LT8697
Typical perForMance characTerisTics
Transient Response Output
Current Limit
10
FRONT PAGE
APPLICATION CIRCUIT
V
LOAD
CURRENT (A)
VOLTAGE (V)
V
PG
V
OUT
(V)
0
6
5.5
USB5V
SHORTED
TO GND
12
6.5
T
A
= 25°C, unless otherwise noted.
Transient Response USB5V
Shorted to GND
I
LOAD
= 0A
FRONT PAGE
APPLICATION CIRCUT
5
9
6.0
–5
I
LOAD
50mA/µs
–10
3
0
5.0
4.5
–15
100µs/DIV
–3
8697 G33
4.0
100µs/DIV
8697 G34
Start-Up Dropout Performance
R
LOAD
= 5.6
V
IN
2V/DIV
V
IN
V
IN
2V/DIV
Start-Up Dropout Performance
R
LOAD
= ∞
V
IN
V
OUT
2V/DIV
V
OUT
V
OUT
2V/DIV
V
OUT
100ms/DIV
8697 G35
100ms/DIV
8697 G36
pin FuncTions
SYNC (Pin 1):
External Clock Synchronization Input.
Tie to a clock source for synchronization to an external
frequency and forced continuous mode. Tie to INTV
CC
if
not used. Do not float.
TR/SS (Pin 2):
Output Tracking and Soft-Start Pin. This
pin allows user control of output voltage ramp rate during
start-up. A TR/SS voltage below 0.97V forces the LT8697
to regulate V
USB5V
to 5 times the TR/SS voltage. When
TR/SS is above 0.97V, the tracking function is disabled
and the internal reference resumes control of the error
amplifier. An internal 2.2µA pull-up current from INTV
CC
on this pin allows a capacitor to program output voltage
slew rate. This pin is pulled to ground when EN/UV is low,
during thermal shutdown and when V
IN
below its under-
voltage lockout threshold; use a series resistor of at least
10k if driving from a low impedance output.
RT (Pin 3):
Tie a resistor between RT and ground to set
the switching frequency.
EN/UV (Pin 4):
The LT8697 is shut down when this pin
is low and active when this pin is high. The hysteretic
threshold voltage is 1.00V going up and 0.96V when going
down. Tie to V
IN
if the shutdown feature is not used. An
external resistor divider from V
IN
can be used to program
a V
IN
threshold below which the LT8697 will shut down.
8697p
8
For more information
LINEAR_DIMENSIONS [ LINEAR DIMENSIONS SEMICONDUCTOR ]
