PM6681A STMicroelectronics, PM6681A Datasheet - Page 41

• Manufacturer Part Number: PM6681A
• Description: Dual synchronous step down controller with adjustable LDO
• Manufacturer: STMicroelectronics

PM6681A
9.8.5
9.8.6
9.8.7
9.8.8
(Let's assume T
Input capacitor
Maximum input capacitor RMS current is about 1.1 A. Then I
We can put two 10 µF ceramic capacitors with I
Synchronous rectifier
OUT1: Schottky diode STPS1L40M
OUT2: Schottky diode STPS1L40M
Integrator loop
(Refer to
OUT1: The ripple is smaller than 40mV, then the virtual ESR network is required.
C
C = 5.6 nF; R = 36 kΩ; R1 = 3 kΩ
OUT2: The ripple is smaller than 40mV, then the virtual ESR network is required.
C
C = 5.6 nF; R = 22 kΩ; R1 = 3.3 kΩ
Output feedback divider
(Refer to
OUT1: R1 = 10 kΩ; R2 = 6.8 kΩ
OUT2: R1 = 11 kΩ; R2 = 1.8 kΩ
INT
INT
= 1 nF; C
= 1 nF; C
Figure 40
Figure 32
filt
filt
max
= 47 pF; R
= 110 pF; R
)
)
= 75 °C in R
R
INT
INT
CSENSE
= 1 kΩ
DS(on)
= 1 kΩ
≡
100
calculation)
4
2 .
µ
A
A
⋅
16
rms
.
25
= 1.5 A.
m
Ω
≈
680
CinRMS
Ω
> 1.1 A
Design guidelines
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