pip202-12m NXP Semiconductors, pip202-12m Datasheet - Page 10

• Manufacturer Part Number: pip202-12m
• Description: Dc To Dc Converter Powertrain
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9397 750 11943
Product data
11.2 Advantages of an integrated driver
11.3 External connection of power and signal lines
At 500 KHz and 20 A output current, the maximum dissipation in each PIP202-12M is
typically 4.5 W. The typical thermal resistance from junction to ambient is given in
Table
PIP202-12M from junction to ambient is 15 K/W. Assuming an ambient temperature
of 55 C, the junction temperature (T
The thermal resistance between the junction and the printed-circuit board is 5 K/W.
Therefore, the printed-circuit board temperature (T
One problem in the design of low-voltage, high-current DC-to-DC converters using
discrete components, is stray inductance between the various circuit elements.
Stray inductance in the gate drive circuit increases the switching times of the
MOSFETs and causes high-frequency oscillation of the gate voltage.
Stray inductance in the high-current loop between V
losses and electromagnetic interference. In discrete designs, high-frequency electric
and magnetic fields radiate from PCB tracks and couple into adjacent circuits.
By integrating the power MOSFETs and their drive circuits into a single package,
stray inductance is virtually eliminated, resulting in a compact, efficient design.
In discrete designs, the delays in the MOSFET drivers must be long enough to
ensure no cross-conduction even when using the slowest MOSFETs. Use of an
integrated driver allows the propagation delays in the MOSFET drivers to be precisely
matched to the MOSFETs. This minimizes switching losses and eliminates
cross-conduction whilst allowing the circuit to operate at a higher frequency.
A major benefit of the PIP202-12M module is the ability to switch the internal power
MOSFETs faster than a DC-to-DC converter built from discrete components. This not
only reduces switching losses and increases system efficiency but also results in
higher transient voltages on the device supply lines (V
the high rate of change of current (dI/dt) through the combined parasitic inductance of
the PCB tracks and the decoupling capacitors.
To minimize the amplitude of these transients, decoupling capacitors must be placed
between V
chip ceramic capacitors are recommended.
T
pcb max
T
j
=
4. With thermal vias and forced air cooling, the thermal resistance of each
P
tot
=
DDO
T
R
j max
and V
th j a
Rev. 02 — 24 November 2003
–
–
SSO
P
+
tot
T
, as close as possible to the device pins. Low inductance,
amb
R
th j
=
4.5 15
–
pcb
j
) is given by:
=
+
122.5 4.5 5
55
=
–
122.5 C
pcb
DC-to-DC converter powertrain
DDO
) is given by:
© Koninklijke Philips Electronics N.V. 2003. All rights reserved.
DDO
PIP202-12M-2
=
and V
100 C
and V
SSO
SSO
causes switching
). This is due to
10 of 20
(1)
(2)