LTC1649 Linear Technology, LTC1649 Datasheet - Page 2

• Manufacturer Part Number: LTC1649
• Description: 3.3V Input High Power Step-Down Switching Regulator Controller
• Manufacturer: Linear Technology

ABSOLUTE
LTC1649
(Note 1)
Supply Voltage
Input Voltage
Operating Temperature Range ..................... 0 C to 70 C
Storage Temperature Range ................. – 65 C to 150 C
Lead Temperature (Soldering, 10 sec).................. 300 C
SYMBOL
V
V
V
I
I
f
f
V
V
I
gm
gm
I
I
t
t
DC
The
temperature range.
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a part may be impaired.
Note 2: All currents into device pins are positive; all currents out of device
pins are negative. All voltages are referenced to ground unless otherwise
specified.
Note 3: Maximum Duty Cycle limitations will limit the output voltage
obtainable at very low supply voltages.
2
ELECTRICAL CHARACTERISTICS
IN
PVCC1, 2
CP
OSC
IN
IMAX
SS
r
NOV
, t
IN
FB
CPOUT
IH
IL
MAX
V
I
f
V
V
P
I
C
All Other Inputs ....................... – 0.3V to (V
FB .......................................................................
IN ...........................................................................................
CC ...........................................................................................
VCC1, 2 ................................................................................
+
denotes specifications which apply over the full operating
, C
– ................................................
PARAMETER
Minimum Supply Voltage
Feedback Voltage
Charge Pump Output Voltage
Supply Current (V
Supply Current (P
Internal Charge Pump Frequency
Internal PWM Oscillator Frequency
SHDN Input High Voltage
SHDN Input Low Voltage
SHDN Input Current
Error Amplifier Transconductance
I
I
Soft Start Source Current
Driver Rise/Fall Time
Driver Non-Overlap Time
Maximum Duty Cycle
LIM
MAX
W
MAXIMUM
Amplifier Transconductance
Sink Current
W W
IN
VCC1, 2
)
)
– 0.3V to (V
RATINGS
– 0.3V to 18V
U
CC
IN
CONDITIONS
Figure 1 (Note 3)
Figure 1
Figure 1
V
V
P
V
I
(Note 6)
V
V
P
P
V
CPOUT
+ 0.3V)
+ 0.3V)
SHDN
SHDN
VCC
SHDN
IMAX
SS
VCC1
VCC1
COMP
V
= 0V
IN
13V
= 5V, V
= VCC
= P
= P
= V
= 0V
= 0V
6V
9V
= 20mA (Note 5)
= V
= 3.3V, T
VCC2
VCC2
CC
CC
, I
SHDN
LOAD
= 5V
= 5V
PACKAGE/ORDER
Consult factory for Industrial and Military grade parts.
Note 4: Supply current at P
needed to charge and discharge the external MOSFET gates. This current
will vary with the operating voltage and the external MOSFETs used.
Note 5: Under normal operating conditions, the charge pump will skip
cycles to maintain regulation and the apparent frequency will be lower than
700kHz.
Note 6: The I
(not current limited) operation, the I
A
= V
= 0
= 25 C unless otherwise noted. (Note 2)
P
SHDN
VCC1
GND
CC
V
G1
SS
FB
C
IN
–
(Note 4)
T
JMAX
1
2
3
4
5
6
7
8
16-LEAD PLASTIC SO
LIM
= 150 C,
S PACKAGE
TOP VIEW
amplifier can sink but not source current. Under normal
JA
= 110 C/ W
VCC1
16
15
14
13
12
11
10
9
G2
P
V
I
I
COMP
CP
C
FB
MAX
and P
VCC2
CC
+
OUT
LIM
1.25
90.5
MIN
140
2.7
4.8
2.4
–8
25
VCC2
8
output current will be zero.
INFORMATION
U
is dominated by the current
1.265
1300
TYP
700
200
650
–12
130
1.5
0.1
0.01
10
12
80
93
ORDER PART
5
3
LTC1649CS
NUMBER
W
MAX
1.28
260
–16
250
250
5.2
0.8
25
16
5
1
UNITS
U
Mho
Mho
kHz
kHz
mA
mA
ns
ns
%
V
V
V
A
A
V
V
A
A
A