LTC1159
LTC1159-3.3/LTC1159-5
The
q
denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, V
SHDN1
= 0V (Note 3), unless otherwise noted.
SYMBOL
V
CC
V
IN
– V
CC
V
EXT
– V
CC
PARAMETER
Internal Regulator Voltage
V
CC
Dropout Voltage
EXTV
CC
Switch Drop
CONDITIONS
V
IN
= 12V to 40V, EXTV
CC
= 0V, I
CC
= 10mA
V
IN
= 4V, EXTV
CC
= Open, I
CC
= 10mA
V
IN
= 12V, EXTV
CC
= 5V, I
SWITCH
= 10mA
V
IN
= 12V
V
IN
= 40V
V
SENSE –
= 5V, V
FB
= 1.32V (Forced)
V
SENSE –
= 5V, V
FB
= 1.15V (Forced)
V
SENSE –
= 3.4V (Forced)
V
SENSE –
= 3.1V (Forced)
V
SENSE –
= 5.2V (Forced)
V
SENSE –
= 4.7V (Forced)
– 0.2
– 0.2
q
ELECTRICAL CHARACTERISTICS
MIN
4.25
TYP
4.5
300
250
0
0
25
150
25
150
25
150
0.8
1.4
12
70
2
5
100
MAX
4.75
400
350
UNITS
V
mV
mV
V
V
mV
mV
mV
mV
mV
mV
V
V
µA
µA
µA
µs
ns
V
P-GATE
– V
IN
P-Gate to Source Voltage (Off)
V
SENSE +
–
V
SENSE –
Current Sense Threshold Voltage
LTC1159
LTC1159-3.3
LTC1159-5
V
SNDN1
V
SHDN2
I
SHDN2
I
CT
t
OFF
t
r
, t
f
SHDN1 Threshold
LTC1159CG, LTC1159-3.3, LTC1159-5
SHDN2 Threshold
Shutdown 2 Input Current
C
T
Pin Discharge Current
Off-Time (Note 5)
Driver Output Transition Times
q
q
q
130
130
130
0.5
0.8
170
170
170
2
2
20
90
10
6
200
V
SHDN2
= 5V
V
OUT
in Regulation
V
OUT
= 0V
C
T
= 390pF, I
LOAD
= 700mA, V
IN
= 10V
C
L
= 3000pF (Pins P-Drive and N-Gate), V
IN
= 6V
50
4
– 40°C
≤
T
A
≤
85°C (Note 6)
SYMBOL
V
FB
V
OUT
PARAMETER
Feedback Voltage (LTC1159 Only)
Regulated Output Voltage
LTC1159-3.3
LTC1159-5
V
IN
Pin Current (Note 4)
Normal
Shutdown
I
EXTVCC
V
CC
V
SENSE +
–
V
SENSE –
V
SHDN2
t
OFF
EXTV
CC
Pin Current (Note 4)
Internal Regulator Voltage
Current Sense Threshold Voltage
SHDN2 Threshold
Off-Time (Note 5)
C
T
= 390pF, I
LOAD
= 700mA, V
IN
= 10V
V
IN
= 9V
I
LOAD
= 700mA
I
LOAD
= 700mA
V
IN
= 12V, EXTV
CC
= 5V
V
IN
= 40V, EXTV
CC
= 5V
V
IN
= 12V, V
SHDN2
= 2V
V
IN
= 40V, V
SHDN2
= 2V
EXTV
CC
= 5V, Sleep Mode
V
IN
= 12V to 40V, EXTV
CC
= 0V, I
CC
= 10mA
Low Threshold (Forced)
High Threshold (Forced)
CONDITIONS
MIN
1.2
3.17
4.85
TYP
1.25
3.30
5.05
200
300
15
25
250
4.5
25
150
1.4
5
MAX
1.3
3.43
5.25
UNITS
V
V
V
µA
µA
µA
µA
µA
V
mV
mV
V
µs
I
IN
125
0.8
3.5
175
2
6.5
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 formulas:
LTC1159CG, LTC1159CG-3.3, LTC1159CG-5: T
J
= T
A
+ (P
D
• 135°C/W)
LTC1159CN, LTC1159CN-3.3, LTC1159CN-5: T
J
= T
A
+ (P
D
• 80°C/W)
LTC1159CS, LTC1159CS-3.3, LTC1159CS-5: T
J
= T
A
+ (P
D
• 110°C/W)
Note 3:
On LTC1159 versions which have a SHDN1 pin, it must be at
ground potential for testing.
Note 4:
The LTC1159 V
IN
and EXTV
CC
current measurements exclude
MOSFET driver currents. When V
CC
power is derived from the output via
EXTV
CC
, the input current increases by (I
GATECHG
• Duty Cycle)/(Efficiency).
See Typical Performance Characteristics and Applications Information.
Note 5:
In applications where R
SENSE
is placed at ground potential, the off-
time increases approximately 40%.
3
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