MAX14527ETA+T [MAXIM]
Adjustable Overvoltage Protector with High Accuracy; 可调过电压保护器，高精度
| 型号： | MAX14527ETA+T |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Adjustable Overvoltage Protector with High Accuracy |
| 文件： | 总7页 (文件大小：107K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-4357; Rev 0; 10/08
Adjustable Overvoltage Protector
with High Accuracy
7/MAX14528
General Description
Features
The MAX14527/MAX14528 overvoltage protection
♦ Input Voltage Protection Up to +28V
devices feature a low 100mΩ (typ) R
internal FET
ON
♦ Preset Internal 2ꢀ.5 ꢁccurate ꢂVꢃꢂ ꢄTresTolꢅs
.ꢀ7.V (MꢁX14.27)
and protect low-voltage systems against voltage faults
up to +28V. When the input voltage exceeds the over-
voltage threshold, the internal FET is turned off to pre-
vent damage to the protected components.
6ꢀ76V (MꢁX14.28)
♦ ꢁꢅjustable ꢂvervoltage Protection ꢄrip ꢃevel
The overvoltage protection threshold can be adjusted
with optional external resistors to any voltage between
4V and 8V. With the OVLO input set below the external
OVLO select voltage, the MAX14527/MAX14528 auto-
matically choose the internal 2.5ꢀ accurate trip
thresholds. The internal overvoltage thresholds (OVLO)
are preset to 5.75V typical (MAX14527) or 6.76V typical
(MAX14528). The MAX14527/MAX14528 are also
protected against overcurrent events with an internal
thermal shutdown.
♦ Integrateꢅ 100mΩ (typ) n-CTannel MꢂSFEꢄ
SwitcT
♦ Soft-Start to Minimize In-RusT Current
♦ ꢁutomatic ꢂvervoltage Protection ꢄrip-ꢃevel
Selection
♦ Internal 1.ms Startup Delay
♦ ꢄTermal STutꢅown Protection
♦ 8-Pin ꢄDFN (2mm x 2mm) Package
♦ -40°C to +8.°C ꢂperating ꢄemperature Range
The MAX14527/MAX14528 are offered in a small, 8-pin
TDFN-EP package and operate over the -40°C to
+85°C extended temperature range.
Ordering Information
Applications
Cell Phones
ꢄꢂP
MꢁRK
ꢂVꢃꢂ
(V)
PꢁRꢄ
PIN-PꢁCKꢁGE
Media Players
MꢁX14.27ETA+T 8 TDFN-EP*
MꢁX14.28ETA+T 8 TDFN-EP*
ACR
ACS
5.75
6.76
PDAs and Palmtop Devices
Note: Devices are specified over the -40°C to +85°C tempera-
ture range.
+Denotes a lead-free/RoHS-compliant package.
T = Tape and reel.
*EP = Exposed pad.
Pin Configuration appears at enꢅ of ꢅata sTeetꢀ
Typical Application Circuit
VBUS
USB
CONNECTOR
CHARGER
INPUT
IN
IN
OUT
1µF
OUT
PMIC
MAX14527
MAX14528
R1
R2
OVLO
GND
*
*R1 AND R2 ARE REQUIRED ONLY FOR ADJUSTABLE OVLO; OTHERWISE, CONNECT OVLO TO GND.
________________________________________________________________ Maxim Integrateꢅ Proꢅucts
1
For pricing, ꢅelivery, anꢅ orꢅering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim's website at wwwꢀmaxim-icꢀcomꢀ
Adjustable Overvoltage Protector
with High Accuracy
ꢁBSꢂꢃUꢄE MꢁXIMUM RꢁꢄINGS
(All voltages referenced to GND.)
Package Junction-to-Ambient Thermal Resistance (θ )
JA
IN............................................................................-0.3V to +30V
(Note 2) .....................................................................83.9°C/W
Package Junction-to-Case Thermal Resistance (θ
OUT .............................................................-0.3V to (V + 0.3V)
)
IN
JC
OVLO........................................................................-0.3V to +6V
Continuous IN Current .............................................................1A
Peak IN Current (Note 1)..........................................................5A
Continuous OVLO Current ...................................................50µA
(Note 2) ........................................................................37°C/W
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering).........................................+300°C
Continuous Power Dissipation (T = +70°C)
A
8-Pin TDFN (derate 11.9mW/°C above +70°C) ...........954mW
Note 1: Limited by thermal shutdown.
Note 2: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to wwwꢀmaxim-icꢀcom/tTermal-tutorial.
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.
EꢃECꢄRICꢁꢃ CHꢁRꢁCꢄERISꢄICS
(V = +2.2V to +28V, T = -40°C to +85°C, unless otherwise noted. Typical values are at V = +5.0V and T = +25°C.) (Note 3)
IN
A
IN
A
PꢁRꢁMEꢄER
SYMBꢂꢃ
CꢂNDIꢄIꢂNS
MIN
ꢄYP
MꢁX
28
UNIꢄS
V
Input Voltage Range
Input Supply Current
V
2.2
IN
7/MAX14528
I
V
V
< OVLO
rising
80
160
5.9
µA
IN
IN
IN
MAX14527
5.6
6.55
5.54
6.5
5.75
6.765
MAX14528
MAX14527
MAX14528
7
IN Overvoltage Trip Level
V
V
IN_OVLO
5.84
6.95
V
falling
IN
IN Overvoltage Lockout Hysteresis
OVLO Set Threshold
V
1
ꢀ
V
IN_OVLO_HYS
V
1.2
4
1.245
1.29
8
OVLO_THRESH
Adjustable OVLO Threshold Range
External OVLO Select Threshold
Switch On-Resistance
V
V
0.15
0.33
100
0.5
V
OVLO_SELECT
R
ON
200
5.5
mΩ
V
OVLO Clamp
I
= 10µA
3
4.56
CLAMP
OUT Capacitor
C
1000
+100
µF
nA
°C
°C
OUT
OVLO Input Leakage Current
Thermal Shutdown
I
V
= 1.245V
-100
OVLO
OVLO_THRESH
150
20
Thermal Shutdown Hysteresis
ꢄIMING CHꢁRꢁCꢄERISꢄICS (Figure 1)
Time from 2.2V < V < V
to
IN_OVLO
IN
Debounce Time
t
15
ms
ms
INDBC
V
= 10ꢀ of V
OUT
IN
2.2V < V < V
, R
= 100Ω,
IN
IN_OVLO LOAD
C
= 100µF; V
from 10ꢀ to
0.7
LOAD
OUT
90ꢀ of V
IN
Switch Turn-On Time
t
ON
2.2V < V < V
, R
IN_OVLO LOAD
= 100Ω,
IN
1.4
1.3
C
of V
= 1mF; V
from 10ꢀ to 90ꢀ
LOAD
OUT
IN
V
V
> V
to V
= 80ꢀ of
OUT
IN
OVLO_THRESH
; R
Switch Turn-Off Time
t
3.5
µs
= 1kΩ, V rising at
IN
OFF
IN_OVLO LOAD
2V/100ns
Note 3: All specifications are 100ꢀ production tested at T = +25°C, unless otherwise noted. Specifications are over -40°C to +85°C
A
and are guaranteed by design.
2
_______________________________________________________________________________________
Adjustable Overvoltage Protector
with High Accuracy
7/MAX14528
Timing Diagram
OVLO
2.2V
IN
t
t
ON
ON
V
IN_OVLO
80% V
IN_OVLO
90%
90%
10%
10%
OUT
t
OFF
t
t
INDBC
INDBC
NOTE: WAVEFORMS ARE NOT TO SCALE.
Figure 1. Timing Characteristics
_______________________________________________________________________________________
3
Adjustable Overvoltage Protector
with High Accuracy
Typical Operating Characteristics
(T = +25°C, unless otherwise noted.)
A
IN SUPPLY CURRENT
vs. IN VOLTAGE
NORMALIZED R
vs. TEMPERATURE
NORMALIZED OVLO THRESHOLD
vs. TEMPERATURE
0N
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
1.05
1.04
1.03
1.02
1.01
1.00
0.99
0.98
0.97
0.96
0.95
90
80
70
60
V
= 3.6V
= 5.0V
IN
IN
T
T
= +85°C
= -40°C
50
40
30
20
10
0
A
T
= +25°C
A
V
A
0
7
14
IN VOLTAGE (V)
21
28
-40
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
7/MAX14528
NORMALIZED EXTERNAL OVLO SET
THRESHOLD vs. TEMPERATURE
NORMALIZED EXTERNAL OVLO SELECT
THRESHOLD vs. TEMPERATURE
NORMALIZED DEBOUNCE TIME
vs. TEMPERATURE
1.05
1.04
1.03
1.02
1.01
1.00
0.99
0.98
0.97
0.96
0.95
1.05
1.04
1.03
1.02
1.01
1.00
0.99
0.98
0.97
0.96
0.95
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
-40
-15
10
35
60
85
-40
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
POWER-UP RESPONSE
OVERVOLTAGE FAULT RESPONSE
MAX14527/8 toc08
MAX14527/8 toc07
V
IN
5V/div
V
IN
5V/div
V
OUT
V
OUT
5V/div
5V/div
I
OUT
I
100mA/div
OUT
50mA/div
10ms/div
1μs/div
4
_______________________________________________________________________________________
Adjustable Overvoltage Protector
with High Accuracy
7/MAX14528
Pin Description
PIN
NꢁME
FUNCꢄIꢂN
Voltage Input. Bypass IN with a 1µF ceramic capacitor as close as possible to the device to obtain 15kV
Human Body Model (HBM) ESD protection. Connect all the IN pins together for proper operation. IN is
protected to 2kV HBM when IN is not bypassed with a capacitor to GND.
1, 2
IN
External OVLO Adjustment. Connect OVLO to GND when using the internal threshold. Connect a resistor-
divider to OVLO to set a different OVLO threshold; this external resistor-divider is completely independent
from the internal threshold.
3
OVLO
4, 5
6
I.C.
GND
OUT
Internally Connected. Do not connect. Leave I.C. unconnected.
Ground
7, 8
Output Voltage. Output of internal switch. Connect all the OUT outputs together for proper operation.
Exposed Pad. Connect exposed pad to ground. For enhanced thermal dissipation, connect EP to a copper
area as large as possible. Do not use EP as a sole ground connection.
—
EP
Functional Diagram
IN
IN
OUT
OUT
CHARGE
PUMP
TEMPERATURE
FAULTS
V
BG
LOGIC
CONTROL
+
-
REFERENCE
OVLO
SEL
MAX14527
MAX14528
GND
Device ꢂperation
The MAX14527/MAX14528 have timing logic that
controls the turn-on of the internal FET. If V
OVLO_THRESH
The charge-pump startup, after a 15ms debounce
delay, turns on the internal FET (see the Functional
Detailed Description
The MAX14527/MAX14528 overvoltage protection
devices feature a low R internal FET and protect low-
<
IN
ON
V
, the internal charge pump is enabled.
voltage systems against voltage faults up to +28V. If
the input voltage exceeds the overvoltage threshold,
the internal FET is turned off to prevent damage to the
protected components. The 15ms debounce time pre-
vents false turn-on of the internal FET during startup.
Diagram). At any time, if V rises above V
THRESH
IN
OVLO_
, OUT is disconnected from IN.
_______________________________________________________________________________________
.
Adjustable Overvoltage Protector
with High Accuracy
ESD Test Conditions
Internal Switch
ESD performance depends on a number of conditions.
The MAX14527/MAX14528 incorporate an internal FET
The MAX14527/MAX14528 are specified for 15kV
(HBM) typical ESD resistance on IN when IN is
bypassed to ground with a 1µF ceramic capacitor.
with a 100mΩ (typ) R . The FET is internally driven by
ON
a charge pump that generates a necessary gate volt-
age above IN. The internal FET is capable of passing
more than 5A inrush current.
HBM ESD Protection
Figure 2a shows the Human Body Model, and Figure
2b shows the current waveform it generates when dis-
charged into a low impedance. This model consists of a
100pF capacitor charged to the ESD voltage of interest,
which is then discharged into the device through a
1.5kΩ resistor.
Overvoltage Lockout (OVLO)
The MAX14527 has a 5.75V (typ) overvoltage threshold
(OVLO).The MAX14528 has a 6.76V (typ) OVLO
threshold.
Thermal-Shutdown Protection
The MAX14527/MAX14528 feature thermal shutdown
circuitry. The internal FET turns off when the junction
temperature exceeds +150°C (typ). The device exits
thermal shutdown after the junction temperature cools
by 20°C (typ).
R
C
R
D
1.5kΩ
1MΩ
DISCHARGE
RESISTANCE
CHARGE-CURRENT-
LIMIT RESISTOR
Applications Information
HIGH-
VOLTAGE
DC
DEVICE
UNDER
TEST
IN Bypass Capacitor
For most applications, bypass IN to GND with a 1µF
ceramic capacitor as close as possible to the device to
enable 15kV (HBM) ESD protection on IN. If 15kV
(HBM) ESD is not required, there is no capacitor
required at IN. If the power source has significant
inductance due to long lead length, take care to pre-
vent overshoots due to the LC tank circuit and provide
protection if necessary to prevent exceeding the +30V
absolute maximum rating on IN.
7/MAX14528
C
s
100pF
STORAGE
CAPACITOR
SOURCE
Figure 2a. Human Body ESD Test Model
OUT Output Capacitor
The slow turn-on time provides a soft-start function that
allows the MAX14527/MAX14528 to charge an output
capacitor up to 1000µF.
I
100%
90%
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
I
P
R
AMPERES
External OVLO Adjustment Functionality
If OVLO is connected to ground, the internal OVLO
comparator uses the internally set OVLO value.
36.8%
10%
0
If an external resistor-divider is connected to OVLO
TIME
0
t
RL
and V
V
exceeds the OVLO select voltage,
, the internal OVLO comparator reads
OVLO
OVLO_ SELECT
the IN fraction fixed by the external resistor divider. R =
t
DL
CURRENT WAVEFORM
1
Figure 2b. Human Body Current Waveform
1MΩ is a good starting value for minimum current con-
sumption. Since V
, V
, and R are
IN_OVLO OVLO_THRESH 1
known, R can be calculated from the following formula:
2
⎡
⎤
⎥
⎦
R1
R2
V
= V
× 1+
⎢
IN_OVLO
OVLO_THRESH
⎣
This external resistor-divider is completely independent
from the internal resistor-divider.
6
_______________________________________________________________________________________
Adjustable Overvoltage Protector
with High Accuracy
7/MAX14528
Pin Configuration
Chip Information
PROCESS: BiCMOS
TOP VIEW
IN
IN
1
2
3
4
8
7
6
5
OUT
OUT
GND
I.C.
MAX14527
MAX14528
OVLO
I.C.
*EP
ꢄDFN
2mm x 2mm
*CONNECT EXPOSED PAD TO GND.
Package Information
For the latest package outline information and land patterns, go to wwwꢀmaxim-icꢀcom/packages.
PꢁCKꢁGE ꢄYPE
PꢁCKꢁGE CꢂDE
DꢂCUMENꢄ Nꢂꢀ
21-0168
8 TDFN-EP
T822+2
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 _____________________ 7
© 2008 Maxim Integrated Products
is a registered trademark of Maxim Integrated Products, Inc.
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