MAX4987AEETA+ [MAXIM]
Overvoltage-Protection Controller with USB ESD Protection; 过压保护控制器与USB ESD保护
| 型号： | MAX4987AEETA+ |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Overvoltage-Protection Controller with USB ESD Protection |
| 文件： | 总10页 (文件大小：195K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-1059; Rev 0; 11/07
Overvoltage-Protection Controller
with USB ESD Protection
/MAX4987BE
General Description
Features
The MAX4987AE/MAX4987BE are overvoltage protection
devices with built-in ESD protection for USB data lines.
o Input Voltage Protection Up to +28V
o Integrated Low R (100mΩ) nFET Switch
ON
These devices feature a low 100mΩ (typ) R
internal
ON
o Internal Overcurrent Protection 1.5A (min)
o Overcurrent Protection (Autoretry)
o Enable Input
nFET switch and protect low-voltage systems against volt-
age faults up to +28V. When the input voltage exceeds
the overvoltage threshold or decreases below the under-
voltage threshold, the internal nFET switch is turned off to
prevent damage to the protected components.
o Internal 30ms Startup Delay
o Low-Capacitance USB High-Speed Data Line ESD
Protection (3pF)
All switches feature a minimum 1.5A current-limit pro-
tection. During a short-circuit occurrence, the switch
operates in an autoretry mode where the internal nFET
switch is turned on to check if the fault has been
removed. The autoretry interval is 30ms, and if the fault
is removed, the nFET switch remains on.
15ꢀV Human Body ꢁodel
15ꢀV IECꢂ1000-ꢃ-2 Air ꢄap
ꢂꢀV IECꢂ1000-ꢃ-2 Contact
o Thermal-Shutdown Protection
The MAX4987AE/MAX4987BE feature low-capacitance
(3pF) ESD protection for USB data lines that allow
transmission of high-speed USB 2.0 signals.
o 2mm x 3mm, 8-Pin TDFN Pacꢀage
Pin Configuration
The overvoltage threshold (OVLO) is preset to 6.15V.
The undervoltage thresholds (UVLO) are preset to 2.55V
(MAX4987AE) or 4.2V (MAX4987BE). When the input
voltage drops below the undervoltage (UVLO) thresh-
old, the devices enter a low-current standby mode.
TOP VIEW
V
OUT ACOK EN
CC
5
8
7
6
All devices are offered in a small 2mm x 3mm, 8-pin
TDFN package and operate over the -40°C to +85°C
extended temperature range.
Applications
MAX4987AE/
MAX4987BE
Cell Phones
Media Players
*EP
4
1
2
3
IN
CD+ GND CD-
Typical Operating Circuit appears at end of data sheet.
*CONNECT EXPOSED
PAD TO GND.
TDFN-EP
2mm x 3mm
Ordering Information/Selector Guide
PIN-
PACKAꢄE
PACKAꢄE
OVERCURRENT
PART
TOP ꢁARK
UVLO (V)
OVLO (V)
CODE
T823-1
T823-1
ꢁODE
ꢁAXꢃ987AEETA+
ꢁAXꢃ987BEETA+*
8 TDFN-EP**
8 TDFN-EP**
AAI
2.55
4.2
6.15
6.15
Autoretry
Autoretry
AAJ
Note: All devices are specified over the -40°C to +85°C operating temperature range.
+Denotes a lead-free package.
*Future product—contact factory for availability.
**EP = Exposed paddle.
________________________________________________________________ ꢁaxim Integrated Products
1
For pricing, delivery, and ordering information, please contact ꢁaxim Direct at 1-888-ꢂ29-ꢃꢂꢃ2,
or visit ꢁaxim’s website at www.maxim-ic.com.
Overvoltage-Protection Controller
with USB ESD Protection
ABSOLUTE ꢁAXIꢁUꢁ RATINꢄS
(All voltages referenced to GND.)
Package Junction-to-Case Thermal Resistance
IN............................................................................-0.3V to +30V
OUT.............................................................-0.3V to +(IN + 0.3V)
(θ ) (Note 1) ................................................................10.8°C/W
JC
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
V
, EN, ACOK, CD+, CD-......................................-0.3V to +6V
CC
Continuous Power Dissipation (T = +70°C) for multilayer board:
A
8-Pin TDFN (derate 16.7mW/°C above +70°C) .........1333mW
Package Junction-to-Ambient Thermal Resistance
(θ ) (Note 1) ................................................................60.0°C/W
JA
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a 4-layer
board. For detailed information on package thermal considerations, go to www.maxim-ic.com/thermal-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.
ELECTRICAL CHARACTERISTICS
(V = +2.2V to +28V, T = -40°C to +85°C, unless otherwise noted. Typical values are at V = +5V and T = +25°C.)
IN
A
IN
A
PARAꢁETER
SYꢁBOL
CONDITIONS
ꢁIN
TYP
ꢁAX
UNIT
ANALOꢄ SWITCH
Input-Voltage Range
V
2.2
28
5.5
150
100
40
V
V
IN
V
Input Voltage
V
CC
CC
/MAX4987BE
EN = 0V, V > V
60
50
IN
UVLO
UVLO
Input Supply Current
UVLO Supply Current
I
µA
µA
IN
EN = 5V, V > V
IN
UVLO
I
V
< V
IN
UVLO
MAX4987AE
MAX4987BE
MAX4987AE
MAX4987BE
2.3
3.8
(V falling)
IN
IN Undervoltage Lockout
V
V
V
UVLO
OVLO
2.35
3.85
2.55
4.2
1
2.75
4.45
(V rising)
IN
IN Undervoltage Lockout Hysteresis
Overvoltage Trip Level
%
V
(V rising)
IN
5.55
5.5
6.15
6.45
(V falling)
IN
IN Overvoltage Lockout Hysteresis
Switch On-Resistance
1
%
mΩ
A
R
V
= 5V, I = 500mA
OUT
100
200
4.2
ON
IN
Overcurrent Protection Threshold
Maximum Output Capacitance
CD+ and CD- Leakage Current
CD+ and CD- Capacitance
DIꢄITAL SIꢄNALS
I
1.5
LIM
V
V
= 5V, no overcurrent shutdown
1000
3
µF
nA
pF
IN
I
= 5.5V, V = 0V, 3.3V
CD_
-300
+300
LKG_CD
CC
C
f = 1MHz, V
= 0.5
CD_ P-P
CD
ACOK Output Low Voltage
ACOK High-Leakage Current
EN Input-Voltage High
V
I
= 1mA
0.4
1
V
µA
V
OL
SINK
V
= 5.5V, flag deasserted
ACOK
V
1.4
-1
IH
EN Input-Voltage Low
V
0.4
+1
V
IL
EN Input-Leakage Current
I
V
= 5.5V
EN
µA
LEAK
2
_______________________________________________________________________________________
Overvoltage-Protection Controller
with USB ESD Protection
/MAX4987BE
ELECTRICAL CHARACTERISTICS (continued)
(V = +2.2V to +28V, T = -40°C to +85°C, unless otherwise noted. Typical values are at V = +5V and T = +25°C.)
IN
A
IN
A
PARAꢁETER
SYꢁBOL
CONDITIONS
ꢁIN
TYP
ꢁAX
UNIT
TIꢁINꢄ CHARACTERISTICS (Note 2)
Time from V
charge-pump enable
< V < V
to
OVLO
UVLO
IN
Debounce Time
t
30
30
3
ms
ms
ms
INDBC
ACOK Assertion Time
t
V
V
< V < V
, to ACOK low
OVLO
ACOK
UVLO
IN
< V < V
, R
= 100Ω,
UVLO
IN
OVLO LOAD
Switch Turn-On Time
t
ON
from 10% to 90% of V
OUT
V
< V
or V > V
to internal
OVLO
IN
UVLO
IN
Switch Turn-Off Time
Current-Limit Turn-Off Time
Autoretry Time
t
10
µs
µs
OFF
switch off, R
= 100Ω
LOAD
t
Overcurrent fault to internal switch off
10
30
BLANK
From overcurrent fault to internal switch
turn-on
t
ms
RETRY
THERꢁAL PROTECTION
Thermal Shutdown
T
150
40
°C
°C
SHDN
Thermal-Shutdown Hysteresis
ESD PROTECTION
Human Body Model
IEC61000-4-2 Air Gap
IEC61000-4-2 Contact
Human Body Model
15
15
6
CD+ and CD-
All Other Pins
kV
kV
2
Note 2: All timing is specified using 20% and 80% levels, unless otherwise noted.
Typical Operating Characteristics
(T = +25°C, unless otherwise noted.)
A
SWITCH ON-RESISTANCE
vs. TEMPERATURE
IN SUPPLY CURRENT
vs. IN VOLTAGE
NORMALIZED UVLO THRESHOLD
vs. TEMPERATURE
200
180
160
140
120
100
80
1.010
1.008
1.006
1.004
1.002
1.000
0.998
0.996
0.994
0.992
0.990
80
MAX4987AE
70
60
50
40
30
20
60
40
10
0
20
0
-40
-15
10
35
60
85
2
6
10
14
IN VOLTAGE (V)
22
26
18
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
_______________________________________________________________________________________
3
Overvoltage-Protection Controller
with USB ESD Protection
Typical Operating Characteristics
(T = +25°C, unless otherwise noted.)
A
NORMALIZED OVLO THRESHOLD
NORMALIZED CURRENT LIMIT
vs. TEMPERATURE
TURN-ON TIME
vs. TEMPERATURE
vs. TEMPERATURE
1.010
1.20
1.16
1.12
1.08
1.04
1.00
0.96
0.92
0.88
0.84
0.80
5.0
4.0
1.008
1.006
1.004
1.002
1.000
0.998
0.996
0.994
0.992
0.990
3.0
2.0
1.0
0
-40
-15
10
35
60
85
-40
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
DEBOUNCE TIME
vs. TEMPERATURE
POWER-UP RESPONSE
OVERVOLTAGE FAULT RESPONSE
MAX4987AE/BE toc09
MAX4987AE/BE toc08
50.0
45.0
40.0
35.0
30.0
25.0
20.0
8V
5V
8V
5V
V
/MAX4987BE
IN
V
5V/div
IN
5V/div
V
5V/div
V
OUT
5V/div
OUT
0
0
0
V
V
ACOK
ACOK
5V/div
5V/div
I
I
OUT
1A/div
OUT
1A/div
-40
-15
10
35
60
85
10ms/div
2μs/div
TEMPERATURE (°C)
UNDERVOLTAGE FAULT RESPONSE
SHORT-CIRCUIT FAULT RESPONSE
MAX4987AE/BE toc10
MAX4987AE/BE toc11
C
= 100μF
5
2
IN
0
V
V
IN
IN
2V/div
5V/div
V
OUT
V
OUT
5V/div
0
0
0
2V/div
0
0
0
V
ACOK
5V/div
V
ACOK
5V/div
I
OUT
1A/div
I
OUT
1A/div
4μs/div
10μs/div
ꢃ
_______________________________________________________________________________________
Overvoltage-Protection Controller
with USB ESD Protection
/MAX4987BE
Pin Description
PIN
NAꢁE
FUNCTION
Voltage Input. Bypass IN with a 1µF ceramic capacitor as close to the device as possible to obtain
15kV HBM ESD protection. No capacitor reꢀuired to obtain 2kV HBM ESD protection.
1
IN
2
3
4
5
6
CD+
GND
CD-
USB Data Line
Ground
USB Data Line
V
Positive Supply-Voltage Input. V
is reꢀuired only when USB signals are present.
CC
CC
EN
Enable Active-Low Input. Drive EN low to enable the switch. Drive EN high to disable the switch.
Open-Drain Adapter-Voltage Indicator Output. ACOK is driven low after the V voltage is stable
IN
7
ACOK
between UVLO and OVLO for 30ms (typ). Connect a pullup resistor from ACOK to the logic I/O voltage
of the host system.
8
OUT
EP
Output Voltage. Output of internal switch.
EP
Exposed Pad. Connect exposed pad to ground. Do not use EP as a sole ground connection.
Functional Diagram
IN
OUT
OVERCURRENT
FAULT
CHARGE
PUMP
ACOK
CONTROL
LOGIC
+
-
OV
UV
EN
V
BG
REFERENCE
+
EN
-
V
CC
CD+
CD-
MAX4987AE/
MAX4987BE
GND
_______________________________________________________________________________________
5
Overvoltage-Protection Controller
with USB ESD Protection
OVLO
UVLO
t
OFF
IN
t
OFF
t
ON
90% V
OUT
10% V
OUT
OUT
t
t
INDBC
t
INDBC
INDBC
ACOK
/MAX4987BE
Figure 1. MAX4987AE/MAX4987BE Timing Diagram
Detailed Description
Internal nFET Switch
The MAX4987AE/MAX4987BE are overvoltage protec-
tion devices with integrated ESD protection for USB
The MAX4987AE/MAX4987BE incorporate an internal
nFET switch with a 100mΩ (typ) on-resistance. The
nFET switch is internally driven by a charge pump that
generates a voltage above the input voltage. The
MAX4987AE/MAX4987BE is eꢀuipped with a 1.5A (min)
current-limit protection that turns off the nFET switch
within 5µs (typ) during an overcurrent fault condition.
data lines. These devices feature a low R
internal
ON
FET and protect low-voltage systems against voltage
faults up to +28V. If the input voltage exceeds the over-
voltage threshold, the internal nFET switch is turned off
to prevent damage to the protected components. The
30ms debounce time prevents false turn-on of the inter-
nal nFET switch during startup. An open-drain active-
low logic output is available to signal that a successful
power-up has occurred.
Autoretry
The MAX4987AE/MAX4987BE have an overcurrent
autoretry function that turns on the nFET switch again
after a 30ms (typ) retry time (see Figure 2). If the faulty
load condition is still present after the blanking time, the
switch turns off again and the cycle is repeated. The fast
turn-off time and 30ms retry time result in a very low duty
cycle in order to keep power consumption low. If the
faulty load condition is not present, the switch remains on.
Device Operation
The MAX4987AE/MAX4987BE have an internal oscilla-
tor and charge pump that control the turn-on of the
internal nFET switch. The internal oscillator controls the
timers that enable the turn-on of the charge pump and
controls the state of the open-drain ACOK output. If V
IN
Undervoltage Lockout (UVLO)
The MAX4987AE has a 2.55V undervoltage-lockout
threshold (UVLO), while the MAX4987BE has a 4.15V
< V
or if V > V
, the internal oscillator
UVLO
IN
OVLO
remains off, thus disabling the charge pump. If V
<
UVLO
V
IN
< V
, the internal charge pump is enabled. The
OVLO
UVLO threshold. When V is less than V
IN
, ACOK is
UVLO
charge-pump startup, after a 30ms internal delay, turns
on the internal nFET switch and asserts ACOK (see
high impedance.
Figure 1). At any time, if V drops below V
or rises
IN
UVLO
above V
, ACOK is pulled high and the charge
OVLO
pump is disabled.
ꢂ
_______________________________________________________________________________________
Overvoltage-Protection Controller
with USB ESD Protection
/MAX4987BE
Overvoltage Lockout (OVLO)
The MAX4987AE/MAX4987BE have a 6.15V (typ) over-
voltage threshold (OVLO). When V is greater than
t
OFF
IN
nFET SWITCH
ON
nFET SWITCH
ON
V
, ACOK is high impedance.
OVLO
ACOK
ACOK is an active-low open-drain output that asserts
low when V < V < V following the 30ms
UVLO
IN
OVLO
(typ) debounce period. Connect a pullup resistor from
ACOK to the logic I/O voltage of the host system.
During a short-circuit fault, ACOK may deassert due to
t
RETRY
SWITCH OFF
V
not being in the valid operating voltage range.
IN
Thermal-Shutdown Protection
CURRENT
THROUGH
nFET SWITCH
The MAX4987AE/MAX4987BE feature thermal-shutdown
circuitry. The internal nFET switch turns off when the
I
LIM
junction temperature exceeds T
and immediately
SHDN
goes into a fault mode. The device exits thermal shut-
down after the junction temperature cools by +40°C (typ).
Figure 2. Autoretry Timing Diagram
Applications Information
IN Bypass Capacitor
For most applications, bypass IN to GND with a 1µF
ceramic capacitor as close to the device as possible to
enable 15kV HBM ESD protection on IN. If 15kV HBM
ESD protection is not reꢀuired, there is no capacitor
reꢀuired at IN. If the power source has significant induc-
tance due to long lead length, take care to prevent over-
shoots due to the LC tank circuit and provide protection if
necessary to prevent exceeding the absolute maximum
rating on IN.
R
1MΩ
R
D
1.5kΩ
C
DISCHARGE
RESISTANCE
CHARGE CURRENT-
LIMIT RESISTOR
HIGH-
VOLTAGE
DC
DEVICE
UNDER
TEST
C
s
STORAGE
CAPACITOR
100pF
SOURCE
ESD Test Conditions
ESD performance depends on a number of conditions.
The MAX4987AE/MAX4987BE are specified for 15kV
HBM ESD protection on the CD+, CD-, and IN pins
when IN is bypassed to ground with a 1µF ceramic
capacitor. The CD+ and CD- inputs are also protected
against 15kV airgap and 6kV contact IEC61000-4-2
ESD events.
Figure 3. Human Body ESD Test Model
I
100%
90%
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
I
P
r
Human Body Model
Figure 3 shows the Human Body Model, and Figure 4
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 inter-
est, that is then discharged into the device through a
1.5kΩ resistor.
AMPERES
36.8%
10%
0
TIME
0
t
RL
t
DL
CURRENT WAVEFORM
IEC 61000-4-2
The IEC 61000-4-2 standard covers ESD testing and per-
formance of finished eꢀuipment. It does not specifically
refer to integrated circuits. The MAX4987AE/ MAX4987BE
Figure 4. Human Body Current Waveform
_______________________________________________________________________________________
7
Overvoltage-Protection Controller
with USB ESD Protection
are specified for 15kV Air-Gap Discharge and 6kV
Contact Discharge IEC 61000-4-2 on the CD+ and CD-
pins.
R
R
D
330Ω
C
50MΩ TO 100MΩ
DISCHARGE
RESISTANCE
CHARGE-CURRENT-
LIMIT RESISTOR
The major difference between tests done using the
Human Body Model and IEC 61000-4-2 is a higher peak
current in IEC 61000-4-2, due to lower series resistance.
Hence, the ESD withstand voltage measured to IEC
61000-4-2 generally is lower than that measured using
the Human Body Model. Figure 5 shows the IEC 61000-
4-2 model. The Contact Discharge method connects the
probe to the device before the probe is charged. The
Air-Gap Discharge test involves approaching the device
with a charged probe.
HIGH-
VOLTAGE
DC
DEVICE
UNDER
TEST
C
s
150pF
STORAGE
CAPACITOR
SOURCE
Figure 5. IEC 61000-4-2 ESD Test Model
Typical Operating Circuit
IN
OUT
BATTERY
CHARGER
PHONE
LOAD
V
IO
OVERCURRENT
FAULT
CHARGE
PUMP
/MAX4987BE
ACOK
CONTROL
LOGIC
+
OV
-
V
BG
REFERENCE
V
CC
EN
+
UV
-
V
V
CC
CC
VBUS
D+
D+
D-
USB
TRANSCEIVER
USB
CONNECTOR
CD+
CD-
D-
MAX4987AE/
MAX4987BE
GND
Chip Information
PROCESS: BiCMOS
8
_______________________________________________________________________________________
Overvoltage-Protection Controller
with USB ESD Protection
/MAX4987BE
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/pacꢀages.)
PACKAGE OUTLINE
8L TDFN, EXPOSED PAD, 2x3x0.8mm
1
21-0174
B
2
_______________________________________________________________________________________
9
Overvoltage-Protection Controller
with USB ESD Protection
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/pacꢀages.)
DIMENSIONS
SYMBOL
MIN.
0.70
2.95
1.95
0.00
0.30
NOM.
0.75
MAX.
0.80
3.05
2.05
0.05
0.50
A
E
3.00
D
A1
L
2.00
EXPOSED PAD PACKAGE
E2 D2
MIN. NOM. MAX. MIN. NOM. MAX.
1.60 1.75 1.90 1.50 1.63 1.75
0.02
PKG.
CODE
0.40
k
0.20 MIN.
0.20 REF.
T823-1
A2
N
e
8
0.50 BSC
0.25
0.18
0.30
b
/MAX4987BE
PACKAGE OUTLINE
8L TDFN, EXPOSED PAD, 2x3x0.8mm
2
21-0174
B
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.
10 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2007 Maxim Integrated Products
SPRINGER
is a registered trademark of Maxim Integrated Products, Inc.
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