Datasheet

4
LT1305
TYPICAL PERFORMANCE CHARACTERISTICS
U
W
TEMPERATURE (°C)
–50
1.200
LBI VOLTAGE (V)
1.210
1.215
1.220
1.225
1.230
1.235
–25
0
25 50
LT1305 • G10

75
1.240
1.245
1.250
1.205
100
Low-Battery Detect Trip Point
TEMPERATURE (°C)
–50
0
SWITCH SATURATION VOLTAGE (mV)
50
100
150
200
300
–25
02550
LT1305 • G13
75 100
250
I
SW
= 1A
Switch Saturation Voltage
SWITCH CURRENT (A)
0
SWITCH SATURATION VOLTAGE (mV)
300
400
1.6
LT1305 • F12
200
100
250
350
150
50
0
0.4
0.8
1.2
2.0
1.4
0.2
0.6
1.0
1.8
T
A
= 25°C
Switch Saturation Voltage
GND (Pin 1): Signal Ground. Tie to PGND under the
package.
LBO (Pin 2): Open-Collector Output of Comparator C3.
Can sink 100µA. High impedance when device is in shut-
down.
SHDN (Pin 3): Shutdown. Pull high to shut down the
LT1305. Ground for normal operation.
FB (Pin 4): Feedback Input. Connects to main comparator
C1 input.
LBI (Pin 5): Low-Battery Comparator Input. When voltage
on this pin is below 1.24V, LBO is low.
V
IN
(Pin 6): Supply Pin. Must be bypassed with a large
value capacitor to gound. Keep bypass within 0.2" of the
device.
SW (Pin 7): Switch Pin. Connect inductor and diode here.
Keep layout short and direct to minimize radio frequency
interference.
PGND (Pin 8): Power Ground. Tie to signal ground (pin 1)
under the package. Bypass capacitor from V
IN
should be
tied directly to PGND within 0.2" of the device.
PI FU CTIO S
U
UU