参数资料
| 型号： | MAX3669EHJ+T |
| 厂商： | Maxim Integrated |
| 文件页数： | 9/13页 |
| 文件大小： | 0K |
| 描述： | IC LASR DRVR 622MBPS 5.5V 32TQFP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 类型： | 激光二极管驱动器（光纤） |
| 数据速率： | 622Mbps |
| 通道数： | 1 |
| 电源电压： | 3.14 V ~ 5.5 V |
| 电流 - 电源： | 40mA |
| 电流 - 调制： | 75mA |
| 电流 - 偏置： | 80mA |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | 32-TQFP |
| 供应商设备封装： | 32-TQFP（5x5） |
| 包装： | 带卷 (TR) |
| 安装类型： | 表面贴装 |
MAX3669
+3.3V, 622Mbps SDH/SONET
Laser Driver with Current Monitors and APC
Resistor graph in the Typical Operating Character-
istics and select the value of R BIASMAX that corre-
sponds to the required current at +25°C.
When using the MAX3669 in closed-loop operation, the
R BIASMAX resistor sets the maximum bias current avail-
able to the laser diode over temperature and life. The
APC loop can subtract from this maximum value but
cannot add to it. See the Bias Current vs. Maximum
Bias Set Resistor graph in the Typical Operating
Characteristics and select the value of R BIASMAX that
corresponds to the end-of-life bias current at +85°C.
Referring to Figure 4, the droop resulting from long time
periods without transitions can be represented by the
following equation:
-t
(100% - DROOP) = e τ
AC-coupling of I MOD results in a discharge level for τ
that is equal to P AVG . An overall droop of 6% relative to
P p-p equates to a 12% droop relative to P AVG . To
ensure a droop of less than 12% (6% relative to P p-p ),
this equation can be solved for τ as follows:
Programming the APC Loop
When the MAX3669’s APC feature is used, program the
τ =
-t
ln (1 - 0.12)
= 7.8t
average optical power by adjusting the APCSET resis-
tor. To select this resistor, determine the desired moni-
tor current to be maintained over temperature and life.
See the Monitor Diode Current vs. APC Set Resistor
graph in the Typical Operating Characteristics and
select the value of R APCSET that corresponds to the
required current.
Interfacing with the Laser Diode
To minimize optical output aberrations due to the laser
parasitic inductance, an RC shunt network may be
used (see Typical Operating Circuit). If R L represents
the laser diode resistance, the recommended total
resistance for R D + R L is 10 Ω . Starting values for coaxi-
al lasers are R FILT = 20 Ω and C FILT = 5pF. R FILT and
C FILT should be experimentally adjusted to optimize
the output waveform. A bypass capacitor should also
be placed as close to the laser anode as possible for
best performance.
Pattern-Dependent Jitter (PDJ)
When transmitting NRZ data with long strings of consec-
utive identical digits (CIDs), LF droop can contribute to
PDJ. To minimize this PDJ, two external components
If t 1 equals 80 consecutive unit intervals without a tran-
sition, the time constant associated with the DC block-
ing capacitor needs to be longer than:
τ AC ≥ R AC C D = 7.8 (80 bits) (1.6ns/bit) = 1.0μs
R FILT can be ignored for C FILT << C D ; therefore, the
estimated value of R AC is:
R AC = 20 Ω ?? (R D + r LASER )
Assuming R D = 5 Ω , and r LASER = 5 Ω :
R AC = 6.7 Ω
with C D = 1μF, τ AC = 6.7μs.
Input Termination Requirement
The MAX3669 data inputs are PECL compatible.
However, it is not necessary to drive the MAX3669 with
a standard PECL signal. As long as the specified com-
mon-mode voltage and differential voltage swings are
met, the MAX3669 will operate properly.
τ=∞
must be properly chosen: capacitor C APC , which domi-
nates the APC loop time constant, and AC-coupling
capacitor C D .
τ << τ AC
τ AC
DROOP
To filter out noise effects and guarantee loop stability,
the recommended value for C APC is 0.1μF. This results
in an APC loop bandwidth of 20kHz. Consequently, the
PDJ associated with an APC loop time constant can be
P p-p
P AVG
ignored.
The time constant associated with the DC blocking
capacitor on I MOD will have an effect on PDJ. It is
important that this time constant produce minimum
droop for long consecutive bit streams.
Maxim Integrated
Figure 4. Droop
t 1
t
9
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX3669ETG | 功能描述:激光驱动器 RoHS:否 制造商:Micrel 数据速率:4.25 Gbps 工作电源电压:3 V to 3.6 V 电源电流:80 mA 最大工作温度:+ 85 C 封装 / 箱体:QFN-16 封装:Tube |
| MAX3669ETG+ | 功能描述:激光驱动器 3.3V 622Mbps SDH/SONET RoHS:否 制造商:Micrel 数据速率:4.25 Gbps 工作电源电压:3 V to 3.6 V 电源电流:80 mA 最大工作温度:+ 85 C 封装 / 箱体:QFN-16 封装:Tube |
| MAX3669ETG+T | 功能描述:激光驱动器 3.3V 622Mbps SDH/SONET RoHS:否 制造商:Micrel 数据速率:4.25 Gbps 工作电源电压:3 V to 3.6 V 电源电流:80 mA 最大工作温度:+ 85 C 封装 / 箱体:QFN-16 封装:Tube |
| MAX3669ETGEVKIT | 功能描述:激光驱动器 Evaluation Kit for the MAX3669ETG RoHS:否 制造商:Micrel 数据速率:4.25 Gbps 工作电源电压:3 V to 3.6 V 电源电流:80 mA 最大工作温度:+ 85 C 封装 / 箱体:QFN-16 封装:Tube |
| MAX3669ETG-T | 功能描述:激光驱动器 RoHS:否 制造商:Micrel 数据速率:4.25 Gbps 工作电源电压:3 V to 3.6 V 电源电流:80 mA 最大工作温度:+ 85 C 封装 / 箱体:QFN-16 封装:Tube |
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