• LTC4125 NTC thermistor fault behavior

    We are using the LTC4125 in conjunction with an LTC4120.  In our design, we are overriding the duty cycle by connecting a resistive divider (237K over 100K) to the PTH1 and PTH2 pins, which are shorted together.  I am trying to test the NTC thermistor fault…

  • LTC4125 not tuning with LTC4120

    LTC4125 does not appear to be connecting with LTC4120 (not LTC4120-4.2)

    I've copied the data sheet circuit(s) to create a system. I'm using the exact parts that the applications suggest.

    While most pins appear to have what I expect, I can't seem…

  • LTC4125- indication of the end of charge

    Hello! How can I indicate the end of charge on the DC2773A-B transmitter board(featuring LTC4125)

  • Help in understanding LTC4125 PTH1 and PTH2 pins

    First off I want to say that this is a really interesting part, and the combined system using the 4120 to control the charging of a battery without the use of a digital communication channel is innovative.

    I have the demo board for the LTC4125, and am…

  • LTC4125 and LT4120-4.2, no persistent power delivery.

    We are working on a custom made Wireless Power Charging solution using LTC4125 and LTC4120-4.2. We used the reference design as per DC2330A-2-SCH and DC2445A-1-SCH. We just didn't do the LED bar graph part of the reference design and most passives are…

  • RE: LTC4120-4.2 Problems

    Hi drmike,

    Your schematic should not be compatible with the DC2330A transmitter, as it does not include a detection cricuit for LTC4125 to find the optimum operating point. The original DHC function is supposed to work with a push-pull type transmitter…

  • RE: LTC4120 2.5 kHz operating frequency

    From the LTC4125 datasheet, p 10.

    The transmitter starts with at 2.5kHz but quickly synchronizes to the resonant frequency of the transmitter LC circuit.  This frequency is typically hundreds of kilohertz.  I have never heard the 2.5kHz when starting up…

  • Uising LCT4125 with LTC4124 configured at 10mA


    I am involved in designing a wearable device that is to be charged wireless, the system includes a docking wireless transmitter.

    I have chosen LTC4125 Power Transmitter to work with LTC4124 Power Receiver configured at 10mA.

    I know you have Eval…

  • RE: LTC4124 EVB Charging Problem (DC2770A-B KIT)

    Hi Mike,

    Could you check the BAT pin voltage on your LTC4124 board when you see 30 to 40mA of charge current? The impedance of the cable you used to connect the battery may cause the BAT pin to be close to 4.2V when charging. According to the charging…

  • RE: Purpose of Presence Detect and FAULT, CHRG Pin in DEMO CIRCUIT 2445A - A / B

    Hi Prithivi,

    1. The presence detection circuit is designed for the LTC4125 search algorithm only. During search period, LTC4125 gradually increases its output power, searching for the optimum power condition for the load. UVCL features in LTC4120 keeps…