MAX8903JETI+ Maxim Integrated, MAX8903JETI+ Datasheet - Page 18

• Manufacturer Part Number: MAX8903JETI+
• Description: Battery Management 2A 1-Cell Li+ DC-DC USB/Adapter Charger
• Manufacturer: Maxim Integrated
• Series: MAX8903A, MAX8903B, MAX8903C, MAX8903D, MAX8903E, MAX8903G, MAX8903H, MAX8903J, MAX8903Yr

Specifications of MAX8903JETI+

• Rohs: yes
• Battery Type: Li-Ion
• Output Voltage: 5 V
• Output Current: 1 mA
• Operating Supply Voltage: 4.1 V to 16 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Charge Safety Timers: Yes
• Maximum Power Dissipation: 1666.7 mW
• Operating Supply Current: 2.3 mA
• Product Type: Charge Management
• Temperature Monitoring: Yes
• Uvlo Start Threshold: 3.2 V

voltage, the SYS voltage is connected to the battery.
The USB input then supplies the SYS load and charges
the battery with any extra available current, while not
exceeding the maximum-allowed USB current. Load
transients can be absorbed by the battery while mini-
mizing the voltage disturbance on SYS. When battery
charging is completed, or the charger is disabled, SYS
is regulated to V
valid, power is only taken from the DC input.
Driving USUS high and DCM low turns off charging as
well as the SYS output and reduces input current to
170µA to accommodate USB suspend mode. See
Table 2 for settings.
When CEN is low, the charger is on. When CEN is high,
the charger turns off. CEN does not affect the SYS out-
put. In many systems, there is no need for the system
controller (typically a microprocessor) to disable the
2A 1-Cell Li+ DC-DC Chargers
for USB and Adapter Power
MAX8903A–E/G/H/J/N/Y
Table 2. Input Limiter Control Logic
** Charge current cannot exceed the input current limit. Charge may be less than the maximum charge current if the total SYS load
exceeds the input current limit.
*** There is an internal diode from DCM (anode) to DC (cathode) as shown in Figure 1. If the DCM level needs to be set by a µP, use
a MOSFET for isolation as shown in FIgure 3.
X = Don’t care.
18
AC Adapter at DC Input
USB Power at DC Input
USB Power at USB Input,
DC Unconnected
DC and USB Unconnected
POWER SOURCE
SYSREG
. If both USB and DC inputs are
DOK
Charge Enable ( CEN )
H
H
H
H
L
L
L
L
UOK
X
X
X
X
H
L
L
L
USB Suspend
DCM*** IUSB USUS
H
X
X
X
X
L
L
L
H
H
X
L
X
L
X
X
X
H
H
X
L
L
L
L
charger, because the MAX8903_ smart power selector
circuitry independently manages charging and
adapter/battery power hand-off. In these situations, CEN
may be connected to ground.
To prevent input transients that can cause instability in
the USB or AC adapter power source, the rate of change
of the input current and charge current is limited. When
an input source is valid, SYS current is ramped from
zero to the set current-limit value in typically 50µs. This
also means that if DC becomes valid after USB, the
SYS current limit is ramped down to zero before switch-
ing from the USB to DC input. At some point, SYS is no
longer able to support the load and may switch over to
BAT. The switchover to BAT occurs when V
This threshold is a function of the SYS capacitor size
and SYS load. The SYS current limit then ramps from
zero to the set current level and SYS supports the load
again as long as the SYS load current is less than the
set current limit.
DC STEP-DOWN
CURRENT LIMIT
USB suspend
No DC input
6000V/R
OUTPUT
100mA
500mA
IDC
CURRENT LIMIT
USB input off. DC
input has priority.
USB suspend
No USB input
USB INPUT
100mA
500mA
1200V/R
1200V/R
1200V/R
1200V/R
1200V/R
CURRENT**
Maxim Integrated
6000V/R
MAXIMUM
Soft-Start
CHARGE
SYS
Lesser of
Lesser of
Lesser of
Lesser of
Lesser of
100mA
500mA
100mA
500mA
0
0
0
ISET
ISET
ISET
ISET
ISET
< V
IDC
BAT
and
and
and
and
and
.