ISL8033AIRZ Intersil, ISL8033AIRZ Datasheet - Page 16

• Manufacturer Part Number: ISL8033AIRZ
• Description: IC REG SYNC BUCK DUAL 3A 24QFN
• Manufacturer: Intersil
• Type: Step-Down (Buck), PWM - Current Moder

Specifications of ISL8033AIRZ

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 2
• Voltage - Output: 0.8 V ~ 6 V
• Current - Output: 3A
• Frequency - Switching: 2.5MHz
• Voltage - Input: 2.85 V ~ 6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: *
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

relative to the internal reference voltage and feed it back to the
inverting input of the error amplifier. Refer to Figure 2.
The output voltage programming resistor, R
2), will depend on the desired output voltage of the regulator. The
value for the feedback resistor is typically between 0Ω and
750kΩ. Let R
For better performance, add 12pF in parallel to R
voltage desired is 0.8V, then leave R
Input Capacitor Selection
The main functions for the input capacitor is to provide
decoupling of the parasitic inductance and to provide filtering
function to prevent the switching current flowing back to the
battery rail. One 22µF X5R or X7R ceramic capacitor is a good
starting point for the input capacitor selection per channel.
PCB Layout Recommendation
The PCB layout is a very important converter design step to make
sure the designed converter works well. For ISL8033, the power
loop is composed of the output inductor L’s, the output capacitor
C
necessary to make the power loop as small as possible and the
connecting traces among them should be direct, short and wide.
The switching node of the converter, the LX_ pins, and the traces
connected to the node are very noisy, so keep the voltage
feedback trace away from these noisy traces. The input capacitor
should be placed as closely as possible to the VIN pin . Also, the
ground of the input and output capacitors should be connected
as closely as possible. The heat of the IC is mainly dissipated
through the thermal pad. Maximizing the copper area connected
to the thermal pad is preferable. In addition, a solid ground plane
is helpful for better EMI performance. It is recommended to add
at least 5 vias ground connection within the pad for the best
thermal relief.
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time
without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be
accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third
parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
R
OUT1
3
=
------------------------------ -
V
and C
OUT
R
2
x0.8V
–
OUT2
0.8V
2
= 124kΩ, then R
, the LX’s pins, and the SGND pin. It is
Intersil products are manufactured, assembled and tested utilizing ISO9000 quality systems as noted
16
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3
will be:
3
in the quality certifications found at
unpopulated and short R
For additional products, see
2
(or R
ISL8033, ISL8033A
2
5
. If the output
in Channel
(EQ. 2)
2
.
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March 24, 2011
FN6854.2