- 您现在的位置：买卖IC网 > PDF目录1776 > ADN2870ACPZ-RL7 (Analog Devices Inc)IC LSR DRVR 3.3GPBS 3.6V 24LFCSP PDF资料下载
参数资料
| 型号： | ADN2870ACPZ-RL7 |
| 厂商： | Analog Devices Inc |
| 文件页数： | 12/20页 |
| 文件大小： | 0K |
| 描述： | IC LSR DRVR 3.3GPBS 3.6V 24LFCSP |
| 标准包装： | 1,500 |
| 类型： | 激光二极管驱动器（光纤） |
| 数据速率： | 3.3Gbps |
| 通道数： | 1 |
| 电源电压： | 3 V ~ 3.6 V |
| 电流 - 电源： | 30mA |
| 电流 - 调制： | 90mA |
| 电流 - 偏置： | 100mA |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | 24-VFQFN 裸露焊盘，CSP |
| 供应商设备封装： | 24-LFCSP-VQ（4x4） |
| 包装： | 带卷 (TR) |
| 安装类型： | 表面贴装 |
ADN2870
Operation with Lasers with Temperature-Dependent
Nonlinearity of Laser LI Curve
The ADN2870 ERCL extracts information from the monitor
photodiode signal relating to the slope of the LI characteristics
at the Optical 1 level (P1). For lasers with good linearity over
temperature, the slope measured by the ADN2870 at the Optical 1
level is representative of the slope anywhere on the LI curve.
This slope information is used to set the required modulation
current to achieve the required optical extinction ratio.
The ER correction scheme, while using the average nonlinearity
for the laser population, in fact, supplies a corrective measure-
ment based on each laser’s actual performance as measured
during operation. The ER correction scheme corrects for errors
due to laser nonlinearity while the dual loop continues to adjust
for changes in the Laser LI.
For more details on maintaining average optical power and
extinction ratio over temperature when working with lasers
displaying a temperature-dependent nonlinearity of LI curve,
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
RELATIVELY LINEAR LI CURVE AT 25°C
NONLINEAR LI CURVE AT 80°C
refer to the Application Note AN-743 available through Analog
Devices sales.
CONTROL
The ADN2870 has two methods for setting the average power
(P AV ) and extinction ratio (ER). The average power and
extinction ratio can be voltage set using a microcontroller’s
voltage DAC outputs to provide controlled reference voltages to
PAVREF and ERREF. Alternatively, the average power and
extinction ratio can be resistor set using potentiometers at the
PAVSET and ERSET pins, respectively.
VOLTAGE SETPOINT CALIBRATION
0
0 20 40 60 80 100
CURRENT (mA)
Figure 25. Measurement of a Laser LI Curve Showing
Laser Nonlinearity at High Temperatures
Some types of lasers have LI curves that become progressively
more nonlinear with increasing temperature (see Figure 25). At
temperatures where the LI curve shows significant nonlinearity,
the LI curve slope measured by the ADN2870 at the Optical 1
level is no longer representative of the overall LI curve. It is
evident that applying a modulation current based on this slope
information cannot maintain a constant extinction ratio over
The ADN2870 allows an interface to a microcontroller for both
control and monitoring (see Figure 26). The average power at
the PAVSET pin and extinction ratio at the ERSET pin can be
set using the microcontroller’s DAC to provide controlled
reference voltages PAVREF and ERREF. After power-on, the
ADN2870 starts an initial process that takes 25 ms before
enabling the alarms; therefore, the customer must ensure that
stable reference voltages to PAVREF and ERREF are available
within 20 ms.
PAVREF = P AV × R SP × RPAV (Volts)
temperature.
However, the ADN2870 can be configured to maintain near
ERREF = R ERSET ×
I MPD _ CW
P CW
×
ER ? 1
ER + 1
× P AV
(Volts)
constant optical bias and an extinction ratio with a laser
exhibiting a monotonic temperature-dependent nonlinearity.
To implement this correction, it is necessary to characterize
a small sample of lasers for their typical nonlinearity by
measuring them at two temperature points, typically 25°C
and 85°C. The measured nonlinearity is used to determine the
amount of feedback to apply.
Typically, one must characterize 5 to 10 lasers of a particular
model to get a good number. The product can then be cali-
brated at 25°C only, avoiding the expense of temperature
where:
R SP (A/W) is the monitor photodiode responsivity.
P CW (mW) is the dc optical power specified on the laser data
sheet.
I MPD_CW (mA) is the MPD current at the specified P CW .
P AV (mW) is the average power required.
ER is the desired extinction ratio (ER = P1/P0).
In voltage setpoint, RPAV and R ERSET must be 1 kΩ resistors with
a 1% tolerance and a temperature coefficient of 50 ppm/°C.
calibration. Typically, the microcontroller supervisor is used
to measure the laser and apply the feedback. This scheme is
particularly suitable for circuits that already use a microcon-
troller for control and digital diagnostic monitoring.
Rev. A | Page 12 of 20
相关PDF资料 |
PDF描述 |
|---|---|
| ADN2871ACPZ-RL7 | IC LASER DRIVER 4.25GBPS 24LFCSP |
| ADN2872ACPZ-R7 | IC LASR DVR 3.3GBPS 3.3V 24LFCSP |
| ADN2873ACPZ-R7 | IC LASER DRIVER 4.25GBPS 24LFCSP |
| ADN8830ACPZ-REEL | IC THERMO COOLER CNTRLR 32-LFCSP |
| ADP1046ACPZ-RL | IC DGTL CTRLR 32LFCSP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ADN2871 | 制造商:AD 制造商全称:Analog Devices 功能描述:3.3 V, 50 Mbps to 4.25 Gbps Single-Loop Laser Diode Driver |
| ADN2871ACPZ | 功能描述:IC LASER DRIVER 4.25GBPS 24LFCSP RoHS:是 类别:集成电路 (IC) >> PMIC - 激光驱动器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:60 系列:- 类型:激光二极管驱动器 数据速率:- 通道数:4 电源电压:3.3V 电流 - 电源:- 电流 - 调制:- 电流 - 偏置:- 工作温度:0°C ~ 70°C 封装/外壳:40-TQFN 裸露焊盘 供应商设备封装:40-TQFN EP 包装:托盘 安装类型:表面贴装 |
| ADN2871ACPZ-RL | 功能描述:IC LASER DRIVER 4.25GBPS 24LFCSP RoHS:是 类别:集成电路 (IC) >> PMIC - 激光驱动器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:60 系列:- 类型:激光二极管驱动器 数据速率:- 通道数:4 电源电压:3.3V 电流 - 电源:- 电流 - 调制:- 电流 - 偏置:- 工作温度:0°C ~ 70°C 封装/外壳:40-TQFN 裸露焊盘 供应商设备封装:40-TQFN EP 包装:托盘 安装类型:表面贴装 |
| ADN2871ACPZ-RL7 | 功能描述:IC LASER DRIVER 4.25GBPS 24LFCSP RoHS:是 类别:集成电路 (IC) >> PMIC - 激光驱动器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:60 系列:- 类型:激光二极管驱动器 数据速率:- 通道数:4 电源电压:3.3V 电流 - 电源:- 电流 - 调制:- 电流 - 偏置:- 工作温度:0°C ~ 70°C 封装/外壳:40-TQFN 裸露焊盘 供应商设备封装:40-TQFN EP 包装:托盘 安装类型:表面贴装 |
| ADN2872 | 制造商:AD 制造商全称:Analog Devices 功能描述:3.3 V Dual-Loop, 50 Mbps to 3.3 Gbps Laser Diode Driver |
发布紧急采购，3分钟左右您将得到回复。