LTC1142/LTC1142L/LTC1142HV
ELECTRICAL CHARACTERISTICS
SYMBOL
PARAMETER
CONDITIONS
LTC1142, LTC1142HV
V
14
= V
OUT
+ 100mV (Forced)
V
14
= V
OUT
– 100mV (Forced)
V
SHDN
t
OFF
Shutdown Pin Threshold
Off-Time (Note 4)
C
T
= 390pF, I
LOAD
= 700mA
– 40°C
≤
T
A
≤
85°C (Note 5), V
10
= V
24
= 10V, unless otherwise noted.
MIN
TYP
25
150
0.8
5
MAX
UNITS
mV
mV
V
µs
125
0.55
3.8
175
2
6
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2:
T
J
is calculated from the ambient temperature T
A
and power
dissipation P
D
according to the following formula:
LTC1142CG: T
J
= T
A
+ (P
D
×
95°C/ W)
Note 3:
This current is for one regulator block. Total supply current is the
sum of Pins 10 and 24 currents. Dynamic supply current is higher due to
the gate charge being delivered at the switching frequency. See the
Applications Information section.
Note 4:
In applications where R
SENSE
is placed at ground potential, the off-
time increases approximately 40%.
Note 5:
The LTC1142/LTC1142L/LTC1142HV are guaranteed to meet
specified performance from 0°C to 70°C and are designed, characterized
and expected to meet these extended temperature limits, but are not tested
at – 40°C and 85°C. Guaranteed I-grade parts are available, consult the
factory.
Note 6:
The LTC1142L-ADJ allows operation down to V
IN
= 3.5V.
TYPICAL PERFOR A CE CHARACTERISTICS
5V Output Efficiency
100
V
IN
= 6V
V
IN
= 5V
EFFICIENCY (%)
V
IN
= 10V
EFFICIENCY (%)
EFFICIENCY (%)
95
90
85
0.01
0.1
LOAD CURRENT (A)
3.3V Efficiency vs Input Voltage
100
98
96
FIGURE 1 CIRCUIT
V
OUT
= 3.3V
40
30
20
EFFICIENCY (%)
94
∆V
OUT
(mV)
92
90
88
86
84
82
80
0
4
I
LOAD
= 100mA
0
– 10
– 20
– 30
– 40
∆V
OUT
(mV)
I
LOAD
= 1A
12
8
INPUT VOLTAGE (V)
4
U W
1
2
1142 G01
3.3V Output Efficiency
100
100
98
96
94
92
90
88
86
84
82
5V Efficiency vs Input Voltage
FIGURE 1 CIRCUIT
V
OUT
= 5V
I
LOAD
= 1A
95
I
LOAD
= 100mA
V
IN
= 10V
90
85
0.01
80
0.1
LOAD CURRENT (A)
1
2
0
4
12
8
INPUT VOLTAGE (V)
16
20
1142 G03
1142 G02
Line Regulation
20
FIGURE 1 CIRCUIT
I
LOAD
= 1A
0
–20
– 40
– 60
– 80
– 100
Load Regulation
FIGURE 1 CIRCUIT
R
SENSE
= 0.05Ω
V
IN
= 6V
V
IN
= 12V
10
V
IN
= 6V
V
IN
= 12V
V
OUT
= 5V
V
OUT
= 3.3V
0
0.5
1.5
2.0
1.0
LOAD CURRENT (A)
2.5
1142 G06
16
20
1142 G04
0
4
12
8
INPUT VOLTAGE (V)
16
20
1142 G05
LINER [ LINEAR TECHNOLOGY ]
