LTM8048 datasheet(11/22 Pages) LINER

11 / 22 page

LTM8045

8045fa

For more information www.linear.com/8045

OPERATION

The LTM8045 is a stand-alone switching DC/DC converter

that may be configured either as a SEPIC (single-ended

primary inductance converter) or inverting power supply

simply by tying VOUT– or VOUT+ to GND, respectively.

It accepts an input voltage up to 18VDC. The output is

adjustable between 2.5V and 15V for the SEPIC, and

between –2.5V and –15V for the inverting configuration.

The LTM8045 can provide 700mA at VIN = 12V when VOUT

= 2.5V or –2.5V.

As shown in the Block Diagram, the LTM8045 contains a

current mode controller, power switching element, power

coupled inductor, power Schottky diode and a modest

amount of input and output capacitance. The LTM8045

is a fixed frequency PWM converter.

The LTM8045 switching can free run by applying a resis-

tor to the RT pin or synchronize to an external source at

a frequency between 200kHz and 2MHz. To synchronize

to an external source, drive a valid signal source into the

SYNC pin. An RT resistor is required whether or not a

SYNC signal is applied. See the Applications Information

section for more details.

The LTM8045 also features RUN and SS pins to control

the start-up behavior of the device. The RUN pin may also

be used to implement an accurate undervoltage lockout

function by applying just one or two resistors.

The LTM8045 is equipped with a thermal shutdown to

protect the device during momentary overload conditions.

It is set above the 125°C absolute maximum internal tem-

perature rating to avoid interfering with normal specified

operation, so internal device temperatures will exceed

the absolute maximum rating when the overtemperature

protection is active. Therefore, continuous or repeated

activation of the thermal shutdown may impair device

reliability.

LTM8048 Datasheet(PDF) 11 Page - Linear Technology