LT1304/LT1304-3.3/LT1304-5
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TYPICAL PERFORMANCE CHARACTERISTICS
Burst ModeTM Operation
Load Transient Response
VOUT
100mV/DIV
VOUT
100mV/DIV
AC COUPLED
AC COUPLED
VSW
5V/DIV
ILOAD
200mA
0
IL
500mA/DIV
100µs/DIV
1304 G07
20µs/DIV
1304 G08
VIN = 2.5V
OUT = 5V
LOAD = 185mA
L = 22µH
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Burst Mode is a trademark of Linear Technology Corporation.
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PIN FUNCTIONS
ILIM (Pin6):CurrentLimitSetPin. Floatfor1Apeakswitch
current; a resistor to ground will lower peak current.
LBI (Pin 1): Low-Battery Detector Input. When voltage on
this pin is less than 1.17V, detector output is low.
SHDN (Pin 7): Shutdown Input. When low, switching
regulator is turned off. The low-battery detector remains
active. The SHDNinput should not be left floating. IfSHDN
is not used, tie the pin to VIN.
LBO (Pin 2): Low-Battery Detector Output. Open collector
cansinkupto500µA. Low-batterydetectorremainsactive
when device is shut down.
VIN (Pin 3): Input Supply. Must be bypassed close (<0.2")
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.
to the pin. See required layout in the Typical Applications.
SW(Pin4):CollectorofPowerNPN.Keepcoppertraceson
this pin short and direct to minimize RFI.
GND (Pin 5): Device Ground. Must be low impedance;
solder directly to ground plane.
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