ISL9205IRZ Intersil, ISL9205IRZ Datasheet - Page 11

• Manufacturer Part Number: ISL9205IRZ
• Description: IC CHRGR LI-ION SGL 4.2V 16-QFN
• Manufacturer: Intersil

Specifications of ISL9205IRZ

• Function: Charge Management
• Battery Type: Lithium-Ion (Li-Ion), Lithium-Polymer (Li-Pol)
• Voltage - Supply: 4.25 V ~ 6.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-VQFN Exposed Pad, 16-HVQFN, 16-SQFN, 16-DHVQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Indications
The ISL9205 has two open-drain status indication pins.
These two pins are FAULT and STATUS. These pins require
an external pull-up resistor to function properly. The V2P8
pin can be used as the presence of AC adapter.
Charger Disable
The EN pin allows the user to disable the charger. When the
charger is disabled, all internal circuits are shut down and
the quiescent current at the input pin is less than a typical
value of 150mA.
Remote Battery Voltage Sensing
In the ISL9205 and the ISL9205A, ISL9205B and ISL9205C
versions, a kelvin sense pin is provided for battery terminal
voltage monitoring. Thus, the IR drop due to the connection
leads and PCB traces can be eliminated, resulting a more
accurate battery voltage monitoring, especially when the
battery is located at a significant distance away from the
ISL9205. If remote sensing is not needed, the VSEN pin can
be connected to VBAT at the IC.
Applications Information
PCB Layout Guidance
The ISL9205 uses a thermally-enhanced QFN/DFN
packages that has an exposed thermal pad at the bottom
side of the package. The layout should connect as much as
possible to copper on the exposed pad. Typically the
component layer is more effective in dissipating heat. The
thermal impedance can be further reduced by using other
layers of copper connecting to the exposed pad through a
thermal via array. A minimum of four (4) such thermal vias
are recommended. Each thermal via is recommended to
have 0.3mm diameter and 0.7mm distance from other
thermal vias.
11
ISL9205
Stability Consideration
The ISL9205 should behave like a current and thermal
limited linear regulator. The charger operation is stable with
an output ceramic decoupling capacitor in the range of 1µF
to 200µF, with or without a battery connected.
Input Bypass Capacitor
Due to the inductance of the power leads of the wall adapter
or USB source, the input capacitor type must be properly
selected to prevent high voltage transient during a hot-plug
event. A tantalum capacitor is a good choice for its high
ESR, providing damping to the voltage transient. Multi-layer
ceramic capacitors, however, have a very low ESR and
hence when chosen as input capacitor, a 1Ω series resistor
must be used, as shown in the “Typical Applications” on
page 3, to provide adequate damping.
State Machine Diagram
The state machine diagram is shown in Figure 14. The
diagram starts with the Power-Off state. When the input
voltage rises above the POR threshold, the charger resets
itself. Then, if the charger is disabled, the charger stays in
the Charger Disabled state. If the charger is enabled, the
trickle charge starts. Anytime when entering the trickle
charge state, the internal TIMEOUT timer is reset. There are
two paths to exit the trickle charge, one is when the battery
voltage rises above the preconditioning charge threshold
within the 1/8 TIMEOUT interval and the other is when the
1/8 TIMEOUT interval has been elapsed before reaching the
preconditioning charge voltage threshold. When TIMEOUT
fault occurs, the charger enters the TIMEOUT fault state.
There are only two ways to exit the TIMEOUT fault state, by
toggling the EN input or re-cycling the input power. If the
charger finishes the trickle charger before the 1/8 TIMEOUT
limit, it moves to the fast charge state. When entering the
fast charge state, the TIMEOUT timer is reset as well. If the
charger hits EOC conditions before the TIMEOUT, the
charger enters Charge Compete state. The charger stays on
but the STATUS indicates EOC condition. When VBAT drops
below the recharge threshold, the STATUS pin will turn to
logic low to indicate charging again.
July 28, 2010
FN9252.2