参数资料
型号: CS42L55-CNZR
厂商: Cirrus Logic Inc
文件页数: 9/68页
文件大小: 0K
描述: IC CODEC STER H-HDPN AMP 36-QFN
标准包装: 6,000
类型: 立体声音频
数据接口: 串行
分辨率(位): 24 b
ADC / DAC 数量: 1 / 1
三角积分调变:
动态范围,标准 ADC / DAC (db): 95 / 99
电压 - 电源,模拟: 1.65 V ~ 2.71 V
电压 - 电源,数字: 1.65 V ~ 2.71 V
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 36-QFN
供应商设备封装: 36-QFN-EP(5x5)
包装: 带卷 (TR)
配用: 598-1506-ND - BOARD EVAL FOR CS42L55 CODEC
October 2004
17
M9999-101204
MIC3000
Micrel
Laser Diode Bias Control
The MIC3000 can be configured to generate a constant bias
current using electrical feedback, or regulate average trans-
mitted optical power using a feedback signal from a monitor
photodiode, see Figure 3. An operational amplifier is used to
control laser bias current via the VBIAS output. The VBIAS pin
can drive a maximum of ±10mA. An external bipolar transistor
provides current gain. The polarity of the op amp’s output is
programmable BIASREF in OEMCFG1 in order to accommo-
date either NPN or PNP transistors that drive common anode
and common cathode laser, respectively. Additionally, the
polarity of the feedback signal is programmable for use with
either common-emitter or emitter-follower transistor circuits.
Furthermore, the reference level for the APC circuit is select-
able to accommodate electrical, i.e., current feedback, or
optical feedback via a monitor photodiode. Finally, any one of
seven different internal feedback resistors can be selected.
This internal resistor can be used alone or in parallel with an
external resistor. This wide range of adjustability (50:1)
accommodates a wide range of photodiode current, i.e, wide
range of transmitter output power. The APC operating point
can be kept near the mid-scale value of the APC DAC,
insuring maximum SNR, maximum effective resolution for
digital diagnostics, and the widest possible DAC adjustment
range for temperature compensation, etc. See Figure 4.
The APCCAL bit in OEMCAL0 is used to turn the APC
function on and off. It will be turned off in the MIC3000’s
default state as shipped from the factory. When APC is on,
the value in the selected APCSETx register is added to the
signed value taken from the APC look-up table and loaded
into the VBIAS DAC. When APC is off, the VBIAS DAC may be
written directly via the VBIAS register, bypassing the look-up
table entirely. This provides direct control of the laser diode
bias during setup and calibration. In either case, the VBIAS
DAC setting is reported in the APCDAC register. The APCCFG
bits determine the DACs response to higher or lower numeric
values.
DAC
INV
GAIN
APC
Look-Up
Table
Temp
Sensor
VMOD
Look-Up
Table
APCSET
DAC
MODSET
MODREF
VMOD–
VMOD
FB
COMP
VBIAS
RFB[2:0]
VDD
VOUT
VDD-OUT
VOUT
VDD-OUT
BIASREF
Figure 3. MIC3000 APC and Modulation Control
Block Diagram
APC Op-Amp
FB
RFB[2:0]
BIASREF
R7
51.2k
7
R6
25.6k
R5
12.8k
R4
6.4k
R3
3.2k
R2
1.6k
R1
0.8k
VDD
Figure 4. Programmable Feedback Resistor
Laser Modulation Control
As shown in Figure 3, a temperature-compensated DAC is
provided to set and control the laser modulation current via an
external laser driver circuit. MODREF in OEMCFG0 selects
whether the VMOD DAC output swings up from ground or
down from VDD. If the laser driver requires a voltage input to
set the modulation current, the MIC3000’s VMOD output can
drive it directly. If a current input is required, a fixed resistor
can be used between the driver and the VMOD output. Several
different configurations are possible, as shown in Figure 6.
When APC is on, i.e., the APCCAL bit in OEMCAL0 is set to
0, the value corresponding to the current temperature is taken
from the MODLUT look-up table, added to MODSET, and
loaded into the VMOD DAC. When APC is off, the value in
VMOD is loaded directly into the VMOD DAC, bypassing the
look-up table entirely. This provides for direct modulation
control for setup and calibration. The MODREF bit deter-
mines the DACs response to higher or lower numeric values.
VDD
Common-cathode with
monitor photodiode
Common-anode with
monitor photodiode
Common-anode
Common-cathode
VDD
Figure 5. Transmitter Configurations
Supported by MIC3000
相关PDF资料
PDF描述
DSP56F807VF80 IC DSP 80MHZ 60K FLASH 160-BGA
VI-B20-IW-B1 CONVERTER MOD DC/DC 5V 100W
MC9328MXLCVM15 IC MCU I.MXL 150MHZ 256-MAPBGA
VI-2NX-CU-S CONVERTER MOD DC/DC 5.2V 200W
CS42L51-CNZR IC CODEC LOW-V 24BIT 32-QFP
相关代理商/技术参数
参数描述
CS42L55-DNZ 功能描述:接口—CODEC Portble Stereo CODEC Class H HP Amp RoHS:否 制造商:Texas Instruments 类型: 分辨率: 转换速率:48 kSPs 接口类型:I2C ADC 数量:2 DAC 数量:4 工作电源电压:1.8 V, 2.1 V, 2.3 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:DSBGA-81 封装:Reel
CS42L55DNZR 制造商:Cirrus Logic 功能描述:PORTABLE STEREO CODEC AND UNIQUE CLASS H HP AMP AUTO GRADE & - Tape and Reel
CS42L55-DNZR 功能描述:接口—CODEC Portable Ster CODEC w/Class H HP Amp RoHS:否 制造商:Texas Instruments 类型: 分辨率: 转换速率:48 kSPs 接口类型:I2C ADC 数量:2 DAC 数量:4 工作电源电压:1.8 V, 2.1 V, 2.3 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:DSBGA-81 封装:Reel
CS42L56-CNZ 功能描述:接口—CODEC IC 24Bit UltraLowPwr Ster Codec w/clH HP RoHS:否 制造商:Texas Instruments 类型: 分辨率: 转换速率:48 kSPs 接口类型:I2C ADC 数量:2 DAC 数量:4 工作电源电压:1.8 V, 2.1 V, 2.3 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:DSBGA-81 封装:Reel
CS42L56-CNZR 功能描述:接口—CODEC IC 24Bit UltraLowPwr Ster CD w/clH HP RoHS:否 制造商:Texas Instruments 类型: 分辨率: 转换速率:48 kSPs 接口类型:I2C ADC 数量:2 DAC 数量:4 工作电源电压:1.8 V, 2.1 V, 2.3 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:DSBGA-81 封装:Reel