TI TPS54494RSAR

The TPS54494 is a dual-channel, adaptive on-time D-CAP2™ mode synchronous buck converter. It helps system designers complete power bus regulator sets for various end equipment with cost-effective, low component count, and low standby current solutions. The main control loop employs D-CAP2™ mode control, which provides extremely fast transient response without external compensation components. Adaptive on-time control supports seamless transition between PWM mode under heavy load conditions and Eco-mode™ operation under light load. Eco-mode™ enables the TPS54494 to maintain high efficiency under light load conditions. It is also compatible with low ESR output capacitors such as POSCAP or SP-CAP polymer capacitors, as well as ultra-low ESR ceramic capacitors. The device provides convenient and efficient operation at input voltages between 4.5V and 18V. Available in a 4.4mm×5mm 16-pin TSSOP (PWP) package and a 4mm×4mm 16-pin VQFN (RSA) package, with a rated ambient operating temperature range of -40°C to 85°C.

The TPS54494 is a 4A/2A dual synchronous step-down (buck) converter with two integrated N-channel MOSFETs for each channel. It operates using D-CAP2™ control mode. The fast transient response of D-CAP2™ control reduces the required output capacitance to meet a specific level of performance. Proprietary internal circuitry allows the use of low ESR output capacitors including ceramic and special polymer types.

The main control loop of the TPS54494 is an adaptive on-time pulse width modulation (PWM) controller that supports a proprietary D-CAP2™ control mode. D-CAP2™ control combines constant on-time control with an internal compensation circuit for pseudo-fixed frequency and low external component count configuration with both low ESR and ceramic output capacitors. It is stable even with virtually no ripple at the output.

TPS54494 uses an adaptive on-time control scheme and does not have a dedicated on board oscillator. The TPS54494 runs with a pseudo-fixed frequency of 700 kHz by using the input voltage and output voltage to set the on-time timer.

The TPS54494 is designed with Auto-Skip Eco-mode™ to increase light load efficiency.

• D-CAP2™ control mode, fast transient response, no external components required for loop compensation, compatible with ceramic output capacitors
• Wide input voltage range: 4.5V to 18V
• Output voltage range: 0.76V to 7V
• Optimized high-efficiency integrated FETs for low duty cycle applications, 90mΩ (high-side) and 60mΩ (low-side)
• High initial reference accuracy
• 4A CH1 / 2A CH2 continuous load current
• Low-side rDS(on) low-loss current sensing
• Fixed soft-start time: 1ms
• Non-sinking pre-bias soft-start
• Power Good
• 700kHz switching frequency
• Cycle-by-cycle overcurrent limit control
• OCL / UVLO / TSD protection
• Hiccup timer for overload protection
• Adaptive gate driver with integrated boost PMOS switch
• Constant OCP due to thermally compensated rDS(on) of 4000ppm/°C
• 16-pin HTSSOP, 16-pin VQFN packages
• Auto-skip Eco-mode™ for high efficiency at light loads

• Point-of-load regulation for low-power systems in broad applications
• Digital TV power supplies
• Networked home terminal equipment
• Digital set-top boxes (STB)
• DVD players/recorders
• Game consoles and other devices