Datasheet

4
LTC3776
3776fa
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Efficiency vs Load Current
Step from Sinking to Sourcing
Load Current (CH2)
Load Step (Load Connected
Between V
OUT1
and V
OUT2
)
Tracking Start-Up with Internal
Soft-Start (C
SS
= 0μF)
Oscillator Frequency
vs Input Voltage
Tracking Start-Up with External
Soft-Start (C
SS
= 0.15μF)
T
A
= 25°C unless otherwise noted.
Maximum Current Sense Voltage
vs I
TH1
Pin Voltage (CH1)
LOAD CURRENT (mA)
EFFICIENCY (%)
100
60
90
80
70
10 100 1000 10000
3776 G01
0
50
40
30
20
10
FIGURE 14 CIRCUIT
CHANNEL 2 (V
IN
= 3.3V)
CHANNEL 1 (V
IN
= 5V)
CHANNEL 1 (V
IN
= 3.3V)
CHANNEL 2 (V
IN
= 5V)
V
IN
= 3.3V
FIGURE 14 CIRCUIT
20μs/DIV
3776 G02
V
OUT2
100mV/DIV
AC-COUPLED
LOAD CURRENT
500mA/DIV
V
IN
= 3.3V
FIGURE 14 CIRCUIT
V
OUT1
SOURCING
V
OUT2
SINKING
20μs/DIV
3776 G03
V
OUT1
100mV/DIV
AC-COUPLED
V
OUT2
100mV/DIV
AC-COUPLED
LOAD CURRENT
1A/DIV
V
IN
= 3.3V
FIGURE 14 CIRCUIT
4ms/DIV
3776 G05
V
OUT1
=
2.5V
V
OUT2
=
1.25V
500mV/DIV
INPUT VOLTAGE (V)
2
–5
NORMALIZED FREQUENCY SHIFT (%)
–4
–2
–1
0
5
2
4
6
7
3736 G06
–3
3
4
1
35
8
9
10
I
TH
VOLTAGE (V)
0.5
–20
CURRENT LIMIT (%)
0
20
40
60
100
1 1.5
3776 G07
2
80
V
IN
= 3.3V
FIGURE 14 CIRCUIT
500μs/DIV
3776 G04
V
OUT1
=
2.5V
V
OUT2
=
1.25V
500mV/DIV