LTC3736EUF-1#TRPBF Linear Technology, LTC3736EUF-1#TRPBF Datasheet - Page 15

• Manufacturer Part Number: LTC3736EUF-1#TRPBF
• Description: IC CTRLR SW SYNC DUAL 2PH 24QFN
• Manufacturer: Linear Technology
• Series: PolyPhase®r
• Type: Step-Down (Buck)r

Specifications of LTC3736EUF-1#TRPBF

• Internal Switch(s): No
• Synchronous Rectifier: Yes
• Number Of Outputs: 2
• Voltage - Output: 0.6 ~ 9.8 V
• Current - Output: 1A
• Frequency - Switching: 450kHz ~ 580kHz
• 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: -

APPLICATIO S I FOR ATIO
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 LTC3736-1 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-chan-
nel 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
=
=
•
2.0
1.5
1.0
0.5
V
V
I
0
V
IN
OUT
OUT MAX
– 50
IN
Figure 5. R
–
V
(
IN
V
•
OUT
I
OUT MAX
JUNCTION TEMPERATURE (°C)
U
0
)
•
(
•
2
C
DS(ON)
I
R losses and the P
OUT MAX
RSS
U
)
50
2
(
•
vs Temperature
•
f
ρ
OSC
T
)
2
•
W
100
•
R
ρ
DS ON
T
37361 F05
(
•
R
150
DS ON
)
TOP
+
(
U
2
•
equation
)
V
IN
2
G
)
less than 25nC to 30nC (at 4.5V
(t
to differences in test and specification methods of various
MOSFET manufacturers, and in the variations in Q
t
ultimately should be evaluated in the actual LTC3736-1
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 in-
creases, 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
Table 1 shows a selection of P-channel MOSFETs from
different manufacturers that are known to work well in
LTC3736-1 applications.
Selecting the N-channel MOSFET is typically easier, since
for a given R
off delays are much smaller than for a P-channel MOSFET.
Table 1. Selected P-Channel MOSFETs Suitable for LTC3736-1
Applications
PART
NUMBER
Si7540DP
Si9801DY
FDW2520C
FDW2521C
Si3447BDV
Si9803DY
FDC602P
FDC606P
FDC638P
FDW2502P
FDS6875
HAT1054R
NTMD6P02R2-D
D(OFF)
IN
D(OFF)
> 5V) may work fine at lower voltages (e.g., 3.3V).
with gate drive (V
) of less than approximately 140ns. However, due
DS(ON)
MANUFACTURER
Siliconix
Siliconix
Fairchild
Fairchild
Siliconix
Siliconix
Fairchild
Fairchild
Fairchild
Fairchild
Fairchild
On Semi
, the gate charge and turn-on and turn-
Hitachi
IN
) voltage, the P-channel MOSFET
Complementary
Complementary
Complementary
Complementary
GS
Single P
Single P
Single P
Single P
Single P
Dual P
Dual P
Dual P
Dual P
TYPE
) and a turn-off delay
P/N
P/N
P/N
P/N
LTC3736-1
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
37361f
and