ISL8014IRZ-T Intersil, ISL8014IRZ-T Datasheet - Page 14

• Manufacturer Part Number: ISL8014IRZ-T
• Description: IC REG SYNC BUCK 4A 1.0MHZ 16QFN
• Manufacturer: Intersil
• Type: Step-Down (Buck)r

Specifications of ISL8014IRZ-T

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 0.8 ~ 5.5 V
• Current - Output: 4A
• Frequency - Switching: 1MHz
• Voltage - Input: 2.7 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-VQFN Exposed Pad, 16-HVQFN, 16-SQFN, 16-DHVQFN
• Rohs Compliant: YES
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Other names: ISL8014IRZ-TTR

Thermal Shut-Down
The ISL8014 has built-in thermal protection. When the
internal temperature reaches +140°C, the regulator is
completely shut down. As the temperature drops to
+115°C, the ISL8014 resumes operation by stepping
through the soft-start.
Applications Information
Output Inductor and Capacitor Selection
To consider steady state and transient operations,
ISL8014 typically uses a 1.5µH output inductor. The
higher or lower inductor value can be used to optimize
the total converter system performance. For example, for
higher output voltage 3.3V application, in order to
decrease the inductor current ripple and output voltage
ripple, the output inductor value can be increased. It is
recommended to set the ripple inductor current
approximately 30% of the maximum output current for
optimized performance. The inductor ripple current can
be expressed as shown in Equation 3:
The inductor’s saturation current rating needs to be at
least larger than the peak current. The ISL8014 protects
the typical peak current 6A. The saturation current needs
be over 7A for maximum output current application.
ISL8014 uses internal compensation network and the
output capacitor value is dependent on the output
voltage. The ceramic capacitor is recommended to be
X5R or X7R. The recommended X5R or X7R minimum
output capacitor values are shown in Table 1.
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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.
ΔI
=
TABLE 1. OUTPUT CAPACITOR VALUE vs V
V
------------------------------------ -
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O
V
⋅
(V)
0.8
1.2
1.5
1.8
2.5
3.3
3.6
L f
OUT
⎛
⎜
⎝
1
⋅
–
S
---------
V
V
IN
O
For information regarding Intersil Corporation and its products, see
⎞
⎟
⎠
in the quality certifications found at
14
2 x 22
2 x 22
2 x 22
2 x 22
2 x 22
2 x 22
2 x 22
C
(µF)
OUT
For additional products, see
1.0~2.2
1.0~2.2
1.5~3.3
1.5~3.3
1.5~3.3
2.2~4.7
2.2~4.7
(µH)
L
OUT
(EQ. 3)
ISL8014
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In Table 1, the minimum output capacitor value is given
for the different output voltage to make sure that the
whole converter system is stable. Additional output
capacitance should be added for better performances in
applications where high load transient or low output
ripple is required. It is recommended to check the
system level performance along with the simulation
model.
Output Voltage Selection
The output voltage of the regulator can be programmed
via an external resistor divider that is used to scale the
output voltage relative to the internal reference voltage
and feed it back to the inverting input of the error
amplifier. Refer to Figure 1.
The output voltage programming resistor, R
on the value chosen for the feedback resistor and the
desired output voltage of the regulator. The value for the
feedback resistor is typically between 10kΩ and 100kΩ,
as shown in Equation 4.
If the output voltage desired is 0.8V, then R
unpopulated and R
current from VIN to LX. It is recommended to preload the
output with 10µA minimum. For better performance, add
47pF in parallel with R
Input Capacitor Selection
The main functions for the input capacitor are to provide
decoupling of the parasitic inductance and to provide
filtering function to prevent the switching current flowing
back to the battery rail. Two 22µF X5R or X7R ceramic
capacitors are a good starting point for the input
capacitor selection.
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R
3
=
----------------------------------
V
OUT
R
2
⋅
0.8V
–
0.8V
2
is shorted. There is a leakage
2
(100kΩ).
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November 23, 2009
3
3
, will depend
is left
(EQ. 4)
FN6576.4