19-0614; Rev 0; 8/06
Battery Power-Up Logic with Overvoltage
and Overcurrent Protection
General Description
The MAX4919B/MAX4920B/MAX4921B overvoltage
protection controllers protect low-voltage systems
against high-voltage faults up to +28V. An internal 1.8A
(min) pFET with low R
ON
(100mΩ) switches a battery to
the load and also protects the battery against short-cir-
cuit faults. When a short circuit occurs, the current
through the internal pFET is limited for a blanking peri-
od. If the short condition is present after the blanking
period, the switch is latched off and remains off until
one of the input signals (IN, HP_PWR, PWR_ON) is
cycled. The pFET is turned on by a logic-high voltage
at PWR_HOLD, HP_PWR, PWR_ON, or IN .
The overvoltage thresholds (OVLO) are preset to
+6.38V (MAX4919B), +5.80V (MAX4920B), and +4.65V
(MAX4921B). When the input voltage drops below the
undervoltage lockout (UVLO) threshold, the devices enter
a low-current standby mode. In shutdown mode, the
current is reduced to 0.4µA. The MAX4919B/MAX4920B
have a +4.27V UVLO threshold, and the MAX4921B has
a +2.35V UVLO threshold.
The MAX4919B/MAX4920B/MAX4921B are offered in a
small 14-pin TDFN package (3mm x 3mm) with an
exposed paddle and are specified over the extended
-40°C to +85°C temperature range.
Features
o
Input Overvoltage Protection Up to +28V
o
Preset Overvoltage Protection Trip Level
6.38V (MAX4919B)
5.80V (MAX4920B)
4.65V (MAX4921B)
o
Adapter/Car-Kit Auto-Selector
o
Low-Current Undervoltage Lockout Mode
o
Internal 1.8A (min) Battery Switchover FET
o
Integrated Low-Battery Detect
o
Battery Short-Circuit Protection
o
Low-Cost External nMOS Overvoltage FET
o
14-Pin TDFN Package (3mm x 3mm)
MAX4919B/MAX4920B/MAX4921B
Pin Configuration
TOP VIEW
ACOK
EN
PWR_HOLD
ONOK
9
6
HP_PWR
14
13
12
11
10
Applications
Cell Phones
Digital Still Cameras
PDAs and Palmtop Devices
MP3 Players
1
GP1
+
MAX4919B
MAX4920B
MAX4921B
*EP
2
IN
3
GN1
4
BTI
5
BTI
7
PWR_ON
TDFN (3mm x 3mm)
*EXPOSED PADDLE
+DENOTES LEAD-FREE PACKAGE
Ordering Information/Selector Guide
PART
MAX4919BETD+T
MAX4920BETD+T
MAX4921BETD+T
PIN-
PACKAGE
14 TDFN-EP*
14 TDFN-EP*
14 TDFN-EP*
OVLO (V)
6.38
5.80
4.65
UVLO (V)
4.27
4.27
2.35
TOP MARK
ABY
ABZ
ACA
PKG CODE
T1433-2
T1433-2
T1433-2
Note:
All devices are specified over the -40°C to +85°C operating temperature range.
+Denotes
lead-free package.
*EP
= Exposed paddle.
________________________________________________________________
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.
GND
8
BTO
BTO
Battery Power-Up Logic with Overvoltage
and Overcurrent Protection
MAX4919B/MAX4920B/MAX4921B
ABSOLUTE MAXIMUM RATINGS
IN to GND ...............................................................-0.3V to +30V
GP1, GN1 to GND ..................................................-0.3V to +12V
IN to GP1 ................................................................-0.3V to +20V
BTO to GND ..........................................................-0.3V to +6.1V
BTI to BTO ................................................................-0.3V to +6V
BTI,
ACOK,
PWR_ON,
EN
to GND ...........................-0.3V to +6V
HP_PWR,
ONOK,
PWR_HOLD to GND ....................-0.3V to +6V
Continuous Power Dissipation (T
A
= +70°C)
14-Pin TDFN (derate 18.5mW/°C above +70°C) .......1482mW
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 (MAX4919B/MAX4920B) or V
IN
= 4.2V (MAX4921B), V
BTI
= 4V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values
are at T
A
= +25°C.) (Note 1)
PARAMETER
Input Voltage Range
Input Supply Current
UVLO Supply Current
Shutdown Supply Current
IN Undervoltage Lockout
IN Undervoltage Lockout
Hysteresis
MAX4919B
Overvoltage Trip Level
IN Overvoltage Lockout
Hysteresis
BATTERY SWITCHOVER
BTI Input Range
BTI UVLO
BTI UVLO Hysteresis
BTI Low-Battery Threshold
BTI Low-Battery Hysteresis
BTI Supply Current
BTI Shutdown Current
INTERNAL pFET
Switch On-Resistance
Forward-Overload Current Limit
R
ON
I
LIM
V
BTI
= 2.7V, I
BTI to
BTO
= 0.5A
BTO shorted to GND
T
A
= +25°C
T
A
= -40°C to +85°C
1.8
100
120
mΩ
A
Adapter out, V
PWR_HOLD
= high,
EN
= high
V
BTO
= 0V
T
A
= +25°C
T
A
= -40°C to +85°C
V
LVBTI
V
BTI
falling
2.65
V
BTI
V
UVBTI
V
BTI
falling
2.30
2.0
2.15
1.5
2.82
1.5
7
2
2.8
3
5.50
2.3
V
V
%
V
%
µA
µA
V
OVLO
V
IN
rising
MAX4920B
MAX4921B
6.00
5.44
4.35
SYMBOL
V
IN
I
IN
I
UVL
I
SHDN
V
UVLO
MAX4919B/MAX4920B
MAX4921B
V
EN
= 0V; V
IN
= 3.9V; MAX4919B/MAX4920B
V
EN
= 0V; V
IN
= 2.1V; MAX4921B
V
EN
= 1.6V, V
IN
= 3.6V
V
IN
falling
MAX4919B/MAX4920B
MAX4921B
4.00
2.20
CONDITIONS
MIN
1.2
77
75
10
8
0.4
4.27
2.35
1
6.38
5.80
4.65
1
6.76
6.17
4.95
%
V
TYP
MAX
28
120
110
22
18
2
4.54
2.50
UNITS
V
µA
µA
µA
V
V
%
2
_______________________________________________________________________________________
Battery Power-Up Logic with Overvoltage
and Overcurrent Protection
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 5V (MAX4919B/MAX4920B) or V
IN
= 4.2V (MAX4921B), V
BTI
= 4V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values
are at T
A
= +25°C.) (Note 1)
PARAMETER
GATE DRIVERS
V
GN1
referenced to GND, I
GN1
sourcing 1µA;
MAX4919B/MAX4920B
V
GN1
referenced to GND, I
GN1
sourcing 1µA;
MAX4921B
V
IN
> OVLO, V
GN1
= 5.5V
V
IN
- V
GP1
when V
IN
= 28V
12.5
31
V
BTI
= 5.50V
V
BTI
= 2.3V for PWR_HOLD, HP_PWR and
EN;
V
BTI
= 3V for PWR_ON
EN,
PWR_HOLD = GND or 5.5V
-1
200
1.5
0.4
+1
9
7.8
30
16.5
51.5
19.5
72
10
V
8.4
mA
V
kΩ
V
V
µA
kΩ
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX4919B/MAX4920B/MAX4921B
GN1 Turn-On Voltage
V
GN1
GN1 Pulldown Current
GP1 Clamp Voltage
GP1 Pulldown Resistor
Input-High Voltage
Input-Low Voltage
PWR_HOLD,
EN
Input Leakage
Current
PWR_ON, HP_PWR Pulldown
Resistance
LOGIC OUTPUTS (ACOK,
ONOK)
Output-Low Voltage
Output-High Leakage Current
TIMING
IN Debounce Time
ACOK
Blanking Time
HP_PWR Debounce Time
ACOK
One-Shot Time
HP_PWR One-Shot Time
Current-Limit Blanking Time
I
GPD
V
CLAMP
R
GPD
V
IH
V
IL
I
LKG
R
IPD
LOGIC INPUTS (PWR_HOLD, HP_PWR, PWR_ON,
EN)
V
OL
I
SINK
= 1mA
0.4
1
V
µA
t
INDBC
t
BLNKAC
t
HPDBC
t
1SHAC
t
1SHHP
t
CLIM
Time from UVLO < V
IN
< OVLO to V
GN1
>
0.3V, C
GN1
= 500pF
Time from V
GN1
> 0.3V to
ACOK
low,
C
GN1
= 500pF
Time for internal pFET to turn on after
V
HP_PWR
> V
IH
V
PWR_HOLD
= 0V; time for internal pFET to
turn off after
ACOK
< V
OL
(Figure 1)
V
PWR_HOLD
= 0V; time for internal pFET to
turn off after V
HP_PWR
> V
IH
(Figure 2)
V
BTI
= 2.7V; V
BTO
shorted to GND; time for
internal pFET current to reduce to 10mA
V
GN1
= 0.3V to 8V
(MAX4919B/MAX4920B),
V
GN1
= 0.3V to 7V (MAX4921B),
C
GN1
= 500pF
10
10
10
488
488
4
25
25
25
1220
1220
10
40
40
40
1952
1952
16
ms
ms
ms
ms
ms
ms
GN1 Turn-On Time
t
GON
10
ms
_______________________________________________________________________________________
3
Battery Power-Up Logic with Overvoltage
and Overcurrent Protection
MAX4919B/MAX4920B/MAX4921B
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 5V (MAX4919B/MAX4920B) or V
IN
= 4.2V (MAX4921B), V
BTI
= 4V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values
are at T
A
= +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
V
IN
rising at 1V/µs from 5V to 8V
(MAX4919B/MAX4920B), or from 4V to 7V
(MAX4921B); V
GN1
= 0.3V,
C
GN1
= 500pF
V
IN
rising at 1V/µs from 0V to 9V, time from
V
IN
= 5V to I
GN1
= 80% of I
GPD
V
IN
rising at 1V/µs from 5V to 8V
(MAX4919B/MAX4920B), or from 4V to 7V
(MAX4921B); V
ACOK
pullup
voltage = 3V; R
ACOK
= 10kΩ (Figure 3)
V
EN
= 2.4V, V
GN1
= 0.3V, C
GN1
= 500pF
MIN
TYP
MAX
UNITS
GN1 Turn-Off Time
t
GOFF
6
20
µs
Initial Overvoltage Fault Delay
t
OVLO
1.5
µs
ACOK
Deassertion Delay
t
ACOK
5.8
µs
Disable Time
t
DIS
2
µs
Note 1:
All specifications are 100% production tested at T
A
= +25°C, unless otherwise noted. Specifications over T
A
= -40°C to
+85°C are guaranteed by design.
Typical Operating Characteristics
(V
BTI
= 4V, T
A
= +25°C, unless otherwise noted.)
GN1 GATE VOLTAGE
vs. INPUT VOLTAGE
MAX4919/20/21B toc01
GN1 GATE VOLTAGE
vs. INPUT VOLTAGE
MAX4919/20/21B toc02
NORMALIZED BATTERY SWITCH R
ON
vs. TEMPERATURE
NORMALIZED BATTERY SWITCH R
ON
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
MAX4919/20/21B toc03
14
12
GN1 GATE VOLTAGE (V)
10
8
6
4
2
0
2
MAX4919B
V
GN1
REFERENCED TO GND
14
12
GN1 GATE VOLTAGE (V)
10
8
6
4
2
0
1.5
MAX4921B
V
GN1
REFERENCED TO GND
3
4
5
6
7
2.0
2.5
3.0
3.5
4.0
4.5
5.0
-40
-15
10
35
60
85
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
TEMPERATURE (°C)
4
_______________________________________________________________________________________
Battery Power-Up Logic with Overvoltage
and Overcurrent Protection
MAX4919B/MAX4920B/MAX4921B
Typical Operating Characteristics (continued)
(V
BTI
= 4V, T
A
= +25°C, unless otherwise noted.)
CURRENT LIMIT
vs. TEMPERATURE
3.8
3.6
CURRENT LIMIT (A)
3.4
3.2
3.0
2.8
2.6
2.4
2.2
2.0
-40
-15
10
35
60
85
TEMPERATURE (°C)
MAX4919/20/21B toc04
NORMALIZED OVLO THRESHOLD
vs. TEMPERATURE
1.015
1.010
1.005
1.000
0.995
0.990
0.985
0.980
-40
-15
10
35
60
85
TEMPERATURE (°C)
MAX4919/20/21B toc05
4.0
1.020
NORMALIZED OVLO THRESHOLD
NORMALIZED UVLO THRESHOLD
vs. TEMPERATURE
MAX4919/20/21B toc06
ADAPTER POWER-UP RESPONSE
MAX4919/20/21B toc07
1.020
NORMALIZED UVLO THRESHOLD
1.015
1.010
1.005
1.000
0.995
0.990
0.985
0.980
-40
-15
10
35
60
MAX4919B
V
ADAPTER
(5V/div)
V
IN
(5V/div)
V
GN1
(5V/div)
V
ACOK
(5V/div)
V
OUT
(5V/div)
85
10ms/div
TEMPERATURE (°C)
ADAPTER POWER-UP RESPONSE
MAX4919/20/21B toc08
OVERVOLTAGE RESPONSE
MAX4919/20/21B toc09
MAX4919B
V
ADAPTER
(5V/div)
V
IN
(5V/div)
V
GN1
(5V/div)
MAX4919B
7V V
ADAPTER
(2V/div)
5V
7V V
IN
(2V/div)
5V
V
GN1
(5V/div)
V
ACOK
(5V/div)
2µs/div
PWR_ON, HP_PWR, PWR_HOLD = 0V
V
ACOK
(5V/div)
V
BTO
(5V/div)
200ms/div
_______________________________________________________________________________________
5
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