33730_10 Datasheet, PDF (12/26 Pages) Freescale Semiconductor, Inc – Switch Mode Power Supply with Multiple Linear Regulators

FUNCTIONAL DESCRIPTION
FUNCTIONAL PIN DESCRIPTION
PROGRAMMING PIN 2 (P2)
Programming Pin 2 for the VDD3, VDDL, and VKAM
reference voltage. The output voltage of the VDD3, VDDL
and VKAM regulators can be programmed by the P1, P2, and
P3 pins (see Table 6).
PROGRAMMING PIN 3 (P3)
Programming Pin 3 for the VDD3, VDDL, and VKAM
reference voltages. The output voltage of the VDD3, VDDL
and VKAM regulators can be programmed by the P1, P2, and
P3 pins (see Table 6).
PROTECTION FET DRIVE (PFD)
Reverse battery protection FET gate drive. This pin is an
output drive for the gate of the external Reverse Battery
Protection N-channel FET.
BOOTSTRAP (BOOT)
This pin is connected to the bootstrap capacitor. It
provides the supply power for the switching regulator high-
side drive.
SLEW-RATE (SR)
Slew-rate Control of the switching regulator. The slew-rate
of the switching regulator can be adjusted by connecting this
pin to switch node (SW pin, slow slew-rate selection), BOOT
pin (fast slew-rate selection), or it can be left open (medium
slew-rate selection).
SWITCH NODE (SW)
This pin is the source of the switching regulator internal
power switch (N-channel MOSFET source).
BATTERY VOLTAGE SUPPLY (VBAT)
Voltage supply to the IC (external reverse battery
protection is recommended).
KEEP ALIVE SUPPLY (KA_VBAT)
This pin is the keep alive supply input. This input is reverse
battery protected. This input supplies power to the internal
supply and bias circuits that have to do with this VKAM and
other always-on supplies.
CHARGE PUMP (CP)
External reservoir capacitor of the internal charge pump.
This charge pump provides the voltage needed to sufficiently
enhance the gates of the internal n-channel mosfets (VREF1,
VREF2, and VDDH) during the low battery condition.
KEEP ALIVE MEMORY (VKAM)
Keep Alive Memory (standby) supply output. This output
supplies power for the module Keep-Alive memory. This
output is always on, if the voltage at the KA_VBAT pin is
above 4.5 V.
VDD3 LINEAR REGULATOR (VDD3)
This is a VDD3 regulator output feedback pin.The emitter
of VDD3 regulator external NPN pass transitory is connected
to this pin.
This pin can programmed to be the output of the VDD3
Standby regulator (see Table 6).
VDD3 LINEAR REGULATOR BASE DRIVE
(VDD3_B)
This pin can be used also as an additional standby
regulator without the external pass transistor.This output
supplies current into the base of the regulator external pass
NPN transistor.
GROUND (GND)
This pin is the ground pin of the integrated circuit.
VOLTAGE IGNITION (VIGN)
This pin is the turn-on control input that is controlled
through an ignition switch. This pin is reverse battery
protected.
33730
12
Analog Integrated Circuit Device Data
Freescale Semiconductor