Alternative solutions for high-voltage resistors

Based on your inquiry, I will start from the principle of replacing high-voltage resistors and analyze the feasibility of Tianma series resistors replacing the original model by comparing specific model parameters. The following is a comprehensive evaluation:
 
 
1、 Basic principles for replacing high-voltage resistors
1. Voltage resistance:
Replacing low-voltage resistors with high-voltage resistors is feasible in terms of electrical performance (high withstand voltage covers low withstand voltage requirements), but it is necessary to ensure that parameters such as size, power, and temperature coefficient match.
2. Key parameter matching:
Package size: must be consistent (e.g. 0603 cannot replace 1206).   
Resistance and accuracy: must be exactly the same (e.g. ± 1% cannot replace ± 5%).   
Power and temperature coefficient: rated power ≥ original model, temperature coefficient (TCR) needs to be the same or better.   
3. Application scenarios:
 
If used in high-frequency circuits (such as automotive inverters), attention should be paid to the high-frequency characteristics of resistors and the influence of parasitic inductance. In this case, cylindrical resistors (MELF) may be superior to chip resistors.
 
 
2、 Specific model substitution analysis
The following is a comparison of the four sets of resistors you listed, and the key parameters are summarized in the table below:
 
Prototype number, Tian'er replacement model, packaging resistance accuracy, original working voltage, replacement model, voltage power
RVS-03K4703FT    HR0603F470KP05Z    0603    470KΩ    ±1%    300V    350V    1/10W
 
RVS-06K106JT    HR1206J10M0P05Z    1206    10MΩ    ±5%    500V    500V    1/4W
RVS-03K1243FT    HR0603F124KP05Z    0603    124KΩ    ±1%    300V    350V    1/10W
RVS-03K3482FT    HR0603F34K8P05Z    0603    34.8KΩ    ±1%    300V    350V    1/10W
 
Detailed description:
 
1. RVS03K4703FT → HR0603F470KP05Z  
Advantages: Package (0603), resistance (470K Ω), accuracy (± 1%), and power (1/10W) are all matched.   
Risk: The working voltage of the prototype is 300V, and it is necessary to confirm whether the withstand voltage of the Tian'er model is ≥ 300V (if the withstand voltage of Tian'er is only 200V, it is not feasible).   
Suggestion: Request the Tian'er specification sheet to verify the withstand voltage value.
 
2. RVS06K106JT → HR1206J10M0P05Z  
 
Advantages: Package (1206), resistance (10M Ω) matching.   
Attention points:
The precision of the prototype number is ± 5%, and the suffix "P05" for the Tian'er model may indicate ± 5% (to be confirmed).   
 
The temperature coefficient of the prototype number is not indicated (for Fenghua with the same specifications, it is mostly ± 250ppm/℃), and it is better if it is ± 100ppm/℃ on Tian'er.   
Risk: The original working voltage is 500V, and the second day withstand voltage needs to be ≥ 500V (HVM series columnar resistors can reach 500V, but chip resistors are often 200-300V).
 
3. RVS03K1243FT/RVS03K3482FT → HR0603F124KP05Z/HR0603F34K8P05Z  
 
High feasibility: The packaging, resistance, accuracy, and power are all matched (refer to the parameters of Fenghua RS03K series).   
Voltage requirement: The prototype model should withstand a voltage of 300V, and Tian'er should meet the same withstand voltage (0603 high-voltage resistors usually support 300V).
 
 
3、 Comprehensive recommendations for alternative solutions
1. Prioritize verifying the withstand voltage and temperature coefficient:
 
The "P05" in the Tian'er model may indicate an accuracy of ± 5%, but it is necessary to verify the withstand voltage value and temperature coefficient in the data manual (such as HR1206J10M0P05Z, which may be ± 250ppm/℃).   
If the withstand voltage is insufficient, consider high-voltage dedicated series (such as Vishay RCVAT e3 withstand voltage of 3kV) or columnar resistors (HVM series).