JAJSFQ6E March 2014 – July 2018 TPS92601-Q1 , TPS92602-Q1
UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.
The output overvoltage protection threshold of the TPS92602y-Q1 device is externally adjustable using a resistor divider network. In the application circuit of Figure 22, this divider network comprises of R1 and R3 for channel1 and R2 and R4 for channel2. The following equation gives the relationship of the overvoltage-protection threshold (V(OVPT)) to the resistor divider.
The load is four white LEDs, the forward voltage is about 13.2 V, maximum V(VIN) is 16 V, so the maximum output is 13.2 + 16 = 29.2 V, which is close to 30 V. Allowing 20% margin for overvoltage protection, V(OVPT) is: V(OVPT) = 30 × 1.2 = 36 V. So R1 / R3 = R2 / R4 = (36 – 2.2) / 2.2 = 15.36. Select R3 = R4 = 30 kΩ; then R1 = R2 = 460 kΩ. Use the nearest standard value of 464 kΩ.