LTC1772 Linear Technology, LTC1772 Datasheet - Page 2

• Manufacturer Part Number: LTC1772
• Description: Constant Frequency Current Mode Step-Down DC/DC Controller in SOT-23
• Manufacturer: Linear Technology

ABSOLUTE
(Note 1)
Input Supply Voltage (V
SENSE
V
PGATE Peak Output Current (< 10 s) ....................... 1A
Storage Ambient Temperature Range ... – 65 C to 150 C
Operating Temperature Range (Note 2) ....... 0 C to 70 C
Junction Temperature (Note 3) ............................. 150 C
Lead Temperature (Soldering, 10 sec).................. 300 C
LTC1772
range, otherwise specifications are at T
PARAMETER
Input DC Supply Current
Undervoltage Lockout Threshold
Shutdown Threshold (at I
Start-Up Current Source
Regulated Feedback Voltage
Output Voltage Line Regulation
Output Voltage Load Regulation
V
Overvoltage Protect Threshold
Overvoltage Protect Hysteresis
Oscillator Frequency
Gate Drive Rise Time
Gate Drive Fall Time
Maximum Current Sense Voltage
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LTC1772 is guaranteed to meet specified performance over
the 0 C to 70 C operating temperature range.
Note 3: T
dissipation P
2
ELECTRICAL CHARACTERISTICS
FB
FB
Normal Operation
Sleep Mode
Shutdown
UVLO
T
Input Current
, I
J
= T
TH
J
–
A
/RUN Voltages ..............................– 0.3V to 2.4V
, PGATE Voltages ............. – 0.3V to (V
is calculated from the ambient temperature T
+ (P
D
according to the following formula:
D
•
J
C/W)
W
MAXIMUM
TH
/RUN)
IN
).........................– 0.3V to 10V
W W
A
= 25 C. V
RATINGS
A
CONDITIONS
Typicals at V
V
V
V
(Note 5)
2.4V V
I
I
(Note 5)
Measured at V
V
V
C
C
and power
TH
TH
U
IN
IN
IN
ITH
FB
FB
LOAD
LOAD
2.4V V
2.4V V
2.4V V
V
/RUN Sinking 5 A (Note 5)
/RUN Sourcing 5 A (Note 5)
IN
Falling
Rising
= 4.2V unless otherwise specified. (Note 2)
= 0.8V
= 0V
/RUN = 0V
IN
< UVLO Threshold
= 3000pF
= 3000pF
+ 0.3V)
IN
IN
IN
IN
The
IN
9.8V (Note 5)
FB
9.8V
9.8V
9.8V, V
= 4.2V (Note 4)
denotes specifications that apply over the full operating temperature
ITH
PACKAGE/ORDER
Consult factory for Industrial and Military grade parts.
Note 4: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency.
Note 5: The LTC1772 is tested in a feedback loop that servos V
output of the error amplifier.
/RUN = 0V
I
TH
/RUN 1
GND 2
V
T
FB
JMAX
6-LEAD PLASTIC SOT-23
3
= 150 C,
S6 PACKAGE
TOP VIEW
JA
= 230 C/ W
6 PGATE
5 V
4 SENSE
IN
0.780
0.820
1.85
0.25
MIN
500
1.6
0.2
–
INFORMATION
U
0.800
0.860
0.35
0.05
TYP
270
230
550
120
120
2.0
2.3
0.5
2.5
2.5
10
20
40
40
S6 PART MARKING
8
6
ORDER PART
LTC1772CS6
NUMBER
W
0.820
0.895
MAX
0.85
LTIL
420
370
650
2.3
2.5
0.5
22
10
50
FB
to the
mV/ A
mV/ A
UNITS
U
mV/V
kHz
kHz
mV
mV
nA
ns
ns
A
A
A
A
V
V
V
A
V
V