DESCRIPCIÓN

The LTM8063 is a 40VIN, 2A continuous, 2.5A peak, stepdown μModule (power module) regulator. Included in the package are the switching controller, power switches, inductor, and all support components. Operating over an input voltage range of 3.2V to 40V, the LTM8063 supports an output voltage range of 0.8V to 15V and a switching frequency range of 200kHz to 2.2MHz, each set by a single resistor. Only the input and output filter capacitors are needed to finish the design.

The low profile package enables utilization of unused space on the bottom of PC boards for high density point of load regulation. The LTM8063 is packaged in a thermally enhanced, compact over-molded ball grid array (BGA) package suitable for automated assembly by standard surface mount equipment. The LTM8063 is RoHS compliant.

 

CARACTERÍSTICAS

Arquitectura Silent Switcher® de bajo ruido

Amplio rango de tensión de entrada: 3,2 V a 40 V

Wide Output Voltage Range: 0.8V to 15V

2A Continuous Output Current at 12VIN, 5VOUT,

TA = 85°C

2.5A Peak Current

Frecuencia de conmutación seleccionable: de 200 kHz a 2,2 MHz

Sincronización externa

Configurable como inversor

6.25mm × 4mm × 2.22mm BGA Package

 

APLICACIONES

Regulación de baterías de automoción

Alimentación para productos portátiles

Regulación del suministro distribuido

Suministros industriales

Regulación del transformador de pared

 

OPERACIÓN

The LTM8063 is a stand-alone non-isolated step-down switching DC/DC power supply that can deliver up to 2.5A. The continuous current is determined by the internal operating temperature. It provides a precisely regulated output voltage programmable via one external resistor from 0.8V to 15V. The input voltage range is 3.2V to 40V. Given that the LTM8063 is a step-down converter, make sure that the input voltage is high enough to support the desired output voltage and load current.

The LTM8063 contains a current mode controller, power switching elements, power inductor and a modest amount of input and output capacitance. The LTM8063 is a fixed frequency PWM regulator. The switching frequency is set by simply connecting the appropriate resistor value from the RT pin to GND.

The RUN pin is used to place the LTM8063 in shutdown, disconnecting the output and reducing the input current to a few μA.

To enhance efficiency, the LTM8063 automatically switches to Burst Mode operation in light or no load situations. Between bursts, all circuitry associated with controlling the output switch is shut down reducing the input supply current to just a few μA.

The oscillator reduces the LTM8063’s operating frequency when the voltage at the FB pin is low. This frequency foldback helps to control the output current during start-up and overload.

The TR/SS node acts as an auxiliary input to the error amplifier. The voltage at FB servos to the TR/SS voltage until TR/SS goes above 0.77V. Soft-start is implemented by generating a voltage ramp at the TR/SS pin using an external capacitor which is charged by an internal constant current. Alternatively, driving the TR/SS pin with a signal source or resistive network provides a tracking function. Do not drive the TR/SS pin with a low impedance voltage source.

The LTM8063 contains a power good comparator which trips when the FB pin is at about 90% to 110% of its regulated value. The PG output is an open-drain transistor that is off when the output is in regulation, allowing an external resistor to pull the PG pin high. The PG signal is valid when VIN is above 3.2V. If VIN is above 3.2V and RUN is low, PG will drive low.

The LTM8063 is equipped with a thermal shutdown that inhibits power switching at high junction temperatures. The activation threshold of this function is above the maximum temperature rating to avoid interfering with normal operation, so prolonged or repetitive operation under a condition in which the thermal shutdown activates may damage or impair the reliability of the device.