10A with 96% efficiency ... no problem for TLF51801

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Modern DC/DC controllers from company Infineon, like TLF51801ELV manage even big challenges.

Perhaps everyone knows, that modern switch-mode power supplies are able to efficiently convert voltage and to replace linear power supplies. Features of ready-made DC/DC modules as well as SMPS controllers themselves are still better and nowadays it´s no problem to construct a 10A power supply on a small area. It is necessary to say, that for the most of applications it´s more advisable to use a ready-made module with proven features, developed by specialists in a given segments, like for example modules from company Traco. Despite this, there are surely many applications, where from several reasons it´s beneficial to use an own design. Offer of controllers for switch-mode power supplies is wide and this time we´d like to introduce you a modern step-down (buck) controller TLF51801ELV from company Infineon.

TLF51801 is interesting mainly by its overall „robustness“, because it´s directly designed for a construction of power supplies with a high output current (up to approx. 10A), what is also reflected in the MosFET drivers sizing, integrated soft start, under- and over-voltage protection, temperature protection, possibility of current limit setting and another features. Very beneficial is also a duty cycle of up to 99% enabling operation with a minimum difference (dropout) between input and output voltage.

TLF51801 is designed as a controller with a voltage feedback requiring 2 external N-FET transistors sized for a desired output current. Current monitoring (via pins SenseLow+SenseHigh) can be done through external sensing (shunt) resistor or with an advantage of a higher overall efficiency even an internal resistance of an FET transistor (RDSon). TLF5180 can operate in a wide range of input voltages 4,75-45V and at frequencies of 100-700kHz, while the clock frequency can be synchronized to an external clock. The circuit can be easily switched off via the “En” pin (enable), when it consumes only 2uA. An integrated thermal protection switches off the circuit at exceeding 175°C and switches on again (+SoftStart) after cooling down to 160°C.