pip202-12m NXP Semiconductors, pip202-12m Datasheet - Page 11

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

Philips Semiconductors
9397 750 11943
Product data
11.4 Switching frequency
11.5 Thermal design
To protect the control circuit from the transient voltages, the following precautions
must be taken. Refer to
A high operating frequency reduces the size and number of capacitors needed to
filter the output current, and also reduces the size of the output inductors. The
disadvantage, however is higher dissipation due to switching and MOSFET driver
losses. For example, doubling the operating frequency of the circuit in
500 kHz to 1 MHz would increase the power dissipation in each PIP202-12M from
4 W to 6 W, at an output current of 20 A in each PIP202-12M.
The maximum switching frequency is limited by thermal considerations, the
dissipation in the PIP202-12M device(s) and the thermal resistance from junction to
ambient.
The PIP202-12M has three pads on its underside. These are designated PAD1, PAD2
and PAD3
PAD3 is connected to VO. In addition to providing low inductance electrical
connections, these pads conduct heat away efficiently from the MOSFETs and
control IC to the printed-circuit board. The thermal resistance from junction to
printed-circuit board is approximately 5 K/W. In order to take full advantage of the low
1. The output stage ground (V
2. The control circuit supply must be filtered using a resistor-capacitor (RC) filter.
3. It is essential that the V
4. It is also essential that the input to the V
Fig 12. External connection of power and signal lines.
(C
couple into the control circuit ground (V
The values shown in
connected in the current return path between the V
connection at the device and the V
the current path between the V
in
) before joining the ground plane. Otherwise, the switching noise on V
(Figure
Rev. 02 — 24 November 2003
output stage supply voltage
input voltage
from PWM controller
2). PAD1 is connected to V
10
1 F
Figure
Figure 12
SSC
control circuit
supply (12 V)
12.
SSO
(signal ground) connection at the device is not
DDO
) must be connected to the decoupling capacitor
are suitable for most applications.
VI
V DDC
power ground
signal ground
DDO
(conversion power) connection at the device.
V SSC
CB
input capacitor.
SSC
DDC
100
nF
DDO
V DDO
V SSO
).
(logic power) filter is not connected in
VO
, PAD2 is connected to V
DC-to-DC converter powertrain
© Koninklijke Philips Electronics N.V. 2003. All rights reserved.
C in
SSO
PIP202-12M-2
L out
(power ground)
output
C out
03ae27
Figure 11
SSC
SSO
and
11 of 20
from
will