34704_11 Datasheet, PDF (24/54 Pages) Freescale Semiconductor, Inc – Multiple Channel DC-DC Power Management IC

FUNCTIONAL DESCRIPTION
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
• 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 GrpC (OR GrpE) shutdown command through
the I²C interface AND
• No faults exist that would cause GrpC (OR GrpE) to shut
down
REG6 (Only 34704A)
This is a synchronous boost PWM voltage-mode control
DC/DC regulator.
See Power-Up Sequence on page 28 for more details on
when REG6 is powered up in the sequence.
The switcher will operate in DCM at very light loads to
allow pulse skipping.
VOUT6 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_SW2
• Drives integrated low R_DS(ON) N-channel power
MOSFETs (NVHV_LC) as its output stage
• It offers load disconnect from the input battery when the
output is off (True Cut-Off)
• The output is ±4% accuracy
• Output voltage is adjustable by means of an internal
resistor divider
• The output can be adjusted up or down at 2.5% steps for
a total of 10% on each direction allowing Dynamic Voltage
Scaling
• Uses a bootstrap network with an internal diode to power
its synchronous 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 GrpC shutdown command through the I²C
interface AND
• No faults exist that would cause GrpC to shut down
REG7 (Only 34704A)
This is a none-synchronous buck-boost inverting PWM
voltage-mode control DC/DC regulator.
See Power-Up Sequence on page 28 for more details on
when REG7 is powered up in the sequence.
The switcher will operate in DCM at very light loads to
allow pulse skipping.
VOUT7 will be discharged every time the regulator is
shutting down and it will be held high to ground by the
discharge FET as long as possible.
Characteristics
• It powers up directly from the battery
• Operates at a switching frequency equals to F_SW2
• Drives an external P-channel power MOSFET
• 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 10% on each direction allowing Dynamic Voltage
Scaling.
• All gate drive circuits are supplied from V_G
• Uses external compensation, the type is up to the designer
• The output is monitored for under-voltage and over-
voltage conditions
Operation Modes
The switcher will be active when:
• VG is in regulation AND
• There is no GrpC shutdown command through the I²C
interface AND
• No faults exist that would cause GrpC to shut down
REG8
This is a synchronous boost PWM voltage-mode control
DC/DC regulator.
See Power-Up Sequence on page 28 for more details on
when REG8 is powered up in the sequence.
VOUT8 will be discharged every time the regulator is
shutting down and it will be held to ground by the discharge
FET as long as possible.
This regulator offers either voltage regulation for organic
LEDs or current regulation for LCD backlighting LEDs. It
provides either voltage or current feedback for these
purposes through the same feedback pin.
The regulator cannot drive only 1LED with a forward
voltage drop of less than the battery input voltage.
The processor would set the REG8 register through I²C
before enabling REG8 to indicate if voltage regulation or
current regulation will be used.
Characteristics
• It powers up directly from the battery
34704
24
Analog Integrated Circuit Device Data
Freescale Semiconductor