SC900841JVK Freescale Semiconductor, SC900841JVK Datasheet - Page 79

• Manufacturer Part Number: SC900841JVK
• Description: IC POWER MGT 338-MAPBGA
• Manufacturer: Freescale Semiconductor

Specifications of SC900841JVK

• Applications: PC's, PDA's
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 338-TBGA
• Input Voltage: 2.8 V to 4.4 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Supply: -
• Voltage - Supply: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

VYMXPA
mode control DC/DC regulator with internal low side FET.
WiMAX module, it provides a fixed 4.2V output voltage, and
capability to supply up to 700 mA of drive current. It can also be
used to support many applications that need a 5.0 V supply
voltage, as in motor drives and high current OTG Buses. If
used as a 5.0 V supply then the current capability is limited to
a 500 mA maximum.
battery voltage, at very high battery input voltage conditions,
the output will track the battery voltage minus a diode forward
voltage drop (output is directly connected to the input through
the inductor and an external diode).
boost from the actual load, an external PMOS switch (M
will be used to switch in VYMXPA output to the load, as shown
in
Under-voltage Detection
comparator that serves as an output ready signal, along with
the absence of faults. When VYMXPA is turned on, a
VYMXPAFAULT is asserted, the under-voltage comparator is
turned on, and V
(measured at FBYMXPA) reaches a steady state,
VYMXPAFAULT is de-asserted to indicate the VYMXPA output
readiness to start. During operation, if the output voltage is
decreased below the under-voltage threshold, an under-
voltage condition is detected, and VYMXPAFAULT is asserted.
Analog Integrated Circuit Device Data
Freescale Semiconductor
Figure
This is a 2.0 MHz non-synchronous Boost PWM current-
VYMXPA is designed to supply the Power Amplifier for the
Since the output of VYMXPA is close to the maximum
Due to the possible need to isolate the output of VYMXPA
VYMXPA features an output under-voltage detection
M
If not used then
Connect YMXPAGTIN and YMXPAGT to GND
Then short V
YMXPA
13. M
is an Optional Isolation Switch
OYMXPA
YMXPA
OYMXPA
to FBYMXPA pin
is always enabled and if it is not needed,
starts ramping up. When V
C
OYMXPA
V
OYMXPA
Load
Figure 35. VYMXPA Detailed Internal Block Diagram
M
YMXPA
D
YMXPA
L
YMXPA
V
PWR
PGNDYMXPA
YMXPAGTIN
SWYMXPA
YMXPAGT
FBYMXPA
C
INYMXPA
OYMXPA
YMXPA
R
SENSE
Discharge FET
Internal
Compensation
V
)
REF
Z1
Driver
V
V
V
REFUV
REFOV
REFSC
then do not populate the switch and ground the YMXPAGTIN
and YMXPAGT pins.
feedback node after or before the switch. Accuracy is
maintained where the feedback node is connected. The output
capacitor C
recommended to follow the feedback node connection.
feedback node is taken after the switch. The discharge FET is
connected internally to the FBYMXPA pin. If M
used, then the discharge FET should be disabled by setting the
VYMXPADISDSCH bit, since VYMXPA cannot be discharged
due to the lack of an isolation FET (the output is directly
connected to the input through the inductor and an external
diode).
module, it can be presented with a high load transient current,
so close attention to the VYMXPA transient response is in
order here to account for these possible load changes.
current, and short-circuit protection.
If the output voltage rises above the under-voltage threshold
plus hysteresis, the VYMXPAFAULT signal is cleared,
assuming no other faults are occurring.
Over-current Protection
switch MOSFET current. The over-current threshold value is
set higher than the worst peak inductor current value. If an
over-current is detected, the switch MOSFET turns off, the
VYMXPAFAULT flag is asserted, and the regulator goes into a
cycle by cycle current limiting until the fault is serviced. If the
When M
VYMXPA can be discharged only if M
Since VYMXPA is supplying the power amplifier of a WiMAX
VYMXPA includes under-voltage, over-voltage, over-
VYMXPA limits the peak inductor current by sensing the
Driver
EA
Z2
OC
SC
UV
OV
YMXPA
OYMXPA
Controller
is used, then users can either connect the
can also connect to either node but is
FUNCTIONAL DEVICE OPERATION
AOACCTLVYMX3GPA
VYMXPADISDSCH
VYMXPAFAULT
CTLVYMX3GPA
SELVYMX 3GPA
YMXPA
Interface
POWER SUPPLIES
SPI
is used and the
YMXPA
is not
900841
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