Datasheet
AS1507
D u a l 2 5 6 - Ta p D i g i ta l P o t e n t i o m e t e r w i t h S P I I n t e r f a c e
and High Endurance EEPROM
1 General Description
The AS1507 is a linear, dual 256-tap digital potentiome-
ter specifically designed to replace discrete/mechanical
potentiometers and is ideal for applications requiring a
low-temperature-coefficient variable resistor.
The device is controlled via a 3-wire SPI-compatible
interface and features an internal EEPROM for storing
wiper positions.
Several device variants are available differentiated by
end-to-end resistance as shown in
Table 1
(see also
Ordering Information on page 17).
Table 1. Standard Products
Model
AS1507-10
AS1507-50
AS1507-100
End-to-End Resistance (kΩ)
10
50
100
2 Key Features
!
!
High Endurance: EEPROM up to 10M cycles
High Reliability: EEPROM up to 150 years data
retention @ 85°C
Wiper Position Retained in EEPROM and loaded at
Power-Up
256 Tap Positions
±0.5LSB DNL in Voltage Divider Mode
±0.5LSB INL in Voltage Divider Mode
End-to-End Resistance: 10/50/100kΩ
Low End-to-End Resistance Temperature
Coefficient: 90ppm/ºC
Low-Power Standby Mode: 100nA
5MHz SPI-Compatible Serial Interface
Single-Supply Operation: +2.7 to +5.5V
TQFN 3x3mm 16-pin Package
!
!
!
!
!
!
!
!
!
The 3-wire SPI-compatible serial interface allows com-
munication at data rates up to 5MHz. The internal
EEPROM stores the last wiper position for initialization
during power-up.
The devices are available in an TQFN 3x3mm 16-pin
package.
!
3 Applications
The device is ideal for mechanical potentiometer
replacement, low-drift programmable gain amplifiers,
audio volume control, LCD contrast control, and low-drift
programmable filters.
Figure 1. AS1507 - Block Diagram
9
1
VDD
8-Bit
Latch
8
256-Position
Decoder
SPI
Interface
25
READY
15
HIGH A
14
WIPER A
13
LOW A
12
HIGH B
256-Position
Decoder
8-Bit
Latch
7
GND
8
25
11
WIPER B
10
16
MUTE
2
SCLK
3
SDIO
4
CSN
16-Bit
EEPROM
Power-
On
Reset
AS1507
LOW B
www.austriamicrosystems.com/Digital-Potentiometers/AS1507
Revision 1.01
1 - 18
AS1507
Datasheet - P i n o u t
4 Pinout
Pin Assignments
Figure 2. Pin Assignments (Top View)
15 HIGH A
14 WIPER A
13 LOW A
12 HIGH B
11 WIPER B
10 LOW B
9 READY
NC 5
NC 6
GND 7
NC 8
VDD 1
SCLK 2
16 MUTE
SDIO 3
CSN 4
AS1507
Pin Descriptions
Table 2. Pin Descriptions
Pin Number
1
2
3
4
5, 6, 8
7
9
10
11
12
13
14
15
16
N/A
Description
2.5V to 5.5V Supply Voltage.
Bypass with a 0.1µF capacitor to GND.
Serial Clock Input
Serial Data Input
Active-Low Chip Select
Not Connected
Ground
EEPROM Ready.
Active-Low indicates an ongoing write operation in the EEPROM.
Low Terminal of Resistor B.
The voltage at this pin can be greater than or less
LOW B
than the voltage at pin HIGH. Current can flow into or out of this pin.
Wiper Terminal for Resistor B
WIPER B
High Terminal of Resistor B.
The voltage at this pin can be greater than or less
HIGH B
than the voltage at pin LOW. Current can flow into or out of this pin.
Low Terminal of Resistor A.
The voltage at this pin can be greater than or less
LOW A
than the voltage at pin HIGH. Current can flow into or out of this pin.
Wiper Terminal for Resistor A
WIPER A
High Terminal of Resistor A.
The voltage at this pin can be greater than or less
HIGH A
than the voltage at pin LOW. Current can flow into or out of this pin.
Mute.
Both wiper registers are asynchronously set to zero. Data stored in the
EEPROM is not affected. Active-High signal. Internal pull-down resistor. Can be left
MUTE
unconnected if not used.
Exposed Pad The exposed pad is not internally connected. Connect to GND or leave floating.
Pin Name
VDD
SCLK
SDIO
CSN
NC
GND
READY
www.austriamicrosystems.com/Digital-Potentiometers/AS1507
Revision 1.01
2 - 18
AS1507
Datasheet - A b s o l u t e M a x i m u m R a t i n g s
5 Absolute Maximum Ratings
Stresses beyond those listed in
Table 3
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
Electrical Character-
istics on page 4
is not implied. Exposure to absolute maximum rating conditions for extended periods may affect
device reliability.
Table 3. Absolute Maximum Ratings
Parameter
V
DD
to GND
All Other Pins to GND
AS1507-10
Maximum Continuous Current into
Pins HIGH, WIPER, and LOW
Electrostatic Discharge
Latch-Up
1
Min
-0.3
-0.3
Max
+7.0
V
DD
+
0.3
+1
+1
+1
1
Units
V
V
Comments
AS1507-50
AS1507-100
mA
kV
100
mA
ºC/W
+85
+150
+150
ºC
ºC
ºC
The reflow peak soldering temperature
(body temperature) specified is in
accordance with
IPC/JEDEC J-STD-020D
“Moisture/Reflow Sensitivity Classification
for Non-Hermetic Solid State Surface
Mount Devices”.
The lead finish for Pb-free leaded
packages is matte tin (100% Sn).
HBM MIL-Std. 883E 3015.7
methods
JEDEC 78
on PCB
-100
48
-40
-60
Thermal Resistance
Θ
JA
Operating Temperature Range
Storage Temperature Range
Junction Temperature
Package Body Temperature
+260
ºC
1. The maximum rating voltage must not be exceeded during Latch-up test of the device.
www.austriamicrosystems.com/Digital-Potentiometers/AS1507
Revision 1.01
3 - 18
AS1507
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
6 Electrical Characteristics
V
DD
= +2.7 to +5.5V, HIGH = V
DD
, LOW = GND, T
AMB
= -40 to +85ºC. Typ values are at V
DD
= +5.0V, T
AMB
= +25ºC
(unless otherwise specified).
Table 4. Electrical Characteristics
Symbol
Power Supply
V
DD
I
DD
Parameter
Condition
Min
2.70
0.1
110
Typ
Max
5.5
0.5
200
Unit
V
µA
µA
Standby Current
Digital Inputs = V
DD
or GND, T
AMB
= +25ºC
Operating Current
1
I
OP
Includes Non-Volatile Write to Memory
(CMOS write)
DC Performance (Voltage Divider Mode)
N
Resolution
AS1507-10
2
INL
Integral Linearity
AS1507-50 & -100
DNL
TC
R
Differential Non-Linearity
End-to-End Resistance
Temperature Coefficient
Full Scale Error
2
256
±0.5
±0.25
±0.5
±0.25
90
2.5
1.5
1.5
1
0.1
0.1
±1
±0.6
±0.5
±0.5
±0.5
200
120
15
10
50
100
4
2.5
2.5
2
0.7
0.7
±2
±1.5
±1
±1
±1
±1
±0.5
±1
±0.5
Taps
LSB
LSB
ppm/ºC
AS1507-10
AS1507-50 & -100
T
AMB
= 0 to +85ºC
AS1507-10
AS1507-50
AS1507-100
AS1507-10
AS1507-50
AS1507-100
AS1507-10
AS1507-50 & -100 @ 3V
AS1507-50 & -100 @ 5V
AS1507-10
AS1507-50 & -100
V
DD
= 3V
V
DD
= 5V
AS1507-10
AS1507-50
AS1507-100
7.5
37.5
75
LSB
Zero Scale Error
DC Performance (Variable Resistor Mode)
INL
Integral Linearity
3
LSB
LSB
DNL
Differential Non-Linearity
LSB
DC Performance (Resistor Characteristics)
R
W
C
W
R
EE
Wiper Resistance
4
Ω
pF
12.5
62.5
125
kΩ
Wiper Capacitance
End-to-End Resistance
Inputs and Outputs
WIPER Voltage Range
HIGH Voltage Range
LOW Voltage Range
V
IH
V
IL
I
LEAK
C
IN
I
CONT
Digital Input High Voltage
Digital Input Low Voltage
5
GND-
0.3
V
DD
= 3V
V
DD
= 5V
V
DD
= 3V
V
DD
= 5V
2.1
2.4
V
DD
+
0.3
V
V
0.6
0.8
500
1000
V
nA
pF
µA
5
Digital Input Leakage Current
Digital Input Capacitance
Continuous DAC current
200
5
www.austriamicrosystems.com/Digital-Potentiometers/AS1507
Revision 1.01
4 - 18
AS1507
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
Table 4. Electrical Characteristics (Continued)
Symbol
Parameter
Condition
AS1507-10
AS1507-50
AS1507-100
AS1507-10
AS1507-50
AS1507-100
T
AMB
= +85ºC
T
AMB
= +25ºC
T
AMB
= +85ºC
Min
Typ
1200
220
120
1100
1600
2200
150
10M
1M
20
Max
Unit
Dynamic Characteristics
Wiper -3dB Bandwidth
6
kHz
t
S
Wiper Settling Time
7
ns
Non-Volatile Memory Reliability
Data Retention
Endurance
t
BUSY
8
8
Years
Write
Cycles
ms
Write Non-Volatile Register
Busy Time
1. The programming current operates only during power-up and non-volatile memory writes.
2. DNL and INL are measured with the potentiometer configured as a voltage-divider with HIGH = V
DD
and LOW =
GND. The wiper terminal is unloaded and measured with a high-input-impedance voltmeter.
3. DNL and INL are measured with the potentiometer configured as a variable resistor. HIGH is unconnected and
LOW = GND. For the 5V condition, the wiper terminal is driven with a source current of 400µA @ 10kΩ, 80µA @
50kΩ, 40µA @ 100kΩ. In 3V conditions, the wiper terminal is driven with a source current of 200µA @ 10kΩ,
40µA @ 50kΩ, 20µA @ 100kΩ.
4. The wiper resistance is measured using the source currents given in Note 3. The number is the worst case
resistance over TAP positions.
5. The device draws higher supply current when the digital inputs are driven with voltages between (V
DD
- 0.5V)
and (GND + 0.5V).
6. Wiper at midscale with a 10pF load (DC measurement) V
DD
= 5V, LOW = GND. An AC source (5V peak to peak
sinus signal) is applied to HIGH and the WIPER output is measured. A 3dB bandwidth occurs when the AC
WIPER/HIGH value is 3dB lower than the DC WIPER/HIGH value.
7. Wiper-settling time is the worst-case 0 to 50% rise-time measured between successive wiper positions. HIGH =
V
DD
, LOW = GND; WIPER is unloaded and measured with a 10pF load.
8. This parameter is not tested but ensured by characterization.
Note:
All limits are guaranteed. The parameters with min and max values are guaranteed with production tests or
SQC (Statistical Quality Control) methods.
www.austriamicrosystems.com/Digital-Potentiometers/AS1507
Revision 1.01
5 - 18