ISL6292CCR3Z Intersil, ISL6292CCR3Z Datasheet - Page 10

• Manufacturer Part Number: ISL6292CCR3Z
• Description: IC CHARGER LI-ION POLYMER 10-DFN
• Manufacturer: Intersil
• Type: Battery Chargerr

Specifications of ISL6292CCR3Z

• Function: Charge Management
• Battery Type: Lithium-Ion (Li-Ion), Lithium-Polymer (Li-Pol)
• Voltage - Supply: 4.3 V ~ 6.5 V
• Operating Temperature: -20°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 10-VFDFN Exposed Pad
• Output Current: 0.4 to 1.5A
• Output Voltage: 4.2V
• Operating Supply Voltage (min): 4.3V
• Operating Supply Voltage (max): 6.5V
• Operating Temp Range: -20C to 70C
• Package Type: DFN
• Mounting: Surface Mount
• Pin Count: 10
• Operating Temperature Classification: Commercial
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Stability With Large Ceramic Output Capacitors
The ISL6292C partially relies on the ESR (equivalent series
resistance) of the output capacitor for the loop stability.
When the system has a large ceramic capacitor or a number
of ceramic capacitors in parallel, the ESR value can be too
low for a stable operation. A low-value resistor should be
inserted between the sensed feedback (VSEN pin) and the
external large-value ceramic capacitor to improve the
stability, as shown in Figure 9.
In applications that have a sense resistor between the VBAT
pin and the VSEN pin, such as the R
two small resistors can be used to create an equivalent low
value resistor between the VSEN pin and the large capacitor,
to avoid another more expensive low-value sense resistor.
R
connected. The equivalent low-value resistance is,
The value of (R
that of the sense resistor R
current sensing. The parallel value of R
significantly smaller than 72kΩ (internal resistive divider
value for setting the charger output voltage) to minimize the
impact on the output voltage. Figure 10 shows two 20Ω
resistor. The sum is 40Ω, much higher than the 150mΩ R
The parallel value is 10Ω, negligible compared to the 72kΩ
resistive divider. Such a selection is a good trade-off to result
in 75mΩ equivalent low-value resistance between the VSEN
pin and the large capacitor.
R
10µF
Ceramic
2
To INPUT
eq
C
and R
FIGURE 9. INSERTING R
1
=
-------------------- - R
R
2
R
3
+
3
in Figure 10 show how the two resistors are
R
3
ISL6292C
VIN
APPLICATIONS WITH LARGE CERAMIC
CAPACITOR IS USED AT THE OUTPUT
⋅
2
1
+ R
GND
3
) should be significantly larger than
VSEN
VBAT
1
1
TO IMPROVE THE STABILITY OF
to minimize the accuracy of the
10
1
shown in Figure 10,
2
R
1
and R
75mΩ
3
should be
To Battery
Large
Ceramic
Capacitor
C
2
(EQ. 7)
1
ISL6292C
.
Working with Current-Limited Adapter
The ISL6292C can work with a current-limited adapter to
significantly reduce the thermal dissipation during charging.
Refer to the ISL6292 data sheet, which can be found at
http://www.intersil.com, for more details.
Board Layout Recommendations
The ISL6292C internal thermal foldback function limits the
charge current when the internal temperature reaches
approximately 100°C. In order to maximize the current
capability, it is very important that the exposed pad under the
package is properly soldered to the board and is connected
to other layers through thermal vias. More thermal vias and
more copper attached to the exposed pad usually result in
better thermal performance. On the other hand, the number
of vias is limited by the size of the pad. The 3x3 DFN
package allows 8 vias be placed in two rows. Since the pins
on the 3x3 DFN package are on only two sides, as much top
layer copper as possible should be connected to the
exposed pad to minimize the thermal impedance. Refer to
the ISL6292 evaluation boards for layout examples.
10µF
Ceramic
To INPUT
FIGURE 10. THE CIRCUIT TO GENERATE THE EQUIVALENT
C
1
ISL6292C
VIN
LOW-VALUE RESISTOR
GND
VBAT
VSEN
R
2
20Ω
R
1
150mΩ
R
3
20Ω
To Battery
July 22, 2005
Large
Ceramic
Capacitor
C
FN9133.2
2