STD55NH2LL
Product Page
The increasing demand for greater power from the latest CPUs means
that synchronous buck converters used in Voltage Regulator Modules
(VRM) and POLs must have very high performance in terms of overall
electrical behavior during switching transients and ON state. This
demand may be satisfied by using low voltage Power MOSFETs in VRMs
with very low gate charge (Qg) and low on-resistance RDS(on).
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The efficiency of the overall system can be improved
with STD55NH2LL, ST’s new high side Power
MOSFET, in the synchronous buck converter.
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STD55NH2LL General
Features |
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RDS(on) * Qg industry’ benchmark
Conduction losses reduced
Switching losses reduced
Low threshold device
High avalanche ruggedness
Synchronous buck converter circuit used to provide high current,
low voltage power for CPUs, chipsets and peripherals etc.
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The majority of the power lost in power conversion is due to losses
in the Power MOSFET switches. The loss profiles for the high side
and low side Power MOSFET are quite different. The main parameters
that impact on the high side losses are given by Ciss and Qg.
Instead the main parameter that impacts on the low-side switch is
give by the RDS(on).
In order to demonstrate the benefits of using STD55NH2LL, a test
was performed on the L6710 controller demoboard assuming the same
low side switching and the following conditions:
Vin = 12 V
Vout = 1.5 V
2 phase: 1xHS, 2xLS
Tamb = 25 °C
fsw = 440 kHz
The comparison made against two similar high side Power MOSFETs
in DPAK, shows that the STD55NH2LL is an optimum solution to boost
the efficiency by 1% in synchronous buck converters.
Efficiency comparison showing the 1 % higher efficiency
shown by STD55NH2LL
Part
number
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BVDSS
[V]
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Ciss
[pF] |
RDS(on)
@ 10 V
max
[Ω]
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Qg
@ 5 V
typ
[nC]
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STD55NH2LL |
24
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990
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0.011*
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8.7*
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STD70N02L |
24
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1400
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0.008
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12
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STD50N03L |
30
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1434
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0.001
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10
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* values @ 4.5V
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