LTC1514-3.3/LTC1514-5
U W
TYPICAL PERFORMANCE CHARACTERISTICS
LTC1514-5 Step-Down Mode
Load Transient Response
LTC1514-5 Step-Up Mode
Load Transient Response
VOUT
VOUT
AC COUPLED
100mV/DIV
AC COUPLED
100mV/DIV
50mA
0mA
IOUT
50mA/DIV
IOUT
50mA/DIV
VIN = 8V, VOUT = 5V, COUT = 10µF, TA = 25°C
VIN = 3.3V, VOUT = 5V, COUT = 10µF, TA = 25°C
1514 G10
1514 G11
W
BLOCK DIAGRAM
–
+
C1
C1
V
IN
STEP-UP/STEP-DOWN
CHARGE PUMP
V
OUT
SHDN
–
+
650kHz
OSCILLATOR
LBO
LBI
–
+
1.145V
V
REF
1514 BD
GND
U
U
U
PIN FUNCTIONS
LBO (Pin 2): Open-Drain, Low-Battery Comparator Out-
put. This pin will pull low whenever the voltage on the LBI
pinislessthantheinternalreferencevoltage(1.145Vtyp).
SHDN (Pin 1): Shutdown Input. A logic low on the SHDN
pin puts the part into shutdown mode. A logic high
(VSHDN ≥ 1.6V) enables the charge pump regulator. At
high VIN voltages, the SHDN pin may still be controlled
with3VlogicwithoutcausingalargeriseinVIN quiescent
current. The SHDN pin may not float; connect to VIN if
unused.
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
Linear [ Linear ]
