FCP280 RH924YA自动化模块
输入电容器
升压转换器的输入电容器不那么关键，因为输入电流波形是三角形的，并且不包含输出电容器中发现的大的方波电流。10µF至100µF范围内的电容器，ESR为0.1Ω 或更少的工作很好，直到全6A开关电流。在低开关电流下，可以接受较高的ESR电容器。升压变换器的输入电容器纹波电流为：IRIPPLE=f=500kHz开关频率0.3（VIN）（VOUT–VIN）。几家制造商已经开发了专门测试浪涌能力的钽电容器（例如AVX TPS系列），但如果在高浪涌期间输入电压接近电容器的最大额定电压，即使这些装置也可能出现故障。
铝电解电容器
AVX建议在高电涌应用中将电容器电压降低2:1。也可以使用陶瓷、OS-CON和铝电解电容器，并且对导通电涌具有高耐受性。陶瓷电容器价值更高、成本更低的陶瓷电容器现在可用于更小的外壳尺寸。由于它们的ESR非常低，因此对于开关稳压器来说很有吸引力。不幸的是，ESR太低，可能导致环路稳定性问题。固体钽电容器ESR在5kHz至50kHz产生环路“零”，这有助于提供可接受的环路相位裕度。陶瓷电容器在超过300kHz时保持电容性，通常在ESR生效之前与ESL共振。由于其高纹波电流额定值和对接通浪涌的耐受性，它们适合于输入旁路。
Input capacitor
The input capacitor of the boost converter is less critical because the input current waveform is triangular and does not include the large square wave current found in the output capacitor. Capacitors in the range of 10 µ F to 100 µ F with an ESR of 0.1 Ω or less work well until the full 6A switching current. Higher ESR capacitors can be accepted at low switching current. Ripple current of input capacitor of boost converter: IRIPPLE=f=500kHz switching frequency 0.3 (VIN) (VOUT – VIN). Several manufacturers have developed tantalum capacitors (such as AVX TPS series) for testing surge capacity, but if the input voltage is close to the maximum rated voltage of the capacitor during high surge, even these devices may fail.
Aluminum electrolytic capacitor
AVX recommends reducing the capacitor voltage by 2:1 in high surge applications. Ceramic, OS-CON and aluminum electrolytic capacitors can also be used and have high resistance to conducting surges. Ceramic capacitors, which have higher value and lower cost, can now be used for smaller case sizes. Because their ESR is very low, they are very attractive for switching regulators. Unfortunately, ESR is too low, which may cause loop stability problems. The solid tantalum capacitor ESR generates a loop "zero" at 5kHz to 50kHz, which helps to provide an acceptable loop phase margin. Ceramic capacitors maintain capacitance when exceeding 300kHz, and usually resonate with ESL before ESR takes effect. They are suitable for input bypass due to their high ripple current rating and resistance to switching surges.
