PM6600 STMicroelectronics, PM6600 Datasheet - Page 34

• 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

Operation description
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nominal value to permit to use inductors with lower saturation current value; the nominal
switching frequency is restored after the SS pin voltage has crossed 0.8 V. In this mode, the
current runaway is avoided.
Figure 51. Soft-start sequence waveforms in case of floating ROWs
During the soft-start phase it is also performed the floating ROWs detection. In presence of
one or more floating ROWs, the error amplifier is unbalanced and the output voltage
increases; when it reaches the floating ROW Detection (FRD) threshold (93% of the OVP
threshold), the floating ROWs are managed according to
39
protections turn active. The soft-start duration can be calculated with the following formula:
Equation 15
Where I
Please refer to the application note section for the CSS value settings according to the
different working conditions.
). After the SS voltage reaches a 2.4 V threshold, the start-up finishes and all the
SS
= 5 µA.
AVCC
100%
OVP
2.4V
1.2V
0.8V
Vth,FRD=
93% of OVP
Doc ID 14248 Rev 7
t
ss
Floating ROWs detection
t
SS
≅
2
5 .
C
I
SS
SS
Protections turn active
Nominal switching
frequency release
Output voltage
Current limit
EN pin voltage
SS pin voltage
Table 8
(see
Section 9 on page
t
PM6600