A6986F Datasheet, PDF (64/72 Pages) STMicroelectronics – 38 V 1.5 A synchronous step-down switching regulator

EMC testing results
A6986F
Figure 58 shows the schematic of the EMC board that can be configured for CE and DPI
testing.
Figure 58. CE - 150R / DPI
VIN_PIN
TP9
VCC
TP7
GND
SYNCH
PGND
C13B +
DNM
8X10
+ C13A
220uF
50V
10X10
SS/INH
GND
TP1
TP11
R14 1K
0603
R3 DNM
0603
R1 DNM
0603
R2
R4
0R
0R
R12 1K
0603
A6986F - 500kHz - CE VERSION
R29
DNM
R10 DNM
0603
SS_INH
Q1
2N7002
SOT23
R11
10K
C5
100nF
50V
X7R
0603
R5 DNM
0603
U1
A6986F5V
4
SYNCH
15
VIN
2
VCC
5
FSW
6
MLF
3
SS/INH
8
DELAY
1
RST
16
VBIAS
13
LX 14
LX
9
FB
7
COMP
C6
EP SGND PGND PGND
10nF
50V
17 10
11 12
X7R
0603
signal GND
power GND
RST
C8
150pF
50V
COG/NP0
0603
R8
110K
C4
2.2pF
50V
COG/NP0
0603
R6 1M
0603
JP3
2A DC
R13
DNM
L1 6.8uH
XAL50/XAL40
JP2
R9 DNM
0603
C7
DNM
0603
R7 0R
0603
C17
DNM
0805
C12
DNM
0603
TP5
VS
M1
1
12
2
MORS2V1P
PGND
VS1
JP4
L3 220R
3A 0805
2A DC
C16
4.7uF
50V
X5R
1206
VS2
JP5
L2 4.7uH
XAL40
2A DC
C15
4.7uF
50V
X5R
1206
PGND
TP8
VIN_EMI
VIN_PIN
C14
4.7uF
50V
X5R
1206
CE 150ohm ASSEMBLY VERSION:
RF Networks: Mount 120R
Mount 6.8nF
Mount 51R
DPI ASSEMBLY VERSION:
RF Networks: Change 120R into 0R
Mount 6.8nF
Don't mount 51R
J1
BNC-SMA-FEM-180-SMD
1 50ohm
R17
51R
R15
0603
120R
GND-RF GND-RF
J3
BNC-SMA-FEM-180-SMD
1 50ohm
R21
51R
R19
0603
120R
GND-RF GND-RF
J5
BNC-SMA-FEM-180-SMD
1 50ohm
R25
51R
R23
0603
120R
GND-RF GND-RF
J7
BNC-SMA-FEM-180-SMD
1 50ohm
R28
51R
R27
0603
120R
GND-RF GND-RF
VS1
C18
6.8nF
100V
X7R
0603
VS2
C20
6.8nF
100V
X7R
0603
C22
6.8nF
100V
X7R
0603
VIN_PIN
J2
BNC-SMA-FEM-180-SMD
1 50ohm
R18
51R
R16
0603
120R
GND-RF GND-RF
J4
BNC-SMA-FEM-180-SMD
1 50ohm
R22
51R
R20
0603
120R
GND-RF GND-RF
J6
BNC-SMA-FEM-180-SMD
1 50ohm
R26
51R
R24
0603
120R
GND-RF GND-RF
C24
6.8nF
100V
X7R
0603
VOUT
RST
C19
6.8nF
100V
X7R
0603
C21
6.8nF
100V
X7R
0603
SS_INH
C23
6.8nF
100V
X7R
0603
SYNCH
TP4
VOUT
VOUT
C9
C10
10uF
10uF
50V
50V
X5R
X5R
1206
1206
M2
1
21
2
MORS2V1P
PGND
TP2
RST
RST
TP10
GND
PGND
SYNCH
GND
TP3
SYNCH
TP6
PGND
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DocID027739 Rev 1