34704_09 Datasheet, PDF (23/49 Pages) Freescale Semiconductor, Inc – Multiple Channel DC-DC Power Management IC

FUNCTIONAL DESCRIPTION
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
The switcher will operate in DCM at very light loads to
allow pulse skipping.
VOUT3 will be discharged every time the regulator is
shutting down and it will be held low by the discharge FET as
long as possible.
Characteristics
• It powers up directly from the battery
• Operates at a switching frequency equals to F_SW1
• Drives integrated low R_DS(ON) N-channel power
MOSFETs (NHV_HC) as its output stage
• The output is ±4% accuracy
• Output voltage is adjustable by means of an external
resistor divider
• The output can be adjusted up or down at 2.5% steps to
achieve from +17.5% to -20.0% on each direction allowing
Dynamic Voltage Scaling using the I²C DVS register.
• An extra fine voltage scaling in 0.5% steps helps to adjust
down the output voltage as low as -XX%.
• Uses a bootstrap network with an internal diode to power
its switch MOSFET
• All gate drive circuits are supplied from VG.
• Uses integrated compensation.
• The output is monitored for under-voltage and over-
voltage conditions
• The output is monitored for over-current and short-circuit
conditions
• The regulator is monitored for over-temperature
conditions
Operation Modes
The switcher will be active when:
• VG is in regulation AND
• There is no GrpB shutdown command through the I²C
interface AND
• No faults exist that would cause GrpB to shut down
REG4
This is a 4-switch synchronous buck-boost PWM voltage-
mode control DC/DC regulator.
See Power-Up Sequence on page 27 for more details on
when REG4 is powered up in the sequence.
The switcher will operate in DCM at very light loads to
allow pulse skipping.
VOUT4 will be discharged every time the regulator is
shutting down and it will be held low by the discharge FET as
long as possible.
Characteristics
• It powers up directly from the battery
• Operates at a switching frequency equals to F_SW1
• Drives integrated low R_DS(ON) N-channel power
MOSFETs (NHV_HC) as its output stage
• The output is ±2% accuracy
• Output voltage is adjustable by means of an external
resistor divider
• The output can be adjusted up or down at 2.5% steps for
a total of +17.5% to -20.0% on each direction allowing
Dynamic Voltage Scaling.
• Uses bootstrap networks with an internal diode to power
its high side MOSFETs
• All gate drive circuits are supplied from VG.
• Uses external compensation
• The output is monitored for under-voltage and over-
voltage conditions
• The output is monitored for over-current and short-circuit
conditions
• The regulator is monitored for over-temperature
conditions
Operation Modes
The switcher will be active when:
• VG is in regulation AND
• There is no GrpB shutdown command through the I²C
interface AND
• No faults exist that would cause GrpB to shut down
REG5
This is a 4-switch synchronous buck-boost PWM voltage-
mode control DC/DC regulator.
See Power-Up Sequence on page 27 on for more details
on when REG5 is powered up in the sequence.
The switcher will operate in DCM at very light loads to
allow pulse skipping.
VOUT5 will be discharged every time the regulator is
shutting down and it will be held low by the discharge FET as
long as possible.
Characteristics
• It powers up directly from the battery
• Operates at a switching frequency equals to F_SW1
• Drives integrated low R_DS(ON) N-channel power
MOSFETs (NHV_HC) as its output stage
• The output is ±2% accuracy
• Output voltage is adjustable by means of an external
resistor divider
• The output can be adjusted up or down at 2.5% steps for
a total of +17.5% to -20.0% on each direction allowing
Dynamic Voltage Scaling.
• Uses bootstrap networks with an internal diodes to power
its high side MOSFETs
• All gate drive circuits are supplied from VG.
• Uses external compensation
• The output is monitored for under-voltage and over-
voltage conditions
• The output is monitored for over-current and short-circuit
conditions
• The regulator is monitored for over-temperature conditions
Analog Integrated Circuit Device Data
Freescale Semiconductor
34704
23