9.3.2 Synchronizing to an External Clock

The TPSM8281x can be synchronized by applying a clock on the MODE/SYNC pin. There is no need for

any additional circuitry. See Figure 9-35. The clock can be applied, changed, and removed during operation.

The value of the RCF resistor is recommended to be chosen such that the internally defined frequency and

the externally-applied frequency are close to each other to have a fast settling time to the external clock.

Synchronizing to a clock is not possible, if the COMP/FSET pin is connected to Vin or GND. Figure 9-36 and

Figure 9-37 show the external clock being applied and removed. When an external clock is applied, the device

operates in PWM mode.

Figure 9-35. Frequency Synchronization

VIN = 5V

RCF = 8.06kΩ

IOUT = 0.1A

VOUT = 1.8V

fEXT = 2.5MHz

Figure 9-36. Applying and Removing the

Synchronization Signal (PFM)

VIN = 5V

RCF = 8.06kΩ

IOUT = 1A

VOUT = 1.8V

fEXT = 2.5MHz

Figure 9-37. Applying and Removing the

Synchronization Signal (FPWM)

9.4 Power Supply Recommendations

The TPSM8281x device family has no special requirements for the input power supply. The output current of the

input power supply needs to be rated according to the supply voltage, output voltage, and output current of the

TPSM8281x.

TPSM82810, TPSM82813

SLUSDN6D – SEPTEMBER 2019 – REVISED JUNE 2026

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