ISL6567CRZ Intersil, ISL6567CRZ Datasheet - Page 22

• Manufacturer Part Number: ISL6567CRZ
• Description: IC CTLR PWM 2PHASE BUCK 24-QFN
• Manufacturer: Intersil

Specifications of ISL6567CRZ

• Pwm Type: Voltage Mode
• Number Of Outputs: 1
• Frequency - Max: 1.5MHz
• Duty Cycle: 66%
• Voltage - Supply: 4.9 V ~ 5.5 V
• Buck: Yes
• Boost: No
• Flyback: No
• Inverting: No
• Doubler: No
• Divider: No
• Cuk: No
• Isolated: No
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 24-VQFN
• Frequency-max: 1.5MHz
• Rohs Compliant: YES
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The power components should be placed first. Locate the
input capacitors close to the power switches. Minimize the
length of the connections between the input capacitors, C
and the power switches. Locate the output inductors and
output capacitors between the MOSFETs and the load.
Locate all the high-frequency decoupling capacitors
(ceramic) as close as practicable to their decoupling target,
making use of the shortest connection paths to any internal
planes, such as vias to GND immediately next, or even onto
the capacitor’s grounded solder pad.
The critical small components include the bypass capacitors
for VCC and PVCC. Locate the bypass capacitors, C
close to the device. It is especially important to locate the
components associated with the feedback circuit close to
their respective controller pins, since they belong to a
high-impedance circuit loop, sensitive to EMI pick-up. It is
+12V
+5V
IN
IN
R
C
EN
R
R
R
2
2
2
1
R
(C
FS
R
REFTRK
F1
PGOOD
PG
C
COMP
)
MON
1
C
EN
FS
SS
FB
SS
(MINIMIZE CONNECTION PATH)
22
LOCATE CLOSE TO IC
VDIFF
FIGURE 26. PRINTED CIRCUIT BOARD POWER PLANES AND ISLANDS
VCC
ISL6567
VSEN
PVCC
RGND
(C
F2
)
BP
PHASE1
UGATE2
PHASE2
PGND
BOOT1
UGATE1
LGATE1
BOOT2
LGATE2
ISEN1
ISEN2
GND
,
L
IN
IN
,
ISL6567
C
BIN1
R
R
ISEN1
ISEN2
C
C
BOOT1
BOOT2
important to place the R
respective terminals of the ISL6567.
A multi-layer printed circuit board is recommended. Figure 26
shows the connections of the critical components for one output
channel of the converter. Note that capacitors C
C
Dedicate one solid layer, usually the one underneath the
component side of the board, for a ground plane and make all
critical component ground connections with vias to this layer.
Dedicate another solid layer as a power plane and break this
plane into smaller islands of common voltage levels. Keep the
metal runs from the PHASE terminal to inductor L
The power plane should support the input power and output
power nodes. Use copper filled polygons on the top and bottom
circuit layers for the phase nodes. Use the remaining printed
circuit layers for small signal wiring.
xxOUT
Q4
Q2
Q3
Q1
LOCATE NEAR SWITCHING TRANSISTORS
could each represent numerous physical capacitors.
(C
L
HFIN1
(C
OUT1
(MINIMIZE CONNECTION PATH)
HFIN2
L
)
C
KEY
OUT2
BIN2
)
ISLAND ON POWER PLANE LAYER
ISLAND ON CIRCUIT PLANE LAYER
VIA CONNECTION TO GROUND PLANE
HEAVY TRACE ON CIRCUIT PLANE LAYER
ISEN
resistors close to the
(MINIMIZE CONNECTION PATH)
C
BOUT
LOCATE NEAR LOAD
(C
xxIN
OUT
HFOUT
R
and
R
P
May 28, 2009
S
short.
)
V
FN9243.3
OUT