Si8410/20/21
2.4. Layout Recommendations
To ensure safety in the end user application, high voltage circuits (i.e., circuits with >30 V AC ) must be physically
separated from the safety extra-low voltage circuits (SELV is a circuit with <30 V AC ) by a certain distance
(creepage/clearance). If a component, such as a digital isolator, straddles this isolation barrier, it must meet those
creepage/clearance requirements and also provide a sufficiently large high-voltage breakdown protection rating
(commonly referred to as working voltage protection). Table 6 on page 13 and Table 7 on page 14 detail the
working voltage and creepage/clearance capabilities of the Si84xx. These tables also detail the component
standards (UL1577, IEC60747, CSA 5A), which are readily accepted by certification bodies to provide proof for
end-system specifications requirements. Refer to the end-system specification (61010-1, 60950-1, etc.)
requirements before starting any design that uses a digital isolator.
The following sections detail the recommended bypass and decoupling components necessary to ensure robust
overall performance and reliability for systems using the Si84xx digital isolators.
2.4.1. Supply Bypass
Digital integrated circuit components typically require 0.1 μF (100 nF) bypass capacitors when used in electrically
quiet environments. However, digital isolators are commonly used in hazardous environments with excessively
noisy power supplies. To counteract these harsh conditions, it is recommended that an additional 1 μF bypass
capacitor be added between VDD and GND on both sides of the package. The capacitors should be placed as
close as possible to the package to minimize stray inductance. If the system is excessively noisy, it is
recommended that the designer add 50 to 100 ? resistors in series with the VDD supply voltage source and 50 to
300 ? resistors in series with the digital inputs/outputs (see Figure 6). For more details, see "3. Errata and Design
All components upstream or downstream of the isolator should be properly decoupled as well. If these components
are not properly decoupled, their supply noise can couple to the isolator inputs and outputs, potentially causing
damage if spikes exceed the maximum ratings of the isolator (6 V). In this case, the 50 to 300 ? resistors protect
the isolator's inputs/outputs (note that permanent device damage may occur if the absolute maximum ratings are
exceeded). Functional operation should be restricted to the conditions specified in Table 1, “Recommended
2.4.2. Pin Connections
No connect pins are not internally connected. They can be left floating, tied to V DD , or tied to GND.
2.4.3. Output Pin Termination
The nominal output impedance of an isolator driver channel is approximately 85 ? , ±40%, which is a combination
of the value of the on-chip series termination resistor and channel resistance of the output driver FET. When driving
loads where transmission line effects will be a factor, output pins should be appropriately terminated with controlled
impedance PCB traces. The series termination resistor values should be scaled appropriately while keeping in
mind the recommendations described in “2.4.1. Supply Bypass” above.
V Source 1
R1 (50 – 100 ? )
VDD1
VDD2
V Source 2
R2 (50 – 100 ? )
C1
0.1 ? F
C2
50 – 300 ?
A1
B1
50 – 300 ?
C3
C4
0.1 ? F
1 ? F
Input/Output
50 – 300 ?
Ax
GND1
Bx
GND2
Input/Output
50 – 300 ?
1 ? F
Figure 6. Recommended Bypass Components for the Si84xx Digital Isolator Family
20
Rev. 1.5
相关PDF资料
SILICON-EXPLORER II SOFTWARE ANALYSIS EXPLORER LOGIC
SILINKPS-EVB DAUGHTER CARD PROSLIC PS
SKP16C26A DEV EVALUATION KIT M16C/26A
SKP32C85-100-CL DEV EVALUATION KIT M32C/85 100PN
SKP8CMINI-13 BOARD DEV EVALUATION FOR R8C/13
SKP8CMINI-17 KIT EVAL STARTER FOR R8C/17
SKP8CMINI DEV EVALUATION KIT R8C/11
SL03 10001 CURRENT LIMITER INRUSH 10 OHM 1A
相关代理商/技术参数
Si84XXISO-KIT 功能描述:界面开发工具 Si84XX Ultra Low Pwr Eval Kit RoHS:否 制造商:Bourns 产品:Evaluation Boards 类型:RS-485 工具用于评估:ADM3485E 接口类型:RS-485 工作电源电压:3.3 V
SI85 制造商:未知厂家 制造商全称:未知厂家 功能描述:SMT Power Inductor
Si8501-B-GM 功能描述:板上安装电流传感器 5A Current Sensr Single Out RoHS:否 制造商:Honeywell 电流额定值:+/- 56 A 传感器/变换器类型: 电源电压:4.75 VDC to 5.25 VDC 响应时间:< 0.2 us 输出电压: 工作温度:- 40 C to + 85 C 准确性:+/- 0.24 % 频率范围:
Si8501-C-GM 功能描述:板上安装电流传感器 5A Current Sensor Single Output RoHS:否 制造商:Honeywell 电流额定值:+/- 56 A 传感器/变换器类型: 电源电压:4.75 VDC to 5.25 VDC 响应时间:< 0.2 us 输出电压: 工作温度:- 40 C to + 85 C 准确性:+/- 0.24 % 频率范围:
SI8501-C-GMR 制造商:Silicon Laboratories Inc 功能描述:5A CURRENT SENSOR, SINGLE OUTPUT - Tape and Reel
Si8501-C-IM 功能描述:板上安装电流传感器 5A SINGLE OUTPUT 1kV RoHS:否 制造商:Honeywell 电流额定值:+/- 56 A 传感器/变换器类型: 电源电压:4.75 VDC to 5.25 VDC 响应时间:< 0.2 us 输出电压: 工作温度:- 40 C to + 85 C 准确性:+/- 0.24 % 频率范围:
SI8501-C-IMR 制造商:Silicon Laboratories Inc 功能描述:5A CURRENT SENSOR, SINGLE OUTPUT 1KV QFN12 - Tape and Reel 制造商:Silicon Laboratories Inc 功能描述:SENSOR CURRENT 5A 5.5V UNI 12QFN 制造商:Silicon Laboratories Inc 功能描述:5A Current Sensor Single Output 1kV
Si8501-C-IS 功能描述:板上安装电流传感器 5A SINGLE OUTPUT 5kV RoHS:否 制造商:Honeywell 电流额定值:+/- 56 A 传感器/变换器类型: 电源电压:4.75 VDC to 5.25 VDC 响应时间:< 0.2 us 输出电压: 工作温度:- 40 C to + 85 C 准确性:+/- 0.24 % 频率范围: