LTC1514-3.3/LTC1514-5
TYPICAL PERFORMANCE CHARACTERISTICS
LTC1514-5 Step-Down Mode
Load Transient Response
LTC1514-5 Step-Up Mode
Load Transient Response
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
BLOCK DIAGRAM
V
IN
SHDN
LBO
PIN FUNCTIONS
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.
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-
4
U W
V
OUT
AC COUPLED
100mV/DIV
50mA
0mA
I
OUT
50mA/DIV
V
IN
= 3.3V, V
OUT
= 5V, C
OUT
= 10µF, T
A
= 25°C
1514 G11
W
C1
–
C1
+
STEP-UP/STEP-DOWN
CHARGE PUMP
V
OUT
–
650kHz
OSCILLATOR
+
–
+
1.145V
V
REF
LBI
GND
1514 BD
U
U
U
LINER [ LINEAR TECHNOLOGY ]
