19-3776; Rev 0; 7/05
Overvoltage-Protection Controller with
Internal Disconnect Switch
General Description
The MAX4880 is an overvoltage-protection controller
with an internal current-limited switch that can be con-
figured 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 full-
charged state (4.2V), and a flag (BAT_OK) asserts to
notify the processor. The MAX4880 includes a switch-
control 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 pro-
tection 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.
♦
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
Features
MAX4880
Ordering Information
PART
MAX4880ETB
TEMP RANGE
-40°C to +85°C
PIN-
PACKAGE
10 TDFN-EP*
TOP
MARK
APJ
Applications
Cell Phones
Digital Still Cameras
PDAs and Palmtop Devices
MP3 Players
* EP = Exposed Pad
Typical Operating Circuit
AC-DC
ADAPTER
5.25V
IN
GATE
BTA
Pin Configuration
BAT_OK
FLAGV
TOP VIEW
BTB_SNS
GND
10
9
8
BTB
V
IO
7
6
DC-DC
CONVERTER
Li+
BTB_SNS
BTB
MAX4880
MAX4880
FLAGV
BAT_OK
CB
EN
1
IN
2
EN
3
GATE
4
BTA
5
CB
GND
3mm x 3mm TDFN
________________________________________________________________
Maxim Integrated Products
1
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.
Overvoltage-Protection Controller with
Internal Disconnect Switch
MAX4880
ABSOLUTE MAXIMUM RATINGS
(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
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.
ELECTRICAL CHARACTERISTICS
(V
IN
= 5V, T
A
= -40°C
to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
INPUT VOLTAGE (IN)
Input Voltage Range
Overvoltage Trip Level
Overvoltage-Trip-Level Hysteresis
Undervoltage-Lockout Threshold
Undervoltage-Lockout Hysteresis
Supply Current
INTERNAL SWITCH
BTA Input Range
BTA Undervoltage Lockout
BTA-Undervoltage-Lockout
Hysteresis
BTB-Switch-Disconnect Trip
Level
BTB-Switch-Disconnect
Hysteresis
Switch-Forward Current Limit
Switch-Reverse Current Limit
Voltage Drop (V
BTA
– V
BTB
)
BTB Off Current
GATE
GATE Voltage
GATE Pulldown Current
TIMING
GATE Startup Delay
FLAGV
Delay Time
GATE Turn-On Time
GATE Turn-Off Time
t
START
t
DELAY
t
GON
t
GOFF
V
IN
> V
UVLO
, V
GATE
> 0.3V (Figure 1)
V
GATE
= 0.3V,V
FLAGV
= 2.4V (Figure 1)
V
GATE
= 0.3V to 8V, C
GATE
= 1500pF (Figure 1)
V
IN
increasing from 5V to 8V at 3V/µs,
V
GATE
= 0.3V, C
GATE
= 1500pF (Figure 2)
20
20
50
50
7
6
20
80
80
ms
ms
ms
µs
V
GATE
I
PD
I
GATE
sourcing 1µA , V
IN
= 5V
V
IN
> V
OVLO
, V
GATE
= 5V
9
60
10
V
mA
I
BTB-OFF
I
FWD
I
REV
T
A
= +25°C
I
L
= 400mA
V
EN
= 0 (V
CB
= 0, or V
IN
< V
UVLO
and V
BTA
= 0)
450
BTB
TRIP
4.10
200
525
600
600
650
110
1
V
BTA
BTA
UVLO
Falling edge
2.8
2.4
50
4.20
5.7
2.7
V
V
mV
V
mV
mA
mA
mV
µA
I
IN
+ I
BTA
No load, V
IN
= 5.4V, V
EN
= 0 or 5.5V,
V
CB
= 0 or V
IN
UVLO
V
IN
falling
4.2
V
IN
OVLO
V
IN
rising
1.2
5.5
5.6
50
4.35
50
240
380
4.5
28.0
5.7
V
V
mV
V
mV
µA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
2
_______________________________________________________________________________________
Overvoltage-Protection Controller with
Internal Disconnect Switch
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
FLAGV
Assertion Delay
Initial Overvoltage Fault Delay
Disable Time
EN,
CB INPUTS
Input-High Voltage
Input-Low Voltage
Input Leakage
FLAGV, BAT_OK
OUTPUTS
Output Voltage Low
Leakage Current
THERMAL PROTECTION
Thermal Shutdown
Thermal Hysteresis
+150
40
°C
°C
V
OL
I
SINK
= 1mA,
FLAGV, BAT_OK
assert
V
BAT_OK
= V
FLAGV
= 5.5V
0.4
1
V
µA
V
IH
V
IL
1.4
0.5
1
V
V
µA
SYMBOL
t
FLAGV
t
OVP
t
DIS
CONDITIONS
V
IN
increasing from 5V to 8V at 3V/µs,
V
FLAGV
= 0.4V (Figure 2)
V
IN
increasing from 0 to 8V,
I
GATE
= 80% of I
PD
(Figure 3)
V
EN
= 2.4V, V
GATE
= 0.3V (Figure 4)
MIN
TYP
5.8
100
580
MAX
UNITS
µs
ns
ns
MAX4880
Note 1:
All devices are 100% tested at T
A
= +25°C. Electrical limits over the full temperature range are guaranteed by design.
Typical Operating Characteristics
(V
IN
= 5V, T
A
= +25°C, otherwise noted.)
I
IN
+ I
BTA
CURRENT vs. INPUT VOLTAGE
MAX4880 toc01
I
IN
+ I
BTA
CURRENT vs. TEMPERATURE
MAX4880 toc02
GATE VOLTAGE vs. INPUT VOLTAGE
OVLO TRIP POINT
9
GATE VOLTAGE (V)
MAX4880 toc03
400
350
I
IN
+ I
BTA
CURRENT (μA)
300
250
200
150
100
50
0
0
5
10
15
20
INPUT VOLTAGE (V)
25
UVLO TRIP POINT
OVLO TRIP POINT
V
EN
= 0
V
CB
= 5V
400
350
I
IN
+ I
BTA
CURRENT (μA)
300
250
200
150
100
50
0
12
6
UVLO TRIP POINT
3
0
-40
-15
10
35
TEMPERATURE (°C)
60
85
0
1
2
3
4
5
6
INPUT VOLTAGE (V)
7
8
30
_______________________________________________________________________________________
3
Overvoltage-Protection Controller with
Internal Disconnect Switch
MAX4880
Typical Operating Characteristics (continued)
(V
IN
= 5V, T
A
= +25°C, otherwise noted.)
BTB TRIP LEVEL vs. INPUT VOLTAGE
MAX4880 toc04
BTB TRIP LEVEL vs. TEMPERATURE
MAX4880 toc05
BTB OFF CURRENT vs. TEMPERATURE
V
EN
= 0V
V
CB
= 0V
V
BTB
= 5.5V
MAX4880 toc06
4.20
4.20
4.16
BTB TRIP LEVEL (V)
1000
4.16
BTB TRIP LEVEL (V)
4.12
4.12
BTB OFF CURRENT (nA)
100
10
4.08
4.08
4.04
4.04
1
4.00
5.0
5.1
5.2 5.3 5.4 5.5
INPUT VOLTAGE (V)
5.6
5.7
4.00
-40
-15
10
35
TEMPERATURE (°C)
60
85
0.1
-40
-15
10
35
TEMPERATURE (°C)
60
85
POWER-UP RESPONSE
MAX4880 toc07
POWER-DOWN RESPONSE
MAX4880 toc08
IN
5V
IN
0
10V
5V
0
10V
GATE
0
5V
0
5V
FLAGV
0
20ms/div
GATE
0
BTA
5V
0
5V
FLAGV
0
20ms/div
BTA
EN vs. GATE
MAX4880 toc09
OVERVOLTAGE RESPONSE
MAX4880 toc10
5V
EN
0
IN
8V
5V
10V
GATE
0
50mA
I
GATE
0
5V
FLAGV
0
400ns/div
10V
GATE
0
100μs/div
4
_______________________________________________________________________________________
Overvoltage-Protection Controller with
Internal Disconnect Switch
MAX4880
Typical Operating Characteristics (continued)
(V
IN
= 5V, TA = +25°C, otherwise noted.)
CURRENT LIMIT vs. TEMPERATURE
MAX4880 toc11
CURRENT LIMIT vs. V
BTB
700
600
CURRENT LIMIT (mA)
500
400
300
200
V
CB
= 5V
V
BTA
= 5V
MAX4880 toc12
800
700
600
CURRENT LIMIT (mA)
500
400
300
200
100
0
-40
-15
10
35
TEMPERATURE (°C)
60
V
CB
= 5V
V
BTA
= 5V
V
BTB
= 3.6V
800
100
0
85
1.0
1.5
2.0
2.5 3.0
V
BTB
(V)
3.5
4.0
4.5
Pin Description
PIN
1
2
NAME
IN
EN
FUNCTION
Input. IN is the power input for the overvoltage (OVP) charge pump. Bypass IN to GND with a 1µF or
larger capacitor to achieve 15kV ESD protection.
Active-Low Enable Input. Driving
EN
high turns off the external MOSFET. Pulling
EN
low activates the
overvoltage-protection circuitry and turns on the external MOSFET.
Gate-Drive Output. GATE is the output of an on-chip OVP charge pump. When V
UVLO
< V
IN
< V
OVLO
,
GATE is driven high to turn on the external n-channel MOSFET. When V
IN (MIN)
< V
IN
< V
UVLO
or V
IN
>
V
OVLO
, GATE is driven low to turn off the external n-channel MOSFET.
Input Terminal for the Internal-Current-Limited Switch. Connect BTA to the source of the external n-
channel MOSFET. BTA is the power input for the entire device (except the OVP charge pump). Bypass
BTA to GND with a 0.1µF capacitor as close to the device as possible.
Control Input for the Internal-Current-Limited Switch. Drive CB high to leave the internal switch control for
the internal logic. The internal switch turns on and off depending on the battery voltage level. The internal
switch turns off when the battery voltage reaches the BTB trip level (4.2V), and turns back on when the
battery falls by 200mV. Driving CB low turns off the internal switch regardless of the battery voltage.
Ground
Output Terminal for the Internal-Current-Limited Switch. When the BTB voltage exceeds the trip level
(4.2V), the internal switch opens. The switch closes only when the BTB voltage drops 200mV below the
trip level.
Battery-Voltage-Sensing Input. BTB_SNS must be connected to BTB for proper operation. Bypass
BTB_SNS to GND with a 0.1µF capacitor as close to the device as possible.
Active-Low, Open-Drain, Battery-Voltage-Limit Flag Output.
BAT_OK
asserts low when the voltage on BTB
exceeds the BTB trip level (4.2V).
BAT_OK
is disabled when
EN
goes high.
3
GATE
4
BTA
5
CB
6
7
GND
BTB
8
9
BTB_SNS
BAT_OK
_______________________________________________________________________________________
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