.01k
-20
VDD = 1.8V
VIN = 1VP-P
CW = 10pF
MAX5394 toc17
-20
-0.5
VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON
VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF
0
32
64
96
128 160 192 224 256
TAP POSITION
Maxim Integrated │ 8
MAX5394
Single, 256-Tap Volatile, SPI, Low-Voltage Linear
Taper Digital Potentiometer
Typical Operating Characteristics (continued)
(VDD = 1.8V, TA = +25°C, unless otherwise noted.)
INL (LSB)
0
-0.1
-0.2
VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON
VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF
-0.5
0
0.5
64
96
0.3
0.1
0
-0.1
-0.2
-0.3
-0.3
-0.4
-0.4
32
0
64
96
-0.5
128 160 192 224 256
64
96
128 160 192 224 256
TAP POSITION
TAP POSITION
VOLTAGE-DIVIDER DNL
vs. TAP POSITION (50kΩ)
VOLTAGE-DIVIDER DNL
vs. TAP POSITION (100kΩ)
VOLTAGE-DIVIDER INL
vs. TAP POSITION (10kΩ)
VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON
VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF
VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF
0.4
0.3
0.5
0.3
0.2
0.1
0.1
0.1
DNL (LSB)
0.2
0
-0.1
0
-0.1
0
-0.1
-0.2
-0.2
-0.2
-0.3
-0.3
-0.3
-0.4
-0.4
-0.4
-0.5
-0.5
32
64
96
128 160 192 224 256
0
TAP POSITION
64
96
0.3
0.1
INL (LSB)
0.2
0
-0.1
0
-0.2
-0.3
-0.3
-0.4
-0.4
64
96
128 160 192 224 256
TAP POSITION
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128 160 192 224 256
-0.1
-0.2
32
96
VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON
VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF
VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF
0.4
0.1
0
64
VOLTAGE-DIVIDER INL
vs. TAP POSITION (100kΩ)
0.5
0.2
-0.5
32
TAP POSITION
MAX5394 toc21b
0.3
0
TAP POSITION
VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON
VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF
VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF
0.4
-0.5
128 160 192 224 256
VOLTAGE-DIVIDER INL
vs. TAP POSITION (50kΩ)
0.5
INL (LSB)
32
VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON
VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF
VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF
0.4
0.2
0
32
0
TAP POSITION
0.5
MAX5394 toc20a
0
-0.1
-0.2
-0.5
128 160 192 224 256
VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON
VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF
VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF
0.4
DNL (LSB)
32
MAX5394 toc20b
-0.4
0.2
0.1
MAX5394 toc21c
-0.3
0.3
0.2
INL (LSB)
INL (LSB)
0.1
0.3
VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON
VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF
VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF
0.4
MAX5394 toc21a
VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF
0.2
0.4
VOLTAGE-DIVIDER DNL
vs. TAP POSITION (10kΩ)
0.5
MAX5394 toc20c
0.3
VDD = 1.8V, VH = 5.0V, CHARGE PUMP ON
VDD = 2.6V, VH = 2.6V, CHARGE PUMP OFF
VDD = 5.0V, VH = 5.0V, CHARGE PUMP OFF
DNL (LSB)
0.4
0.5
MAX5394 toc19b
0.5
VARIABLE-RESISTOR INL
vs. TAP POSITION (100kΩ)
MAX5394 toc19c
VARIABLE-RESISTOR INL
vs. TAP POSITION (50kΩ)
-0.5
0
32
64
96
128 160 192 224 256
TAP POSITION
Maxim Integrated │ 9
MAX5394
Single, 256-Tap Volatile, SPI, Low-Voltage Linear
Taper Digital Potentiometer
Pin Configuration
TOP VIEW
1
GND
2
CS
3
DIN
+
L
MAX5394
EP
4
8
H
7
W
6
VDD
5
SCLK
TDFN
Pin Description
PIN
NAME
FUNCTION
1
L
2
GND
Ground
3
Active-Low Chip-Select Digital Input
4
CS
DIN
5
SCLK
6
VDD
Power Supply
7
W
Wiper Terminal
8
H
High Terminal. The voltage at H can be greater than or less than the voltage at L. Current can flow into or out
of H.
—
EP
Exposed Pad. Internally connected to GND. Connected to ground.
Low Terminal. The voltage at L can be greater than or less than the voltage at H. Current can flow into or out
of L.
Serial-Interface Data Input
Serial-Interface Clock Input
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Maxim Integrated │ 10
MAX5394
Single, 256-Tap Volatile, SPI, Low-Voltage Linear
Taper Digital Potentiometer
Functional Diagram
Charge Pump
The MAX5394 contains an internal charge pump that
guarantees the maximum wiper resistance, RWL, to be less
than 50Ω (25Ω typ) for supply voltages down to 1.7V and
allows pins H, W, and L to be driven between GND and 5.25V
independent of VDD. Minimal charge-pump feedthrough
is present at the terminal outputs and is illustrated by the
Charge-Pump Feedthrough at W vs. Frequency graph in the
Typical Operating Characteristics. The charge pump is on by
default but can be disabled with QP_OFF and enabled with
the QP_ON commands (Table 1). The MAX5394 minimum
supply voltage with charge pump disabled is limited to 2.6V
and terminal voltage cannot exceed -0.3V to (VDD + 0.3V).
MAX5394
L
H
GND
W
VDD
CS
SCLK
SPI
INTERFACE
DIN
SPI Interface
The digital interface is powered from VDD, not the internal
charge-pump voltage. Therefore the VIH and VIL logic
thresholds will follow VDD as specified in the Electrical
Characteristics table.
Detailed Description
The MAX5394 single, 256-tap volatile, low-voltage
linear taper digital potentiometer offers three end-toend resistance values of 10kΩ, 50kΩ, and 100kΩ.
Potentiometer terminals are independent of supply for
voltages up to +5.25V with single-supply operation from
1.7V to 5.5V (charge pump enabled). User-controlled
shutdown modes allow the H, W, or L terminals to be
opened with the wiper position set to zero-code, midcode,
full-code, or the value contained in the wiper register. Ultralow-quiescent supply current (< 1μA) can be achieved
for supply voltages between 2.6V and 5.5V by disabling
the internal charge pump and not allowing potentiometer
terminals to exceed the supply voltage by more than
0.3V. The MAX5394 provides a low 50ppm/°C end-to-end
temperature coefficient and features a SPI serial interface.
The SPI digital interface uses a 3-wire serial data interface
to control the wiper tap position. This write-only interface
contains three inputs: Chip Select (CS), Data In (DIN),
and Data Clock (SCLK). When CS is taken low, data
from the DIN pin is synchronously loaded into the serial
shift register on each falling edge of each SCLK pulse
(Figure 3). After all the data bits have been shifted in, they
are latched into the potentiometer control register. Data
written to a memory register immediately updates the
wiper position.
Keep CS low during the entire data stream to prevent the
data from being terminated. The power-on default position
of the wiper is midscale (D[7:0] = 80H).
The small package size, low supply operating voltage,
low supply current, and automotive temperature range
of the MAX5394 make the device uniquely suited for the
portable consumer market and battery-backup industrial
applications.
CS
SCLK
DIN
C7
C6
C5
C4
C3
C2
C1
C0
D7
D6
D5
D4
D3
D2
D1
D0
WIPER REGISTER
LOADED
Figure 3. SPI Digital Interface Format
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Maxim Integrated │ 11
MAX5394
Single, 256-Tap Volatile, SPI, Low-Voltage Linear
Taper Digital Potentiometer
Table 1. SPI Write Command Byte Summary
COMMAND
COMMAND BYTE
DATA BYTE
C7
C6
C5
C4
C3
C2
C1
C0
D7
D6
D5
D4
D3
D2
D1
D0
WIPER
0
0
0
0
0
0
0
0
D7
D6
D5
D4
D3
D2
D1
D0
SD_CLR
1
0
0
0
0
0
0
0
X
X
X
X
X
X
X
X
SD_H_WREG
1
0
0
1
0
0
0
0
X
X
X
X
X
X
X
X
SD_H_ZERO
1
0
0
1
0
0
0
1
X
X
X
X
X
X
X
X
SD_H_MID
1
0
0
1
0
0
1
0
X
X
X
X
X
X
X
X
SD_H_FULL
1
0
0
1
0
0
1
1
X
X
X
X
X
X
X
X
SD_L_WREG
1
0
0
0
1
0
0
0
X
X
X
X
X
X
X
X
SD_L_ZERO
1
0
0
0
1
0
0
1
X
X
X
X
X
X
X
X
SD_L_MID
1
0
0
0
1
0
1
0
X
X
X
X
X
X
X
X
SD_L_FULL
1
0
0
0
1
0
1
1
X
X
X
X
X
X
X
X
SD_W
1
0
0
0
0
1
X
X
X
X
X
X
X
X
X
X
QP_OFF
1
0
1
0
0
0
0
0
X
X
X
X
X
X
X
X
QP_ON
1
0
1
0
0
0
0
1
X
X
X
X
X
X
X
X
RST
1
1
0
0
0
0
0
0
X
X
X
X
X
X
X
X
WIPER Command
The data byte writes to the wiper register and the
potentiometer moves to the appropriate position. D[7:0]
indicates the position of the wiper. D[7:0] = 0x00 moves
the wiper to the position closest to L. D[7:0] = 0xFF moves
the wiper closest to H. D[7:0] = 0x80 following power-on.
SD_CLR Command
Removes any existing shutdown condition. Connects all
potentiometer terminals and returns the wiper to the value
stored in the wiper register. The command does not affect
the current status of the charge pump.
SD_H_WREG Command
Opens the H terminal and maintains the wiper at the
wiper register location. Writes cannot be made to the
wiper register while shutdown mode is engaged. Clearing
shutdown mode will close the H terminal and allow the
wiper register to be written. A RST will also deassert
shutdown mode and return the wiper to midscale (0x80).
This command does not affect the charge-pump status.
SD_H_ZERO Command
Moves wiper to zero-scale position (0x00) and opens the
H terminal. The wiper register remains unaltered. Writes
cannot be made to the wiper register while shutdown mode
is engaged. Clearing shutdown mode will return the wiper
to the position contained in the wiper register and close
www.maximintegrated.com
the H terminal. A RST will also deassert shutdown mode
and return the wiper to midscale (0x80). This command
does not affect the charge-pump status.
SD_H_MID Command
Moves wiper to midscale position (0x80) and opens the
H terminal. The wiper register remains unaltered. Writes
cannot be made to the wiper register while shutdown mode
is engaged. Clearing shutdown mode will return the wiper
to the position contained in the wiper register and close
the H terminal. A RST will also deassert shutdown mode
and return the wiper to midscale (0x80). This command
does not affect the charge-pump status.
SD_H_FULL Command
Moves wiper to full-scale position (0xFF) and opens H
terminal. The wiper register remains unaltered. Writes
cannot be made to the wiper register while shutdown mode
is engaged. Clearing shutdown mode will return the wiper
to the position contained in the wiper register and close
the H terminal. A RST will also deassert shutdown mode
and return the wiper to midscale (0x80). This command
does not affect the charge-pump status.
SD_L_WREG Command
Opens the L terminal and maintains the wiper at the
wiper register location. Writes cannot be made to the
wiper register while shutdown mode is engaged. Clearing
shutdown mode will close the L terminal and allow wiper
Maxim Integrated │ 12
MAX5394
Single, 256-Tap Volatile, SPI, Low-Voltage Linear
Taper Digital Potentiometer
register to be written. A RST will also deassert shutdown
mode and return the wiper to midscale (0x80). This
command does not affect the charge-pump status.
SD_L_ZERO Command
Moves wiper to zero-scale position (0x00) and opens the
L terminal. The wiper register remains unaltered. Writes
cannot be made to the wiper register while shutdown mode
is engaged. Clearing shutdown mode will return the wiper
to the position contained in the wiper register and close
the L terminal. A RST will also deassert shutdown mode
and return the wiper to midscale (0x80). This command
does not affect the charge-pump status.
SD_L_MID Command
to the position contained in the wiper register and close
the L terminal. A RST will also deassert shutdown mode
and return the wiper to midscale (0x80). This command
does not affect the charge-pump status.
SD_W Command
Opens the W terminal keeping the internal tap position
the same as the wiper register. Writes cannot be made
to the wiper registers while shutdown mode is engaged.
Clearing shutdown mode will return the wiper to the
position contained in the wiper register and close W
terminal. A RST will also deassert shutdown mode and
return the wiper to midscale (0x80). This command does
not affect the charge-pump status.
Moves wiper to midscale position (0x80) and opens the
L terminal. The wiper register remains unaltered. Writes
cannot be made to the wiper register while shutdown mode
is engaged. Clearing shutdown mode will return the wiper
to the position contained in the wiper register and close
the L terminal. A RST will also deassert shutdown mode
and return the wiper to midscale (0x80). This command
does not affect the charge-pump status.
QP_ON Command
SD_L_FULL Command
RST Command
Moves wiper to full-scale position (0xFF) and opens the
L terminal. The wiper register remains unaltered. Writes
cannot be made to the wiper register while shutdown mode
is engaged. Clearing shutdown mode will return the wiper
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Enables the onboard charge pump to allow low-supply
voltage operation. This is the power-on default condition.
Low supply voltage is 1.7V.
QP_OFF Command
Disables the on-board charge pump and places device in
low power mode. Low supply voltage is limited to 2.6V.
Returns device to power-on default conditions. Resets the
wiper register to midscale (0x80), enables charge pump,
and deasserts any shutdown modes.
Maxim Integrated │ 13
MAX5394
Single, 256-Tap Volatile, SPI, Low-Voltage Linear
Taper Digital Potentiometer
Ordering Information
PIN-PACKAGE
INTERFACE
TAPS
END-TO-END
RESISTANCE (kΩ)
MAX5394LATA+T
8 TDFN-EP*
SPI
256
10
MAX5394MATA+T
8 TDFN-EP*
SPI
256
50
MAX5394NATA+T
8 TDFN-EP*
SPI
256
100
PART
Note: All devices operate over the -40°C to +125°C temperature range.
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
Chip Information
PROCESS: BiCMOS
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Package Information
For the latest package outline information and land patterns
(footprints), go to www.maximintegrated.com/packages. Note
that a “+”, “#”, or “-” in the package code indicates RoHS status
only. Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
8 TDFN-EP
T822+2
21-0168
90-0065
Maxim Integrated │ 14
MAX5394
Single, 256-Tap Volatile, SPI, Low-Voltage Linear
Taper Digital Potentiometer
Revision History
REVISION
NUMBER
REVISION
DATE
0
7/12
Initial release
—
1
9/12
Revised the Absolute Maximum Ratings
2
2
10/14
Removed automotive reference from data sheet
DESCRIPTION
PAGES
CHANGED
1, 11
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits)
shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
© 2014 Maxim Integrated Products, Inc. │ 15