PM6600 STMicroelectronics, PM6600 Datasheet - Page 50

• Manufacturer Part Number: PM6600
• Description: IC LED DRIVR WHT BCKLT 24-VFQFPN
• Manufacturer: STMicroelectronics
• Type: Backlight, White LEDr

Specifications of PM6600

• Topology: PWM, Step-Up (Boost)
• Number Of Outputs: 6
• Internal Driver: Yes
• Type - Primary: Backlight
• Type - Secondary: White LED
• Frequency: 200kHz ~ 1MHz
• Voltage - Supply: 4.7 V ~ 28 V
• Voltage - Output: 36V
• Mounting Type: Surface Mount
• Package / Case: 24-VFQFN, 24-VFQFPN
• Operating Temperature: -40°C ~ 85°C
• Current - Output / Channel: 32mA
• Internal Switch(s): Yes
• Number Of Segments: 60
• Operating Supply Voltage: 4.7 V to 28 V
• Maximum Power Dissipation: 2.3 W
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• For Use With: 497-8414 - BOARD EVAL BASED ON PM6600
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Efficiency: -
• Lead Free Status / Rohs Status: Details

Application note
50/60
Equation 25
whereas R
Equation 26
and
Equation 27
The output voltage in the above calculations is considered as the maximum value (LED with
the maximum forward voltage connected to the leading generator):
Equation 28
Figure 57. Inductor current in DCM operation
Considering the input voltage range, the lower L
the condition to assure the DCM operation becomes:
Equation 29
An inductor value of 6.8 µH could be a suitable value, considering also a margin from the
boundary condition.
I
I
L, p eak
L, p eak
I
I
L
L
T
T
0
ON
ON
is:
T
T
SW
SW
T
T
OF F
OF F
= 1/F
= 1/F
D
V
=
OUT
1
SW
SW
−
Doc ID 14248 Rev 7
,
max
V
V
OUT
I
L
IN
OUT
=
<
R
8
=
L
0
⋅
=
B
V
⎧
⎨
⎩
=
(
, F
. 0
6
V
. 0
V
I
LEDs
⋅
IN
52
OUT
OUT
I
68
ROW
,
min
,
max
)
@
=
B
@
=
=
250
will be at the lower input voltage. Hence
13
+
120
V
400
2 .
V
IN
Ω
IN
mA
μ
,
max
,
mV
H
min
=
=
=
14
9
30
6 .
4 .
V
V
V
PM6600
t
t