Datasheet

4
LTC1514-3.3/LTC1514-5
TYPICAL PERFORMANCE CHARACTERISTICS
UW
LTC1514-5 Step-Up Mode
Load Transient Response
LTC1514-5 Step-Down Mode
Load Transient Response
50mA
0mA
V
OUT
AC COUPLED
100mV/DIV
I
OUT
50mA/DIV
V
IN
= 8V, V
OUT
= 5V, C
OUT
= 10µF, T
A
= 25°C
1514 G10
V
OUT
AC COUPLED
100mV/DIV
I
OUT
50mA/DIV
V
IN
= 3.3V, V
OUT
= 5V, C
OUT
= 10µF, T
A
= 25°C
1514 G11
BLOCK DIAGRAM
W
–
+
–
+
650kHz
OSCILLATOR
1.145V
V
REF
STEP-UP/STEP-DOWN
CHARGE PUMP
V
IN
V
OUT
LBI
1514 BD
C1
–
C1
+
SHDN
LBO
GND
SHDN (Pin 1): Shutdown Input. A logic low on the SHDN
pin puts the part into shutdown mode. A logic high
(V
SHDN
≥ 1.6V) enables the charge pump regulator. At
high V
IN
voltages, the SHDN pin may still be controlled
with 3V logic without causing a large rise in V
IN
quiescent
current. The SHDN pin may not float; connect to V
IN
if
unused.
PIN FUNCTIONS
UUU
LBO (Pin 2): Open-Drain, Low-Battery Comparator Out-
put. This pin will pull low whenever the voltage on the LBI
pin is less than the internal reference voltage (1.145V typ).
LBI (Pin 3): Low-Battery Comparator Input. The voltage
on this pin is compared to the internal reference voltage
(1.145V). The LBO output will sink current when the
voltage on the LBI pin is less than 1.145V typ. The low-