MAX5078AATT-T Maxim Integrated Products, MAX5078AATT-T Datasheet - Page 10

• Manufacturer Part Number: MAX5078AATT-T
• Description: MOSFET & Power Driver ICs 4A 20ns MOSFET Driver
• Manufacturer: Maxim Integrated Products
• Type: Low Sider

Specifications of MAX5078AATT-T

• Rise Time: 85 ns
• Fall Time: 75 ns
• Supply Voltage (min): 4 V
• Supply Current: 0.04 mA
• Maximum Power Dissipation: 1454 mW
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Maximum Turn-off Delay Time: 35 ns
• Maximum Turn-on Delay Time: 35 ns
• Minimum Operating Temperature: - 40 C
• Number Of Drivers: 1
• Number Of Outputs: 1

Use the following PC board layout guidelines when
designing with the MAX5078A/MAX5078B:
•
•
•
•
•
The TDFN-EP package has an exposed pad on the bot-
tom of its package. This pad is internally connected to
GND. For the best thermal conductivity, solder the
exposed pad to the ground plane in order to dissipate
1.9W. Do not use the ground-connected pad as the
only electrical ground connection or ground return. Use
GND (pins 2 and 3) as the primary electrical ground
connection.
4A, 20ns, MOSFET Driver
Table 1. MAX5078 Truth Table
10
Place one or more 0.1µF decoupling ceramic
capacitors from V
as possible. Connect V
areas. Place one bulk capacitor of 10µF (min) on
the PC board with a low resistance path to the V
input and GND of the MAX5078A/MAX5078B.
Two AC current loops form between the device and
the gate of the driven MOSFET. The MOSFET looks
like a large capacitance from gate to source when the
gate pulls low. The active current loop is from the
MOSFET gate to OUT of the MAX5078A/MAX5078B,
to GND of the MAX5078A/MAX5078B, and to the
source of the MOSFET. When the gate of the MOSFET
pulls high, the active current is from the V
of the decoupling capacitor, to V
MAX5078A/MAX5078B, to OUT of the MAX5078A/
MAX5078B, to the MOSFET gate, to the MOSFET
source, and to the negative terminal of the decoupling
capacitor. Both charging current and discharging
current loops are important. Minimize the physical dis-
tance and the impedance in these AC current paths.
Keep the device as close to the MOSFET as possible.
In a multilayer PC board, the inner layers should
consist of a GND plane containing the discharging
and charging current loops.
Pay extra attention to the ground loop and use a
low-impedance source when using a TTL logic-
input device. Fast fall time at OUT may corrupt the
input during transition.
______________________________________________________________________________________
High
High
Low
Low
IN+
DD
to GND as close to the device
High
High
DD
Low
Low
IN-
and GND to large copper
Exposed Pad
DD
DD
OUT
High
Low
Low
Low
terminal
of the
DD
Figure 3. Unused Input as an ON/OFF Function
Figure 4. Noninverting Application
Figure 5. Boost Converter
4V TO 15V
CONTROLLER
V
FROM PWM
Additional Application Circuits
DD
(BOOST)
INPUT
PWM
ON
IN+
IN+
V
IN-
V
IN-
DD
DD
MAX5078A
MAX5078B
MAX5078A
MAX5078B
OFF
GND
GND
OUT
IN+
IN-
OUT
MAX5078
GND
V
DD
V
S
V
N
S
N
OUT
V
OUT