LM5100AMR/NOPB National Semiconductor, LM5100AMR/NOPB Datasheet - Page 12

• Manufacturer Part Number: LM5100AMR/NOPB
• Description: IC DVR HALF-BRIDGE HV 8-PSOP
• Manufacturer: National Semiconductor

Specifications of LM5100AMR/NOPB

• Configuration: High and Low Side, Synchronous
• Input Type: Non-Inverting
• Delay Time: 20ns
• Current - Peak: 3A
• Number Of Configurations: 1
• Number Of Outputs: 2
• High Side Voltage - Max (bootstrap): 118V
• Voltage - Supply: 9 V ~ 14 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-PSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: *LM5100AMR/NOPB; LM5100AMR; LM5100AMRTR; LM5100AMRTR

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Layout Considerations
The optimum performance of high and low-side gate drivers
cannot be achieved without taking due considerations during
circuit board layout. Following points are emphasized.
1.
2.
3.
4.
Low ESR / ESL capacitors must be connected close to
the IC, between VDD and VSS pins and between the HB
and HS pins to support the high peak currents being
drawn from VDD during turn-on of the external MOSFET.
To prevent large voltage transients at the drain of the top
MOSFET, a low ESR electrolytic capacitor must be
connected between MOSFET drain and ground (VSS).
In order to avoid large negative transients on the switch
node (HS pin), the parasitic inductances in the source of
top MOSFET and in the drain of the bottom MOSFET
(synchronous rectifier) must be minimized.
Grounding Considerations:
is to confine the high peak currents that charge and
a) The first priority in designing grounding connections
12
A recommended layout pattern for the driver is shown in the
following figure. If possible a single layer placement is pre-
ferred.
discharge the MOSFET gate into a minimal physical
area. This will decrease the loop inductance and
minimize noise issues on the gate terminal of the
MOSFET. The MOSFETs should be placed as close as
possible to the gate driver.
capacitor, the bootstrap diode, the local ground
referenced bypass capacitor and low-side MOSFET
body diode. The bootstrap capacitor is recharged on a
cycle-by-cycle basis through the bootstrap diode from
the ground referenced VDD bypass capacitor. The
recharging occurs in a short time interval and involves
high peak current. Minimizing this loop length and area
on the circuit board is important to ensure reliable
operation.
b) The second high current path includes the bootstrap
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