pip401 NXP Semiconductors, pip401 Datasheet - Page 4

• Manufacturer Part Number: pip401
• Description: Intelligent Switch 7-pin 6+tab D2pak
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9397 750 10578
Product data
7.3.1 Soft turn-on
7.3.2 Low voltage drop
7.3.3 Low current operation
7.3.4 Fast turn-off with no reverse current
7.3 Driver and series power switch
At switch on, the PIP401 turns on slowly to avoid current surges. These can cause
oscillations in the output voltage and may cause the protected power supply to shut
down. Typical turn-on time is 7 s.
The on-state characteristic of the PIP401 is shown in
PIP401 has very low voltage drop, typically 70 mV at 40 A, 25 C. This produces a
power dissipation of 2.8 W. In comparison, a Schottky diode with a forward voltage
drop of 320 mV would have a power dissipation of 12.8 W.
At low current levels, the voltage drop is only a few millivolts. This makes it difficult for
the comparator to determine when to switch off. The PIP401 overcomes this problem
by backing off the gate drive to the series power switch at current levels below 2 A.
The effect is to increase the resistance between VI and VO so that the voltage drop is
maintained at a constant level of approximately 6 mV. This is above the minimum
detectable threshold voltage of the comparator. This is shown in
flattening of the curves at low current.
When the input voltage (V
PIP401 switches off very quickly, blocking the flow of reverse current.
switching waveforms from an initial forward current of 20 A. Note the smooth ramp
down of current from 20 A with no reverse current flow and minimum disruption of the
output voltage. Total turn-off time is less than 400 ns.
The gate drive circuit in the PIP401 is referenced to VI. When the input voltage is less
than the remote sense voltage, current flows into V
current is 35 mA. In order to prevent charging of the output capacitors of the
protected supply connected to VI, a 100 W resistor should be connected between VI
and GND. This is shown as R1 in
Rev. 03 — 5 November 2002
I
) falls below the remote sense input voltage (V
Figure
2.
CC
Figure
© Koninklijke Philips Electronics N.V. 2002. All rights reserved.
and out of VI. The maximum
OR-ing Intelligent Switch
5. In the on-state, the
Figure 5
Figure 3
PIP401
RS
by the
), the
shows
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