PM6600 STMicroelectronics, PM6600 Datasheet - Page 31

• 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
Figure 47. Poor phase margin (a) and properly damped (b) load transient responses
Equation 9
Once the output capacitor has been chosen, the R
Equation 10
Where G
The C
times lower than the loop bandwidth:
Equation 11
Where f
The close loop gain function (G
Equation 12
A simple technique to optimize different applications is to replace R
trimmer and adjust its value to properly damp the output transient response. Insufficient
damping will result in excessive ringing at the output and poor phase margin. Figures 5a and
5b give an example of compensation adjustment for a typical application.
COMP
Z
M
= f
= 2.7 S and g
U
capacitor is determined to place the frequency of the compensation zero 5
/ 5.
G
LOOP
EA
=
= 375 µS.
G
Δ
M
Doc ID 14248 Rev 7
V
LOOP
⋅
OUT
g
C
EA
R
COMP
) is thus given by equation 10:
=
COMP
⋅
⎛
⎜ ⎜
⎝
2
R
⋅ π
COMP
I
=
OUT
=
f
U
2
G
⋅ π
⋅
C
2
+
M
⋅ π
f
Z
⎛
⎜
⎜
⎝
sC
⋅
1
g
⋅
f
1
U
R
−
EA
COMP
COMP
1
⋅
COMP
V
V
C
⋅
IN
M
IN
_
_
can be calculated as:
⎞
⋅ ⎟ ⎟
⎠
MAX
MIN
RM
⎞
⎟
⎟
⎠
1
1
−
+
s
sRC
M
COMP
Operation description
L
2
R
with a 20 kΩ
31/60