小尺寸的ECS无源晶体支持时序解决方案ECS-200-20-5PXDN-TR，更高的等效串联电阻 (ESR) 是工程师在使用更小的无源晶振晶体时会看到的其他东西。ESR是内部电阻，代表电子电路中的能量损失。几乎每个电路都会有不同程度的某种 ESR。
ESR的水平取决于许多因素，例如特定的结构、材料、质量等。ESR可以在从几毫欧到几欧（或 1,000 毫欧）的任何地方测量。如果ESR太高，您可能会看到不同的结果，例如晶振功率损耗、效率低下和电路不稳定。
| Manufacturer Part Number原厂编码 | Manufacturer厂家 | Series型号 | Type 系列 | Frequency | Operating Temperature 工作温度 |
| ECS-.327-6-12-TR | ECS晶振 | ECX-12 | kHz Crystal (Tuning Fork) | 32.768kHz | -40°C ~ 85°C |
| ECS-200-20-5PXDN-TR | ECS晶振 | CSM-7X-DN | MHz Crystal | 20MHz | -40°C ~ 85°C |
| ECS-200-20-5PXDN-TR | ECS晶振 | CSM-7X-DN | MHz Crystal | 20MHz | -40°C ~ 85°C |
| ECS-200-20-5PXDN-TR | ECS晶振 | CSM-7X-DN | MHz Crystal | 20MHz | -40°C ~ 85°C |
| ECS-135.6-20-3X-EN-TR | ECS晶振 | CSM-3X | MHz Crystal | 13.56MHz | -40°C ~ 85°C |
| ECS-135.6-20-3X-EN-TR | ECS晶振 | CSM-3X | MHz Crystal | 13.56MHz | -40°C ~ 85°C |
| ECS-135.6-20-3X-EN-TR | ECS晶振 | CSM-3X | MHz Crystal | 13.56MHz | -40°C ~ 85°C |
| ECS-200-CDX-0914 | ECS晶振 | CSM-3X | MHz Crystal | 20MHz | -60°C ~ 105°C |
| ECS-200-CDX-0914 | ECS晶振 | CSM-3X | MHz Crystal | 20MHz | -60°C ~ 105°C |
| ECS-200-CDX-0914 | ECS晶振 | CSM-3X | MHz Crystal | 20MHz | -60°C ~ 105°C |
| ECS-40.3-20-5PX-TR | ECS晶振 | CSM-7X | MHz Crystal | 4.032MHz | -10°C ~ 70°C |
| ECS-40.3-20-5PX-TR | ECS晶振 | CSM-7X | MHz Crystal | 4.032MHz | -10°C ~ 70°C |
| ECS-40.3-20-5PX-TR | ECS晶振 | CSM-7X | MHz Crystal | 4.032MHz | -10°C ~ 70°C |
Higher equivalent series resistance (ESR) is something else engineers will see with smaller crystals. ESR is the internal resistance and represents the loss of energy in an electronic circuit. Almost every electrical circuit will have some kind of ESR to differing degrees.
The level of ESR depends on many factors such as the specific construction, materials, quality, etc. ESR can be measured anywhere from a few milliohms to several ohms (or 1,000 milliohms). If the ESR is too high, you may see varying results like power losses, poor efficiency and instability in circuits.
As a general rule, smaller crystals result in higher ESR, but there are several other factors including frequency, electrode size and mounting structure. With all of these factors involved and the potential effects of ESR, it’s easy to see why it can’t be overlooked when considering using smaller quartz crystals in oscillators. A stable oscillator can’t be guaranteed without it.
