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参数资料
| 型号： | DS1874T+T&R |
| 厂商： | Maxim Integrated |
| 文件页数： | 27/88页 |
| 文件大小： | 0K |
| 描述： | IC CTLR SFP+ ANLG LDD 28-TQFN |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 类型： | 激光二极管控制器 |
| 通道数： | 1 |
| 电源电压： | 2.85 V ~ 3.9 V |
| 电流 - 电源： | 2.5mA |
| 工作温度： | -40°C ~ 95°C |
| 封装/外壳： | 28-WFQFN 裸露焊盘 |
| 供应商设备封装： | 28-TQFN-EP（5x5） |
| 包装： | 带卷 (TR) |
| 安装类型： | 表面贴装 |
| 其它名称： | 90-1874T+TRL |
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SFP+ Controller with Digital LDD Interface
sequence or as an indication that the device is not
receiving data.
Byte write: A byte write consists of 8 bits of informa-
tion transferred from the master to the slave (most
significant bit first) plus a 1-bit acknowledgement
from the slave to the master. The 8 bits transmitted
by the master are done according to the bit-write
definition and the acknowledgement is read using
the bit-read definition.
Byte read: A byte read is an 8-bit information trans-
fer from the slave to the master plus a 1-bit ACK or
NACK from the master to the slave. The 8 bits of
information that are transferred (most significant bit
first) from the slave to the master are read by the
master using the bit-read definition, and the master
transmits an ACK using the bit-write definition to
receive additional data bytes. The master must
NACK the last byte read to terminate communication
so the slave returns control of SDA to the master.
Slave address byte: Each slave on the I 2 C bus
responds to a slave address byte sent immediately
following a START condition. The slave address byte
contains the slave address in the most significant 7
bits and the R/ W bit in the least significant bit.
The DS1874 responds to two slave addresses. The
auxiliary memory always responds to a fixed I 2 C
slave address, A0h. The Lower Memory and Tables
00h–08h respond to I 2 C slave addresses that can
be configured to any value between 00h–FEh using
the DEVICE ADDRESS byte (Table 02h, Register
8Ch). The user also must set the ASEL bit (Table
02h, Register 89h) for this address to be active. By
writing the correct slave address with R/ W = 0, the
master indicates it will write data to the slave. If R/ W
= 1, the master reads data from the slave. If an
incorrect slave address is written, the DS1874
assumes the master is communicating with another
I 2 C device and ignores the communications until the
next START condition is sent. If the main device’s
slave address is programmed to be A0h, access to
the auxiliary memory is disabled.
Memory address: During an I 2 C write operation to
the DS1874, the master must transmit a memory
address to identify the memory location where the
slave is to store the data. The memory address is
always the second byte transmitted during a write
operation following the slave address byte.
I 2 C Protocol
Writing a single byte to a slave: The master must
generate a START condition, write the slave address
byte (R/ W = 0), write the memory address, write the
byte of data, and generate a STOP condition.
Remember the master must read the slave ’s
acknowledgement during all byte-write operations.
Writing multiple bytes to a slave: To write multiple
bytes to a slave, the master generates a START con-
dition, writes the slave address byte (R/ W = 0),
writes the memory address, writes up to 8 data
bytes, and generates a STOP condition. The
DS1874 writes 1 to 8 bytes (one page or row) with a
single write transaction. This is internally controlled
by an address counter that allows data to be written
to consecutive addresses without transmitting a
memory address before each data byte is sent. The
address counter limits the write to one 8-byte page
(one row of the memory map). Attempts to write to
additional pages of memory without sending a STOP
condition between pages results in the address
counter wrapping around to the beginning of the
present row.
For example, a 3-byte write starts at address 06h
and writes 3 data bytes (11h, 22h, and 33h) to three
“consecutive” addresses. The result is that address-
es 06h and 07h would contain 11h and 22h, respec-
tively, and the third data byte, 33h, would be written
to address 00h.
To prevent address wrapping from occurring, the
master must send a STOP condition at the end of
the page, then wait for the bus-free or EEPROM
write time to elapse. Then the master can generate a
new START condition and write the slave address
byte (R/ W = 0) and the first memory address of the
next memory row before continuing to write data.
Acknowledge polling: Any time a EEPROM page is
written, the DS1874 requires the EEPROM write time
(t W ) after the STOP condition to write the contents of
the page to EEPROM. During the EEPROM write
time, the DS1874 will not acknowledge its slave
address because it is busy. It is possible to take
advantage of that phenomenon by repeatedly
addressing the DS1874, which allows the next page
to be written as soon as the DS1874 is ready to
receive the data. The alternative to acknowledge
polling is to wait for maximum period of t W to elapse
before attempting to write again to the DS1874.
EEPROM write cycles: When EEPROM writes occur,
the DS1874 writes the whole EEPROM memory page,
even if only a single byte on the page was modified.
Writes that do not modify all 8 bytes on the page are
allowed and do not corrupt the remaining bytes of
memory on the same page. Because the whole page
is written, bytes on the page that were not modified
during the transaction are still subject to a write
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相关代理商/技术参数 |
参数描述 |
|---|---|
| DS1875 | 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:PON Triplexer and SFP Controller |
| DS1875RT+ | 制造商:Maxim Integrated Products 功能描述:PON TRIPLEXER AND SFP CONTROLLER - Rail/Tube |
| DS1875RT+T&R | 制造商:Maxim Integrated Products 功能描述:PON TRIPLEXER AND SFP CONTROLLER - Tape and Reel |
| DS1875T+ | 功能描述:ADC / DAC多通道 PON Triplexer & SFP Controller RoHS:否 制造商:Texas Instruments 转换速率: 分辨率:8 bit 接口类型:SPI 电压参考: 电源电压-最大:3.6 V 电源电压-最小:2 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-40 |
| DS1875T+T&R | 制造商:Maxim Integrated Products 功能描述:PON TRIPLEXER 38TQFN EP - Tape and Reel 制造商:Maxim Integrated Products 功能描述:IC SFP CTRLR/TRIPLEXER 38-TQFN 制造商:Maxim Integrated Products 功能描述:ADC / DAC Multichannel PON Triplexer & SFP Controller |
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