SNVSCU9A May 2025 – November 2025 TPS7H4012-SEP , TPS7H4013-SEP
PRODMIX
The TPS7H401x is configured for external clock mode if a clock signal is input on SYN1. In this mode, a clock is input on SYNC1 and the TPS7H401x switching will switch 180° out of phase with SYNC1.
In external clock mode, RT may be left floating as it is not required to program the switching frequency with a resistor from RT to GND. However, a resistor from RT to GND must be configured (as shown in Section 9.3.6.1) if it is desired to have a fallback default switching frequency if the input clock is not available (such as before the clock is provided to the TPS7H401x device or during a clock fault). If RT is populated in this mode and no external clock signal is detected for tCLK_E_I (typically 2 clock cycles), the TPS7H401x will transition to the internal clock. This is shown in Figure 9-5. If the external clock is again provided, it will switch back to the external clock in tCLK_I_E (typically 1 clock cycle). This is shown in Figure 9-6. When this configuration is utilized, program the internal clock frequency to the same nominal value as the external clock frequency.
The external clock may be provided by an oscillator, FPGA, or other suitable device. Alternatively, the external clock may be provided by a TPS7H4011 device that is configured in internal oscillator mode.