LT1579 LINER [Linear Technology], LT1579 Datasheet - Page 11

• Manufacturer Part Number: LT1579
• Description: 300mA Dual Input Smart Battery Backup Regulator
• Manufacturer: LINER [Linear Technology]

PIN
BLOCK
LBO1: This is the open collector output of the low-battery
comparator LB1. This output pulls low when the com-
parator input drops below the threshold voltage. The
LBO1 output voltage is 1V when sinking 5mA, dropping
to under 200mV at 20 A (see curve of Logic Flag Voltage
vs Current in the Typical Performance Characteristics).
This makes the LBO1 pin equally useful in driving both
bipolar and CMOS logic inputs with the addition of an
external pull-up resistor. It is also capable of driving
higher current devices, such as LEDs. This pin is inter-
nally clamped to 7V and – 0.6V (one V
pin can be left open circuit. Device operation is unaffected
if this pin is not connected.
U
FUNCTIONS
U
DIAGRAM
BIASCOMP
SHDN
LBI1
LBI2
V
V
U
IN1
IN2
SS
W
1.5V REFERENCE
BIAS CURRENT
CONTROL
BE
+
–
). If unused, this
LB1
DROPOUT
OUTPUT DRIVER
DETECT
CONTROL
+
–
LB2
LBO2: This is the open collector output of the low-battery
comparator LB2. This output pulls low when the com-
parator input drops below the threshold voltage. The
LBO2 output voltage is 1V when sinking 5mA, dropping
to under 200mV at 20 A (see curve of Logic Flag Voltage
vs Current in the Typical Performance Characteristics).
This makes the LBO2 pin equally useful in driving both
bipolar and CMOS logic inputs with the addition of an
external pull-up resistor. It is also capable of driving
higher current devices, such as LEDs. This pin is
internally clamped to 7V and – 0.6V (one V
this pin can be left open circuit. Device operation is
unaffected if this pin is not connected.
E/A
WARNING
FLAGS
–
+
INTERNAL
RESISTOR DIVIDER
FOR FIXED VOLTAGE
DEVICES ONLY
V
ADJ
BACKUP
DROPOUT
LBO1
LBO2
1579 • BD
OUT
BE
LT1579
). If unused,
11