LTC3443 Linear Technology, LTC3443 Datasheet - Page 5

• Manufacturer Part Number: LTC3443
• Description: High Current Micropower 600kHz Synchronous Buck-Boost DC/DC Converter
• Manufacturer: Linear Technology

PI FU CTIO S
TYPICAL PERFOR A CE CHARACTERISTICS
SHDN/SS (Pin 1): Combined Soft-Start and Shutdown.
Applied voltage < 0.4V shuts down the IC. Tie to >1.4V to
enable the IC and >2.4V to ensure the error amp is not
clamped from soft-start. An RC from the shutdown com-
mand signal to this pin will provide a soft-start function by
limiting the rise time of the V
GND (Pin 2): Signal Ground for the IC.
PGND (Pins 3, 6, 13 Exposed Pad): Power Ground for the
Internal NMOS Power Switches. The exposed pad must be
soldered to PCB ground for optimal thermal performance.
SW1 (Pin 4): Switch pin where the internal switches A and
B are connected. Connect inductor from SW1 to SW2. An
optional Schottky diode can be connected from this SW1
to ground. Minimize trace length to keep EMI down.
0.15
0.13
0.11
0.09
0.07
0.05
250
400
350
300
200
U
–55
–55
NMOS R
Error Amp Sink Current
V
V
SWITCHES B AND C
IN
IN
= V
= V
–25
–25
U
OUT
OUT
DS(ON)
= 3.6V
TEMPERATURE (°C)
= 3.6V
TEMPERATURE (°C)
5
5
35
35
U
65
65
W
C
95
95
pin.
3443 G12
3443 G15
U
125
125
0.55
0.15
0.13
0.11
0.09
0.05
0.70
0.65
0.60
0.50
0.07
–50
–55
Output Frequency
PMOS R
V
V
SWITCHES A AND D
IN
IN
= V
= V
–25
–25
OUT
OUT
DS(ON)
= 3.6V
= 3.6V
TEMPERATURE (°C)
TEMPERATURE (°C)
5
5
35
35
SW2 (Pin 5): Switch pin where the internal switches C
and D are connected. An optional Schottky diode can be
connected from SW2 to V
V
MODE/SYNC (Pin 7): Burst Mode Select and Oscillator
Synchronization.
OUT
MODE/SYNC = High: Enable Burst Mode Operation.
During the period where the IC is supplying energy to
the output, the inductor peak inductor current will reach
0.8A and return to zero current on each cycle. In Burst
Mode operation the operation is variable frequency,
which provides a significant efficiency improvement at
light loads. The Burst Mode operation will continue until
the pin is driven low.
65
65
> 4.3V). Minimize trace length to keep EMI down.
95
95
(T
3443 G16
3443 G13
A
125
125
= 25°C unless otherwise specified)
2.25
2.15
2.10
2.30
2.20
3.0
3.4
3.2
2.8
–55
–55
Minimum Start Voltage
Current Limit
V
IN
= V
OUT
–25
–25
OUT
www.DataSheet4U.com
= 3.6V
TEMPERATURE (°C)
TEMPERATURE (°C)
(it is required where
5
5
LTC3443
35
35
65
65
sn3443 3443fs
95
95
3443 G14
3443 G17
5
125
125