PM6600 STMicroelectronics, PM6600 Datasheet - Page 53

• 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

PM6600
B.4.7
B.4.8
V
Equation 37
Where
Equation 38
R
the resistor divider. For example, setting R
The OVSEL divider capacitors should be chosen according to the formula
Equation 39
For most cases, C10 = 220 pF and C13 = 22 pF are recommended.
Compensation network
For the compensation network, the suggestions provided in section 7.4 are always valid.
The following value of R3 and C8 are usually a good choice for the loop stability:
R
C
These values are correct when working with 6 ROWs. For applications using less then 4
ROWs it is recommended to calculate again the value of the compensation components.
Please refer to the
Boost current limit
The boost current limit is set to protect the internal power switch against excessive current.
The slope compensation may reduce the programmed current limit. Hence, to take into
account this effect, as a rule of thumb, the current limit can be set as twice as much the
maximum inductor peak current (see section 1.2.4):
I
Therefore choosing I
Equation 40
BOOST, PEAK
OVP
1
3
8
can be chosen is in the order of hundreds of kilo-ohms to reduce the leakage current in
= 2.4 kΩ
= 4.7 nF
has to be chosen in the range
> 2.09 A
Table 11 on page 54
V
BOOST, PEAK
OUT
max
V
OUT
=
Doc ID 14248 Rev 7
n
R
max
WLED
BILIM
= 2.5 A, R
+
C
_
3
=
series
13
V
I
for a detailed components check
<
BOOST
=
V
2
1
⋅
BILIM
OVP
5 .
V
= 15 kΩ leads to R
K
F
B
⋅
,
PEAK
_
C
WLED
<
10
will be:
V
⋅
OUT
=
R
R
max
2
1
240
max
+
k
400
+
Ω
4
5 .
mV
1
V
= 390 kΩ (V
=
30
V
Application note
OVP
= 33.5 V).
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