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| Silabs Si88xx高速多通道数字隔离器解决方案 |
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| 文章来源： 更新时间：2015/4/27 9:00:00 |
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Silabs公司的Si88xx系列产品是集成了78%高效DC/DC转换器的高速多通道数字隔离器, 可提供高达2W的功率输出,极低电磁干扰（EMI）和高噪声抑制能力,主要用在工厂自动化,过程控制,可编程逻辑控制器（PLC）和太阳能逆变器和汽车电池管理.本文介绍了Si88xx主要特性,框图和应用电路,以及评估板Si88xxxISO-EVB主要特性别,电路图,材料清单和PCB设计图.
The Si88xx integrates Silicon Labs’ proven digital isolator technology with an on-chip isolated dc-dc converter that provides regulated output voltages of 3.3 or 5.0 V (or >5 V with external components) at peak output power levels of up-to 2 W. These devices provide up-to four digital channels. The dc-dc converter has user-adjustable frequency for minimizing emissions, a soft-start function for safety, a shut-down option and loop compensation. The device requires only minimal passive components and a miniature transformer.
The ultra-low-power digital isolation channels offer substantial data-rate, propagation delay, size and reliability advantages over legacy isolation technologies. Data rates up to 100 Mbps are supported, and all devices achieve propagation delays of only 23 ns. Ordering options include a choice of dc-dc converter features, isolation channel configurations and a fail-safe mode. All products are certified by UL, CSA, VDE, and CQC.
Si88xx主要特性:
High-speed isolators with integrated dc-dc converter
Fully-integrated secondary sensing feedback-controlled converter with dithering for low EMI
dc-dc converter efficiency of 78%
Up to 2 W isolated power with integrated power switches
Options include dc-dc shutdown, frequency control, and soft start
Conversion
3/5 V to isolated 3/5 V
24 V to isolated 3/5 V supported
Precise timing on digital isolators
0–100 Mbps
18 ns typical prop delay
Highly-reliable: 100 year lifetime
High electro-magnetic immunity and ultra-low emissions
RoHS compliant packages
SOIC-20 wide body
Isolation of up to 5000 Vrms
High transient immunity of 100 kV/μs (typical)
AEC-Q100 qualified
Wide temp range
–40 to +125 ℃
Si88xx应用:
Industrial automation systems
Hybrid electric and electric vehicles
Isolated power supplies
Inverters
Data acquisition
Motor control
PLCs, distributed control systems
图1. Si88xx框图:3V/3V或5V/5V工作
图2. Si88xx框图:24V输入,5V输出
评估板Si88xxxISO-EVB
Power the EVB by applying a 3.0 to 5.5 V dc supply to terminal block J1. The isolated output is available at terminal block J2. Test points for these are available at the upper edge of the EVB.
The default EVB configuration has the header JP13 shorted, so the dc-dc output powers the VDDB supply (U1 pin 19) of the Si88241ED-IS. The acceptable input voltage to the VDDB supply pin is 3.0 to 5.5 V. If the user chooses to generate an output voltage outside this voltage range, the jumper at JP13 must be removed and a separate supply source connected to VDDB through JP13.
To measure input supply current, clip a differential probe across JP12 to access each side of sense resistor R20.
The SH input (U1 pin 7) disables the dc-dc converter function. Install a jumper across JP9 to pull the SH input high and disable the dc-dc converter. If interfacing to an external controller board through the JP9 header, the controller must drive SH low for normal operation and high to disable the dc-dc.
The EVB has a series of headers for connecting to each digital channel. The inside conductor of each 2x1 header is connected to the device pin and the outer conductor is tied to ground through a protection resistor. Connect to each side of the Si88xxxISO-EVB to external controllers through a two-row ribbon cables with one row grounded.
The Si88xxxISO Evaluation Kit contains the following items:
Si88xxxISO-EVB
Si88241ED-IS installed on the evaluation board.
图3. 评估板Si88xxxISO-EVB外形图
图4. 评估板Si88xxxISO-EVB电路图(1)
图5. 评估板Si88xxxISO-EVB电路图(2)
评估板Si88xxxISO-EVB材料清单:
图6. 评估板Si88xxxISO-EVB PCB设计图 |
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