CDH2D09 View Datasheet(PDF) - Maxim Integrated
Part Name
Description
MFG CO.
'CDH2D09' PDF : 44 Pages View PDF
PMIC with Integrated Charger and
Smart Power Selector for Handheld Devices
Detailed Description
The MAX8671X highly integrated PMIC is ideally suited
for use in portable audio player and handheld applica-
tions. As shown in Figure 2, the MAX8671X integrates
USB power input, AC-to-DC adapter power input (DC),
Li+/Li-Poly battery charger, three step-down regulators,
two linear regulators, and various monitoring and status
outputs. The MAX8671X offers adjustable output volt-
ages for all outputs.
Smart Power Selector
The MAX8671X Smart Power Selector seamlessly dis-
tributes power between the two current-limited external
inputs (USB and DC), the battery (BAT), and the sys-
tem load (SYS). The basic functions performed are:
• With both an external power supply (USB or DC)
and battery (BAT) connected:
When the system load requirements are less than
the input current limit, the battery is charged with
residual power from the input.
Table 1. Input Limiter Control Logic
When the system load requirements exceed the
input current limit, the battery supplies supple-
mental current to the load through the internal sys-
tem load switch.
• When the battery is connected and there is no exter-
nal power input, the system (SYS) is powered from
the battery.
• When an external power input is connected and
there is no battery, the system (SYS) is powered
from the external power input.
The dual-input Smart Power Selector supports end
products with dual and single external power inputs.
For end products with dual external power inputs, con-
nect these inputs directly to the DC and USB nodes of
the MAX8671X. For end products with a single input,
connect the single input to the DC node and connect
USB to ground or leave it unconnected. In addition to
AC-to-DC adapters current limits, the DC input also
supports USB current limit to allow for end products
POWER SOURCE
DOK UOK PEN1 PEN2 USUS
DC INPUT
CURRENT
LIMIT
USB INPUT
CURRENT
LIMIT
MAXIMUM
CHARGE
CURRENT*
AC-to-DC Adapter at
DC Input
L
X
H
X
X
IDCLIM
Lower of ICHGMAX
and
IDCLIM
L
X
L
L
L
USB Power at DC Input
L
X
L
H
L
100mA
500mA
USB input off,
DC input has
priority
Lower of ICHGMAX
and
100mA
Lower of ICHGMAX
and
500mA
L
X
L
X
H
Suspend
0
H
L
X
L
USB Power at USB
Input, DC Unconnected
H
L
X
H
L
L
No DC input
100mA
500mA
Lower of ICHGMAX
and
100mA
Lower of ICHGMAX
and
500mA
DC and USB
Unconnected
H
L
X
X
H
H
H
X
X
X
Suspend
0
No USB input
0
*Charge current cannot exceed the input current limit. Charge can be less than the maximum charge current if the total SYS load
exceeds the input current limit.
X = Don’t care.
24 ______________________________________________________________________________________
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