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TPS65053: TPS65053

Part Number: TPS65053
Other Parts Discussed in Thread: OMAP-L138,

Hello, I am using TPS65053 power chip to supply power to OMAP-L138 processor. When the power input of the chip is unstable for a moment, one OF the LDO output will be abnormal. Normally, the output should be 1.8V, but after abnormal, the output voltage can reach 2.7V In an abnormal state, power chip heating obviously,DSP chip heating obviously. When I give the RESET foot of the power chip a low level signal to RESET, the power chip can work normally. The circuit diagram of the chip is as follows:

中文如下(中文):

你好,我在TPS65053电源芯片给OMAP-L138处理器供电,当芯片电源输入突然异常会导致一路LDO,应该正常是1.8V输出,后电压输出可到2.7V,当我通过使能脚来关闭LDO时是无法关闭的,这个控制台系统状态出现异常状态,电源芯片发热,DSP芯片也明确。当我给电源芯片的RESET脚一个低信号信号来复位时,电源芯片正常工作.电路图如下:

  • Junyao,

    What do you mean by "when the power input of the chip is unstable for a moment"? If you are applying an abnormal power fault condition, please provide additional detail as to what that is. Taking a look at the schematic, there doesn't appear to be near enough input capacitance on the regulators, specifically VIN_LDO1. If you are applying an unsteady voltage on VSYS, VIN_LDO1 also doesn't have enough capacitance to steady the regulator input. It seems you have 1uF + 300nF = 1.3uF of capacitance, where 1uF + 2.2uF = 3.2uF is the recommended amount.

    Best,
    Emily

  • Hello, the external power supply of our system is 24V lithium battery, through a power switch to control the 24V power on and off. After the lithium battery 24V power supply is converted to 5V through a DCDC power supply chip, it is used as the input of TPS65053 power chip. When the power switch is pressing, a fluctuation of lithium battery 24V output will lead to the TPS65053 chip anomaly. See the original post for the anomaly. When the power switch is pressed, the 24V output of lithium battery does not fluctuate, and the output of TPS65053 chip is normal.

    Normal:

    Error:

  • Junyao,

    Have you added additional input capacitance to the layout? And can you confirm your output capacitor is located close to the PMIC? If there is a load change from a unsteady input that can cause the regulator output to fall suddenly (shown in the ringing scope shot you provided), having sufficient input capacitance (and output capacitance close to the PMIC) can help hold up that input voltage so the PMIC can properly regulate. Please add the input capacitance detailed in my earlier response and confirm the output capacitance seen by the PMIC in layout and attach the resulting scope shots. 

    Best,
    Emily