Design the current-based TS network for the BQ25190 to support the following charging requirements for a medical application:

Suspend charging when the battery NTC temperature is above 45°C or below 10°C.

1. Identify the required battery temperature thresholds.

   • T_HOT = 45°C

   • T_COLD = 10°C

2. Find the TS voltage thresholds from the BQ25190 datasheet.

   • V_HOT = 0.276V

   • V_COLD = 0.580V

3. Determine the resistance of the NTC at T_HOT and T_COLD.

   Assuming a 10kΩ at 25°C NTC with β(25/85°C)=3435K, the exponential form of the beta equation given in Equation 1 is used to calculate R_HOT and R_COLD:

   • R_HOT = 4,847Ω

   • R_COLD = 18,410Ω

4. Calculate the required series and parallel resistors.

   From the BQ25190 datasheet:

   • I_BIAS = 80µA

   • V_HOT = 0.276V

   • V_COLD = 0.580V

   Calculating the series resistor using Equation 2:

   • R_S,1 = 1.79Ω

   • R_S,2 = -23,259Ω

   Calculating the parallel resistor, R_P, using the valid solution, R_S,1, and Equation 3:

   • R_P = 11,959Ω

   Selecting standard E96 series (1% tolerance) resistor values from the calculated values:

   • R_S = 0Ω (short)

   • R_P = 12kΩ

5. Verifying the TS thresholds that result from these resistor values using Equation 4:

   • V_{TS, HOT} = 80µA (12kΩ || (0Ω + 4,847Ω)) = 0.276V

   • V_{TS, COLD} = 80µA (12kΩ || (0Ω + 18,410Ω)) = 0.581V

   These entry thresholds align with the COLD and HOT thresholds of the BQ25190 listed in step 2.