UZXYY [ANALOGICTECH]
PCMCIA Current Limit Interface and Capacitor Charger; PCMCIA限流界面和电容充电器
| 型号： | UZXYY |
| 厂家： | 
ADVANCED ANALOGIC TECHNOLOGIES |
| 描述： | PCMCIA Current Limit Interface and Capacitor Charger |
| 文件： | 总15页 (文件大小：593K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
AAT4620
PCMCIA Current Limit Interface
and Capacitor Charger
™
SmartSwitch
General Description
Features
The AAT4620 SmartSwitch is a current limited P-
channel MOSFET power switch designed for high-
side load-switching applications in PCMCIA
GSM/GPRS/3G modem cards. Used in conjunc-
tion with a super capacitor, the AAT4620 will
ensure that the power ratings of the PCMCIA host
are not exceeded at any time. Featuring two inde-
pendent, programmable current limits and a power
loop, the AAT4620 can ensure that the super
capacitor can be charged without exceeding PCM-
CIA specifications. The current limit is set by two
external resistors allowing a ±±0ꢀ current limit
accuracy over the normal operating temperature
range. The switch can be controlled from either of
the two enable inputs and in the off condition will
block currents in both directions. The AAT4620
also incorporates a System READY function which
can advise the system that the super capacitor is
fully charged and ready for use. Adjustable hys-
teresis is provided with the addition of an external
resistor. The quiescent supply current is typically a
low 40µA. In shutdown mode, the supply current
decreases to less than ±µA.
•
•
VIN Range: 3.0V to 5.5V
Dual Independent Current Limits
— ±00mA to ±200mA
— ±±0ꢀ Current Accuracy
— 20°C Temperature Band
Reverse Current Blocking Protection
Power Loop
Low Quiescent Current
— 40µA Typical
•
•
•
— ±.0µA Max with Switch Off
65mΩ Typical RDS(ON) at 3V
Only ±.4V Needed for Enable Control Pin
System READY Output with Externally
Programmable Hysteresis
Under-Voltage Lockout
•
•
•
•
•
•
Temperature Range: -40 to 85°C
±2-Pin TSOPJW Package
Applications
•
•
•
•
•
CF Card Port Power Protection
Express Card GSM/GPRS/3G Modems
Hot Swap Supplies
PCMCIA Card GSM/GPRS/3G Modems
Personal Communication Devices
The AAT4620 is available in a thermally enhanced,
Pb-free, ±2-pin TSOPJW package and is specified
over the -40°C to 85°C temperature range.
Typical Application
±00kΩ
Reverse
Blocking
OUT
RDY
To Load
To μC
VCC
V CC
Over-Temp
Protection
Power
Loop
Under-
Voltage
Lockout
EN IL
EN IU
ENSUPERCAP
ENOPERATION
Current
Limit
Control
ISETL
ISETU
±.2V
Reference
GND
SuperCap
RHYS
RSETU
RSETL
4620.2007.04.1.1
±
AAT4620
PCMCIA Current Limit Interface
and Capacitor Charger
Pin Descriptions
Pin #
Symbol
Function
±
EN IU
Enable input. Active low enable with internal pull up. Also switches in the higher current limit
to allow the System to start functioning. Can be directly connected to System Ready for
automatic enabling. When both EN IL and EN IU are enabled, ISETU will be selected.
Enable input. Active low enable with internal pull up. Also switches in the lower current limit
initiating the super capacitor to start charging.
2
EN IL
3
4, 5, 6
7, 8
9
GND
VCC
OUT
Device ground connection.
Input pins to the P-channel MOSFET source. Connect ±µF capacitor from VCC to GND.
P-channel MOSFET drain connection. Connect to super capacitor from OUT to GND.
Lower current-limit set input. A resistor from ISETL to ground sets the maximum lower cur-
rent limit for the switch. Current limit can be set between ±00mA and ±200mA.
Upper current limit set input. A resistor from ISETU to ground sets the maximum upper cur-
rent limit for the switch. Current limits can be set between ±00mA and ±200mA. Connect to
ground to disable current limit.
ISETL
±0
ISETU
±±
±2
RHYS
RDY
System READY hysteresis. Connect a resistor to ground to set the System Ready com-
parator hysteresis.
System ready pin. Open drain, active low, initiated when the capacitor is 98ꢀ charged.
Pin Configuration
TSOPJW-12
(Top View)
1
2
3
4
5
6
12
EN IU
EN IL
GND
VCC
VCC
VCC
RDY
11
10
9
RHYS
ISETU
ISETL
OUT
8
7
OUT
2
4620.2007.04.1.1
AAT4620
PCMCIA Current Limit Interface
and Capacitor Charger
1
Absolute Maximum Ratings
Symbol
Description
Value
Units
VCC
VEN
VSET, VOUT
IMAX
VCC to GND
EN to GND
SET, OUT to GND
-0.3 to 6
-0.3 to VCC + 0.3
-0.3 to VCC + 0.3
2.5
V
V
V
A
Maximum Continuous Switch Current
Thermal Characteristics
Symbol
Description
Maximum Thermal Resistance
Maximum Power Dissipation
Operating Junction Temperature Range
Value
±60
625
Units
2
θJA
PD
TJ
°C/W
mW
°C
2
-40 to ±50
±. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at condi-
tions other than the operating conditions specified is not implied. Only one Absolute Maximum Rating should be applied at any one time.
2. Mounted on an FR4 board.
4620.2007.04.1.1
3
AAT4620
PCMCIA Current Limit Interface
and Capacitor Charger
1
Electrical Characteristics
VCC = 3.0V to 5.5V, TA = -40°C to 85°C unless otherwise noted. Typical values are at TA = 25°C.
Symbol Description
Conditions
Min Typ Max Units
VCC
Operation Voltage
3.0
5.5
V
EN IL or EN IU = VCC, IOUT = 0,
RHYS = 200kΩ
EN IL = VCC, EN IU = GND, IOUT = 0,
ISET = GND, RHYS = 200kΩ
EN IL = EN IU = VCC
EN IL = EN IU = VCC, VSUPERCAP = 0
Rising edge, ±ꢀ hysteresis
IQ
Quiescent Current
40
40
75
µA
IQU0
Quiescent Current U0
75
µA
IQ(OFF)
ISD(OFF)
VUVLO
Off Supply Current
Off Switch Current
Under-Voltage Lockout
0.4
0.4
2.7
50
65
200
200
±000 ±±00
±000 ±±50
75
±.0
±0
3.0
±00
±20
220
230
µA
µA
V
V
CC =4.75V, RSETL = RSETU = 0k
VCC =3.0V, RSETL = RSETU = 0k
SETL = 249kΩ; ΔTA ≤ 20°C
RSETL = 249kΩ
SETU = ±.24MΩ; ΔTA ≤ 20°C
RDS(ON)
ILIMLACC
ILIMUACC
On-Resistance
mΩ
mA
mA
R
±80
±70
900
850
Lower Current Limit Accuracy
Upper Current Limit Accuracy
R
RSETU = ±.24MΩ
ILIM(MIN)
VEN(L)
VEN(H)
Lower Minimum Current Limit
EN Input Low Voltage
EN Input High Voltage
EN Input Leakage
mA
V
V
µA
µs
ꢀ of
VOUT
mV
V
2
VCC =3.0V to 5.5V
0.4
2
VCC = 3.0V to 5.5V
VEN = 5.5V
±.4
IEN(SINK)
±.0
±.0
TDEL(OFF) Turn-Off Delay Time
VCC = 5V
0.4
98
VRDY
System READY Trip Threshold VOUT rising, TA = 25°C
VRDYHYS
VRDY(L)
IRDY
System READY Hysteresis
System READY Voltage Low
RDY Leakage Current
RHYS = 200kΩ
ISINK = ±mA
VRDY < 5.5V, VOUT < 98ꢀ of VOUT
200
0.4
±.0
µA
°C
OTMP
Shutdown Temperature
±45
±. The AAT4620 is guaranteed to meet performance specification over the -40°C to 85°C operating temperature range and is assured by
design, characterization and correlation with statistical process controls.
2. For VIN outside this range consult the Typical EN Threshold curve.
4
4620.2007.04.1.1
AAT4620
PCMCIA Current Limit Interface
and Capacitor Charger
Typical Characteristics
Output Current vs. Output Voltage
RSET vs. ILIM
(25°C)
(RSETU = 383kΩ, 25°C)
0.40
1.40
VIN = 3.3V
1.20
1.00
0.80
0.60
0.40
0.20
0.00
0.30
0.20
VIN = 3.3V
VIN = 5V
VIN = 5V
0.10
0.00
0
200
400
600
800
1000
1200
1400
1600
0
0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7
3
3.3
Output Voltage (V)
RSET (kΩ)
Reverse Off-Switch Current vs. Temperature
(ENUB = ENLB = VCC; VIN = 0V)
Off-Switch Current vs. Temperature
(ENUB = ENLB = VCC; VOUT = 0V)
100
100
10
10
1
VOUT = 5V
VIN = 5V
1
0.1
0.1
VOUT = 3.3V
VIN = 3.3V
0.01
0.01
-40
-20
0
20
40
60
80
100
120
-40
-20
0
20
40
60
80
100
120
Temperature (°°C)
Temperature (°C)
Off-Supply Current vs. Temperature
(ENUB = ENLB = VCC; VOUT = Open)
10
VIN = 5V
1
0.1
VIN = 3.3V
0.01
-40
-20
0
20
40
60
80
100
120
Temperature (°°C)
4620.2007.04.1.1
5
AAT4620
PCMCIA Current Limit Interface
and Capacitor Charger
Typical Characteristics
RDS(ON) vs. Input Voltage
RDS(ON) vs. Temperature
(RSET = 0Ω)
(RSET = 0kΩΩ)
90
70
65
60
55
50
45
80
VIN = 3V
70
60
50
40
VIN = 5V
30
2.5
3
3.5
4
4.5
5
5.5
-40
-20
0
20
40
60
80
100
Input Voltage (V)
Temperature (°C)
VRHYS vs. RRHYS
ILIM vs. Temperature
(VIN = 4V; VOUT = 3.85V; ENLB = 0V; RSET = 249kΩΩ)
2.00
210
1.80
1.60
1.40
1.20
1.00
0.80
0.60
0.40
0.20
0.00
205
200
195
190
-50
-25
0
25
50
75
100
0
500
1000
1500
RRHYS (kΩ)
Temperature (°C)
ILIM vs. Temperature
(VIN = 4V; VOUT = 3.85V; ENUB = 0V; RSET = 1.24MΩ)
Quiescent Current IQU vs. Temperature
(ENUB = 0V; ENLB = VCC; or ENLB = 0V; ENUB = VCC;VOUT = Open)
55
1020
50
VIN = 5V
45
40
35
1000
980
30
VIN = 3.3V
25
960
-40
-20
0
20
40
60
80
100
120
-50
-25
0
25
50
75
100
Temperature (°C)
Temperature (°°C)
6
4620.2007.04.1.1
AAT4620
PCMCIA Current Limit Interface
and Capacitor Charger
Typical Characteristics
VIL vs. Input Voltage
(ENUB = Open; Vary ENLB; 25°C)
VIH vs. Input Voltage
(ENLB = Open; Vary ENUB; 25°C)
1.1
1.0
0.9
0.8
0.7
0.6
1.1
1.0
0.9
0.8
0.7
0.6
2.5
3.5
4.5
5.5
6.5
7.5
2.50
3.50
4.50
5.50
6.50
7.50
Input Voltage (V)
Input Voltage (V)
VIL vs. Input Voltage
(ENLB = Open; Vary ENUB; 25°C)
VIH vs. Input Voltage
(ENLB = Open; Vary ENUB; 25°C)
1.1
1.1
1.0
0.9
0.8
0.7
0.6
1.0
0.9
0.8
0.7
0.6
2.50
3.50
4.50
5.50
6.50
7.50
2.5
3.5
4.5
5.5
6.5
7.5
Input Voltage (V)
Input Voltage (V)
Soft Short Circuit with 5ΩΩ Series Impedance
Hard Short Circuit
(VIN = 3.3V)
(VIN = 5V)
6
6
4
2
0
4
2
0
0.4
0.2
0.0
-0.2
0.4
0.2
0.0
-0.2
Time (200ms/div)
Time (200ms/div)
4620.2007.04.1.1
7
AAT4620
PCMCIA Current Limit Interface
and Capacitor Charger
Typical Characteristics
Short Circuit with 5ΩΩ Series Impedance
Hard Short Circuit
(VIN = 5V)
(VIN = 3.3V)
1.0
0.8
6
0.6
4
0.4
2
0.2
0
0.0
0.4
0.2
0.0
-0.2
4
2
0
Time (200ms/div)
Time (200ms/div)
Charging Profile
(ILIMIT = 150mA; VIN = 5V; CO = 0.55F)
Charging Profile
(ILIMIT = 150mA; VIN = 5V; CO = 0.55F)
6
4
2
2
0
0
0.15
0.10
0.05
0.00
-0.05
0.30
0.15
0.00
-0.15
Time (5s/div)
Time (20ms/div)
Charging Profile
(ILIMIT = 1A; VIN = 5V; CO = 0.55F)
Charging Profile
(VIN = 5V, VISETL = VISETU = 0V, CO = 0.55F)
6
4
6
4
2
2
0
1.0
0.8
0.6
0.4
0.2
0.0
-0.2
0
1.5
1.0
0.5
0.0
-0.5
Time (2s/div)
Time (2s/div)
8
4620.2007.04.1.1
AAT4620
PCMCIA Current Limit Interface
and Capacitor Charger
Functional Block Diagram
Reverse
Blocking
OUT
VCC
Over-Temp
Protection
Power
Loop
Under-
Voltage
Lockout
RDY
EN IL
EN IU
Current Limit
Control
±.2V
Reference
ISETL
ISETU
RHYS
GND
host and PCMCIA card where a super capacitor has
been used to "average out" high pulse currents
which would otherwise exceed the PCMCIA/
Express Card power specifications. e.g. GSM/
GPRS modem cards, where pulse currents during
transmit signals can exceed the ±A maximum spec-
ification (±.3A in the case of Express Card).
Functional Description
The AAT4620 is an integrated P-channel MOSFET
load switch with an upper and lower adjustable cur-
rent limits which can be enabled independently,
over temperature protection, a power loop and a
super capacitor charger. The current limit control is
combined with an over temperature thermal limit
and power loop circuit to provide a comprehensive
system to protect the load switch and its supply
from load conditions which exceed the supply spec-
ifications. The AAT4620 has been designed specif-
ically to provide the interface between a PCMCIA
The current limit and over temperature circuits act
independently. The device current limit is activated
when the output load current exceeds an internal
threshold level. There are two internal current lim-
its which are enabled independently. The current
limit threshold in each case is determined by exter-
4620.2007.04.1.1
9
AAT4620
PCMCIA Current Limit Interface
and Capacitor Charger
nal resistors connected between the two SET pins
and ground. The minimum current limit threshold is
specified by ILIM(MIN). If the load condition maintains
the device in current limit and the chip temperature
reaches a critical point, then an internal power loop
will reduce the current to a safe level. Connecting
ISETU to ground disables the current limit protec-
Application Information
ISETU and ISETL Current Limit Set
The AAT4620 current limit is set at two different lev-
els. Resistors from ISETL and ISETU set the lower
and upper current limit levels respectively.
tion allowing a low impedance path to the host VCC
.
The ISETL and ISETU nodes operate within a win-
dow of 0.75V to ±.5V for resistor values ranging from
93.75Ω to ±.5MΩ. Resistor values outside this range
are not recommended. The ISETL and ISETU
source current varies with the resistor value used
according to Table ±. To determine the resulting cur-
rent limit multiply the RSETU or RSETL node voltage
times the gain in Table ±. Note that the voltage at the
node varies from 0.75V to ±.5V and the current limit
gain varies depending on the resistor value used.
The load switch is turned off by applying a logic
high level to both of the EN pins. When both EN IL
and EN IU are selected ISETU will be selected.
The EN function has logic level thresholds that
allow the AAT4620 to be TTL compatible and may
also be controlled by 2.5V to 5.0V CMOS circuits.
The voltage level applied to the EN pins should not
exceed the input supply level present on the VCC
pin. The AAT4620 typically consumes 40µA when
operating, when off, the device draws less then
±µA. In the off state, current is prevented from flow-
ing between the input and output.
VISET = RSET · IISET = 0.75V to ±.5V
Under-voltage lockout circuitry ensures that the
VCC supply is high enough for correct operation of
the IC. Also included is a System Ready function
which will be activated when the capacitor voltage
is charged and the load is permitted to take current.
For automatic functionality, this pin can be directly
connected to the EN IU pin. An external resistor is
provided to add hysteresis to this function.
If the set pin is open circuit or allowed to exceed
2V, all power devices are disabled and the input is
disconnected from the output. Shorting the set pin
to GND enables all power devices and shorts the
VCC to the output pin with no current limit.
To activate the upper current level (RSETU) pull EN IU
low. To activate the lower current level (RSETL) pull
EN IL low. If both EN IU and EN IL are pulled low the
EN IU current limit level (RSETU) will be selected.
RSET Range
IISET (µA)
ILIM/VISET (A/V)
Current Limit Range (A)
Current Limit
±.5Meg - 750k
750k - 375k
375k - ±87.5k
±87.5 - 93.75k
±
2
4
8
0.8
0.4
0.2
0.±
±.2-0.6
0.6-0.3
0.3-0.±5
0.±5-0.075
RSET*±µA*0.8
RSET*2µA*0.4
RSET*4µA*0.2
R
SET*8µA*0.±
Table 1: RSET Table.
±0
4620.2007.04.1.1
AAT4620
PCMCIA Current Limit Interface
and Capacitor Charger
die temperature exceeds ±00°C it decreases the
load current by ±/32 of the current limit set point. If
die temperature is less than ±00°C, it increases the
load current in increments of ±/32 of the current limit
set point until the set current limit point is reached or
the die temperature exceeds ±00°C.
ILOAD vs. RSETU and RSETL
1.2
1.0
0.8
0.6
0.4
0.2
0.0
The delay time between die temperature measure-
ments varies depending on the load current limit
set point. The delay ranges from ±ms for a 75mA
current limit set point to 8ms for a ±.5A current limit
set point.
0.10
0.30
0.50
0.70
0.90
1.10
1.30
1.50
RSETU and RSETL (MΩ)
For the condition where there is no current limit set
point (shorting RSETU or RSETL to ground) the soft
start increments the current limit is ±/32 steps of
±.2A until the current reaches ±.2A, at which point
the power MOSFET turns on fully. At this point, the
current is limited by the RDS(ON) of the power MOS-
FET and other series resistance. The Power Loop
and Over-Temperature Loop then takes control to
limit the current until the output voltage has fully
charged.
Figure 1: Calculated Current Limit RSET
Characteristic.
System Ready Hysteresis (RHYS) and
System Ready (RDY)
In internal comparator senses the output voltage
and delivers a ready signal to the external micro
controller when the output voltage reaches 98ꢀ of
the final value (VCC). The comparator hysteresis is
programmed by a resistor from the RHYS pin to
ground. The RHYS voltage determines the hys-
teresis voltage and is equal to the RHYS source
current (±µA) times the RHYS resistance.
Over-Temperature Protection
If the die temperature rate of rise is fast enough to
exceed the power loop regulated temperature,
over-temperature shutdown disables the device.
The over-temperature threshold is ±45°C. After
over-temperature shutdown, soft start is initiated
once the die temperature drops to ±30°C.
VHYST = RHYS · ±μA
= 200kΩ · ±μA
= 0.2V
Short Circuit Protection
The series pass power MOSFET turns off com-
pletely after the output has charged to within ±8mV
of the input voltage. This protects the device in the
event of a short circuit applied to the output.
Applying a short circuit or heavy load to the output
initiates the digital soft start where the current
ramps from zero to the final programmed value. The
power loop will be activated once the digital soft
start begins.
The system ready pin (RDY) is an open drain out-
put that switches low when the output voltage
reaches 98ꢀ of the input voltage. It requires an
external pull up resistor tied to the input voltage
with a typical value of ±00kΩ.
Power Loop
The AAT4620 power loop limits the load current in
the event that the device power dissipation becomes
excessive. The AAT4620 power loop regulates the
die temperature to ±00°C, decreasing the load cur-
rent in increments of ±/32 of the current limit set point
when the die temperature reaches ±00°C. When the
Under-Voltage Shutdown
Under-voltage lockout enables the device at 2.7V
typical with ±00mV of hysteresis. The maximum
UVLO level is 3.0V.
4620.2007.04.1.1
±±
AAT4620
PCMCIA Current Limit Interface
and Capacitor Charger
Digitally Programmed Soft Start
Current Limit
At turn on, the digital soft start increases the load
current in discrete levels equal to ±/32 of the final
programmed current limit set point from zero to the
final programmed current limit level.
Reverse Current Blocking
An internal comparator disables the internal pass
transistor when the input voltage is less than the
output voltage blocking any reverse current from
the output to the input.
Evaluation Board
The evaluation board schematic is shown in Figure 2.
The PCB layout is shown in Figures 3 and 4.
J2
3
2
±
R±
4.7K
D±
ENIU
J±
±
±2
ENIU
RDY
RDY
3
2
±
2
±±
±0
9
ENIL
RHYS
ISETU
ISETL
OUT
3
GND
ENIL
R2
200K
4
R3
VCC
±.00M
5
8
VCC
2
±
VCC
Out
6
7
VCC
OUT
±
2
GND
GND
AAT4620
R4
±20K
J4
J3
C±
C2
±0μF
±0μF
Figure 2: AAT4620 Evaluation Board Schematic.
Figure 3: AAT4620 Evaluation Board PCB Top Side.
±2
4620.2007.04.1.1
AAT4620
PCMCIA Current Limit Interface
and Capacitor Charger
Figure 4: AAT4620 Evaluation Board PCB Bottom Side.
4620.2007.04.1.1
±3
AAT4620
PCMCIA Current Limit Interface
and Capacitor Charger
Ordering Information
1
2
Package
Marking
Part Number (Tape and Reel)
TSOPJW-±2
UZXYY
AAT4620ITP-T±
All AnalogicTech products are offered in Pb-free packaging. The term “Pb-free” means
semiconductor products that are in compliance with current RoHS standards, including
the requirement that lead not exceed 0.1% by weight in homogeneous materials. For more
information, please visit our website at http://www.analogictech.com/pbfree.
Package Information
TSOPJW-12
+ 0.±0
- 0.05
0.20
0.50 BSC 0.50 BSC 0.50 BSC 0.50 BSC 0.50 BSC
7° NOM
0.04 REF
3.00 0.±0
4° 4°
0.45 0.±
5
0.055 0.045
0.0±0
2.75 0.25
All dimensions in millimeters.
±. XYY = assembly and date code.
2. Sample stock is generally held on part numbers listed in BOLD.
±4
4620.2007.04.1.1
AAT4620
PCMCIA Current Limit Interface
and Capacitor Charger
© Advanced Analogic Technologies, Inc.
AnalogicTech cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an AnalogicTech product. No circuit patent licenses, copyrights, mask work
rights, or other intellectual property rights are implied. AnalogicTech reserves the right to make changes to their products or specifications or to discontinue any product or service with-
out notice. Except as provided in AnalogicTech’s terms and conditions of sale, AnalogicTech assumes no liability whatsoever, and AnalogicTech disclaims any express or implied war-
ranty relating to the sale and/or use of AnalogicTech products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent,
copyright or other intellectual property right. In order to minimize risks associated with the customer’s applications, adequate design and operating safeguards must be provided by the
customer to minimize inherent or procedural hazards. Testing and other quality control techniques are utilized to the extent AnalogicTech deems necessary to support this warranty.
Specific testing of all parameters of each device is not necessarily performed. AnalogicTech and the AnalogicTech logo are trademarks of Advanced Analogic Technologies Incorporated.
All other brand and product names appearing in this document are registered trademarks or trademarks of their respective holders.
Advanced Analogic Technologies, Inc.
830 E. Arques Avenue, Sunnyvale, CA 94085
Phone (408) 737-4600
Fax (408) 737-4611
4620.2007.04.1.1
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