MC34845BEPR2 Freescale Semiconductor, MC34845BEPR2 Datasheet - Page 16
MC34845BEPR2
Manufacturer Part Number
MC34845BEPR2
Description
IC LED DVR BACKLIGHT 6CH 24QFN
Manufacturer
Freescale Semiconductor
Type
Backlight, White LED, Color LEDr
Datasheet
1.MC34845BEPR2.pdf
(20 pages)
Specifications of MC34845BEPR2
Topology
PWM, Step-Up (Boost)
Number Of Outputs
6
Internal Driver
Yes
Type - Primary
Backlight
Frequency
270kHz ~ 330kHz
Voltage - Supply
5 V ~ 21 V
Voltage - Output
8 V ~ 60 V
Mounting Type
Surface Mount
Package / Case
24-QFN Exposed Pad
Operating Temperature
-40°C ~ 85°C
Current - Output / Channel
30mA
Internal Switch(s)
Yes
Efficiency
90%
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