STK984-090A-E APPLICATIONS INFORMATION Functional Description Operation in over-temperature conditions Table 2 shows the truth table for the normal operating mode. The truth table shows the U output which is controlled by the HINU and LINU inputs. The truth tables for the V and W outputs follow the same rules. The input signals are active HIGH. The RESET signal is active LOW. Table 4 shows the truth table for over-temperature operating conditions. Input An internal pull-down resistor (100k typical) is connected to each input signal terminal. If an additional external pull-down resistor is used, it is important to ensure the input voltage threshold requirements are still met. Input Output LINU RESET U DIAG1 DIAG2 L L H OFF L L Output OFF L H H L L L Lo Side ON H L H H L L Hi Side ON H H H OFF L L Output OFF X X L OFF H H Output OFF Operation Mode HINU LINU RESET U DIAG1 DIAG2 X X H OFF L H Over Temperature Protection Operating X X L OFF H H Output OFF Table 4: Truth Table Over-temperature Protection Operation in undervoltage conditions Table 5 shows the truth table for low voltage protection operating conditions. Operation Mode HINU Output Input Output Operation Mode HINU LINU RESET U DIAG1 DIAG2 X X H OFF L L Low voltage Protection Operating X X L OFF H H Output OFF Table 5: Truth Table Low Voltage Protection Table 2: Truth Table Normal Operating Mode Operation in over-voltage conditions Table 6 shows the truth table for over-voltage operating conditions. Operation in over-current and short-circuit conditions Table 3 shows the truth table for over-current and short-circuit protection operating conditions for the U output which is controlled by the HINU and LINU inputs. The truth tables for the V and W outputs follow the same rules. Over-current protection is activated only if LINU, LINV and LINW are in the high state. Short-circuit protection is activated only if LINU, LINV and LINW are in the low state. Input Output Operation Mode HINU LINU RESET U DIAG1 DIAG2 X X H OFF L L Over Voltage Protection Operating X X L OFF H H Output OFF Table 6: Truth Table Over-Voltage Protection DIAG Outputs Input Output HINU LINU RESET U DIAG1 DIAG2 L L H OFF L L L H H L H L Terminal DIAG1 and DIAG2 are open drain outputs. A pull-up resistor of 4.7k for a 5V power supply is recommended. Operation Mode Output OFF Over Current Protection Operating ShortCircuit Protection Operating H L H H H L H H H OFF L L Output OFF L/H L/H L OFF H H Output OFF Layout Voltage ringing due to stray inductance, especially in the power source wiring between VB1 and PG, will occur during switching. Use layout techniques such as short traces and wide traces to minimize the inductance of the power loop. Further, a high frequency capacitor needs to be placed very close to the terminals VB1 and PG, in addition to the electrolytic bulk capacitor. Table 3:Truth Table Over-current and Short-circuit Protection Modes System level fuse A system level fuse in the VB1 power line is recommend to ensure a fail-safe design. www.onsemi.com 9