ZHCS984B June 2012 – May 2019 TPS54678
PRODUCTION DATA.
The TPS54678 uses a settable fixed frequency, peak current mode control. The output voltage is compared through external resistors on the VSENSE pin to an internal voltage reference by an error amplifier which drives the COMP pin. An internal oscillator initiates the turn on of the high-side power switch. The error amplifier output is compared to the high-side power switch current. When the power switch current reaches the COMP voltage level the high-side power switch is turned off and the low-side power switch is turned on. The COMP pin voltage will increase and decrease as the output current increases and decreases. The device implements a current limit by clamping the COMP pin voltage to a maximum level and implements a sleep mode with a minimum clamp.