The TPS61378-Q1 is a fully-integrated synchronous boost converter with load disconnect function. It supports output voltage up to 18.5 V with a maximum of a 4.8-A programmable switching peak current limit. The input voltage ranges from 2.3 V to 14 V while consuming 25-µA quiescent current.

The TPS61378-Q1 utilizes the fixed-frequency peak current control scheme, which has an internal oscillator and supports adjustable switching frequency from 200 kHz to 2.2 MHz.

The TPS61378-Q1 operates with fixed-frequency pulse width modulation (PWM) from medium to heavy load. At the beginning of each switching cycle, the low-side N-MOSFET switch is turned on. The inductor current ramps up to a peak current that is determined by the output of the internal error amplifier (EA). Once the switching peak current triggers the output of the EA, the low-side N-MOSFET is turned off and the high-side N-MOSFET is turned on after a short dead time. The high-side N-MOSFET switch is not turned off until the next cycle as determined by the internal oscillator. The low-side switch turns on again after a short dead time and the switching cycle is repeated.

The TPS61378-Q1 provides either auto PFM or forced PWM for the light load operation by configuring the MODE/SYNC pin. In forced PWM mode, the switching frequency remains constant across the entire load range, which helps avoid frequency variation with load. The internal oscillator can be synchronized to an external clock applied on the MODE/SYNC pin. Spread spectrum modulation of the frequency in forced PWM mode helps optimize the EMI performance for automotive applications. In auto PFM mode, the switching frequency can decrease, resulting in higher efficiency.

The TPS61378-Q1 implements a cycle-by-cycle current limit to protect the device from overload during the boost operation phase. If the output current further increases and triggers the output voltage to fall below the input voltage, the TPS61378-Q1 enters into hiccup mode short protection.

There is a built-in soft-start time, which prevents the inrush current during the start-up. The TPS61378-Q1 also provides a power good (PG) indicator to enable the power sequence control for start-up.

The TPS61378-Q1 also has a number of protection features including output short protection, output overvoltage protection (OVP), and thermal shutdown protection (OTP).