ADP3160 Analog Devices, ADP3160 Datasheet - Page 13

• Manufacturer Part Number: ADP3160
• Description: 5-Bit Programmable 2-Phase Synchronous Buck Controller
• Manufacturer: Analog Devices

AMD Athlon Design Example
The design parameters for a typical high-performance AMD
CPU application (see Figure 8) are as follows:
Using the design procedure previously shown, the final values
for this application were calculated, and are shown in Figure 8.
REV. B
1.8nF
C
20.6k
OC
12V V
Input Voltage (V
Nominal Output Voltage (V
Static Output Tolerance (V ) = (V+) – (V–) =
50 mV – (–50 mV) = 100 mV
Maximum Output Current (I
Output Current di/dt < 50 A/ s
R2
Average Output Voltage (V
V
Figure 7. Transient Response of the 53.4 A
Design Example of Figure 6
100pF
12V V
V
OUT
CC
1
2
IN
R3
16.5k
C2
RTN
RTN
V
CC
5V
Ch1
IN
FROM
+
CPU
(V+) + (V–)
R1
1k
500mV
RUBYCON MBZ SERIES
C12
C1
150pF
1
2
3
4
5
6
7
8
2
1800 F
VID4
VID3
VID2
VID1
VID0
COMP
FB
CT
ADP3167
IN
C13
) = 5 V
Ch2
U1
PWRGD
PWM2
PWM1
GND
VCC
REF
CS–
CS+
4
C14
20mV
= 1.7 V
16
15
14
13
12
11
10
9
OUT
AVG
O
C15
M 200 s
4.7 F
) = 45 A
C22 1nF
) = 1.7 V
C4
) =
10
1 F
R6
Figure 8. 45 A Athlon Duron CPU Supply Circuit
C6
Ch1
MBR052LTI
15pF
15nF
C8
C21
D2
700mV
4.7 F
1
2
3
4
C26
ZMM5236BCT
BST
IN
DLY
VCC
ADP3412
Z1
U3
DRVH
PGND
DRVL
SW
R5
2.4k
–13–
20
C10
1 F
R7
8
7
6
5
Q5
2N3904
1 F
C5
LAYOUT AND COMPONENT PLACEMENT GUIDELINES
The following guidelines are recommended for optimal perfor-
mance of a switching regulator in a PC system.
General Recommendations
1. For good results, at least a four-layer PCB is recommended.
2. Whenever high currents must be routed between PCB layers,
3. If critical signal lines (including the voltage and current
4. The power ground plane should not extend under signal
5. The GND pin of the ADP3160 should be connected first to
MBR052LTI
This should allow the needed versatility for control circuitry
interconnections with optimal placement, a signal ground
plane, power planes for both power ground and the input
power (e.g., 5 V), and wide interconnection traces in the
rest of the power delivery current paths. Keep in mind that
each square unit of 1 ounce copper trace has a resistance of
~0.53 mW at room temperature.
vias should be used liberally to create several parallel current
paths so that the resistance and inductance introduced by
these current paths is minimized and the via current rating is
not exceeded.
sense lines of the ADP3160) must cross through power
circuitry, it is best if a signal ground plane can be interposed
between those signal lines and the traces of the power
circuitry. This serves as a shield to minimize noise injec-
tion into the signals at the expense of making signal ground
a bit noisier.
components, including the ADP3160 itself. If necessary,
follow the preceding guideline to use the signal ground
plane as a shield between the power ground plane and the
signal circuitry.
the timing capacitor (on the CT pin), and then into the
signal ground plane. In cases where no signal ground plane
can be used, short interconnections to other signal ground
circuitry in the power converter should be used.
Q3
FDB7030L
Q4
FDB7035L
15pF
C7
D1
600nH
L2
1
2
3
4
BST
IN
DLY
VCC
ADP3412
4m
C11 C16 C17 C18 C19
R4
RUBYCON 6.3V MBZ SERIES
U2
DRVH
PGND
DRVL
13m
SW
2200 F
1 F
C9
8
7
6
5
ESR (EACH)
10
ADP3160/ADP3167
C20 C24
Q1
FDB7030L
Q2
FDB7035L
C25 C27
600nH
L1
C28
V
1.1V – 1.85V
45A
V
CC(CORE)
CC(CORE)
RTN