Datasheet

4
LT1304/LT1304-3.3/LT1304-5
TYPICAL PERFORMANCE CHARACTERISTICS
UW
Load Transient Response
V
OUT
100mV/DIV
AC COUPLED
I
LOAD
200mA
0
V
SW
5V/DIV
100µs/DIV
1304 G07
20µs/DIV 1304 G08
V
OUT
100mV/DIV
AC COUPLED
Burst Mode
TM
Operation
I
L
500mA/DIV
V
IN
= 2.5V
V
OUT
= 5V
I
LOAD
= 185mA
L = 22µH
PIN FUNCTIONS
UUU
LBI (Pin 1): Low-Battery Detector Input. When voltage on
this pin is less than 1.17V, detector output is low.
LBO (Pin 2): Low-Battery Detector Output. Open collector
can sink up to 500µA. Low-battery detector remains active
when device is shut down.
V
IN
(Pin 3): Input Supply. Must be bypassed close (<0.2")
to the pin. See required layout in the Typical Applications.
SW (Pin 4): Collector of Power NPN. Keep copper traces on
this pin short and direct to minimize RFI.
GND (Pin 5): Device Ground. Must be low impedance;
solder directly to ground plane.
I
LIM
(Pin 6): Current Limit Set Pin. Float for 1A peak switch
current; a resistor to ground will lower peak current.
SHDN (Pin 7): Shutdown Input. When low, switching
regulator is turned off. The low-battery detector remains
active. The SHDN input should not be left floating. If SHDN
is not used, tie the pin to V
IN
.
FB/SENSE (Pin 8): On the LT1304 (adjustable) this pin
goes to the comparator input. On the fixed-output ver-
sions, the pin connects to the resistor divider which sets
output voltage. The divider is disconnected from the pin
during shutdown.
Burst Mode is a trademark of Linear Technology Corporation.