AS1500/AS1501/AS1502/AS1503
D i g i ta l P o t e n t i o m e t e r
D a ta S he e t
1 General Description
The AS1500 is a digital potentiometer with 256 programmable steps. The values of the resistor can be controlled via 3 wire serial interface capable to handle programming rates up to 10MHz. The AS1500 is available in four different resistor values. The AS1500 incorporates a 10kΩ, the AS1501 a 20kΩ, the AS1502 a 50kΩ and the AS1503 a 100kΩ fixed resistor. The wiper contact taps the fixed resistor at points determined by the 8-bit digital code word. The resistance between the wiper and the endpoint of the resistor is linear. The switching action is performed in a way that no glitches occur. The AS150x is available in an 8-pin SOIC package. All parts are guaranteed to operate over the extended industrial temperature range of –40º to +125º.
2 Key Features
256 - Taps Available in four Resistance values - AS1500 resistance 10kΩ - AS1501 resistance 20kΩ - AS1502 resistance 50kΩ - AS1503 resistance 100kΩ Standby current - Less than 1 µA 3-Wire Serial Data Interface 10 MHz Update Data Loading Rate 2.7 V to 5.5 V Single-Supply Operation Temperature Range –40º to +125º 8-pin SOIC Package
3 Applications
The AS1500 is ideal for volume controls in TV sets and audio systems, and applications that require line impedance matching, programmable filters or power supply adjustment. The AS1500 can also be designed in as a replacement for mechanical potentiometers.
Figure 1. Application Diagram
VCC
A SDI CK CSN
10 Bit Serial Latch
8
8-Bit Latch
8
W B
GND
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AS1500 Data Sheet
- Pin Assignments
4 Pin Assignments
Figure 2. Pin Assignments (Top View)
B1 GND 2
8A 7W
AS1500
CSN 3 SDI 4 6 VCC
5 CK
Pin Descriptions
Table 1. Pin Description Pin Name B GND CSN SDI CK VCC W A Pin Number 1 2 3 4 5 6 7 8 Terminal B RDAC Ground Chip Select Input, Active Low. When CSN returns high, data in the serial input register is loaded into the DAC register. Serial Data Input Serial Clock Input, Positive Edge Triggered. Positive power supply, specified for operation at both 3V and 5V. Wiper RDAC Terminal A RDAC Description
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AS1500 Data Sheet
- Absolute Maximum Ratings
5 Absolute Maximum Ratings
(TA = 25º C, unless otherwise noted) Table 2. Absolute Maximum Ratings Parameter VCC to GND VA, VB, VW to GND AX – BX, AX – WX, BX – WX Digital Input and Output Voltage to GND Operating Temperature Range Maximum Junction Temperature (TJ max) Storage Temperature -65 0 -40 Min -0.3 0 ±20 +7 +125 +150 +150 Max +7 VCC Units V V mA V ºC ºC ºC The reflow peak soldering temperature (body temperature) specified is in accordance with IPC/JEDEC J-STD020C “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). (TJ max - TA) / θJA 1 kV HBM MIL-Std883E 3015.7methods. Notes
Package body temperature
+260
ºC
Package Power Dissipation ESD
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AS1500 Data Sheet
- Electrical Characteristics
6 Electrical Characteristics
AS1500 / AS1501 – SPECIFICATIONS
VCC = 3V±10% or 5V±10%, VA = VCC, VB = 0V, –40ºC ≤ TA ≤ +125ºC unless otherwise noted. Table 3. Electrical Characteristics – 10k and 20k Versions Symbol Parameter Conditions Min Typ
1
Max
Units
DC Characteristics Rheostat Mode TA = 25ºC, VCC = 5V, AS1500, Version: 50kΩ TA = 25ºC, VCC = 5V, AS1501, Version: 100kΩ VAB = VCC, Wiper = No Connect VCC = 5V
4
8 16
10 20 500
12 24
kΩ kΩ ppm/ºC
RAB
Nominal Resistance
2
ΔRAB/ΔT RW R-DNL R-INL
Resistance Tempco Wiper Resistance
3
20 -1 -2
100 ±1/4 ±1/2
200 +1 +2
Ω LSB LSB
Resistor Differential NL Resistor Integral NL
RWB, VCC = 5V, VA = No Connect RWB, VCC = 5V, VA = No Connect
DC Characteristics Potentiometer Divider N INL Resolution Integral Nonlinearity VCC = 5.5V TA = 25ºC VCC = 2.7V TA = 25ºC VCC = 5.5V TA = 25ºC VCC = 2.7V TA = 25ºC Code = 80H Code = FFH, VCC = 5.5V Code = 00H, VCC = 5.5V -4 0 -2 -2 -1 -1 8 ±1/2 ±1/2 ±1/4 ±1/4 15 -2.8 1.3 0 2 +2 +2 +1 +1 Bits LSB LSB LSB LSB ppm/ºC LSB LSB
DNL ΔVW /ΔT VWFSE VWFSE
Differential Nonlinearity Voltage Divider Tempco Full-Scale Error Zero-Scale Error
5
Resistor Terminals VA, B, W CA, B CW Voltage Range
6
0 f =1MHz, Measured to GND, Code = 80H f =1MHz, Measured to GND, Code = 80H VCC = 5V VCC = 5V VCC = 3V VCC = 3V VIN = 5V or 0V, VCC = 5V 5 2.1 2.4 75 120
VCC
V pF pF
Capacitance Ax, Bx Capacitance Wx
Digital Inputs and Outputs VIH VIL VIH VIL IIH, IIL CIL VCC IDD IDD Input Logic High Input Logic Low Input Logic High Input Logic Low Input Current Input Capacitance V 0.8 V V 0.6 ±1 V µA pF
Power Supplies Power Supply Range Supply Current (CMOS) VIH = VCC or VIL = 0V, VCC = 5.5V Supply Current (TTL)
7
2.7 0.1 0.9
5.5 1 4
V µA mA
VIH = 2.4V or 0.8V, VCC = 5.5V
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AS1500 Data Sheet
- Electrical Characteristics
Table 3. Electrical Characteristics – 10k and 20k Versions Symbol PDISS Parameter Power Dissipation (CMOS)
8
Conditions VIH = VCC or VIL = 0V, VCC = 5.5V VCC = 5V+0.5VP sine wave @ 1kHz AS1500, Version: 10kΩ AS1501, Version: 20kΩ
Min
Typ
1
Max 27.5
Units µW dB dB
PSSR
Power Supply Suppression Ratio
9
-54 -52
-25 -25
Dynamic Characteristics BW_10k BW_20k THDW tS_10k
Bandwidth –3dB Bandwidth –3dB Total Harmonic Distortion
RWB = 10kΩ, VCC = 5V RWB = 20kΩ, VCC = 5V VA = 1VRMS + 2VDC, VB = 2VDC, f = 1kHz RWB = 5kΩ, VA = VCC, VB = 0V, ±1% Error Band RWB = 10kΩ, VA = VCC, VB = 0V, ±1% Error Band RWB = 5kΩ, f =1kHz RWB = 10kΩ, f =1kHz
1000 500 0.003 2 4 9 13
kHz kHz % µs
VW Settling Time tS_20k eNWB_10k eNWB_20k 1. 2. 3. 4. 5. 6. Resistor Noise Voltage
µs nV/ √ Hz nV/ √ Hz
Typicals represent average readings at 25ºC and VCC = 5V. Wiper is not connected. IAB = 350µA for the 10kΩ version and 175µA for the 20kΩ version. All Tempcos are guaranteed by design and not subject to production test. Terminal A is not connected. IW = 350µA for the 10kΩ version and 175µA for the 20kΩ version. Resistor terminals A, B, W have no limitations on polarity with respect to each other. All capacitances are guaranteed by design and not subject to production test. Resistor-terminal capacitance tests are measured with 2.5V bias on the measured terminal. The remaining resistor terminals are left open circuit. 7. Worst-case supply current consumed when input logic level at 2.4V, standard characteristic of CMOS logic. 8. PDISS is calculated from (IDD×VCC). CMOS logic level inputs result in minimum power dissipation. 9. All dynamic characteristics are guaranteed by design and not subject to production test. All dynamic characteristics use VCC=5V.
AS1502 / AS1503 – SPECIFICATIONS
VCC = 3V±10% or 5V±10%, VA = VCC, VB = 0V, –40ºC ≤ TA ≤ +125ºC unless otherwise noted. Table 4. Electrical Characteristics – 50k and 100k Versions Symbol Parameter Conditions Min Typ
1
Max
Units
DC Characteristics Rheostat Mode TA = 25ºC, VCC = 5V, AS1502, Version: 50kΩ TA = 25ºC, VCC = 5V, AS1503, Version: 100kΩ VAB = VCC, Wiper = No Connect VCC = 5V
4
40 80
50 100 500
60 120
kΩ kΩ ppm/ºC
RAB
Nominal Resistance
2
ΔRAB/ΔT RW R-DNL R-INL
Resistance Tempco Wiper Resistance
3
20 -1 -2
100 ±1/4 ±1/2
200 +1 +2
Ω LSB LSB
Resistor Differential NL Resistor Integral NL
RWB, VCC = 5V, VA = No Connect RWB, VCC = 5V, VA = No Connect
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AS1500 Data Sheet
- Electrical Characteristics
Table 4. Electrical Characteristics – 50k and 100k Versions Symbol Parameter Conditions Min Typ
1
Max
Units
DC Characteristics Potentiometer Divider N INL Resolution Integral Nonlinearity VCC = 5.5V TA = 25ºC VCC = 2.7V TA = 25ºC VCC = 5.5V TA = 25ºC VCC = 2.7V TA = 25ºC Code = 80H Code = FFH, VCC= 5.5V Code = 00H, VCC = 5.5V -1 0 -4 -4 -1 -1 8 ±1 ±1 ±1/4 ±1/4 15 -0.25 0.1 0 1 +4 +4 +1 +1 Bits LSB LSB LSB LSB ppm/ºC LSB LSB
DNL ΔVW /ΔT VWFSE VWFSE
Differential Nonlinearity Voltage Divider Tempco Full-Scale Error Zero-Scale Error
5
Resistor Terminals VA, B, W CA, B CW Voltage Range
6
0 f =1MHz, Measured to GND, Code = 80H f =1MHz, Measured to GND, Code = 80H VCC = 5V VCC = 5V VCC = 3V VCC = 3V VIN = 5V or 0V, VCC = 5V 5 2.1 2.4 15 80
VCC
V pF pF
Capacitance Ax, Bx Capacitance Wx
Digital Inputs and Outputs VIH VIL VIH VIL IIH, IIL CIL VCC IDD IDD PDISS Input Logic High Input Logic Low Input Logic High Input Logic Low Input Current Input Capacitance V 0.8 V V 0.6 ±1 V µA pF
Power Supplies Power Supply Range Supply Current (CMOS) VIH = VCC or VIL = 0V, VCC = 5.5V Supply Current (TTL) Power Dissipation (CMOS)
8 7
2.7 0.1 0.9
5.5 1 4 27.5 -43 -52
V µA mA µW dB dB
VIH = 2.4V or 0.8V, VCC = 5.5V VIH = VCC or VIL = 0V, VCC = 5.5V AS1502, Version: 50kΩ AS1503, Version: 100kΩ
PSSR
Power Supply Suppression Ratio
9
VCC = 5V+0.5VP sine wave @ 1kHz
Dynamic Characteristics BW_50k BW_100k THDW
Bandwidth –3dB Bandwidth –3dB Total Harmonic Distortion
RWB = 50kΩ, VCC = 5V RWB = 100kΩ, VCC = 5V VA = 1VRMS + 2VDC, VB = 2VDC, f = 1kHz
220 110 0.003
kHz kHz %
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AS1500 Data Sheet
- Electrical Characteristics
Table 4. Electrical Characteristics – 50k and 100k Versions Symbol tS_50k VW Settling Time tS_100k eNWB_50k eNWB_100k 1. 2. 3. 4. 5. 6. Resistor Noise Voltage Parameter Conditions RWB = 50kΩ, VA = VCC, VB = 0V, ±1% Error Band RWB = 100kΩ, VA = VCC, VB = 0V, ±1% Error Band RWB = 50kΩ, f =1kHz RWB = 100kΩ, f =1kHz Min Typ 9 18 20 29
1
Max
Units µs
µs nV/ √ Hz nV/ √ Hz
Typicals represent average readings at 25ºC and VCC = 5V. Wiper is not connected. IAB = 70µA for the 50kΩ version and 35µA for the 100kΩ version. All Tempcos are guaranteed by design and not subject to production test. Terminal A is not connected. IW = 70µA for the 50kΩ version and 35µA for the 100kΩ version. Resistor terminals A, B, W have no limitations on polarity with respect to each other. All capacitances are guaranteed by design and not subject to production test. Resistor-terminal capacitance tests are measured with 2.5V bias on the measured terminal. The remaining resistor terminals are left open circuit. 7. Worst-case supply current consumed when input logic level at 2.4V, standard characteristic of CMOS logic. 8. PDISS is calculated from (IDD×VCC). CMOS logic level inputs result in minimum power dissipation. 9. All dynamic characteristics are guaranteed by design and not subject to production test. All dynamic characteristics use VCC=5V.
AS150x – SPECIFICATIONS
VCC = 3V±10% or 5V±10%, VA = VCC, VB = 0V, –40ºC ≤ TA ≤ +125ºC unless otherwise noted. Table 5. Switching Characteristics Symbol Parameter
23
Conditions
Min
Typ
1
Max
Unit
Switching Characteristics tCH, tCL tDS tDH tCSS tCSWH tCSWL tCSH tCS1
Input Clock Pulsewidth Data Setup Time Data Hold Time CSN Setup Time CSN High Pulsewidth CSN Low Pulsewidth CK Fall to CSN Rise Hold Time CSN Rise to Clock Rise Setup
Clock Level High or Low
50 5 5 10 10 100 0 10
ns ns ns ns ns ms ns ns
1. Typicals represent average readings at 25ºC and VCC=5V. 2. Guaranteed by design and not subject to production test. Resistor-terminal capacitance tests are measured with 2.5V bias on the measured terminal. The remaining resistor terminals are left open circuit. 3. See timing diagram for location of measured values. All input control voltages are specified with tR = tF = 1ns (10% to 90% of VCC) and timed from a voltage level of 1.6V. Switching characteristics are measured using VCC=3V or 5V. To avoid false clocking, a minimum input logic slew rate of 1V/µs should be maintained.
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AS1500 Data Sheet
- Detailed Description
7 Detailed Description
Serial-Programming
Programming of the AS150x is done via the 3 wire serial interface. The three input signals are serial data input (SDI), clock(CK) and chip select (CSN). A programming sequence consists of 10-bit, where the last eight bit contain the code word for the resistor value. The first two bits A1 and A0 have to be low to program the resistor value (see Table 6). Otherwise the resistor value is not affected. The data is shifted into the internal 10 Bit register with the rising edge of the CK signal. With the rising edge of the CSN signal the data become valid and the resistance is updated (see Figure 3). A detailed block diagram is shown in Figure 4. Table 6. Serial data format (10 bits) A1 0 A0 0 D7 MSB D6 D5 D4 D3 Data D2 D1 D0 LSB
Figure 3. Timing Diagram 1 SDI 0 CK 1 0 1 CSN 0 VCC VOUT 0V DAC Register Load A1 A0 D7 D6 D5 D4 D3 D2 D1 D0
Figure 4. Detailed Timing Diagram
1
SDI
0
Ax or Dx
Ax or Dx tD tCH tD
tCS1
1
CK
0
tCL
1
tCSH tCSWH tS
tCSS tCSWL
CSN
0 VCC
VOUT
± 1% Error Band
0V
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AS1500 Data Sheet
- Detailed Description
Rheostat Operation
The digital potentiometer family AS150x offers nominal resistor values of 10kΩ, 20kΩ, 50kΩ and 100kΩ. The resistor has 256 contact points where the wiper can access the resistor. The 8-bit code word determines the position of the wiper and is decoded through an internal logic. The lowest code 00h is related to the terminal B. The resistance is then only determined by the wiper resistance (100Ω). The resistance for the next code 01h is the nominal resistor RAB (10kΩ, 20kΩ, 50kΩ or 100kΩ) divided through 256 plus the wiper resistor. In case of AS1501 (10kΩ) the total resistance is 39Ω+100Ω=139Ω. Accordingly the resistor for code 02h is 78Ω+100Ω=178Ω. The last code 255h does not connect to terminal A directly (see Figure 5). So the maximum value is 10000Ω - 39Ω +100Ω = 10061Ω. The general formula for the calculation of the resistance RWB is: RWB (Dx)= (Dx)/256 • RAB + RW (EQ 1)
where RAB is the nominal resistance between terminal A and B, RW is the wiper resistance and DX is the 8-Bit Code word. In Table 7 the resistor values between the wiper and terminal B for AS1500 are given for specific codes DX. In the zero-scale condition the wiper resistance of 100Ω remains present. Table 7. RDAC-Codes WB DX (Dec) 255 128 1 0 RWB (Ω) 10061 5100 139 100 Output State Full Scale Midscale 1 LSB Zero-Scale (Wiper Contact Resistance)
The maximum current through the wiper and terminal B is 5mA. If the current exceeds this limit the internal switches can degrade or even be damaged. As a mechanical potentiometer the resistances RWA and RWB are totally symmetrical. The relation between them is shown in Figure 5. Figure 5. RWA and RWB versa code 10 RWA, RWB - % of Nominal RAB RWA 75 RWB
50
25
0 0 64 12 19 25 CODE - Decimal
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AS1500 Data Sheet
- Detailed Description
The resistance RWA is the complimentary resistor to RWB and can be controlled digitally as well. RWA starts at the maximum value of the nominal resistance and is reduced with increasing 8-Bit code words. The formula to calculate RWA is given below: RWA (Dx)= (256 - Dx)/256 • RAB + RW (EQ 2)
where RAB is the nominal resistance between terminal A and B, RW is the wiper resistance and Dx is the 8-Bit Code word. In Table 8 the resistor values between the wiper and terminal B for AS1500 are given for specific codes Dx. Table 8. RDAC-Codes WA DX (Dec) 255 128 1 0 Figure 6. Equivalent RDAC Circuit RWA (Ω) 89 5050 10011 10050 Output State Full Scale Midscale 1 LSB Zero-Scale
A Rs D7 D6 D5 D4 D3 D2 D1 D0 RDAC LATCH AND DECODE W Rs Rs
Rs Rs=RNOMINAL/256 B
Voltage Output Operation
The AS150x family can easily used in an voltage output mode, where the output voltage is proportional to an applied voltage to a given terminal. When 5V are applied to terminal A and B is set to ground the ouput voltage at the wiper starts at zero volts up to 1LSB less then 5V. One LSB of voltage corresponds to the voltage applied at terminal AB divided through 256 steps of possible wiper settings. The formula is given by VW (Dx)= (Dx)/256 • VAB + VB (EQ 3)
where VAB is the voltage applied between terminal A and B, VW is the voltage at the wiper, Dx is the 8-Bit Code word and VB is the voltage at terminal B. The temperature drift is significant better than in Rheostat mode, since the temperature coefficient is determined by the internal resistor ratio. Therefore the temperature drift is only 15ppm/°C.
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AS1500 Data Sheet
- Detailed Description
Applications
The digital potentiometer can replace in many applications the analog trimming potentiometer. The digital potentiometer is not sensitive to vibrations and shocks. It has an extremely small form-factor and can be adjusted very fast (e.g. AS1500 has an update rate of 600kHz). Furthermore the temperature drift, resolution and noise are significant better and cannot be achieved with a mechanical trimming potentiometer. Due to the programmability the resistor settings can be stored in the system memory, so that after a power down the exact settings can be recalled easily. All analog signals must remain within 0 to VCC range. For standard potentiometer applications the wiper output can be used directly. In the case of a low impedance load, a buffer shall be used.
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AS1500 Data Sheet
- Package Drawings and Markings
8 Package Drawings and Markings
Figure 7. 8-pin SOIC Package
Notes: 1. Lead coplanarity should be 0 to 0.10mm (.004”) max. 2. Package surface finishing: (2.1) Top: matte (charmilles #18-30). (2.2) All sides: matte (charmilles #18-30). (2.3) Bottom: smooth or matte (charmilles #18-30). 3. All dimensions exclusive of mold flash, and end flash from the package body shall not exceed 0.24mm (0.10”) per side (D). 4. Details of pin #1 identifier are optional but must be located within the zone indicated.
Symbol
A1 B C D E e H h L A ZD A2
Min
0.10 0.36 0.19 4.80 3.81 1.27BSC 5.80 0.25 .041 1.52 0º 0.53REF 1.37
Max
0.25 0.46 0.25 4.98 3.99 6.20 0.50 1.27 1.72 8º 1.57
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AS1500 Data Sheet
- Ordering Information
9 Ordering Information
Table 9. Model AS1500 AS1501 AS1502 AS1503 AS1500-T AS1501-T AS1502-T AS1503-T 10kΩ 20kΩ 50kΩ 100kΩ 10kΩ 20kΩ 50kΩ 100kΩ Resistor Delivery Form Tubes Tubes Tubes Tubes T&R T&R T&R T&R Package 8-pin SOIC 8-pin SOIC 8-pin SOIC 8-pin SOIC 8-pin SOIC 8-pin SOIC 8-pin SOIC 8-pin SOIC Description 8-bit Digital Potentiometer 8-bit Digital Potentiometer 8-bit Digital Potentiometer 8-bit Digital Potentiometer 8-bit Digital Potentiometer 8-bit Digital Potentiometer 8-bit Digital Potentiometer 8-bit Digital Potentiometer
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AS1500 Data Sheet
- Ordering Information
Copyrights
Copyright © 1997-2008, austriamicrosystems AG, Schloss Premstaetten, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered ®. All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. All products and companies mentioned are trademarks or registered trademarks of their respective companies.
Disclaimer
Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. austriamicrosystems AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. austriamicrosystems AG reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with austriamicrosystems AG for current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are specifically not recommended without additional processing by austriamicrosystems AG for each application. For shipments of less than 100 parts the manufacturing flow might show deviations from the standard production flow, such as test flow or test location. The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However, austriamicrosystems AG shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of austriamicrosystems AG rendering of technical or other services.
Contact Information
Headquarters austriamicrosystems AG A-8141 Schloss Premstaetten, Austria Tel: +43 (0) 3136 500 0 Fax: +43 (0) 3136 525 01
For Sales Offices, Distributors and Representatives, please visit: http://www.austriamicrosystems.com/contact-us
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