LTC2927

1

2927fb

RAMP

(3.3V)

2.5V

1.8V

1V/DIV

2927 TA01b

10ms/DIV

RAMP

(3.3V)

2.5V

1.8V

1V/DIV

2927 TA01c

10ms/DIV

Single Power Supply

Tracking Controller

tracking and sequencing requirements. By selecting a few

resistors, the supply can be configured to ramp-up and

ramp-down with differing ramp rates, voltage offsets, or

time delays relative to other supplies or a master signal.

By forcing current into a feedback node of an independent

supply, the LTC2927 causes the output to track a ramp

signal without inserting any pass element losses. Because

the current is controlled in an open-loop manner, the

LTC2927 does not affect the transient response or stabil-

ity of the supply. The compact solution at point of load

minimizes the trace length of the DC/DC circuit sensitive

FB node. Furthermore, it presents a high impedance when

power-up is complete, effectively removing it from the

DC/DC circuit.

(3mm

× 2mm) DFN Packages

138k

100k

ON

RAMP

1.8V

3.3V

LTC2927

GND

SDO

RUN/SS

FB

IN

DC/DC

FB = 1.235V

OUT

RAMPBUF

TRACK

0.1μF

16.5k

16.5k

35.7k

13k

ON

RAMP

2.5V

2927 TA01a

3.3V

LTC2927

GND

SDO

RUN/SS

FB

IN

DC/DC

FB = 0.8V

OUT

RAMPBUF

TRACK

0.1μF

0.1μF

887k

887k

412k

412k

, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.

ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the

property of their respective owners. Patents Pending.

APPLICATIO S

FEATURES

DESCRIPTIO

TYPICAL APPLICATIO

Track-Up and Track-Down Waveforms