参数资料
| 型号： | ISL90727UIE627Z |
| 厂商： | Intersil |
| 文件页数： | 6/8页 |
| 文件大小： | 0K |
| 描述： | IC XDCP 128-TAP 50KOHM SC70-6 |
| 产品培训模块： | Digitally Controlled Potentiometers |
| 标准包装： | 1 |
| 系列： | XDCP™ |
| 接片： | 128 |
| 电阻（欧姆）： | 50k |
| 电路数： | 1 |
| 温度系数： | 标准值 ±45 ppm/°C |
| 存储器类型： | 易失 |
| 接口： | I²C |
| 电源电压： | 2.7 V ~ 5.5 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 6-TSSOP，SC-88，SOT-363 |
| 供应商设备封装： | SC-70-6 |
| 包装： | 管件 |
6
FN8247.8
May 10, 2012
Principles of Operation
The ISL90727 and ISL90728 are integrated circuits
incorporating one DCP with its associated registers and an
I2C serial interface providing direct communication between
a host and the potentiometer.
DCP Description
The DCP is implemented with a combination of resistor
elements and CMOS switches. The physical ends of the DCP
are equivalent to the fixed terminals of a mechanical
potentiometer (RH and RL pins). The RW pin of the DCP is
connected to intermediate nodes, and is equivalent to the wiper
terminal of a mechanical potentiometer. The position of the
wiper terminal within the DCP is controlled by a 7-bit volatile
Wiper Register (WR). The DCP has its own WR. When the WR
of the DCP contains all zeroes (WR<6:0> = 00h), its wiper
terminal (RW) is closest to its “Low” terminal (RL). When the
WR of the DCP contains all ones (WR<6:0> = 7Fh), its wiper
terminal (RW) is closest to its “High” terminal (RH). As the value
of the WR increases from all zeroes (00h) to all ones (127
decimal), the wiper moves monotonically from the position
closest to RL to the position closest to RH. At the same time,
the resistance between RW and RL increases monotonically,
while the resistance between RH and RW decreases
monotonically. RL is connected to the GND pin of the device, so
the wiper movement will always be relative to RL.
While the ISL90727 and ISL90728 are being powered up,
the WR is reset to 40h (64 decimal), which locates RW
roughly at the center between RL and RH.
The WR and IVR can be read or written directly using the
I2C serial interface as described in the following sections.
I2C Serial Interface
The ISL90727 and ISL90728 support bidirectional bus
oriented protocol. The protocol defines any device that
sends data onto the bus as a transmitter and the receiving
device as the receiver. The device controlling the transfer is
a master and the device being controlled is the slave. The
master always initiates data transfers and provides the clock
for both transmit and receive operations. Therefore, the
ISL90727 and ISL90728 operate as slave devices in all
applications.
All communication over the I2C interface is conducted by
sending the MSB of each byte of data first.
Protocol Conventions
Data states on the SDA line can change only during SCL
LOW periods. SDA state changes during SCL HIGH are
reserved for indicating START and STOP conditions (see
Figure 1). On power-up of the ISL90727 and ISL90728, the
SDA pin is in the input mode.
All I2C interface operations must begin with a START condition,
which is a HIGH to LOW transition of SDA while SCL is HIGH.
The ISL90727 and ISL90728 continuously monitor the SDA
and SCL lines for the START condition and do not respond to
any command until this condition is met (see Figure 1). A
START condition is ignored during the power-up sequence and
during internal non-volatile write cycles.
All I2C interface operations must be terminated by a STOP
condition, which is a LOW to HIGH transition of SDA while
SCL is HIGH (see Figure 1).
An ACK, Acknowledge, is a software convention used to
indicate a successful data transfer. The transmitting device,
either master or slave, releases the SDA bus after
transmitting 8 bits. During the ninth clock cycle, the receiver
pulls the SDA line LOW to acknowledge the reception of the
eight bits of data (see Figure 2).
The ISL90727 and ISL90728 respond with an ACK after
recognition of a START condition followed by a valid
Identification Byte, and once again after successful receipt of
an Address Byte. The ISL90727 and ISL90728 also respond
with an ACK after receiving a Data Byte of a write operation.
The master must respond with an ACK after receiving a Data
Byte of a read operation.
A valid Identification Byte contains 0101110 as the seven
MSBs for the ISL90727 and 0111110 as the seven MSBs for
the ISL90728. The LSB in the Read/Write bit. Its value is “1”
for a Read operation, and “0” for a Write operation (see
Table 1).
Write Operation
A Write operation requires a START condition, followed by a
valid Identification Byte, a valid Address Byte, a Data Byte,
and a STOP condition. After each of the three bytes, the
ISL90727 and ISL90728 respond with an ACK. At this time,
the device enters its standby state (see Figure 3).
Data Protection
A valid Identification Byte, Address Byte, and total number of
SCL pulses act as a protection of both volatile and
non-volatile registers. During a Write sequence, the Data
Byte is loaded into an internal shift register as it is received.
If the Address Byte is 0, the Data Byte is transferred to the
Wiper Register (WR) at the falling edge of the SCL pulse
that loads the last bit (LSB) of the Data Byte. If an address
other than 00h or an invalid slave address is sent, then the
device will respond with no ACK.
Read Operation
A Read operation consist of a three byte instruction followed
by one or more Data Bytes (See Figure 4). The master
initiates the operation issuing the following sequence: a
TABLE 1. IDENTIFICATION BYTE FORMAT
ISL90727
0
1
0
1
0
R/W
ISL90728
0
1
0
R/W
MSB
LSB
ISL90727, ISL90728
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相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL90727UIE627Z-TK | 功能描述:IC POT DGTL 50K OHM SC70-6 RoHS:是 类别:集成电路 (IC) >> 数据采集 - 数字电位器 系列:XDCP™ 标准包装:3,000 系列:DPP 接片:32 电阻（欧姆）:10k 电路数:1 温度系数:标准值 300 ppm/°C 存储器类型:非易失 接口:3 线串行（芯片选择，递增，增/减） 电源电压:2.5 V ~ 6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:8-WFDFN 裸露焊盘 供应商设备封装:8-TDFN（2x3） 包装:带卷 (TR) |
| ISL90727UIE6Z | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Digitally Controlled Potentiometer (XDCP) |
| ISL90727UIE6Z-TK | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Digitally Controlled Potentiometer (XDCP) |
| ISL90727WIE627Z | 功能描述:IC XDCP 128-TAP 10KOHM SC70-6 RoHS:是 类别:集成电路 (IC) >> 数据采集 - 数字电位器 系列:XDCP™ 标准包装:2,500 系列:XDCP™ 接片:256 电阻（欧姆）:100k 电路数:1 温度系数:标准值 ±300 ppm/°C 存储器类型:非易失 接口:I²C（设备位址） 电源电压:2.7 V ~ 5.5 V 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:14-TSSOP（0.173"，4.40mm 宽） 供应商设备封装:14-TSSOP 包装:带卷 (TR) |
| ISL90727WIE627ZS2568 | 制造商:Intersil Corporation 功能描述:- Bulk |
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