ADP3404ARU Analog Devices, ADP3404ARU Datasheet - Page 12

• Manufacturer Part Number: ADP3404ARU
• Description: GSM Power Management System
• Manufacturer: Analog Devices

ADP3404
Charger Diode Selection
The diode shown in Figure 2 is used to prevent the battery from
discharging into the charger turn-on setting resistors, R1 and R2. A
Schottky diode is recommended to minimize the voltage difference
from the charger to the battery and the power dissipation. Choose
a diode with a current rating high enough to handle both the battery
charging current and the current the ADP3404 will draw if pow-
ered up during charging. The battery charging current is dependent
on the battery chemistry, and the charger circuit. The ADP3404
current will be dependent on the loading.
0.006 (0.15)
0.002 (0.05)
PIN 1
SEATING
PLANE
28
28-Lead Thin Shrink Small Outline (TSSOP)
1
0.0256 (0.65)
BSC
Dimensions shown in inches and (mm).
0.386 (9.80)
0.378 (9.60)
OUTLINE DIMENSIONS
0.0118 (0.30)
0.0075 (0.19)
(RU-28)
0.0433 (1.10)
15
14
0.0035 (0.090)
0.0079 (0.20)
MAX
Printed Circuit Board Layout Considerations
Use the following general guidelines when designing printed
circuit boards:
1. Split the battery connection to the VBAT and SIMBAT pins
2. SIM input and output capacitors should be returned to the
3. VCCA and VTCXO capacitors should be returned to AGND.
4. VCC and VRTC capacitors should be returned to DGND.
5. Split the ground connections. Use separate traces or planes for
0.177 (4.50)
0.169 (4.30)
of the ADP3404. Use separate traces for each connection
and locate the input capacitors as close to the pins as possible.
SIMGND and kept as close as possible to the ADP3404 to
minimize noise. Traces to the SIM charge pump capacitor
should be kept as short as possible to minimize noise.
the analog, digital, and power grounds, and tie them together
at a single point, preferably close to the battery return.
0.256 (6.50)
0.246 (6.25)
8
0
0.028 (0.70)
0.020 (0.50)