Datenblatt-pdf.com


AD5171 Schematic ( PDF Datasheet ) - Analog Devices

Teilenummer AD5171
Beschreibung 64-Position OTP Digital Potentiometer
Hersteller Analog Devices
Logo Analog Devices Logo 




Gesamt 24 Seiten
AD5171 Datasheet, Funktion
64-Position OTP Digital Potentiometer
AD5171
FEATURES
64 position
One-time programmable (OTP) set-and-forget resistance
setting—low cost alternative over EEMEM
Unlimited adjustments prior to OTP activation
5 kΩ, 10 kΩ, 50 kΩ, 100 kΩ end-to-end resistance
Low temperature coefficient: 5 ppm/°C in potentiometer mode
Low temperature coefficient: 35 ppm/°C in rheostat mode
Compact standard 8-lead SOT-23 package
Low power: IDD = 10 μA maximum
Fast settling time: tS = 5 μs typical in power-up
I2C-compatible digital interface
Computer software replaces microcontroller in factory
programming applications
Full read/write of wiper register
Extra I2C device address pin
Low operating voltage: 2.7 V to 5.5 V
OTP validation check function
Automotive temperature range: −40°C to +125°C
APPLICATIONS
System calibrations
Electronics level settings
Mechanical trimmers and potentiometer replacements
Automotive electronics adjustments
Gain control and offset adjustments
Transducer circuit adjustments
Programmable filters up to 1.5 MHz BW1
GENERAL DESCRIPTION
The AD5171 is a 64-position, one-time programmable (OTP)
digital potentiometer2 that uses fuse link technology to achieve
the memory retention of the resistance setting function. OTP is
a cost-effective alternative over the EEMEM approach for users
who do not need to reprogram new memory settings in the
digital potentiometer. This device performs the same electronic
adjustment function as most mechanical trimmers and variable
resistors. The AD5171 is programmed using a 2-wire, I2C®-
compatible digital control. It allows unlimited adjustments
before permanently setting the resistance value. During the
OTP activation, a permanent fuse blown command is sent after the
final value is determined, freezing the wiper position at a given
setting (analogous to placing epoxy on a mechanical trimmer).
FUNCTIONAL BLOCK DIAGRAM
SCL
SDA
I2C INTERFACE
AND
CONTROL LOGIC
A
W
AD0 B
VDD
GND
FUSE
LINK
WIPER
REGISTER
AD5171
Figure 1.
W1
8A
VDD 2 AD5171 7 B
GND
3
TOP VIEW
(Not to Scale)
6
AD0
SCL 4
5 SDA
Figure 2. Pin Configuration
When this permanent setting is achieved, the value does not
change regardless of supply variations or environmental stresses
under normal operating conditions. To verify the success of
permanent programming, Analog Devices, Inc., patterned the
OTP validation such that the fuse status can be discerned from
two validation bits in read mode.
For applications that program the AD5171 in factories, Analog
Devices offers device programming software that operates
across Windows® 95 to XP platforms, including Windows NT.
This software application effectively replaces the need for external
I2C controllers or host processors and, therefore, significantly
reduces the development time of the users.
An AD5171 evaluation kit includes the software, connector, and
cable that can be converted for factory programming applications.
The AD5171 is available in a compact 8-lead SOT-23 package.
All parts are guaranteed to operate over the automotive temper-
ature range of −40°C to +125°C. Besides its unique OTP feature,
the AD5171 lends itself well to other general-purpose digital
potentiometer applications due to its temperature performance,
small form factor, and low cost.
1 Applies to 5 kΩ parts only.
2 The terms digital potentiometer and RDAC are used interchangeably.
Rev. D
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarksandregisteredtrademarksarethepropertyoftheirrespectiveowners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113 ©2004–2008 Analog Devices, Inc. All rights reserved.






AD5171 Datasheet, Funktion
AD5171
ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter
VDD to GND
VA, VB, and VW to GND
Maximum Current
IWB, IWA Pulsed
IWB Continuous (RWB ≤ 1 kΩ, A Open)1
IWA Continuous (RWA ≤ 1 kΩ, B Open)1
Digital Inputs and Output Voltage to GND
Operating Temperature Range
Maximum Junction Temperature (TJ max)
Storage Temperature Range
Reflow Soldering
Peak Temperature
Time at Peak Temperature
Thermal Resistance θJA2
Rating
−0.3 V to +7 V
GND to VDD
±20 mA
±5 mA
±5 mA
0 V to VDD
−40°C to +125°C
150°C
−65°C to +150°C
260°C
20 sec to 40 sec
230°C/W
1 Maximum terminal current is bounded by the maximum applied voltage
across any two of the A, B, and W terminals at a given resistance; the
maximum current handling of the switches, and the maximum power
dissipation of the package. VDD = 5 V.
2 Package power dissipation = (TJ max – TA)/θJA.
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
ESD CAUTION
Rev. D | Page 6 of 24

6 Page









AD5171 pdf, datenblatt
AD5171
THEORY OF OPERATION
SCL
SDA
I2C INTERFACE
DAC
REG.
MUX
DECODER
COMPARATOR
ONE-TIME
PROGRAM/TEST
CONTROL BLOCK
FUSES
EN
FUSE
REG.
A
W
B
Figure 25. Detailed Functional Block Diagram
The AD5171 allows unlimited 6-bit adjustments, except for the
one-time programmable, set-and-forget resistance setting. OTP
technology is a proven, cost-effective alternative over EEMEM
in one-time memory programming applications. The AD5171
employs fuse link technology to achieve the memory retention
of the resistance setting function. It has six data fuses that control
the address decoder for programming the RDAC, one user
mode test fuse for checking setup error, and one programming
lock fuse for disabling any further programming once the data
fuses are blown.
ONE-TIME PROGRAMMING (OTP)
Prior to OTP activation, the AD5171 presets to midscale during
initial power-on. After the wiper is set at the desired position,
the resistance can be permanently set by programming the T bit
high along with the proper coding (see Table 8 and Table 9) and
one-time VDD_OTP. The fuse link technology of the AD517x
family of digital potentiometers requires VDD_OTP between 4.75 V
and 5.25 V to blow the fuses to achieve a given nonvolatile
setting. On the other hand, VDD can be 2.7 V to 5.5 V during
operation. As a result, a system supply that is lower than 4.75 V
requires external supply for OTP. In addition, the user is only
allowed one attempt in blowing the fuses. If the user fails to
blow the fuses at the first attempt, the fuse structures may change
so that they may never be blown regardless of the energy applied
at subsequent events. For details, see the Power Supply
Considerations section.
The device control circuit has two validation bits, E1 and E0,
that can be read back to check the programming status (see
Table 5). Users should always read back the validation bits to
ensure that the fuses are properly blown. After the fuses are
blown, all fuse latches are enabled upon subsequent power-on;
therefore, the output corresponds to the stored setting.
Table 5. Validation Status
E1 E0 Status
0 0 Ready for programming.
0 1 Test fuse not blown successfully. For factory setup
checking purpose only. Users should not see these
combinations.
1 0 Fatal error. Some fuses are not blown. Do not retry.
Discard the unit.
1 1 Successful. No further programming is possible.
This section discusses the fuse operation in detail. When the
OTP T bit is set, the internal clock is enabled. The program then
attempts to blow a test fuse. The operation stops if the test fuse
is not properly blown. The validation bits, E1 and E0, show 01.
This status is intended for factory setup checking purposes
only; users should not see this status. If the test fuse is properly
blown, the data fuses can be programmed. The six data fuses
are programmed in six clock cycles. The output of the fuses is
compared with the code stored in the RDAC register. If they do
not match, E1 and E0 of 10 are issued as fatal errors and the
operation stops. Users should never try blowing the fuses more
than once because the fuse structure may have changed prohibiting
further programming. As a result, the unit must be discarded.
This error status can also occur if the OTP supply voltage goes
above or drops below the VDD_OTP requirement, the OTP supply
current is limited, or both the voltage and current ramp times
are slow. If the output and stored code match, the programming
lock fuse is blown so that no further programming is possible.
In the meantime, E1 and E0 issue 11, indicating the lock fuse is
properly blown. All the fuse latches are enabled at power-on;
therefore, from this point on, the output corresponds to the
stored setting. Figure 25 shows a detailed functional block
diagram.
Rev. D | Page 12 of 24

12 Page





SeitenGesamt 24 Seiten
PDF Download[ AD5171 Schematic.PDF ]

Link teilen




Besondere Datenblatt

TeilenummerBeschreibungHersteller
AD5170I2C Digital PotentiometerAnalog Devices
Analog Devices
AD517164-Position OTP Digital PotentiometerAnalog Devices
Analog Devices
AD5172Dual-Channel I2C Digital PotentiometersAnalog Devices
Analog Devices
AD5173Dual-Channel I2C Digital PotentiometersAnalog Devices
Analog Devices
AD5174Digital Rheostat With SPI Interface And 50-TP MemoryAnalog Devices
Analog Devices

TeilenummerBeschreibungHersteller
CD40175BC

Hex D-Type Flip-Flop / Quad D-Type Flip-Flop.

Fairchild Semiconductor
Fairchild Semiconductor
KTD1146

EPITAXIAL PLANAR NPN TRANSISTOR.

KEC
KEC


www.Datenblatt-PDF.com       |      2020       |      Kontakt     |      Suche