MC34845DEPR2 Freescale Semiconductor, MC34845DEPR2 Datasheet - Page 16

• Manufacturer Part Number: MC34845DEPR2
• Description: IC LED DVR BACKLIGHT 6CH 24QFN
• Manufacturer: Freescale Semiconductor

Specifications of MC34845DEPR2

• Internal Driver: Yes
• Type - Primary: Backlight
• Mounting Type: Surface Mount
• Topology: PWM, Step-Up (Boost)
• Number Of Outputs: 6
• Frequency: 270kHz ~ 330kHz
• Voltage - Supply: 5 V ~ 21 V
• Voltage - Output: 60V
• Package / Case: 24-UFQFN Exposed Pad
• Operating Temperature: -40°C ~ 85°C
• Operating Supply Voltage: 5 V to 21 V
• Maximum Supply Current: 5 mA
• Maximum Power Dissipation: 3.4 W
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Variable definition
Component Suggestions
conditions.
Table 5. Component Suggestion Table
Application
Case
D = Duty cycle
V
V
V
V
ΔV
I
I
I
r = Current ripple ratio at the inductor = ΔI
I
The Component Sugestions only apply to the conditions shown. Therefore, adjustments are necessary for different application
IN-AVG
OUT
IN-MAX
RMS-CIN
TYPICAL APPLICATIONS
COMPONENTS CALCULATION
16
34845
1
2
OUT
D
IN
SW
OUT
= Diode voltage
= Input voltage
= Internal switch voltage drop.
= Output current
= Output voltage
Vin(min) Vin(Max) Vo(max) VOVP fBoost ILED per
= Output voltage ripple
= Average input current = I
= Maximum input current
= RMS current for the input capacitor
9V
6V
12V
12V
30V
43V
35V
48V
L-AVG
600kHz
300kHz
channel
20mA
23mA
L
/ I
L-AVG
Rovp_upper Rovp_lower L(min)
680kOhm
680kOhm
167kOhm
114kOhm
22uH
22uH
I
L = Inductor.
R
F
C
R
G
ESR
f
f
C
C
RMS-COUT
RHPZ
CROSS
Isat min = 2.6A
SW
INDUCTOR
OUT
COMP
M
COMP1
COMP2
= OTA transconductance
= Boost switching frequency
Continuous
COUT
= Right half plane zero frequency
= Output capacitor
L(min)
mode
33uH
33uH
= Crossover frequency
= Compensation resistor
= Compensation capacitor
= Shunt compensation capacitor
= ESR of the output capacitor
= RMS current for output capacitor
= Inductor winding resistor
Cin(min) Cout(min) Rcomp at
X7R; 25V
X7R; 25V
1x10uF;
1x10uF;
X7R; 100V
2 x 4.7uF;
4 x 2.2uF;
X7R; 50V
Analog Integrated Circuit Device Data
V
PWM=3.3V
3.3kOhm
2kOhm
V
Rshunt at
Freescale Semiconductor
PWM=3.3V
10kOhm
16kOhm
Ccomp1
33nF
56nF
Ccomp2
220pF
220pF