ADP1875 Analog Devices, ADP1875 Datasheet - Page 36

• Manufacturer Part Number: ADP1875
• Description: Synchronous Buck Controller with Constant On-Time, Valley Current Mode, and Power Saving Mode
• Manufacturer: Analog Devices

ADP1874/ADP1875
LAYOUT CONSIDERATIONS
The performance of a dc-to-dc converter depends highly on how
the voltage and current paths are configured on the printed circuit
board (PCB). Optimizing the placement of sensitive analog and
power components is essential to minimize output ripple,
maintain tight regulation specifications, and reduce PWM jitter
and electromagnetic interference.
V
V
REG
OUT
C
53pF
PAR
0.1µF
R
C2
R7 10kΩ
TOP
Figure 90. ADP1874 High Current Evaluation Board Schematic (Blue Traces Indicate High Current Paths)
R
1kΩ
2kΩ
BOT
100kΩ
C
430pF
R
57kΩ
R
SEPARATE ANALOG
GROUND PLANE FOR
COMPENSATION AND
FEEDBACK RESISTORS
1µF
C
C
SENSITIVE ANALOG
COMPONENTS
LOCATED FAR
FROM NOISY
POWER SECTION
RES
C1
JP3
1
2
3
4
5
6
7
8
C
22µF
VIN
COMP
EN
FB
GND
RES
VREG
VREG_IN
VIN
Figure 91. Overall Layout of the ADP1870 High Current Evaluation Board
ADP1874/
ADP1875
INPUT CAPACITORS
ARE MOUNTED CLOSE
TO DRAIN OF Q1/Q2
AND SOURCE OF Q3/Q4
PGOOD
TRACK
DRVH
PGND
DRVL
BST
SW
SS
16
15
14
13
12
11
10
9
C
100nF
5kΩ
BST
10kΩ
HIGH VOLTAGE INPUT
Rev. 0 | Page 36 of 44
V
V
REG
REG
V
Q1
Q3
IN
= 12V
C
34nF
Q2
Q4
SS
22µF
C3
Figure 90 shows the schematic of a typical ADP1874/ADP1875
used for a high current application. Blue traces denote high current
pathways. VIN, PGND, and V
possibly replicated, descending down into the multiple layers.
Vias should populate, mainly around the positive and negative
terminals of the input and output capacitors, alongside the source
of Q1/Q2, the drain of Q3/Q4, and the inductor.
R
2Ω
C
1.5nF
1.0µH
SNB
SNB
MURATA: (HIGH VOLTAGE INPUT CAPACITORS)
PANASONIC: (OUTPUT CAPACITORS)
INFINEON MOSFETs:
WÜRTH INDUCTORS:
22µF
22µF, 25V, X7R, 1210 GRM32ER71E226KE15L
270µF, SP-SERIES, 4V, 7mΩ EEFUE0G271LR
BSC042N03MS G (LOWER SIDE)
BSC080N03MS G (UPPER SIDE)
1µH, 3.8mΩ, 16A 7443552100
C4
C24
N/A
270µF
22µF
C20
C5
+
C25
N/A
+
22µF
270µF
OUTPUT
CAPACITORS
ARE MOUNTED
AT RIGHTMOST
AREA OF
EVALUATION
BOARD
C6
C21
+
C26
N/A
V
22µF
+
OUT
270µF
C7
C22
+
= 1.8V, 15A
OUT
C27
N/A
N/A
+
C8
traces should be wide and
270µF
C23
+
C14 TO C19
N/A
N/A
C9
+