pcb设计规范（PCB design specification）.docVIP

pcb设计规范（PCB design specification） The basic circuit design specification The 1. circuit principle diagram design 1.1 components 1.1.1 Designator Designator consists of 3 parts, the category number + number + plate element. This class represents the element belongs to the category of elements, usually represented by 1 or 2 letters. The board said on the number of the circuit board in the system, is a digital. The serial number of said element components on the circuit board components of this type of serial number, usually 2 or 3 digits. For example: C201, category (C), capacitance plate No. 2, No. 01. Select the categories in accordance with the following provisions: Capacitance: C Resistance: R Potentiometer: P Inductance: L Diode: D Triode / FET: T Integrated circuit: U SCR: S Digital tube: G Jumper: J Magnetic sensor: H Temperature sensor: RT Connector: CN Test point: TP Power module: MK Heat sink: YK Transformers: TRF Crystal: XTAL 1.1.2 Part Type Components of the Part Type consists of 3 parts, category + + numerical specifications. The Part Type device consists of 2 parts, category and type. Example: CD-227-25V type aluminum electrolytic capacitor (CD), 220uF (227), numerical specification 25V. R-1K2-1/8W type resistance, numerical 1.2K Omega, 1/8W specifications. CH3, class 2.54 single row spacing socket, size 3 needle. U-74ALS05AN type integrated circuit, model 74ALS05AN The components of the model must be complete model. Resistance: category R. Numerical value: less than 1K, the direct use of digital representation, such as R-680-1/8W, said the 680. The resistance is greater than 1K, with digital +K, such as R-10K-1/8W, said 10K. Such as: R-1K2-1/8W, 1.2K said. Specification: in line with the power that patch package said last +J precision resistor. Capacitance: Category: monolithic capacitors CT, CC ceramic capacitors, polyester capacitors CL, polyester capacitor CB, mica capacitors CY, CD aluminum electrolytic capacitor, tantalum electrolytic capacitor CA