LTC1266IS#PBF Linear Technology, LTC1266IS#PBF Datasheet - Page 6
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LTC1266IS#PBF
Manufacturer Part Number
LTC1266IS#PBF
Description
IC REG CNTRLR N/PCH MOSFET16SOIC
Manufacturer
Linear Technology
Type
Step-Down (Buck), Step-Up (Boost)r
Datasheet
1.LTC1266CSPBF.pdf
(20 pages)
Specifications of LTC1266IS#PBF
Internal Switch(s)
No
Synchronous Rectifier
Yes
Number Of Outputs
1
Voltage - Output
Adjustable
Current - Output
50mA
Frequency - Switching
400kHz
Voltage - Input
3.5 ~ 18 V
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
16-SOIC (3.9mm Width)
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Power - Output
-
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
LTC1266
LTC1266-3.3/LTC1266-5
PI FU CTIO S
TYPICAL PERFOR A CE CHARACTERISTICS
TDRIVE (Pin 1): High Current Drive for Topside MOSFET.
This MOSFET can be either P-channel or N-channel, user
selectable by Pin 3. Voltage swing at this pin is from PWR
V
PWR V
closely decoupled to power ground (Pin 15).
PINV (Pin 3): Phase Invert. Sets the phase of the topside
driver to drive either a P-channel or an N-channel MOSFET
as follows:
BINH (Pin 4): Burst Mode Operation Inhibit. A CMOS logic
high on this pin will disable the Burst Mode operation
feature forcing continuous operation down to zero load.
V
C
the operating frequency. The actual frequency is also
dependent on the input voltage.
I
comparator threshold increases with the Pin 7 voltage.
SENSE
which sets the output voltage in LTC1266-3.3 and
LTC1266-5 versions. Pin 8 is also the (–) input for the
current comparator.
6
TH
IN
IN
T
100
P-channel: Pin 3 = 0V
N-channel: Pin 3 = PWR V
(Pin 6): External Capacitor. C
80
60
40
20
U
(Pin 7): Gain Amplifier Decoupling Point. The current
0
to ground.
(Pin 5): Main Supply Pin.
0
Off-Time vs Output Voltage
IN
LTC1266-3.3
–
(Pin 2): Power Suppy for Drive Signals. Must be
(Pin 8): Connects to internal resistive divider
U
1
OUTPUT VOLTAGE (V)
2
U
LTC1266-5
3
V
SENSE
W
4
–
IN
= V
T
1266 G10
OUT
from Pin 4 to ground sets
U
5
3.0
2.5
2.0
1.5
1.0
0.5
0
Operating Frequency
vs (V
0
V
OUT
2
IN
= 3.3V
– V
(V
4
IN
OUT
– V
6
) Voltage
OUT
) VOLTAGE (V)
SENSE
A built-in offset between Pins 8 and 9 in conjunction with
R
V
serves as the feedback pin from an external resistive
divider used to set the output voltage. On LTC1266-3.3
and LTC1266-5 versions this pin is not used.
SHDN (Pin 11): When grounded, the LTC1266 series
operates normally. Pulling Pin 11 high holds both
MOSFETs off and puts the LTC1266 in micropower shut-
down mode. Requires CMOS logic signal with t
Should not be left floating.
SGND (Pin 12): Small-Signal Ground. Must be routed
separately from other grounds to the (–) terminal of C
LB
input is compared to an internal 1.25V reference.
LB
Comparator. This pin will sink current when Pin 13 is
below 1.25V.
PGND (Pin 15): Driver Power Ground. Connects to source
of N-channel MOSFET and the (–) terminal of C
BDRIVE (Pin 16): High Current Drive for Bottom
N-Channel MOSFET. Voltage swing at Pin 16 is from
ground to PWR V
8
0 C
FB
SENSE
25 C
IN
OUT
10
(Pin 10): For the LTC1266 adjustable version, Pin 10
(Pin 13): Input to the Low-Battery Comparator. This
70 C
(Pin 14): Open Drain Output of the Low-Battery
+
12
sets the current trip threshold.
(Pin 9): The (+) Input to the Current Comparator.
14
1266 G11
16
IN
.
200
150
–50
100
50
0
0
Current Sense Threshold Voltage
MIN THRESHOLD (Burst Mode
20
MIN THRESHOLD (Burst Mode
OPERATION INHIBIT)
OPERATION ENABLED)
TEMPERATURE ( C)
MAX THRESHOLD
40
60
r
, t
IN
80
f
.
< 1 s.
1266 G12
OUT
100
.