MAX8671XETL+ Maxim Integrated Products, MAX8671XETL+ Datasheet - Page 39

• Manufacturer Part Number: MAX8671XETL+
• Description: IC PMIC W/CHARGER 40-TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX8671XETL+

• 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: 40-WFQFN Exposed Pad
• Mounting Style: SMD/SMT
• Input Voltage: 2.6 V to 6.6 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Output Current: 0.5 A
• Output Voltage: 0.6 V to 5 V
• Supply Current: 0.285 mA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Overvoltage lockout (OVLO) prevents an input supply
from being used when its voltage exceeds the operat-
ing range. Both USB and DC withstand input voltages
up to 14V. When the USB voltage is greater than the
USB OVLO threshold (6.9V typ), the USB input is dis-
connected from SYS, and UOK goes high impedance.
When the DC voltage is greater than the DC OVLO
threshold (6.9V typ), the DC input is disconnected from
SYS, and DOK goes high impedance. In addition, when
both DC and USB are in OVLO, the battery charger is
disabled, and BAT is connected to SYS through the
internal system load switch. REG1–REG4 are allowed to
operate from the battery when USB and DC are in over-
voltage lockout. The VL supply remains active in OVLO.
REG5 is intended to power the system USB transceiver
circuitry, which is only active when USB power is avail-
able. A valid source must be present on either the USB
or DC input for REG5 to enable.
A UVLO circuit monitors the voltage from SYS to
ground (V
typ), REG1–REG5 are disabled. V
100mV hysteresis. The VL supply remains active in SYS
UVLO.
A UVLO circuit monitors the PV4 and PV5 LDO power
inputs. When the PV_ voltage is below 1.6V, it is invalid
and the LDO is disabled.
The MAX8671X is packaged in a 5mm x 5mm x 0.8mm
40-pin thin QFN. Table 7 shows the thermal character-
istics of this package. The MAX8671X has several
mechanisms to control junction temperature in the
event of a thermal overload.
Table 7. 5mm x 5mm x 0.8mm Thin QFN
Thermal Characteristics
* θ
Thermal Limiting and Overload Protection
JA
Continuous
Dissipation
is specified according to the JESD51 standard.
Power
*θ
θ
JC
JA
Smart Power Selector for Handheld Devices
SYS
). When V
SINGLE-LAYER PCB
Derate 22.2mW/°C
______________________________________________________________________________________
above +70°C
1777.8mW
1.7°C/W
45°C/W
SYS
falls below V
PMIC with Integrated Charger and
REG4/REG5 UVLO
MULTILAYER PCB
UVLO_SYS
Derate 35.7mW/°C
USB/DC OVLO
UVLO_SYS
above +70°C
2857.1mW
1.7°C/W
28°C/W
SYS UVLO
has a
(2.5V
The MAX8671X reduces the USB and DC current limits
by 5%/°C when the die temperature exceeds +100°C.
The system load (I
current, so input current is first reduced by lowering
charge current. If the junction temperature still reaches
+120°C in spite of charge-current reduction, no input
current is drawn from USB and DC; the battery supplies
the entire load and SYS is regulated 82mV (V
below BAT. Note that this on-chip thermal-limiting cir-
cuit is not related to and operates independently from
the thermistor input.
The MAX8671X disables all regulator outputs (except
VL) when the junction temperature rises above +165°C,
allowing the device to cool. When the junction tempera-
ture cools by approximately 15°C, the regulators
resume the state indicated by the enable input (EN)
by repeating their soft-start sequence. Note that this
thermal-overload shutdown is a fail-safe mechanism;
proper thermal design should ensure that the junction
temperature of the MAX8671X never exceeds the
absolute maximum rating of +150°C.
The THM input connects to an external negative tem-
perature coefficient (NTC) thermistor to monitor battery
or system temperature. Charging is suspended when
the thermistor temperature is out of range. Additionally,
the charge timers are suspended and charge status
indicators report that the charger is in thermistor sus-
pend (CST[1:2] = 01). When the thermistor comes back
into range, charging resumes and the charge timer
continues from where it left off. Table 8 shows THM
temperature limits for various thermistor material con-
stants. If the battery temperature monitor is not
required, bias THM midway between V
with a resistive divider—100kΩ ±5% resistors are rec-
ommended. Biasing THM midway between V
AGND bypasses this function.
Smart Power Selector Thermal-Overload Protection
Battery Charger Thermistor Input (THM)
Regulator Thermal-Overload Shutdown
SYS
) has priority over the charger
L
and AGND
BSREG
L
and
39
)