5
LTC1682/LTC1682-3.3/LTC1682-5
V
OUT
(Pin 1): Low Noise Regulated Output Voltage. V
OUT
should be bypassed with a ≥2µF low ESR capacitor as
close to the pin as possible for best performance. The V
OUT
range is 2.5V to 5.5V.
SHDN (Pin 2): Shutdown Input. A logic low on the SHDN
pin puts the part in shutdown mode. A logic high enables
the part. To continuously enable the part connect SHDN to
V
IN
. When the part is in shutdown, V
OUT
will be connected
to ground via a 100Ω switch and CPO will be high
impedance disconnected from V
IN
.
FB (Pin 3) (LTC1682): The voltage on this pin is compared
to the internal reference voltage (1.235V) by the error
amplifier to keep the output in regulation. An external
resistor divider is required between V
OUT
and FB to adjust
the output voltage.
FILT (Pin 3) (LTC1682-3.3/LTC1682-5): This pin is used
to filter the internal voltage reference. Typically a 1nF
capacitor is connected from FILT to ground.
GND (Pin 4): System Ground.
C
–
(Pin 5): Flying Capacitor Negative Input.
V
IN
(Pin 6): Input Voltage, 1.8V to 4.4V. V
IN
should be
bypassed with a ≥2µF low ESR capacitor as close to the
pin as possible for best performance. A minimum capaci-
tance value of 0.1µF is required.
C
+
(Pin 7): Flying Capacitor Positive Input.
CPO (Pin 8): Unregulated Charge Pump Output Voltage.
Approximately 1.95(V
IN
) at low loads. Bypass with a ≥2µF
low ESR capacitor. If a minimum V
OUT
enable time is
required, the CPO capacitor should be 2× the V
OUT
capacitor.
PIN FUNCTIONS
UUU
TEMPERATURE (°C)
–50
V
OUT
VOLTAGE (V)
5.030
5.020
5.010
5.000
4.990
3.340
3.330
3.320
3.310
3.300
3.290
1.238
1.240
1.236
1.234
1682 G09
–25
25
50 125
0
75
100
LTC1682
LTC1682-3.3
LTC1682-5
V
IN
= 3V
I
OUT
= 10mA
V
OUT
Voltage vs Temperature
TYPICAL PERFOR A CE CHARACTERISTICS
UW
OUTPUT CURRENT (mA)
0
V
OUT
VOLTAGE (V)
4.994
4.993
3.300
4.997
4.996
4.995
5.000
4.999
4.998
15 25 40 45 50
1682 G10
3.299
3.298
3.297
3.296
3.295
3.294
510
20
30 35
V
IN
= 3.3V
T
A
= 25°C
LTC1682-5
LTC1682-3.3
V
OUT
Voltage vs Output Current
