參數(shù)資料
型號(hào)： DS1878T+T&R
廠商： Maxim Integrated Products
文件頁(yè)數(shù)： 8/101頁(yè)
文件大?。?/td> 0K
描述： IC CTLR SFP W/DGTL LDD RX 28TQFN
標(biāo)準(zhǔn)包裝： 2,500
類型： SFP+ 控制器
輸入類型： 模擬，數(shù)字
輸出類型： 數(shù)字
接口： I²C，LDD，串行
電流 - 電源： 2.5mA
安裝類型： 表面貼裝
封裝/外殼： 28-WFQFN 裸露焊盤
供應(yīng)商設(shè)備封裝： 28-TQFN-EP（5x5）
包裝： 帶卷 (TR)
DS1878
SFP+ Controller with Digital LDD Interface
14
______________________________________________________________________________________
(MODTC, Table 02h, Register C6h) and a temperature
index register (MODTI, Table 02h, Register C2h).
BIAS and MODULATION Control
During Power-Up
The device has two internal registers, MODULATION
and BIAS, that represent the values written to the Maxim
laser driver’s modulation DAC and bias DAC through
the 3-wire interface. On power-up, the device sets the
MODULATION and BIAS registers to 0. When VCC is
above POA, the device initializes the Maxim laser driver.
After a temperature conversion is completed and if the
VCC LO alarm is enabled, an additional VCC conversion
above the customer-defined VCC LO alarm level is
required before a Maxim laser driver MODULATION
register is updated with the value determined by the
temperature conversion and the modulation LUT.
When the MODULATION register is set, the BIAS regis-
ter is set to a value equal to ISTEP (see Figure 2). The
startup algorithm verifies whether this bias current caus-
es a feedback voltage above the APC set point, and if
not, it continues increasing the BIAS register by ISTEP
until the APC set point is exceeded. When the APC set
point is exceeded, the device begins a binary search to
quickly reach the bias current corresponding to the
proper power level. After the binary search is complet-
ed, the APC integrator is enabled and single LSB steps
are used to tightly control the average power.
The TXP HI, TXP LO, and BIAS MAX QT alarms are
masked until the binary search is completed. However,
the BIAS MAX alarm is monitored during this time to
prevent
the
BIAS
register
from
exceeding
IBIASMAX. During the bias current initialization, the
BIAS register is not allowed to exceed IBIASMAX. If this
occurs during the ISTEP sequence, then the binary
search routine is enabled. If IBIASMAX is exceeded
during the binary search, the next smaller step is acti-
vated. ISTEP or binary increments that would cause the
BIAS register to exceed IBIASMAX are not taken.
Masking the alarms until the completion of the binary
search prevents false positive alarms during startup.
ISTEP is a value controlled by registers ISTEPH,
ISTEPL, and ISTEPTI (Table 02h, Registers BAh, BBh,
and C5h, respectively). See the register descriptions for
more information. During the first steps, a Maxim laser
driver’s bias DAC is directly written using SET_IBIAS.
ISTEP should be programmed to the maximum safe
increase that is allowable during startup. If this value is
programmed too low, the device still operates, but it
could take significantly longer for the algorithm to con-
verge and hence to control the average power.
If a fault is detected, and TXD is toggled to reenable
the outputs, the device powers up following a similar
sequence to an initial power-up. The only difference is
that the device already has determined the present
12
3
4
56
7
89
10
11
12
13
VPOA
MODULATION REGISTER
BIAS REGISTER
VCC
BIAS SAMPLE
tINIT
tSEARCH
BINARY SEARCH
APC INTEGRATOR ON
4x ISTEP
3x ISTEP
2x ISTEP
ISTEP
Figure 2. Power-Up Timing
相關(guān)PDF資料
PDF描述
DS1881Z-050+T&R IC DGTL POT NV 2CH 45K 16-SOIC
DS1882Z-050+T&R IC POT DIGIT DL LOG 50K 16SOIC
DS1884AT+T IC SFP PON ONU CTRLR 24TQFN
DS2105Z+ IC SCSI TERMINATOR 16-SOIC
DS2106S/T&R IC TERMINATOR SCSI 28-SOIC
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS-187PU 制造商:Shinagawa Shoko 功能描述:
DS-187U 制造商:Shinagawa Shoko 功能描述:
DS1880E-050 功能描述:板上安裝溫度傳感器 RoHS:否 制造商:Omron Electronics 輸出類型:Digital 配置: 準(zhǔn)確性:+/- 1.5 C, +/- 3 C 溫度閾值: 數(shù)字輸出 - 總線接口:2-Wire, I2C, SMBus 電源電壓-最大:5.5 V 電源電壓-最小:4.5 V 最大工作溫度:+ 50 C 最小工作溫度:0 C 關(guān)閉: 安裝風(fēng)格: 封裝 / 箱體: 設(shè)備功能:Temperature and Humidity Sensor
DS1880E-050/T&R 制造商:Maxim Integrated Products 功能描述:DUAL LOG POT + EQUALIZER T&R - Tape and Reel
DS1880E-050/T&R 功能描述:板上安裝溫度傳感器 RoHS:否 制造商:Omron Electronics 輸出類型:Digital 配置: 準(zhǔn)確性:+/- 1.5 C, +/- 3 C 溫度閾值: 數(shù)字輸出 - 總線接口:2-Wire, I2C, SMBus 電源電壓-最大:5.5 V 電源電壓-最小:4.5 V 最大工作溫度:+ 50 C 最小工作溫度:0 C 關(guān)閉: 安裝風(fēng)格: 封裝 / 箱體: 設(shè)備功能:Temperature and Humidity Sensor
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*