MAX8671XETL+ Maxim Integrated Products, MAX8671XETL+ Datasheet - Page 32

• 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

Determine I
of the battery. It is not necessary to limit the charge cur-
rent based on the capabilities of the expected AC-to-
DC adapter or USB charging input, the system load, or
thermal limitations of the PCB. The MAX8671X automat-
ically lowers the charging current as necessary to
accommodate these factors.
For the selected value of R
I
In addition to setting the charge current, CISET also pro-
vides a means to monitor battery charge current. The
CISET output voltage tracks the charge current delivered
to the battery, and can be used to monitor the charge
rate, as shown in Figure 9. A 1.5V output indicates the
battery is being charged at the maximum set fast-charge
current, and 0V indicates no charging. This voltage is
also used by the charger control circuitry to set and
monitor the battery current. Avoid adding capacitance
PMIC with Integrated Charger and
Smart Power Selector for Handheld Devices
Table 5. Ideal Charge Currents vs.
Charge Setting Resistor
32
PQ
R
CISET
, and I
______________________________________________________________________________________
3.01
4.02
4.99
6.04
6.98
8.06
9.09
10.0
11.0
12.1
13.0
14.0
15.0
(kΩ)
TO
CHGMAX
as follows:
I
I
I
PQ
CHGMAX
TO
I
CHGMAX
=
=
1000
10
4
746
601
497
430
372
330
300
273
248
231
214
200
by considering the characteristics
%
%
×
(mA)
=
×
I
CHGMAX
2000
I
CHGMAX
CISET
×
I
PQ
R
, calculate I
1 5
100
CISET
75
60
50
43
37
33
30
27
25
23
21
20
.
(mA)
V
I
TO
CHGMAX
40
30
24
20
17
15
13
12
11
10
(mA)
9
9
8
,
directly to the CISET pin that exceeds 10pF. If filtering of
the charge current monitor is necessary, include a resis-
tor of 100kΩ or more between CISET and the filter
capacitor to preserve charger stability.
REG1, REG2, and REG3 are high-efficiency 2MHz cur-
rent-mode, step-down converters with adjustable out-
puts. Each REG1, REG2, and REG3 step-down
converter delivers at least 425mA.
The step-down regulator power inputs (PV_) must be
connected to SYS. The step-down regulators operate
with V
ensures that the step-down regulators do not operate
with SYS below 2.6V (typ).
See the Enable/Disable (EN) and Sequencing section
for how to enable and disable the step-down convert-
ers. When enabled, the MAX8671X gradually ramps
each output up during a soft-start time. Soft-start elimi-
nates input current surges when regulators are
enabled.
See the PWM section for information about the step-
down converters control scheme.
Figure 9. Monitoring the Battery Charge Current with the
Voltage from CISET to AGND
SYS
DISCHARGING
1.5
0
from 2.6V to 5.5V. Undervoltage lockout
MONITORING THE BATTERY CHARGE
BATTERY CHARGING CURRENT (A)
CURRENT WITH V
0
V
CISET
Step-Down Converters
=
(REG1, REG2, REG3)
R
2000
CISET
CISET
x I
BAT
2000
x
R
1.5V
CISET