PM6685 STMicroelectronics, PM6685 Datasheet - Page 42

• Manufacturer Part Number: PM6685
• Description: IC CTLR DUAL SYNC STDN 5X5VFQFPN
• Manufacturer: STMicroelectronics

Specifications of PM6685

• Applications: Controller, Notebook Power System
• Voltage - Input: 6 ~ 28 V
• Number Of Outputs: 2
• Voltage - Output: -3.3V, 5V
• Operating Temperature: 0°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 32-VFQFN, 32-VFQFPN
• Output Voltage: 5 V, 3.3 V
• Output Current: 0.1 A
• Input Voltage: 5.5 V to 28 V
• Mounting Style: SMD/SMT
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 10 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Design example
10.4
10.5
10.6
10.7
42/48
Current limit
OUT5:
Equation 36
Equation 37
(Let’s assume the maximum temperature Tmax = 75°C in R
OUT3:
Equation 38
Equation 39
(Let’s assume Tmax = 75°C in R
Input capacitor
Maximum input capacitor RMS current is about 3.4 A. Then I
We put three 10 µF ceramic capacitors with Irms = 1.5 A.
Synchronous rectifier
OUT5: Schottky diode STPS1L30M
OUT3: Schottky diode STPS1L30M
Integrator loop
(Refer to
OUT5: The ripple is greater than 30 mV, then the virtual ESR network is not required.
C
INT
=1 nF; C
Low side: STS12NH3LL
Figure 30 on page 22
filt
= 47 pF; R
I
Lvalley
I
Lvalley
INT
R
R
CSENSE
CSENSE
(min)
Doc ID 11674 Rev 8
(min)
= 1 kΩ
)
DSon
=
=
≡
≡
I
LOAD
calculation)
I
100
LOAD
100
. 4
. 4
22
19
(max)
μ
μ
(max)
A
A
A
A
⋅
⋅
16
16
−
.
.
−
25
25
Δ
Δ
I
m
L
m
I
L
(min)
2
Ω
Ω
(min)
2
≈
≈
686
681
=
DSon
=
CinRMS
. 4
Ω
Ω
. 4
19
22
calculation)
A
> 3.4 A
PM6685