LTC3736EUF-2#TRPBF Linear Technology, LTC3736EUF-2#TRPBF Datasheet - Page 15

• Manufacturer Part Number: LTC3736EUF-2#TRPBF
• Description: IC CTRLR SW SYNC DUAL 2PH 24QFN
• Manufacturer: Linear Technology
• Series: PolyPhase®r
• Type: Step-Down (Buck)r

Specifications of LTC3736EUF-2#TRPBF

• Internal Switch(s): No
• Synchronous Rectifier: Yes
• Number Of Outputs: 2
• Voltage - Output: 0.6 ~ 9.8 V
• Current - Output: 1A
• Frequency - Switching: 550kHz ~ 750kHz
• Voltage - Input: 2.75 ~ 9.8 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -

APPLICATIONS INFORMATION
The MOSFET power dissipations at maximum output
current are:
Both MOSFETs have I
includes an additional term for transition losses, which are
largest at high input voltages. The bottom MOSFET losses
are greatest at high input voltage or during a short-circuit
when the bottom duty cycle is nearly 100%.
The LTC3736-2 utilizes a nonoverlapping, antishoot-
through gate drive control scheme to ensure that the
P- and N-channel MOSFETs are not turned on at the same
time. To function properly, the control scheme requires
that the MOSFETs used are intended for DC/DC switching
applications. Many power MOSFETs, particularly P-channel
MOSFETs, are intended to be used as static switches and
therefore are slow to turn on or off.
Reasonable starting criteria for selecting the P-channel
MOSFET are that it must typically have a gate charge (Q
P
P
BOT
TOP
=
=
•
V
V
I
2.0
1.5
1.0
0.5
V
IN
O O UT MAX
OUT
0
IN
–50
Figure 4. R
–
V
(
IN
V
•
OUT
I
OUT MAX
JUNCTION TEMPERATURE (°C)
)
0
2
•
(
•
DS(ON)
R losses and the P
C
I
OUT MA
RSS
)
50
2
(
vs Temperature
•
•
f
OSC
ρ
X X
T
)
2
•
100
•
R
ρ
DS ON
T
(
•
37362 F04
R
150
TOP
)
DS ON
+
(
2
equation
•
)
V
IN
G
2
)
less than 25nC to 30nC (at 4.5V
(t
to differences in test and specifi cation methods of various
MOSFET manufacturers, and in the variations in Q
t
ultimately should be evaluated in the actual LTC3736-2
application circuit to ensure proper operation.
Shoot-through between the P-channel and N-channel
MOSFETs can most easily be spotted by monitoring the
input supply current. As the input supply voltage increases,
if the input supply current increases dramatically, then the
likely cause is shoot-through. Note that some MOSFETs
that do not work well at high input voltages (e.g., V
5V) may work fi ne at lower voltages (e.g., 3.3V). Table 1
shows a selection of P-channel MOSFETs from different
manufacturers that are known to work well in LTC3736-2
applications.
Selecting the N-channel MOSFET is typically easier, since for
a given R
delays are much smaller than for a P-channel MOSFET.
Table 1. Selected P-Channel MOSFETs Suitable for LTC3736-2
Applications
PART
NUMBER
Si7540DP
Si9801DY
FDW2520C
FDW2521C
Si3447BDV
Si9433BDY
FDC602P
FDC606P
FDC638P
FDW2502P
FDS6875
HAT1054R
NTMD6P02R2-D On Semiconductor
D(OFF)
D(OFF)
with gate drive (V
) of less than approximately 140ns. However, due
DS(ON)
MANUFACTURER
, the gate charge and turn-on and turn-off
Siliconix
Siliconix
Fairchild
Fairchild
Siliconix
Siliconix
Fairchild
Fairchild
Fairchild
Fairchild
Fairchild
Hitachi
IN
) voltage, the P-channel MOSFET
Complementary
Complementary
Complementary
Complementary
Single P
Single P
Single P
Single P
Single P
GS
Dual P
Dual P
Dual P
Dual P
TYPE
P/N
P/N
P/N
P/N
) and a turn-off delay
LTC3736-2
PowerPak
PACKAGE
TSSOP-8
TSSOP-8
TSSOP-8
TSOP-6
TSOP-6
TSOP-6
TSOP-6
SO-8
SO-8
SO-8
SO-8
SO-8
SO-8
15
G
37362fb
IN
and
>