ZHCS936A May 2012 – February 2019 TPS53014
PRODUCTION DATA.
7.3.6 Overcurrent Protection
TPS53014 has a cycle-by-cycle over current limit feature. The over current limits the inductor valley current by monitoring the voltage drop across the low-side MOSFET RDS(on) during the low-side driver on-time. If the inductor current is larger than the over current limit (OCL), the TPS53014 delays the start of the next switching cycle until the sensed inductor current falls below the OCL current. MOSFET RDS(on) current sensing is used to provide an accuracy and cost effective solution without external devices. To program the OCL, a resister should be connected between DRVL and PGND. The recommended values are given inTable 1.
Table 1. OCL Resistor Values
| RESISTER VALUE ( kΩ) | Vtrip (V) |
| 6.8 | 0.050 |
| 11 | 0.087 |
| 18 | 0.125 |
| 27 | 0.174 |
| 39 | 0.224 |
| 56 | 0.274 |
| 75 | 0.336 |
IOCL is determined by Equation 3.
The trip voltage is set between 0.05 V to 0.336 V over all operational temperature, including the 4000ppm/°C temperature slope compensation for the temperature dependency of the RDS(on). If the load current exceeds the overcurrent limit, the voltage will begin to drop. If the over-current conditions continues the output voltage will fall below the under voltage protection threshold and the TPS53014 will shut down.