CM9101 Datasheet, PDF (11/12 Pages) California Micro Devices Corp – Compact Cost-effective Fast Charger

PRELIMINARY
CM9101
Application Information (cont’d)
exceeds 150°C (OTP). Pulling ENA low also puts the
charger in Shutdown mode. Charging stops.
Sleep mode is entered when the Adapter is removed
(or is the wrong voltage). Charging stops. In this mode,
the CM9101 draws less than 1 µA of current from the
battery.
Component Selection
The constant voltage AC Adapter must be selected
carefully to minimize power losses and heat dissipation
in the charger. The input supply should be between 5.0
and 6.0V. The lowest allowable input voltage will mini­
mize heat dissipation and simplify the thermal design.
Layout Considerations
Because the internal thermal foldback circuit will limit
the current when the IC reaches 105°C it is important
to keep a good thermal interface between the IC and
the PC board. It is critical that the exposed metal on
the backside of the CM9101 be soldered to the PCB
ground. The Cu pad should is large and thick enough
to provided good thermal spreading.
Thermal vias to other Cu layers provide improved ther­
mal performance.
V_IN and V_OUT are high current paths and the traces
should be sized appropriately for the maximum current
to avoid voltage drops. BSEN is the battery feedback
voltage and should be connected with its trace as close
to the battery as possible.
Typical Evaluation Circuit
VIN
C1
4.7U
VIN _NC
1
NC
NC VSTB
12
BSENSE
2
GND
VOUT ¹¹
3
NC
CM9101
10
THERM
C2
0.1U ₄
VREF
9
STAT
R4
ISET ENSEL NC NC
499
* R5
5K
Li-ion
Battery
+VBAT
C3
4.7U
THERM
R6
500
R7
10K
R8
4K
D1
GLED
© 2006 California Micro Devices Corp. All rights reserved.
06/30/06 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 lTel: [phone] lFax: [phone] lwww.cmd.com
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