ltc1778-1 Linear Technology Corporation, ltc1778-1 Datasheet - Page 5

• Manufacturer Part Number: ltc1778-1
• Description: Wide Operating Range, No Rsense Step-down Controller
• Manufacturer: Linear Technology Corporation

TYPICAL PERFOR A CE CHARACTERISTICS
–100
–200
150
125
100
300
250
150
100
200
300
200
100
75
50
25
50
0
0
0
–50
1.5
Maximum Current Sense
Threshold vs RUN/SS Voltage
On-Time vs Temperature
Current Sense Threshold
vs I
0
V
I
V
ION
RNG
VON
–25
TH
= 30µA
= 1V
0.5
= 0V
Voltage
2
RUN/SS VOLTAGE (V)
0
TEMPERATURE (°C)
1.0
I
TH
25
VOLTAGE (V)
2.5
1.5
50
V
RNG
2.0
75
=
3
W
100
2.5
1.4V
1V
2V
0.7V
0.5V
1778 G23
1778 G22
1778 G08
U
3.5
125
3.0
150
125
100
130
100
100
150
140
120
110
10k
75
50
25
1k
10
0
–50 –25
0
Current Limit Foldback
1
On-Time vs I
Maximum Current Sense
Threshold vs Temperature
V
V
RNG
RNG
= 1V
= 1V
0.2
0
TEMPERATURE (°C)
I
ON
ON
CURRENT (µA)
25
V
FB
0.4
Current
10
(V)
50
75
0.6
V
VON
100
1778 G09
1778 G20
1778 G11
= 0V
0.8
125
100
LTC1778/LTC1778-1
1000
0.79
0.82
0.81
0.80
0.78
800
600
400
200
300
250
200
150
100
50
0
0
–50
0.5
0
Feedback Reference Voltage
vs Temperature
On-Time vs V
Maximum Current Sense
Threshold vs V
I
ION
–25
= 30µA
0.75
0
TEMPERATURE (°C)
1.0
V
V
1
RNG
ON
25
ON
VOLTAGE (V)
VOLTAGE (V)
RNG
1.25
Voltage
50
Voltage
1.5
2
75
1.75
100
1778 G21
1778 G12
1778 G10
1778fb
5
125
2.0
3