AD5171 View Datasheet(PDF) - Analog Devices
Part Name
Description
Manufacturer
AD5171 Datasheet PDF : 24 Pages
| |||
AD5171
CONTROLLING THE AD5171
There are two ways of controlling the AD5171. Users can either
program the devices with computer software or employ external
I2C controllers.
SOFTWARE PROGRAMMING
Due to the advantage of the one-time programmable feature,
users may consider programming the device in the factory
before shipping it to the end users. Analog Devices offers device
programming software that can be implemented in the factory
on PCs running Windows 95 to Windows XP platforms. As a
result, external controllers are not required, which significantly
reduces development time.
The program is an executable file that does not require the user
to know any programming languages or programming skills. It
is easy to set up and use. Figure 32 shows the software interface.
The software can be downloaded from the AD5171 product page.
Figure 32. Software Interface
Write
The AD5171 starts at midscale after power-up prior to the OTP
programming. To increment or decrement the resistance, move
the scrollbar on the left. To write any specific values, use the bit
pattern control in the upper screen and click Run. The format
of writing data to the device is shown in Table 8. Once the
desired setting is found, click Program Permanent to blow the
internal fuse links for permanent setting. The user can also set
the programming bit pattern in the upper screen and click Run
to achieve the same result.
Read
To read the validation bits and data from the device, click Read.
The user may also set the bit pattern in the upper screen and
click Run. The format of reading data out from the device is
shown in Table 9.
DEVICE PROGRAMMING
To apply the device programming software in the factory, users
need to modify a parallel port cable and configure Pin 2, Pin 3,
Pin 15, and Pin 25 for SDA_write, SCL, SDA_read, and DGND,
respectively, for the control signals (see Figure 33). In addition,
lay out the PCB of the AD5171 with SCL and SDA pads, as
shown in Figure 34, such that pogo pins can be inserted for the
factory programming.
13
25
12
24
11
23
10
22
9
21
8
20
7
19
6
18
5
17
R3
4
100Ω
SCL
16
3
R2 READ
100Ω
SDA
15
2
R1 WRITE
14
100Ω
1
Figure 33. Parallel Port Connection: Pin 2 = SDA_write, Pin 3 = SCL,
Pin 15 = SDA_read, and Pin 25 = DGND
W
VDD
GND
SCL
A
B
AD0
SDA
Figure 34. Recommended AD5171 PCB Layout
Table 8. SDA Write Mode Bit Format
S 0 1 0 1 1 0 AD0 0 A T X X X X X X X A X X D5 D4 D3 D2 D1 D0 A P
Slave Address Byte
Instruction Byte
Data Byte
Table 9. SDA Read Mode Bit Format
S 0 1 0 1 1 0 AD0
Slave Address Byte
1 A E1 E0 D5 D4 D3 D2 D1 D0 A P
Data Byte
Rev. D | Page 16 of 24
Share Link: 