EVALPM6680A STMicroelectronics, EVALPM6680A Datasheet - Page 34

• Manufacturer Part Number: EVALPM6680A
• Description: EVAL BOARD FOR PM6680A
• Manufacturer: STMicroelectronics

Specifications of EVALPM6680A

• Mfg Application Notes: PM6680A, AN2565 Appl Note
• Main Purpose: DC/DC, Step Down with LDO
• Outputs And Type: 3, Non-Isolated
• Power - Output: 10.5W
• Voltage - Output: 1.8V, 3.3V, 5V
• Current - Output: 2.5A, 2.5A, 100mA
• Voltage - Input: 6 ~ 36V
• Regulator Topology: Buck
• Frequency - Switching: 200kHz, 300kHz
• Board Type: Fully Populated
• Utilized Ic / Part: PM6680A
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6263

Design guidelines
34/48
Equation 22
Choose a synchronous rectifier with low R
variation of the phase node voltage can bring up even the low side gate through its gate-
drain capacitance C
that minimizes the ratio C
Below there is a list of some possible low side MOSFETs.
Table 10. Low side MOSFET manufacturer
Dual n-channel MOSFETs can be used in applications with a maximum output current of
about 3 A. Below there is a list of some MOSFET manufacturers.
Table 14.
A rectifier across the low side MOSFET is recommended. The rectifier works as a voltage
clamp across the synchronous rectifier and reduces the negative inductor swing during the
dead time between turning the high-side MOSFET off and the synchronous rectifier on. It
can increase the efficiency of the switching section, since it reduces the low side switch
losses. A shottky diode is suitable for its low forward voltage drop (0.3 V). The diode reverse
voltage must be greater than the maximum input voltage V
reverse charge is preferable. Below there is a list of some shottky diode manufacturers.
Table 15.
Manufacturer
Manufacturer
Manufacturer
ST
ST
ST
Dual MOSFET manufacturer
Schottky diode manufacturer
RSS
STPS1L40M
STS4DNF60L
P
, causing cross-conduction problems. Choose a low side MOSFET
Series
conduction
RSS
Type
STS7NF60L
/C
Type
GS
=
(C
R
Forward voltage
DSon
GS
R
DSon
= C
×
0.5
(V)
DSon
⎛
⎜ ⎜
⎝
50
R
1
ISS
[VC11] 19
DSon
(mΩ)
−
. When high side MOSFET turns on, the fast
V
- C
V
IN
OUT
(mΩ)
max
RSS
Gate charge
⎞
⎟ ⎟
⎠
).
×
Rated reverse
I
voltage (V)
LOAD
(nC)
15
INmax
0.0625
C
--------------
C
40
RSS
(max)
GS
. A minimum recovery
2
Rated reverse voltage
Rated reverse voltage
Reverse current
(V)
(V)
60
60
(uA)
21
PM6680A