E910.27A View Datasheet(PDF) - ELMOS Semiconductor AG
Part Name
Description
MFG CO.
'E910.27A' PDF : 50 Pages View PDF
- Preliminary -
E910.27A
The amount of power dissipation is independent of the value of the resistor RSN. If the time constant of the
snubber network is short compared to the switching period of the converter but is long compared to the volt-
age rise time, than the loss can be estimated by:
P _ RSN ≈ Fop ⋅ CSN ⋅VINPUT 2
[35]
With Fop = switching frequency of the converter and VINPUT = maximum input voltage.
without snubber
aperiodic damped
Figure 8.1.6-1: Discontinuous Mode Switch Drain Voltage without and with Snubber
8.1.7 Maximum available Output Current versus Internal Losses and Operating Temperature
The internal E910.27 DC-DC converter losses are a combination of quiescent device power, dynamic gate
driver power and P-channel MOS transistors switching losses.
In any case the maximum allowed peak drain current of the internal P-channel MOS transistor must not
exceed ISWD. With the maximum continuous output current of the buck converter and the specified maxi-
mum operating temperature, the chip temperature must be well lower than the thermal shutdown limit. The
maximum available output current of the converter depends on maximum duty cycle, switching frequency
(dynamic losses) and the thermal transfer of the package provided by the external heat sinking (e.g. printed
circuit board).
ELMOS Semiconductor AG
Specification 31 / 50
03SP0357E.00 05.09.2006
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