MAX8934AETI+ Maxim Integrated Products, MAX8934AETI+ Datasheet - Page 19

• Manufacturer Part Number: MAX8934AETI+
• Description: IC BATTERY CHARGER DUAL 28TQFN
• Manufacturer: Maxim Integrated Products
• Series: Smart Power Selector™r

Specifications of MAX8934AETI+

• Function: Charge Management
• Battery Type: Lithium-Ion (Li-Ion), Lithium-Polymer (Li-Pol)
• Voltage - Supply: 4.1 V ~ 6.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-TQFN Exposed Pad
• Product: Charge Management
• Output Voltage: 1 V
• Operating Supply Voltage: 4.1 V to 6.6 V
• Supply Current: 1 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Charge Safety Timers: Yes
• Mounting Style: SMD/SMT
• Temperature Monitoring: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Table 1. External Components List for Figures 2 and 3
The MAX8934_ is a dual-input linear charger with
Smart Power Selector that safely charges a single Li+/
Li-Poly cell in accordance with JEITA specifications*.
The MAX8934_ integrates power MOSFETs and control
circuitry to manage power flow in portable devices. See
Figure 1. The charger has two power inputs, DC and
USB. These can be separately connected to an AC
adapter output and a USB port, or the DC input could be
a single power input that connects to either an adapter
or USB. Logic inputs, PEN1 and PEN2, select the cor-
rect current limits for two-input or single-input operation.
Figure 2 is the typical application circuit using separate
DC and USB connectors. Figure 3 is the typical applica-
tion circuit using a 5-pin USB connector or another DC/
USB common connector.
In addition to charging the battery, the MAX8934_ also
supplies power to the system through the SYS output.
The charging current is also provided from SYS so that
the set input current limit controls the total SYS current,
where total SYS current is the sum of the system load
current and the battery-charging current. SYS is pow-
ered from either the DC input pin or the USB sources
*JEITA (Japan Electronics and Information Technology Industries Association) Standard, A Guide to the Safe Use of Secondary
Lithium Ion Batteries on Notebook–Type Personal Computers, April 20, 2007.
Dual-Input Linear Chargers, Smart Power Selector
(Figures 2 and 3)
COMPONENT
with Advanced Battery Temperature Monitoring
R
R
C
R
C
PU
THMSW
R
C
THM
C
C
C
BATT
PSET
ISET
LDO
SYS
DC
CT
VL
(x5)
______________________________________________________________________________________
Detailed Description
DC input current-limit programming resistor
Fast-charge current programming resistor
SYS output bypass capacitors
Logic-output pullup resistors
Battery bypass capacitor
Charger timing capacitor
Negative TC thermistor
LDO output capacitor
THM pullup resistor
DC filter capacitor
V
L
FUNCTION
filter capacitor
input pin. If both the DC and USB sources are con-
nected, DC takes precedence.
In some instances, there may not be enough adapter
current or USB current to supply peak system loads. The
MAX8934_ Smart Power Selector circuitry offers flexible
power distribution from an AC adapter or USB source
to the battery and system load. The battery is charged
with any available power not used by the system load.
If a system load peak exceeds the input current limit,
supplemental current is taken from the battery. Thermal
limiting prevents overheating by reducing power drawn
from the input source.
The MAX8934_ features an overvoltage limiter at SYS. If
the DC or USB input voltage exceeds the SYS regulation
voltage, V
at its regulation voltage. The MAX8934_ has numerous
other charging and power-management features that are
detailed in the following sections.
A 3.3V ultra-low quiescent current, always-on LDO pro-
vides up to 30mA for indicator LEDs and for backup
power to the system. This LDO powers the thermistor
monitor circuitry and provides bias to the external pullup
resistor for the thermistor.
10FF ±10%, 16V X5R ceramic capacitor (0805)
Taiyo Yuden EMK212BJ106KG
0.1FF ±10%, 10V X5R ceramic capacitor (0402)
Taiyo Yuden LMK105BJ104KV
10FF ±10%, 6.3V X5R ceramic capacitor (0805)
Taiyo Yuden JMK212BJ106KD
4.7FF ±10%, 6.3V X5R ceramic capacitor (0805)
Taiyo Yuden JMK212BJ475KD
0.068FF ±10%, 16V X5R ceramic capacitor (0402)
Taiyo Yuden EMK105BJ683KV
1FF ±10%, 6.3V X5R ceramic capacitor (0402)
Taiyo Yuden JMK105BJ105KV
1MI ±5% resistor
Vishay NTC Thermistor P/N NTHS0603N01N1003FF
100kI
1.5kI ±1% for 2A limit
3kI ±1% for 1A charging
SYS
does not follow V
PART NUMBER
DC
or V
USB
, but remains
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