Datasheet

LTM8055/LTM8055-1
8
Rev C
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PIN FUNCTIONS
I
OUTMON
(Pin L2): Output Current Monitor. This pin pro-
duces a
voltage that is proportional to the voltage between
V
OUT
and I
OUT
. I
OUTMON
will equal 1.2V when V
OUT
– I
OUT
= 58mV. This feature is generally useful only if a current
sense resistor is applied between V
OUT
and I
OUT
. This is
a high impedance output. Use a buffer to drive a load.
I
INMON
(Pin L3): Input Current Monitor. This pin produces
a voltage that is proportional to the voltage between I
IN
and V
IN
. I
INMON
will equal 1V when I
IN
– V
IN
= 50mV. This
feature is generally useful only if a current sense resistor
is applied between V
IN
and I
IN
.
RUN (Pin L4): LTM8055/LTM8055-1 Enable. Raise the RUN
pin voltage above 1.2V for normal operation. Above 1.2V
(typical), but below 6V, the RUN pin input bias current is
less than 1μA. Below 1.2V and above 0.3V, the RUN pin
sinks 3μA so the user can define the hysteresis with the
external resistor selection. This will also reset the soft-start
function. If RUN is 0.3V or less, the LTM8055/LTM8055-1
is disabled and the SV
IN
quiescent current is below 1μA.
I
IN
(Pin L9): Input Current Sense. Tie this pin to the input
current sense resistor. The input average current sense
threshold is 50mV, so the LTM8055/LTM8055-1 will
regulate the input current to 50mV/R
SENSE
, where R
SENSE
is the value of the input current sense resistor in ohms.
Tie to V
IN
when not used. Keep this pin within ±0.5V of
V
IN
under all conditions.
BLOCK DIAGRAM
0.2µF
4.7µH
0.47µF
50V
0.1µF
CTL
COMP RT SYNC
100k
2V
100k
I
OUTMON
8055 BD
I
INMON
CLKOUT
FB
I
OUT
V
OUT
SS
GND
RUN
I
IN
V
IN
SV
IN
BUCK-BOOST CONTROLLER
LLMODE
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