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General Description
The MAX4880 is an overvoltage-protection controller
with an internal current-limited switch that can be configured as a low-cost battery charger. When the input
voltage exceeds the overvoltage trip level (5.7V), or
drops below the undervoltage-lockout level (4.2V), the
MAX4880 turns off the external n-channel MOSFET and
asserts an undervoltage/overvoltage flag indicator
(FLAGV) low to notify the processor.
The MAX4880 internal current-limited switch limits the
charge current flowing to the battery to 525mA. The
switch opens when the battery voltage reaches its fullcharged state (4.2V), and a flag (BAT_OK) asserts to
notify the processor. The MAX4880 includes a switchcontrol input (CB) to turn off the internal current-limited
switch, regardless of the battery voltage.
The MAX4880 also features a built-in startup delay that
allows the adapter voltage to settle down before turning
on the MOSFET. Other features include 15kV ESD protection for the input and a shutdown function (EN) to
turn off the external n-channel MOSFET.
The MAX4880 is available in a space-saving 10-pin
TDFN package and is specified for operation over the
extended -40°C to +85°C temperature range.
Applications
Cell Phones
Digital Still Cameras
PDAs and Palmtop Devices
MP3 Players
Features
♦ Overvoltage Protection Up to 28V
♦ Preset 5.6V Overvoltage Trip Level
♦ Internal 525mA Current-Limited Switch
♦ ±1.2% Accurate Battery Disconnect (4.2V)
♦ Drives Low-Cost n-Channel MOSFET
♦ Internal 50ms Startup Delay
♦ Overvoltage/Undervoltage-Fault FLAGV Indicator
♦ Battery-Voltage-Trip BAT_OK Indicator
♦ Undervoltage Lockout
♦ Thermal Shutdown Protection
♦ Tiny 10-Pin TDFN Package
MAX4880
Overvoltage-Protection Controller with
Internal Disconnect Switch
________________________________________________________________ Maxim Integrated Products 1
FLAGV
GND
BTB
BTB_SNS
MAX4880
BAT_OK
IN
GATE
BTA
EN
3mm x 3mm TDFN
TOP VIEW
CB
134
10 8 7
2
9
5
6
Pin Configuration
Ordering Information
AC-DC
ADAPTER
5.25V
GATEIN
FLAGV
BAT_OK
BTB_SNS
Li+
BTB
BTA
CB
EN
GND
DC-DC
CONVERTER
V
IO
MAX4880
Typical Operating Circuit
19-3776; Rev 0; 7/05
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.
-40°C to +85°C 10 TDFN-EP*
MAX4880
Overvoltage-Protection Controller with
Internal Disconnect Switch
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VIN= 5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.) (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.
(All voltages referenced to GND.)
IN ............................................................................-0.3V to +30V
GATE ......................................................................-0.3V to +12V
EN, CB, FLAGV, BAT_OK, BTA, BTB, BTB_SNS .....-0.3V to +6V
Continuous Power Dissipation (T
A
= +70°C)
10-Pin TDFN (derate 18.5mW/°C above +70°C) ...1481.5mW
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
INPUT VOLTAGE (IN)
Input Voltage Range V
IN
1.2
V
Overvoltage Trip Level OVLO VIN rising 5.5 5.6 5.7 V
O ver vol tag e- Tr i p - Level H yster esi s
Undervoltage-Lockout Threshold
Undervoltage-Lockout Hysteresis
No load, VIN = 5.4V, VEN = 0 or 5.5V,
V
CB
= 0 or V
IN
380 µA
INTERNAL SWITCH
BTA Input Range V
BTA
2.8 5.7 V
BTA Undervoltage Lockout
Falling edge 2.4 2.7 V
BTA-Undervoltage-Lockout
Hysteresis
50 mV
BTB-Switch-Disconnect Trip
Level
V
BTB-Switch-Disconnect
Hysteresis
mV
Switch-Forward Current Limit I
FWD
600 mA
TA = +25°C 600
Switch-Reverse Current Limit I
REV
650
mA
Voltage Drop (V
BTA
– V
BTB
)I
L
= 400mA 110 mV
BTB Off Current
V EN = 0 ( V
C B
= 0, or V
IN
< V
U V L O
and V
BTA
= 0)
1µA
GATE
GATE Voltage V
GATEIGATE
sourcing 1µA , VIN = 5V 9 10 V
GATE Pulldown Current I
PD
VIN > V
OVLO
, V
GATE
= 5V 60 mA
TIMING
GATE Startup Delay t
START
VIN > V
UVLO
, V
GATE
> 0.3V (Figure 1) 20 50 80 ms
FLAGV Delay Time t
DELAYVGATE
= 0.3V,V
FLAGV
= 2.4V (Figure 1) 20 50 80 ms
GATE Turn-On Time t
GON
7ms
GATE Turn-Off Time t
GOFF
VIN increasing from 5V to 8V at 3V/µs,
V
GATE
= 0.3V, C
GATE
= 1500pF (Figure 2)
620µs
I
+ I
IN
BTA
UVLO
BTB
TRIP
I
BTB-OFF
BTA
V
= 0.3V to 8V , C
GAT E
4.35
240
4.10 4.20
200
450 525
= 1500p F ( Fi g ur e 1)
GAT E
28.0
MAX4880
Overvoltage-Protection Controller with
Internal Disconnect Switch
_______________________________________________________________________________________ 3
Note 1: All devices are 100% tested at TA= +25°C. Electrical limits over the full temperature range are guaranteed by design.
ELECTRICAL CHARACTERISTICS (continued)
(VIN= 5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)
FLAGV Assertion Delay t
FLAGV
VIN increasing from 5V to 8V at 3V/µs,
V
FLAGV
= 0.4V (Figure 2)
5.8 µs
Initial Overvoltage Fault Delay t
OVP
VIN increasing from 0 to 8V,
I
GATE
= 80% of IPD (Figure 3)
ns
Disable Time t
DIS
VEN = 2.4V, V
GATE
= 0.3V (Figure 4)
ns
EN, CB INPUTS
Input-High Voltage V
IH
1.4 V
Input-Low Voltage V
IL
0.5 V
Input Leakage 1µA
FLAGV, BAT_OK OUTPUTS
Output Voltage Low V
OL
I
SINK
= 1mA, FLAGV, BAT_OK assert 0.4 V
Leakage Current V
BAT_OK
= V
FLAGV
= 5.5V 1 µA
THERMAL PROTECTION
Thermal Shutdown
°C
Thermal Hysteresis 40 °C
Typical Operating Characteristics
(VIN= 5V, TA= +25°C, otherwise noted.)
IIN + I
BTA
CURRENT vs. INPUT VOLTAGE
INPUT VOLTAGE (V)
I
IN
+ I
BTA
CURRENT (μA)
MAX4880 toc01
0 5 10 15 20 25 30
0
50
100
150
200
250
300
350
400
VEN = 0
V
CB
= 5V
OVLO TRIP POINT
UVLO TRIP POINT
IIN + I
BTA
CURRENT vs. TEMPERATURE
TEMPERATURE (°C)
I
IN
+ I
BTA
CURRENT (μA)
MAX4880 toc02
-40 -15 10 35 60 85
0
50
100
150
200
250
300
350
400
GATE VOLTAGE vs. INPUT VOLTAGE
INPUT VOLTAGE (V)
GATE VOLTAGE (V)
MAX4880 toc03
012345678
0
3
6
9
12
UVLO TRIP POINT
OVLO TRIP POINT
100
580
+150