General Description
The MAX8804Y/MAX8804Z intelligent, dual-input,
stand-alone, constant-current, constant-voltage
(CCCV), thermally regulated linear chargers are
designed for a single-cell lithium-ion (Li+) battery. They
integrate the current-sense circuit, MOS pass element,
thermal-regulation circuitry, and overvoltage protection
(OVP), and eliminate the reverse-blocking Schottky
diode to create a simple and small charging solution for
handheld equipment.
The MAX8804Z functions as a stand-alone charger to
control the charging sequence from the prequalification
state through fast-charge, top-off charge, and fullcharge indication. The MAX8804Y eliminates the prequalification state to allow startup into a load without a
battery. Proprietary thermal-regulation circuitry limits
the die temperature when fast-charging or while
exposed to high ambient temperatures, allowing maximum charging current without damaging the IC.
The MAX8804Y/MAX8804Z achieve high flexibility by
providing an adjustable DC/USB fast-charge current
through a simple single-wire interface (SET input). The
chargers automatically select between either a USB or
AC adapter input source. The AC adapter charge current is programmable from 400mA to 700mA in 50mA
steps through a serial interface. The USB charge current is programmable to 95mA, 380mA, or 475mA
through the same interface. Other features include an
active-low battery charging-status indicator (CHG), an
active-low power-OK indicator (POK), and an active-low
USB input detection output (USBPWR).
The MAX8804Y/MAX8804Z accept a 4.15V to 30V DC
source voltage or a 4.15V to 16V USB input voltage, but
disable charging when either input voltage exceeds
7.5V to protect against unqualified or faulty input
sources. The MAX8804Y/MAX8804Z operate over the
extended temperature range (-40°C to +85°C) and are
available in a tiny 8-pin thermally enhanced 2mm x
3mm TDFN package.
Applications
Cell Phones/Smartphones
Digital Cameras
Portable Media Players
MP3 Players
Other Handheld Devices
Features
♦ Complete Chargers for Single-Cell Li+ Battery
♦ Dual-Input, 30V AC Adapter/16V USB
♦ No External FET, Blocking Diode, or Sense
Resistor Required
♦ Automatic USB/AC Adapter Input Selection
♦ Easy Programmable Fast-Charge Current and
Top-Off Threshold
♦ Proprietary Die Temperature Regulation Control
♦ ±5% Fast-Charge Current-Limit Accuracy
♦ Power-Present and Charger-Status Outputs
♦ No Prequalification Charge (MAX8804Y)
♦ Tiny 2mm x 3mm Thermally Enhanced TDFN
Package
♦ USB Charging Protected by US Patent #6,507,172
MAX8804Y/MAX8804Z
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
________________________________________________________________
Maxim Integrated Products
1
19-0785; Rev 0; 4/07
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Ordering Information
*
EP = Exposed paddle.
+
Denotes a lead-free package.
Note: All devices are specified to operate over the -40°C to
+85°C operating temperature range.
Pin Configuration appears at end of data sheet.
DC
GND
USB
SET
CHG
POK
USBPWR
BAT
+3.3V
AC
ADAPTER
USB
PORT
ENABLE/DISABLE
AND PROGRAMMING
Li+
1μF
2.2μF
MAX8804Y
MAX8804Z
1μF
Typical Application Circuit
PART
MAX8804YETA+ 8 TDFN-EP* T823+1 AAD
MAX8804ZETA+ 8 TDFN-EP* T823+1 AAC
PINPACKAGE
PKG
CODE
TOP
MARK
MAX8804Y/MAX8804Z
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
((VDC= 5V, V
SET
= 0V) or (V
USB
= 5V, V
SET
= 5V), V
BAT
= unconnected, TA= -40°C to +85°C, unless otherwise noted.) (Note 1)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
DC to GND .............................................................-0.3V to +30V
USB to GND ...........................................................-0.3V to +16V
BAT, CHG, SET, POK, USBPWR to GND ..............-0.3V to +5.5V
Continuous Power Dissipation (T
A
= +70°C)
8-Pin TDFN 2mm x 3mm (derate 16.7mW/°C above +70°C)
(multilayer board) .......................................................1333mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
DC AND USB
DC Input Voltage Range 028V
USB Input Voltage Range 014V
Input Operating Range (Notes 2, 3) 4.15 7.00 V
Input Undervoltage Threshold VIN rising, 500mV hysteresis (typ) (Note 2) 3.85 4.0 4.15 V
Input Overvoltage Threshold VIN rising, 200mV hysteresis (typ) (Note 2) 7.2 7.5 7.8 V
USB Input Supply Current
DC to BAT On-Resistance VDC = 3.7V, V
USB to BAT On-Resistance V
Input to BAT Comparator
Threshold (Note 2)
BAT
BAT Regulation Voltage I
Battery Removal Detection
Threshold
DC Charging Current
PARAMETER CONDITIONS MIN TYP MAX UNITS
V
= 0V, I
USB
V
= 5V, standby mode 300 550DC Input Supply Current
SET
= V
V
DC
BAT
VDC = 0V, V
V
SET
V
USB
USB
VIN rising 145 260 385
falling 55
V
IN
BAT
V
BAT
Hysteresis 0.1
V
USB
V
BAT
rising edge detection
on SET
SET
= 0V, standby mode 300 550
= V
BAT
= 3.7V, V
= 0mA
rising 4.40 4.67 4.90
= 0V,
= 3.6V,
= 0mA, charge mode 800 1200
BAT
= 4.3V, shutdown mode 300 550
= 5V, I
BAT
= 4.3V, shutdown mode 300 550
= 3.6V 0.55 1.0 Ω
BAT
= 3.6V 0.65 1.2 Ω
BAT
= 0mA, charge mode 800 1200
TA = +25°C 4.179 4.200 4.221
T
= -40°C to +85°C 4.158 4.200 4.242
A
Default and 1st to 3rd interface
pulse
4th to 7th interface pulse 523 550 578
8th to 11th interface pulse 570 600 630
12th to 15th interface pulse 428 450 473
16th to 19th interface pulse 380 400 420
20th to 23rd interface pulse 618 650 683
24th to 27th interface pulse 665 700 735
475 500 525
µA
µA
mV
V
V
mA
MAX8804Y/MAX8804Z
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
((VDC= 5V, V
SET
= 0V) or (V
USB
= 5V, V
SET
= 5V), V
BAT
= unconnected, TA= -40°C to +85°C, unless otherwise noted.) (Note 1)
Soft-Start Time Ramping time from 0 to 500mA 250 µs
BAT Prequal Threshold MAX8804Z only, V
BAT Prequal Charge Current MAX8804Z only 95 mA
BAT Leakage Current VDC = V
SET
Logic Input Thresholds
Logic-High Time Pulse width required to program DC charge current 1 1000 µs
Logic-Low Time Pulse width required to program USB charge current 1 1000 µs
SET DC Mode Shutdown Delay V
SET USB Mode Shutdown Delay VDC = 0V, V
SET Internal Pulldown Resistor 24MΩ
POK, CHG, USBPWR
Logic Output-Voltage Low I
Logic Output-Current High
CHG
PARAMETER CONDITIONS MIN TYP MAX UNITS
V
= 0V,
DC
= 3.6V, rising
V
BAT
edge detection on SET
= 0V, V
USB
V
rising 1.6
SET
falling 0.4
V
SET
= 0V, VDC = 5V, measured from V
USB
= 5V, measured from V
USB
= I
= V
= I
CHG
CHG
= 5.5V,
= 0V
USB
USBPWR
=
POK
V
POK
V
USBPWR
V
= V
DC
Default 90 95 100
1st interface pulse 360 380 400USB Charging Current
2nd interface pulse 450 475 500
rising, 300mV hysteresis (typ) 2.35 2.50 2.65 V
BAT
= 4.2V 2 µA
BAT
low to high 1.5 2 2.5 ms
SET
high to low 1.5 2 2.5 ms
SET
= 5mA 60 500 mV
TA = +25°C 0.001 1
T
= +85°C 0.01
A
VDC = 0V, V
= 5V 60 80 100
USB
Default, 4th, 8th,
12th, 16th, 20th,
24th, 28th interface
60 80 100
pulse
mA
V
µA
CHG Top-Off Threshold
I
falling, battery is
BAT
charged, rising edge
on SET
V
V
DC
USB
= 5V,
= 0V
1st, 5th, 9th, 13th,
17th, 21st, 25th
interface pulse
2nd, 6th, 10th,
14th, 18th, 22nd,
26th interface pulse
3rd, 7th, 11th, 15th,
19th, 23rd, 27th
interface pulse
67.5 90 112.5
75 100 125
52.7 70 87.5
mA
MAX8804Y/MAX8804Z
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
((VDC= 5V, V
SET
= 0V) or (V
USB
= 5V, V
SET
= 5V), V
BAT
= unconnected, TA= -40°C to +85°C, unless otherwise noted.) (Note 1)
Note 1: Devices are 100% production tested at TA= +25°C. Limits over the operating temperature range are guaranteed by design
and characterization.
Note 2: V
IN
refers to the input for the IC. For the MAX8804Y/MAX8804Z, VINis VDCwith V
USB
= 0V or V
USB
with VDC= 0V.
Note 3: Guaranteed by undervoltage and overvoltage threshold testing. For charge completion, the input voltage must be greater
than 4.28V.
Note 4: This hysteresis is for all charge current except 95mA. In the case of 95mA charge current, voltage-mode to current-mode
detection gives indication of charge mode.
SUPPLY CURRENT vs. INPUT VOLTAGE
(DC CHARGING MODE)
INPUT VOLTAGE (V)
SUPPLY CURRENT (mA)
MAX8804Y/Z toc01
036912151821242730
0
0.2
0.4
0.6
0.8
1.0
SUPPLY CURRENT vs. INPUT VOLTAGE
(USB CHARGING MODE)
INPUT VOLTAGE (V)
SUPPLY CURRENT (mA)
MAX8804Y/Z toc02
0246810121416
0
0.2
0.4
0.6
0.8
1.0
DISABLED-MODE SUPPLY CURRENT
vs. INPUT VOLTAGE (DC CHARGING MODE)
INPUT VOLTAGE (V)
SUPPLY CURRENT (mA)
MAX8804Y/Z toc03
0 5 10 15 20 25 30
0
0.2
0.4
0.6
0.8
Typical Operating Characteristics
(V
BAT
= 3.6V; DC charge mode: VDC= 5V, V
USB
= 0V, V
SET
= 0V or unconnected; USB charge mode: V
USB
= 5V, VDC= 0V, V
SET
=
5V; TA= +25°C, unless otherwise noted.)
CHG Hysteresis
CHG Detection Delay I
THERMAL LOOP
Thermal-Regulation Set Point
Thermal-Regulation Gain
PARAMETER CONDITIONS MIN TYP MAX UNITS
I
rising after top-off
BAT
is detected (Note 4)
falls below top-off threshold 3 4 5 ms
BAT
Junction temperature when the charge current is reduced,
T
rising
J
Reduction of I
increase of T
BAT
J USB charging -24
DC mode 57
USB mode 51
DC charging -40
for
+105 °C
mA
mA/°C
MAX8804Y/MAX8804Z
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
_______________________________________________________________________________________
5
Typical Operating Characteristics (continued)
(V
BAT
= 3.6V; DC charge mode: VDC= 5V, V
USB
= 0V, V
SET
= 0V or unconnected; USB charge mode: V
USB
= 5V, VDC= 0V, V
SET
=
5V; TA= +25°C, unless otherwise noted.)
STANDBY-MODE SUPPLY CURRENT
vs. INPUT VOLTAGE (USB CHARGING MODE)
0.8
0.6
0.4
SUPPLY CURRENT (mA)
0.2
0
0246810121416
INPUT VOLTAGE (V)
CHARGE CURRENT
vs. DC INPUT VOLTAGE
600
500
400
600
500
MAX8804Y/Z toc04
400
300
200
CHARGE CURRENT (mA)
100
0
120
MAX8804Y/Z toc07
90
CHARGE CURRENT vs. BATTERY VOLTAGE
(DC CHARGING MODE)
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
BATTERY VOLTAGE (V)
CHARGE CURRENT
vs. USB INPUT VOLTAGE
200
160
MAX8804Y/Z toc05
120
80
CHARGE CURRENT (mA)
40
0
V
SET
MAX8804Y/Z toc08
CHARGE CURRENT vs. BATTERY VOLTAGE
(USB CHARGING MODE)
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
BATTERY VOLTAGE (V)
CHARGE CURRENT vs. SET PULSE
(USB CHARGING MODE)
MAX8804Y/Z toc09
MAX8804Y/Z toc06
1V/div
300
200
CHARGE CURRENT (mA)
100
0
0 5 10 15 20 25 30
INPUT VOLTAGE (V)
CHARGE CURRENT vs. SET PULSE
V
SET
700mA
I
CHG
500mA
(DC CHARGING MODE)
600mA
550mA
450mA
400mA
2ms/div
60
CHARGE CURRENT (mA)
30
0
0246810121416
INPUT VOLTAGE (V)
MAX8804Y/Z toc10
1V/div
700mA
650mA
200mA/div
500mA
475mA
I
CHG
95mA 95mA
CHARGE CURRENT
vs. INPUT VOLTAGE HEADROOM
600
INPUT VOLTAGE DECREASING
500
400
300
200
CHARGE CURRENT (mA)
100
0
0 100 200 300 400 500
INPUT VOLTAGE HEADROOM (mV)
DC MODE
USB MODE
475mA
380mA 380mA
2ms/div
MAX8804Y/Z toc11
475mA
200mA/div
95mA
MAX8804Y/MAX8804Z
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
6 _______________________________________________________________________________________
Pin Description
Typical Operating Characteristics (continued)
(V
BAT
= 3.6V; DC charge mode: VDC= 5V, V
USB
= 0V, V
SET
= 0V or unconnected; USB charge mode: V
USB
= 5V, VDC= 0V, V
SET
=
5V; TA= +25°C, unless otherwise noted.)
BATTERY REGULATION VOLTAGE
vs. AMBIENT TEMPERATURE
AMBIENT TEMPERATURE (°C)
BATTERY REGULATION VOLTAGE (V)
MAX8804Y/Z toc12
-40 -15 10 35 60 85
4.180
4.186
4.192
4.198
4.204
4.210
USB MODE
DC MODE
700
CHARGE CURRENT
vs. AMBIENT TEMPERATURE
4.30
BATTERY REGULATION VOLTAGE
vs. LOAD CURRENT
600
500
400
CHARGE CURRENT (mA)
300
DC CHARGE MODE 650mA
200
-40 -15 10 35 60 85
PIN NAME FUNCTION
1 BAT
2 USBPWR
3 POK
4DC
5 USB USB Input Source. Connect USB to a USB port. Bypass USB to GND with a 1µF or larger ceramic capacitor.
6 CHG
Battery Connection. The IC delivers charging current and monitors battery voltage using BAT. Bypass BAT to
GND with a 2.2µF or larger ceramic capacitor. BAT is high impedance when the IC is disabled.
USB Power Status Output. USBPWR is internally pulled low if a valid voltage is present at USB, otherwise it is
high impedance. USBPWR circuitry is active regardless of SET and charger on/off status.
Power-OK Monitor. POK is an open-drain output that is internally pulled low when a valid charging source is
detected at either DC or USB. POK is high impedance when both input voltages are less than V
DC Input Supply. Connect DC to a 4.15V to 7V charging source. Bypass DC to GND with a 1µF or larger
ceramic capacitor. DC takes priority over USB when both are valid.
Charging-Status Output. CHG is internally pulled low when the battery is being charged. CHG is high
impedance when the charger is in top-off mode or disabled.
AMBIENT TEMPERATURE (°C)
MAX8804Y/Z toc13
4.25
4.20
4.15
BATTERY REGULATION VOLTAGE (V)
4.10
0 100 200 300 400 500 600 700
550mA CHARGE-CURRENT SETTING
LOAD CURRENT (mA)
or V
UVLO
BAT
MAX8804Y/Z toc14
.
7 SET
8 GND Ground
— EP Exposed Paddle. Connect to the GND plane for optimum thermal dissipation.
Enable/Disable, Charging Current, and Top-Off Threshold Set Input. Drive SET low to enable DC charge
mode and drive high to enable USB charge mode. If both DC and USB inputs are present, SET is used for
the DC charge mode only and USB charge is disabled. SET is also used for programming the charge current
and top-off threshold. See the DC/USB Mode and Charging Current Setting section for details.
MAX8804Y/MAX8804Z
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
Detailed Description
The MAX8804Y/MAX8804Z dual-input linear battery
chargers use voltage, current, and thermal-control loops
to charge and protect a single Li+ battery. When a Li+
battery with a cell voltage below 2.5V is inserted, the
MAX8804Z charger enters the prequalification stage
where it precharges that cell with 95mA (Figure 2). The
CHG indicator output is driven low to indicate entry into
the prequalification state. When battery voltage exceeds
2.5V, the charger soft-starts as it enters the fast-charge
stage. The MAX8804Y eliminates the prequalification
state and enters fast-charge when the battery is inserted.
In the MAX8804Y/MAX8804Z, the fast-charge current
level is programmed by a simple single-wire interface.
As the battery voltage approaches 4.2V, the charging
current is reduced. If the battery current drops below the
top-off current threshold, the CHG indicator goes high
impedance, signaling that the battery is fully charged.
The ICs then enter a constant voltage-regulation mode to
maintain the battery at full charge.
The MAX8804Y/MAX8804Z automatically select between
either a USB or AC adapter input source. The AC
adapter charge current is programmable from 400mA to
700mA in 50mA steps through a simple single-wire interface. The USB charge current is programmable to 95mA,
380mA, or 475mA through the same interface.
Figure 1. Functional Diagram
_______________________________________________________________________________________ 7
4.15V TO 30V
4.15V TO 16V
USB
DC
MAX8804Y
MAX8804Z
DC
POK
USB
POK
DC AND USB OUTPUT CONTROL
VOLTAGE
LOGIC
CONTROL
BAT
Li+
+105°C
TEMP
SENSOR
LOOP
OVERVOLTAGE
PROTECTION
SET
CHG
POK
USBPWR
REF
BIAS
CIRCUIT
GND
MAX8804Y/MAX8804Z
DC Charging
The MAX8804Y/MAX8804Z are designed to charge a
single-cell Li+ battery from a DC source voltage
between 4.15V and 7V and withstand up to 30V maximum input voltage. The charge current and top-off
threshold are programmed with the SET input.
USB Charging
The MAX8804Y/MAX8804Z contain a USB input that
allows operation from a USB port with voltages between
4.15V and 7V and can withstand up to 16V maximum
input voltage. Pulsing SET allows programming a 95mA,
380mA, or 475mA maximum charging current when
using the USB input.
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
8 _______________________________________________________________________________________
Figure 2. Charger State Diagram
ASYNCHRONOUS
FROM ANYWHERE
= HIGH > 2ms
t
SET
FOR DC MODE
= LOW > 2ms
t
SET
FOR USB MODE
< 2.5V
V
BAT
STANDBY MODE
CHARGER = OFF
POK = LOW
CHG = HIGH IMPEDANCE
t
SET
POK = LOW
CHG = LOW
FOR DC MODE
t
SET
FOR USB MODE
MAX8804Z
PREQUALIFICATION
DEFAULT CHARGE CURRENT
V
< 2.2V
BAT
MAX8804Z
= LOW > 2ms
= HIGH > 2ms
> 2.5V
V
BAT
< VIN < V
V
UVLO
AND VIN > V
BAT
OVP
SHUTDOWN
CHARGER = OFF
POK = HIGH IMPEDANCE*
CHG = HIGH IMPEDANCE
MAX8804Y
= LOW > 2ms
t
SET
FOR DC MODE
= HIGH > 2ms
t
SET
FOR USB MODE
VIN < V
OR V
OR V
IN
BAT
UVLO
> V
> V
OVP
ASYNCHRONOUS
FROM ANYWHERE
< V
V
IN
UVLO
OR VIN > V
IN
OR V
BAT
> V
OVP
IN
FAST-CHARGE
100% CHARGE CURRENT
POK = LOW
CHG = LOW
I
> I
CHG
CHARGE OPTIONS EXCEPT 95mA
CV MODE TO CC MODE FOR 95mA
FAST-CHARGE OPTION
+ 57mA FOR ALL FAST-
TOP-OFF
I
CHG
FULL BAT
= 4.2V
V
BAT
POK = LOW
CHG = HIGH IMPEDANCE
< I
TOP-OFF
*POK = LOW WHEN VIN > V
OVP
DC/USB Mode and
Charging Current Setting
SET is a logic input that sets DC/USB charging mode
and charging current. Drive SET low or leave it unconnected to enable DC charging mode. Drive SET high to
enable USB charging mode (see Table 1). SET can
also be driven by series pulses to program the charging current in both DC and USB mode.
DC Charge Mode
Drive SET low or leave it unconnected to enable DC
charging mode. Subsequent pulses on SET program the
charging current and the top-off threshold. There are
seven fast-charge current options and four top-off threshold options. Default fast-charge current and top-off
threshold current are 500mA and 80mA. Pulse SET high
(1µs to 1ms pulse width) subsequently to realize charging
current and top-off threshold programming and transition.
After the 28th pulse, the MAX8804Y/MAX8804Z go into
the default mode and start a new cycle. See Table 2 and
Figure 3 to set the desired charging current and top-off
threshold. Drive SET high longer than 2ms to disable DC
charging-control circuitry.
MAX8804Y/MAX8804Z
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
_______________________________________________________________________________________ 9
Table 1. SET Truth Table
Table 2. DC Charging Current Programming by Series Pulses
SET V
0 Invalid Invalid Off
0 Invalid Valid Off
0 Valid Invalid
0 Valid Valid
1 Invalid Invalid Off
1 Invalid Valid
1 Valid Invalid Off
1 Valid Valid Off
DC
V
USB
CHARGER STATUS
DC charging mode enabled,
USB charging mode disabled
DC charging mode enabled,
USB charging mode disabled
DC charging mode disabled,
USB charging mode enabled
PULSE
NUMBER
I
(mA) 500 500 500 500 550 550 550 550 600 600 600 600 450 450 450
CHG
Top - O ff C ur r ent
Thr eshol d ( m A)
PULSE
NUMBER
I
(mA) — 450 400 400 400 400 650 650 650 650 700 700 700 700 500
CHG
Top - O ff C ur r ent
Thr eshol d ( m A)
DEFAULT 1st 2nd 3rd 4th 5th 6th 7th 8th 9th 10th 11th 12th 13th 14th
80 90 100 70 80 90 100 70 80 90 100 70 80 90 100
— 15th 16th 17th 18th 19th 20th 21st 2 2 n d 2 3 r d 24th 25th 26th 27th 28th
— 70 80 90 100 70 80 90 100 70 80 90 100 70 80
MAX8804Y/MAX8804Z
USB Charge Mode
Drive SET high to enable USB charging mode when the
USB input is valid. Subsequent low pulses with 1µs to
1ms pulse width on SET program the fast charging current from 95mA, 380mA, to 475mA and then repeat
new cycle as shown in Table 3. Drive SET low or leave
it unconnected longer than 2ms to disable USB charging-control circuitry.
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
10 ______________________________________________________________________________________
Table 3. USB Charging Current
Programming by Series Pulses
Figure 3. DC Charging Current and Top-Off Threshold Programming
DC
POK
234 2425262728
1
SET
t
HIGH
2ms
DELAY
t
SOFTSTART
500mA
550mA
700mA
> 2ms
500mA
I
CHG
0mA
TOP-OFF
CURRENT
THRESHOLD
80mA
90mA
100mA
80mA
70mA
0mA
100mA
80mA
90mA
70mA
80mA
PULSE NUMBER DEFAULT 1st 2nd 3rd
I
(mA) 95 380 475 95
CHG
Top-Off Current
Threshold (mA)
80 80 80 80
Soft-Start
The soft-start circuitry activates when entering fastcharge 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 MAX8804Z has a prequalification
state and the charging current ramps up when the prequalification state is complete (V
BAT
exceeds 2.5V).
Thermal Regulation Control
The thermal-regulation loop limits the 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 temperature without risking
damage to the system.
Charging-Status Output (
CHG
)
CHG is an open-drain output that indicates charger status. CHG goes low during charge cycles where the
MAX8804Y/MAX8804Z are in prequalification or fastcharge 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 MAX8804Y/MAX8804Z are used in conjunction with a microprocessor (µP), connect 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.
MAX8804Y/MAX8804Z
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
______________________________________________________________________________________ 11
Figure 4. USB Charging Current Programming
USB
POK
USBPWR
1
SET
t
LOW
2ms
t
SOFTSTART
DELAY
I
CHG
TOP-OFF
CURRENT
THRESHOLD
95mA
380mA
2
475mA
80mA
3
> 2ms
95mA
0mA0mA
MAX8804Y/MAX8804Z
Power-OK Monitor (
POK
)
The MAX8804Y/MAX8804Z contain 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 MAX8804Y/MAX8804Z are used in conjunction with a µP, connect a pullup resistor 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.
USB Power Status Output (
USBPWR
)
USBPWR is internally pulled low when V
USB
> V
UVLO
and V
USB
- V
BAT
> 250mV. Otherwise, it is high imped-
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.
Applications Information
Capacitor Selection
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.
Thermal Considerations
The 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 temperature increase.
Input Sources
The MAX8804Y/MAX8804Z operate from well-regulated
input sources. The operating input voltage range is
4.15V to 7V. The device survives 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 provide at least 4.2V
plus the voltage drop across the internal pass transistor
when sourcing the desired maximum charging current:
V
IN(MIN)
> 4.2V + I
CHARGE(MAX)
x R
ON
where RONis the input-to-BAT resistance (typically
0.55Ω for DC or 0.65Ω for USB). Failure to meet this
requirement results in an incomplete charge or
increased charge time.
Application Circuits
Stand-Alone Li+ Charger
The MAX8804Y/MAX8804Z provide a complete Li+
charging solution. The
Typical Application Circuit
shows the MAX8804Y/MAX8804Z as a stand-alone Li+
battery charger. The LED indicates when either fastcharge or prequalification has begun. When the battery
is fully charged, the LED turns off.
Microprocessor-Interfaced Li+ Charger
Figure 5 shows the MAX8804Y/MAX8804Z as a µPinterfaced Li+ battery charger. The µP drives SET to
enable/disable DC/USB mode charging. CHG can be
used to detect the charge status of a battery.
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
12 ______________________________________________________________________________________
Layout and Bypassing
Connect the input capacitors as close as possible to
the IC. Provide a large copper GND plane to allow the
exposed paddle to sink heat away from the IC. Connect
the battery to BAT as close as possible to the IC to provide accurate battery voltage sensing. Make all highcurrent traces short and wide to minimize voltage
drops. A sample layout is available in the MAX8804Z
evaluation kit to speed designs.
MAX8804Y/MAX8804Z
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
______________________________________________________________________________________ 13
Figure 5. Microprocessor-Interfaced Li+ Charger with the MAX8804Y/MAX8804Z
Chip Information
PROCESS: BiCMOS
1
+
34
865
GND CHG USB
MAX8804Y
MAX8804Z
2
7
SET
BAT POK
DC
USBPWR
TDFN
2mm × 3mm
TOP VIEW
Pin Configuration
SYSTEM I/O
AC
ADAPTER
USB PORT
Li+
1μF
1μF
2.2μF
DC
USB
BAT
MAX8804Y
MAX8804Z
GND
CHG
POK
USBPWR
SET
μP
MAX8804Y/MAX8804Z
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
14 ______________________________________________________________________________________
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages
.)
8L, TDFN.EPS
PACKAGE OUTLINE
8L TDFN, EXPOSED PAD, 2x3x0.8mm
21-0174
1
B
2
MAX8804Y/MAX8804Z
High-Voltage, Dual-Input, USB/AC
Adapter Chargers in 2mm x 3mm TDFN
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________
15
© 2007 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.
Heaney
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages
.)
SYMBOL
A
E
D
A1
L
k 0.20 MIN.
A2
e
b
MIN.
0.70
1.95
0.00
0.30
DIMENSIONS
NOM.
0.75
3.002.95
2.00
0.02
0.40
0.20 REF.
8N
0.50 BSC
0.250.18 0.30
MAX.
0.80
3.05
2.05
0.05
0.50
PKG.
CODE
T823-1
EXPOSED PAD PACKAGE
E2
MIN.
NOM.
1.60
1.75
MAX.
1.90
MIN.
1.50
D2
NOM.
1.63
MAX.
1.75
PACKAGE OUTLINE
8L TDFN, EXPOSED PAD, 2x3x0.8mm
21-0174
2
B
2
Loading...