MAX8804WETA+T Maxim Integrated Products, MAX8804WETA+T Datasheet - Page 13

• Manufacturer Part Number: MAX8804WETA+T
• Description: IC DUAL-IN ADPTR CHRGR 8-TDFN-EP
• Manufacturer: Maxim Integrated Products

Specifications of MAX8804WETA+T

• Function: Charge Management
• Battery Type: Lithium-Ion (Li-Ion)
• Voltage - Supply: 0 V ~ 28 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-TDFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The soft-start circuitry activates when entering fast-
charge mode. In the MAX8804Y, soft-start is entered
directly after being enabled, and the charging current
ramps up in 250µs from 0 to 500mA (95mA in USB
mode). This reduces the inrush current on the input
supply. Note that the MAX8804V/MAX8804W/
MAX8804Z has a prequalification state and the charg-
ing current ramps up when the prequalification state is
complete (V
The thermal-regulation loop limits the MAX8804V/
MAX8804W/MAX8804Y/MAX8804Z die temperature to
+105°C by reducing the charge current as necessary.
This feature not only protects the ICs from overheating,
but also allows a higher charge current at room temper-
ature without risking damage to the system.
CHG is an open-drain output that indicates charger sta-
tus. CHG goes low during charge cycles where the
MAX8804V/MAX8804W/MAX8804Y/MAX8804Z are in
prequalification or fast-charge mode. CHG goes high
impedance when the charge current reaches the top-
off threshold for more than 4ms, indicating charging is
done. The CHG status is latched after the top-off
threshold is reached. The latch is reset by toggling the
SET input, recycling input power, or increasing the
charging current to the top-off threshold plus 57mA
(typ).
When the MAX8804V/MAX8804W/MAX8804Y/MAX8804Z
are used in conjunction with a microprocessor (µP), con-
nect a pullup resistor between CHG and the logic I/O
voltage to indicate charge status to the µP. Alternatively,
CHG can sink up to 5mA for an LED charge indicator.
The MAX8804V/MAX8804W/MAX8804Y/MAX8804Z con-
tain an open-drain POK output that goes low when a
valid input source is detected at either DC or USB. A
valid input source is one whose voltage is greater than
4.15V and exceeds the battery voltage by 250mV. After a
valid input has been established, charging is sustained
with inputs as low as 3.5V as long as the input voltage
remains above the battery voltage by at least 40mV. POK
status is maintained regardless of SET status.
When the MAX8804V/MAX8804W/MAX8804Y/MAX8804Z
are used in conjunction with a µP, connect a pullup resis-
tor between POK and the logic I/O voltage to indicate
power-OK to the µP. Alternatively, POK can sink up to
5mA for an LED power-OK indicator.
BAT
exceeds 2.5V).
Charging-Status Output ( CHG )
______________________________________________________________________________________
Thermal Regulation Control
Adapter Chargers in 2mm x 3mm TDFN
Power-OK Monitor ( POK )
High-Voltage, Dual-Input, USB/AC
Soft-Start
USBPWR is internally pulled low when V
and V
ance. USBPWR indicates the USB input presence
regardless of SET status and charger status.
When the MAX8804Y/MAX8804Z are used in conjunction
with a µP, connect a pullup resistor between USBPWR
and the logic I/O voltage to indicate USB power status
to the µP. Alternatively, USBPWR can sink up to 5mA
for an LED USB power status indicator.
DETBAT is pulled up to an internal 3V supply through a
63kΩ resistor. Driving DETBAT low or connecting it to
GND allows SET to control the charger. When DETBAT
is left unconnected, the MAX8804V/MAX8804W enters
shutdown.
Connect a 2.2µF ceramic capacitor from BAT to GND for
proper stability. Connect a 1µF ceramic capacitor from
DC to GND. If using the USB input, bypass USB to GND
with a 1µF ceramic capacitor. Use a larger input bypass
capacitor for high charging currents to reduce supply
noise. All capacitors should be X5R dielectric or better.
Be aware that some capacitors have large voltage and
temperature coefficients and should be avoided.
The MAX8804V/MAX8804W/MAX8804Y/MAX8804Z are
available in a thermally enhanced TDFN package with
an exposed paddle. Connect the exposed paddle to a
large copper ground plane to provide a thermal contact
between the device and the PCB for increased power
dissipation. The exposed paddle transfers heat away
from the device, allowing the IC to charge the battery
with maximum current, while minimizing the die temper-
ature increase.
The MAX8804V/MAX8804W/MAX8804Y/MAX8804Z
operate from well-regulated input sources. The operat-
ing input voltage range is 4.15V to 7V. The device sur-
vives DC input supply voltages up to 30V and USB
input source voltages up to 16V without damage to the
IC. If the input voltage is greater than 7.5V (typ), the IC
stops charging. An appropriate power supply must pro-
vide at least 4.2V plus the voltage drop across the
internal pass transistor when sourcing the desired max-
imum charging current:
(DETBAT, MAX8804V/MAX8804W Only)
USB
USB Power Status Output ( USBPWR )
- V
BAT
Applications Information
Battery Pack Dectection Input
> 250mV. Otherwise, it is high imped-
(MAX8804Y/MAX8804Z Only)
Thermal Considerations
Capacitor Selection
Input Sources
USB
> V
UVLO
13