Datasheet

4
LTC1144
TYPICAL PERFORMANCE CHARACTERISTICS
U
W
Power Conversion Efficiency and
Supply Current vs Load Current
OSCILLATOR FREQUENCY (kHz)
0.1
0
OUTPUT RESISTANCE (Ω)
2000
3000
1 10 100
LTC1144 • TPC12
1000
1µF10µF
100µF
T
A
= 25°C
V
+
= 15V
OSCILLATOR FREQUENCY (kHz)
0.1
70
POWER CONVERSION EFFICIENCY (%)
90
95
100
1 10 100
LTC1144 • TPC11
85
80
75
T
A
= 25°C, V
+
= 15V
BOOST = OPEN
I
L
= 20mA
I
L
= 3mA
1µF
1µF
10µF
10µF
100µF
100µF
Power Conversion Efficiency
vs Oscillator Frequency
Output Resistance
vs Oscillator Frequency
Output Voltage vs Load Current
LOAD CURRENT (mA)
–10
OUTPUT VOLTAGE (V)
–5
0
0.001 0.1 1 100
LTC1144 • TPC15
–15
0.01
10
V
+
= 15V
T
A
= 25°C
C1 = C2

BOOST = 15V
0.1µF
0.1µF
1µF
1µF
10µF
10µF
BOOST = OPEN
Output Voltage vs Load Current
LOAD CURRENT (mA)
–4
OUTPUT VOLTAGE (V)
–3
–2
–1
0
0.001 0.1 1 100
LTC1144 • G14
–5
0.01
10
0.1µF
0.1µF10µF
10µF
1µF
1µF
V
+
= 5V
T
A
= 25°C
C1 = C2

BOOST = 5V
BOOST = OPEN
LOAD CURRENT (mA)
0.01
0
RIPPLE VOLTAGE (mV)
500
1000
1µF
1µF
1500
0.1 1
LTC1144 • TPC13
10 100
0.1µF
10µF
10µF
V
+
= 5V
T
A
= 25°C
C1 = C2

BOOST = 5V
BOOST = 
OPEN
0.1µF
Ripple Voltage vs Load Current
PI FU CTIO S
U
UU
Boost (Pin 1): This pin will raise the oscillator frequency
by a factor of 10 if tied high.
CAP
+
(Pin 2): Positive Terminal for Pump Capacitor.
GND (Pin 3): Ground Reference.
CAP
–
(Pin 4): Negative Terminal for Pump Capacitor.
V
OUT
(Pin 5): Output of the Converter.
SHDN (Pin 6): Shutdown Pin. Tie to V
+
pin or leave floating
for normal operation. Tie to ground when in shutdown
mode.
OSC (Pin 7): Oscillator Input Pin. This pin can be overdriven
with an external clock or can be slowed down by connect-
ing an external capacitor between this pin and ground.
V
+
(Pin 8): Input Voltage.
LOAD CURRENT (mA)
0
POWER CONVERSION EFFICIENCY (%)
SUPPLY CURRENT (mA)
60
80
100
16
LTC1144 • TPC10
40
20
0
30
40
50
20
10
0
4
8
12
20
P
EFF
I
S
T
A
= 25°C
V
+
= 5V
C1 = C2 = 10µF
BOOST = OPEN
(SEE TEST CIRCUIT)