Datasheet

4
LTC660
TYPICAL PERFORMANCE CHARACTERISTICS
U
W
(Using Test Circuit in Figure 1)
Oscillator Frequency
vs Temperature
TEMPERATURE (°C)
0
OSCILLATOR FREQUENCY (kHz)
4
8
12
2
6
10
–20 20 60 100
LTC660 • TPC15
140–40–60 0 40 80 120
V
+
= 5V
BOOST = OPEN 
OSC = OPEN
LOAD CURRENT (mA)
0
OUTPUT VOLTAGE DROP FROM
SUPPLY VOLTAGE (V)
0.8
1.0
80
LTC660 • TPC10
0.6
0.4
0.7
0.9
0.5
0.3
0.2
0.1
0
20
40
60
10 90
30
50
70
100
V
+
= 5.5V
T
A
= 25°C
BOOST = V
+
V
+
= 2.5V
V
+
= 1.5V
V
+
= 3.5V
V
+
= 4.5V
Output Voltage Drop
vs Load Current
Output Voltage
vs Oscillator Frequency
OSCILLATOR FREQUENCY (kHz)
0.1
–2.5
OUTPUT VOLTAGE (V)
–4.0
–4.5
–5.0
1 10 100
LTC660 • TPC11
–3.5
–3.0
T
A
=25°C
V
+
= 5V
BOOST = OPEN
I
L
= 1mA
I
L
= 10mA
I
L
= 80mA
Efficiency vs Oscillator Frequency
OSCILLATOR FREQUENCY (kHz)
0.1
70
EFFICIENCY (%)
75
80
85
90
1 10 100
LTC660 • TPC12
65
60
55
50
95
100
T
A
= 25°C
V
+
= 5V
BOOST = OPEN
I
L
= 10mA I
L
= 80mA
I
L
= 1mA
Oscillator Frequency
vs Supply Voltage
SUPPLY VOLTAGE (V)
0
OSCILLATOR FREQUENCY (kHz)
4
8
12
2
6
10
1.0 2.5 3.5 4.5
LTC660 • TPC13

5.50.50 1.5 2.0 3.0 4.0 5.0
T
A
= 25°C
BOOST = OPEN
OSC = OPEN
Oscillator Frequency
vs Supply Voltage
SUPPLY VOLTAGE (V)
0
OSCILLATOR FREQUENCY (kHz)
60
50
40
30
20
80
100
10
70
90
1.0 2.5 3.5 4.5
LTC660 • TPC14
5.50.50 1.5 2.0 3.0 4.0 5.0
T
A
= 25°C
BOOST = V
+

OSC = OPEN
Oscillator Frequency
vs Temperature
TEMPERATURE (°C)
–60
OSCILLATOR FREQUENCY (kHz)
60
80
100
100
LTC660 • TPC16
40
20
10
70
90
50
30
0
–20
20
60
–40 120
0
40
80
140
V
+
= 5V
BOOST = V
+

OSC = OPEN
Oscillator Frequency
vs External Capacitance
CAPACITANCE (pF)
00.1
OSCILLATOR FREQUENCY (kHz)
1
100
1000100101 10000
LTC660 • TPC17
0.1
10
BOOST = V
+
BOOST = OPEN