Controllers DS1863, DS1865 and DS1875 controllers have two outputs for controlling the laser driver: BIAS and MOD. The BIAS output is a 13-bit current DAC with a full-scale range of 1.2mA; the MOD output is an 8-bit voltage DAC with a full-scale range of 1.25V.
The compact laser driver MAX3736 or MAX3741 laser driver has two inputs for controlling the laser driver: BIASSET and MODSET. In order to make full use of the full-scale output of the laser driver, the two input terminals should be connected to a current sink controller with a full-scale 1.2mA.
The BIAS output of the controller between the controller and the laser driver provides the correct range for the BIASSET input of the laser driver. The MOD output is in voltage mode, so it must be properly connected to the laser driver (Figure 1).
The voltage-current conversion operational amplifier and NPN transistor convert the output of the MOD voltage-type DAC to a full-scale output of 1.2mA. The output range of the MOD is 0V to 1.25V. NPN needs to draw current from the MODSET pin, and the voltage of this pin is kept at 1.2V. Select R1 to keep the NPN emitter voltage below 0.3V to ensure that the NPN will not saturate at full-scale current. The maximum full-scale current drawn by NPN can be calculated by the following formula: IMAX = R2 × 1.25V / (R1 × (R3 + R2)).
Figure 1. Interface between controller and laser driver
Component selection There are no special component requirements for this application. Ordinary op amps and NPN transistors can be used; the smallest size and lowest cost components can meet the requirements of this application. Maxim's LMX321AXK-T operational amplifier is packaged in a 2.1mm x 2.0mm SC70-5, which can meet the needs of this application; NPN such as 2N3904 or 2N2222 can also meet the requirements of this application.
Conclusion The DS1863, DS1865, or DS1875 PON controller / monitor and compact laser driver can be connected using small, low-cost circuits. The interface circuit occupies less than 9mm².
Lawn lamp design mainly exterior and downy lamplight add security for urban green space landscape and beautiful, and generally has the characteristic such as easy installation, adornment sex is strong, can be used for park, garden villas, square, greening, greening of the place such as decorative lighting.
Product features
1. The lamp body is made of aluminum alloy with the column in high strength
2. Static powder spray coating process with many different colors for options
3. The LED lighting modules give the highest lighting output to produce the optiumum light beam control and visual comfort.
4. Protection:IP54
5. Heart radiation structure design for lighting assembly,greatly enhancing the stability and lifespan of the lamp.
6. LED Lighting columns with RGB and change program comprising artistic design elements.
7. Reasonable design for assembling and disassembling,convenient for installation and maintenance.
Lawn Lamps,Solar Lawn Lamps,Outdoor Lawn Lamps,Gas Lawn Lamps
Jiangsu chengxu Electric Group Co., Ltd , http://www.chengxulighting.com