SC900841JVKR2 Freescale Semiconductor, SC900841JVKR2 Datasheet - Page 88

• Manufacturer Part Number: SC900841JVKR2
• Description: IC POWER MGT 338-MAPBGA
• Manufacturer: Freescale Semiconductor

Specifications of SC900841JVKR2

• 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

Short-circuit Protection
currents, in case of an output short, by detecting the voltage
on the FBBKLT feedback pin. If the FBBKLT voltage falls
below a set threshold, VBKLT detects a short-circuit, turns off
VBKLT, and asserts the VBKLTFAULT flag. There is no
automatic restart after this event, and VBKLT has to be re-
enabled in order to clear the VBKLTFAULT flag.
prevent false or premature detection of a short-circuit
condition. The block will be subjected to an inrush current,
possibly higher than the trip threshold. If a short were already
present when starting up, the soft-start would end after about
4.0 ms. SC is detected, and the boost is disabled as
described.
Open LED Protection
channels. If an LED fails open, the voltage at the WLEDx pin
for the effected string falls close to ground. When this event
is detected, the affected string is taken out of the VBKLT
control loop, and the output voltage (V
the other two strings. Normal operation can be resumed while
the affected string is disabled. If this open LED event caused
the output voltage to rise, the output voltage will be clamped
to 22 V.
.
VBKLT Status/Control Registers and Bits Description
There are no dedicated registers for VBKLT.
88
900841
FUNCTIONAL DEVICE OPERATION
POWER SUPPLIES
VBKLT protects the internal MOSFET from excessive
Short-circuit protection is disabled during soft-start to
VBKLT monitors the LED status at the 3 main backlight
LED Drivers registers will be detailed in
BKLT
) is determined by
Lighting
Figure 41. VBKLT Efficiency Curves
System.
Leakage Current Limiting
temperature when the current sinks are disabled.
Main Features
• Supplies the LCD backlight and camera scene illumination
• Drives up to 4 parallel strings of up to 5 LED(s) each at
• Uses the V
• 120 mA maximum continuous output current for full
• 2.0 MHz switching frequency
• Uses internal compensation
• Soft-start feature to minimize inrush currents at power up
• Uses an internal 26 V low side switch MOSFET
• Output under-voltage detection and output over-voltage,
• Open LED protection
• Minimum Leakage current in the off state
Efficiency Curves
the recommended external component values and typical
output voltage. 3.0 V ≤ VPWR ≤ 4.4 V
The LED leakage current is limited to 1.0 µA at room
LEDs
30 mA maximum current
voltage capabilities.
short-circuit, and over-current protection
The efficiency curves in
PWR
rail as its power supply
Analog Integrated Circuit Device Data
Figure 41
Freescale Semiconductor
are calculated based on