FUNCTIONAL DESCRIPTION
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
• The output is monitored for over-current and short-circuit
conditions
REG7 (Only 34704A)
This is a none-synchronous buck-boost inverting PWM
voltage-mode control DC/DC regulator.
• The regulator is monitored for over-temperature conditions
See Power-Up Sequence on page 28 for more details on
when REG7 is powered up in the sequence.
Operation Modes
The switcher will be active when:
• VG is in regulation AND
The switcher will operate in DCM at very light loads to
allow pulse skipping.
• There is no GrpC (OR GrpE) shutdown command through
the I2C interface AND
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.
• No faults exist that would cause GrpC (OR GrpE) to shut
down
Characteristics
REG6 (Only 34704A)
• It powers up directly from the battery
• Operates at a switching frequency equals to FSW2
• Drives an external P-channel power MOSFET
• The output is ±2% accuracy
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.
• Output voltage is adjustable by means of an external
resistor divider
The switcher will operate in DCM at very light loads to
allow pulse skipping.
• The output can be adjusted up or down at 2.5% steps for
a total of 10% on each direction allowing Dynamic Voltage
Scaling.
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.
• All gate drive circuits are supplied from VG
• Uses external compensation, the type is up to the designer
Characteristics
• The output is monitored for under-voltage and over-
voltage conditions
• It powers up directly from the battery
• Operates at a switching frequency equals to FSW2
Operation Modes
• Drives integrated low RDS(ON) N-channel power
MOSFETs (NVHV_LC) as its output stage
The switcher will be active when:
• VG is in regulation AND
• There is no GrpC shutdown command through the I2C
interface AND
• 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
• No faults exist that would cause GrpC to shut down
• The output can be adjusted up or down at 2.5% steps for
a total of 10% on each direction allowing Dynamic Voltage
Scaling
REG8
This is a synchronous boost PWM voltage-mode control
DC/DC regulator.
• Uses a bootstrap network with an internal diode to power
its synchronous MOSFET
See Power-Up Sequence on page 28 for more details on
when REG8 is powered up in the sequence.
• All gate drive circuits are supplied from VG.
• Uses integrated compensation.
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.
• The output is monitored for under-voltage and over-
voltage conditions
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 output is monitored for over-current and short-circuit
conditions
• The regulator is monitored for over-temperature conditions
The regulator cannot drive only 1LED with a forward
voltage drop of less than the battery input voltage.
Operation Modes
The processor would set the REG8 register through I2C
before enabling REG8 to indicate if voltage regulation or
current regulation will be used.
The switcher will be active when:
• VG is in regulation AND
• There is no GrpC shutdown command through the I2C
interface AND
Characteristics
• No faults exist that would cause GrpC to shut down
• It powers up directly from the battery
34704
Analog Integrated Circuit Device Data
Freescale Semiconductor
24
FREESCALE [ Freescale ]
