MC34844AEP Freescale Semiconductor, MC34844AEP Datasheet - Page 16

• Manufacturer Part Number: MC34844AEP
• Description: IC LED DVR BACKLIGHT 10CH 32QFN
• Manufacturer: Freescale Semiconductor

Specifications of MC34844AEP

• Constant Current: Yes
• Internal Driver: Yes
• Type - Primary: Backlight
• Mounting Type: Surface Mount
• Topology: PWM, Step-Up (Boost)
• Number Of Outputs: 10
• Frequency: Adjustable/Selectable
• Voltage - Supply: 7 V ~ 28 V
• Voltage - Output: 60V
• Package / Case: 32-VFQFN Exposed Pad
• Operating Temperature: -40°C ~ 105°C
• Operating Supply Voltage: 7 V to 28 V
• Maximum Supply Current: 10 mA
• Maximum Power Dissipation: 3.9 W
• Maximum Operating Temperature: + 105 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

REGULATORS/ POWER DOWN
the 7.0 to 28 V range. This is stepped down internally by
LDOs to 2.5 V (VDC1 and VDC3) and 6 V (VDC3) for
powering internal circuitry. If the input voltage falls below the
UVLO threshold, the device automatically enters in power
down mode.
SCK bus lines, resulting in three distinct operation modes:
• Manual mode, there is no I
Analog Integrated Circuit Device Data
Freescale Semiconductor
The 34844 is designed to operate from input voltages in
Operating Modes:
The device can be operated by the EN pin and/or SDA/
must be tied low, and the EN pin controls the ON/OFF
operation.
MC34844 - Functional Block Diagram
Logic Control
Regulator / Power down
Protection / Failure Detection
Regulators / Power Down
Optical and Temperature Control
2
C capability, the bus line pins
Over-temperature Protection
Under-voltage Protection
Serial Interface Control
Over-voltage Protection
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
Over-current Protection
LED Open Protection
3 Internal Regulators
Logic Control
PWM Dimming
Figure 5. Functional Internal Block Diagram
LED Channels
Protection / Failure Detection
Boost
• SM Bus mode, EN pin must be tied low and the device is
• I
turned ON by any activity on the bus lines. The part shuts
down if the bus lines are held low for more than 27 ms, the
27 ms watchdog timer can be disabled by I
SETI2C bit high) or tying the EN pin high. In Sleep mode
(EN bit=0) the device reduces the power consumption by
leaving “alive” only the blocks required for I
communication.
(SETI2C bit = 1) right after the IC is turned ON, it prevents
the part from being turned ON/OFF by the bus. Sleep
mode is also present and it is intended to save power, but
still keep the IC prepared to communicate by I
the EN pin OFF, the chip enters into a low power mode.
2
C mode, has to be configured by I
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
LED Channels
Boost
FUNCTIONAL DESCRIPTION
2
C communication
2
2
C (setting
C
2
C. Turning
34844
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