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AAT3526/7/8
MicroPower Supervisory Circuit with Manual Reset General Description
The AAT3526/7/8 PowerManagerTM products are members of AATI's Total Power Management ICTM (TPMICTM) product family. These microprocessor reset circuits are ideal for monitoring voltage supplies in portable systems, where extended battery life is critical. They provide a low cost, reliable solution by eliminating external components. The AAT3526/7/8 products operate by monitoring the system power supply voltage. When the input voltage drops below a fixed threshold, the device asserts a reset signal for a minimum of 150ms after VCC has risen back above the fixed threshold. They are guaranteed to operate down to 1.2V and designed to ignore fast line transients appearing on VCC. The AAT3526/7/8 series is available with three output stage versions: AAT3526 push-pull active low output, AAT3527 push-pull active high output and AAT3528 open drain active low output. The quiescent supply current is extremely low, typically 1A, making this device ideal for portable battery operated equipment. The AAT3526/7/8 are available in a 4 pin SOT143 package and are specified over -40 to 85C operating temperature range.
Features
* * * * * * * * *
PowerManagerTM
* *
1.2V to 5.5V Input voltage range Operation down to 1.2V Extremely low quiescent current: less than 2A High accuracy detection threshold: 1.5% Monitor Power Supply Voltages Fixed thresholds from 2.2V to 4.6V Minimum 150ms reset pulse width with fast delay time <20s Debounced Manual Reset Input Available output configurations: * Open-drain output * CMOS active high output * CMOS active low output Temp range -40 to 85C 4 pin SOT143 package
Advanced Information
Applications
* * * * * Notebook Computers Cell Phones Portable Electronics Embedded Systems Intelligent Instruments
Typical Application
VCC
VCC
*
100k (nominal)
VCC
MR
AAT3526 AAT3527 RESET (RESET) AAT3528
RESET uP INPUT
GND
GND
*AAT3528 Only
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AAT3526/7/8
MicroPower Supervisory Circuit with Manual Reset Pin Descriptions
AAT3526, 3527, 3528 (SOT143)
Pin #
1
Symbol
GND RESET (AAT3527)
Function
Ground connection RESET output remains high while VCC is below the reset threshold and remains so for a minimum of 150ms after VCC raises above the reset threshold. RESET output remains low while VCC is below the reset threshold and remains so for a minimum of 150ms after VCC raises above the reset threshold Manual Reset active low input. A logic low signal on MR asserts a reset condition. Asserted reset continues as long as MR is low and for a minimum of 150ms after MR returns high Supply Voltage (+1.2V to +5.5V)
2 RESET (AAT3526, AAT3528) 3 MR
4
Vcc
Part Number Descriptions
Part Number
AAT3526 AAT3527 AAT3528
Output Type
Reset Output Push Pull Active Low with Delay Reset Output Push Pull Active High with Delay Reset Output Open Drain Active Low with Delay
Pin Configuration
SOT143 (Top View)
GND (RESET) RESET
1
4
VCC MR
2
3
2
3526.2002.1.0.62
AAT3526/7/8
MicroPower Supervisory Circuit with Manual Reset Absolute Maximum Ratings
Symbol
VCC VMR VRESET IVCC, IMR IRESET dVcc/dt TJ TLEAD (TA=25C unless otherwise noted)
Description
VCC to GND MR to GND RESET to GND (Push-Pull Output) RESET to GND (Open Drain Output) Maximum Continuous Input Current RESET/RESET Current Rate of rise of VCC Operating Junction Temperature Range Maximum Soldering Temperature (at Leads) for 10s
Value
-0.3 to 5.5 -0.3 to VCC+0.3 -0.3 to VCC+0.3 -0.3 to 5.5 20 20 100 -40 to 150 300
Units
V V V mA mA V/s C C
Note: Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at conditions other than the operating conditions specified is not implied. Only one Absolute Maximum rating should be applied at any one time.
Thermal Information
Symbol
JA PD
Description
Maximum Thermal Resistance (SOT143) Maximum Power Dissipation (SOT143)1
1
Value
200 320
Units
C/W mW
Note 1: Mounted on an FR4 board.
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AAT3526/7/8
MicroPower Supervisory Circuit with Manual Reset Electrical Characteristics (VIN = 5V, TA = -40 to 85C unless otherwise noted. Typical values are at TA=25C, VCC = 5V for 4.63/4.38V versions, VCC = 3.3V for 3.08/2.93V versions, VCC = 3.0V for 2.63V versions and VCC = 2.5V for 2.32/2.2V versions )
Symbol
VCC IQ VTH VTH/C tP tRDY tMR MRGI tMD VIH VIL RMR VOL VOH
Description
Operation Voltage Quiescent Current RESET Threshold (Table 1) RESET Threshold Tempco RESET Propagation Delay RESET Active Timeout Period MR Minimum Pulse Width MR Glitch Immunity MR to Reset Propagation Delay MR Input Threshold MR Input Threshold MR Pull-Up Resistance RESET Low Output Voltage AAT3526, AAT3528 RESET High Output Voltage AAT3526 RESET Low Output Voltage AAT3527
Conditions
TA = 0C to +70C TA = -40C to +85C VCC = 5.5V VCC = 3V TA = 25C TA = -40C to +85C VCC = VTH to (VTH -100mV)
Min
1.0 1.2
Typ
Max
Units
VTH -1.5% VTH -2.5%
150 10
5.5 V 5.5 1.05 3 A 0.85 2 VTH VTH +1.5% V VTH VTH +2.5% 40 ppm/C 15 s 250 400 ms s 100 ns 0.5 s V 0.8 0.25 x VCC 30 0.3 0.4 V k
VCC VCC VCC VCC
= = = =
VTH(MAX), VTH(MAX), VTH(MAX), VTH(MAX),
VTH VTH VTH VTH
4.38V < 4.38V 4.38V < 4.38V
2.3 0.7 x VCC
10 ISINK =1.6mA, VCC > 2.1V, RESET asserted ISINK =100A, VCC >1.2V, RESET asserted ISOURCE = 800 A ISINK =1.2mA, VCC > 1.2V, RESET not asserted ISINK = 3.2mA, VCC > 4.5V, RESET not asserted ISOURCE = 500A, VCC > 2.1V, RESET asserted ISOURCE = 50A, VCC > 1.2V, RESET asserted VCC > VTH
20
V
VCC -1.5 0.3 0.4 0.8VCC 0.8VCC 1
V
VOL
V
VOH IDOFF
RESET High Output Voltage AAT3527 RESET leakage current, AAT3528
V
A
4
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AAT3526/7/8
MicroPower Supervisory Circuit with Manual Reset Typical Characteristics
Supply Current vs. Temperature
1.40
Normalized Reset Threshold vs. Temperature
Normalized Threshold
1.003 1.002 1.001 1.000 0.999 0.998 0.997 -40 -20 0 20 40 60 80
Supply Current (A)
1.20 1.00 0.80 0.60 0.40 0.20 0.00 -40 -20
VCC=5V
VCC=3V
0
20
40
60
80
Temperature (C)
Temperature (C)
Power-Up Reset Timeout vs. Temperature
Reset Propagation Delay (s)
320 300 30 25 20 15 10 5 0 -40
Power-Down Reset Propagation Delay vs. Temperature
Power-Up Reset Timeout (ms)
VOD=10mV
280 260 240 220 200 180 160 -40 -20 0 20 40 60 80 100
VOD=100mV
-20
0
20
40
60
80
Temperature (C)
Temperature (C)
Maximum Transient Duration vs. Reset Threshold Overdrive
400
Maximum Transient Duration (S)
350 300 250 200 150 100 50 0 1 10 100 1000
Reset Threshold Overdrive, VTH-VCC (mV)
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AAT3526/7/8
MicroPower Supervisory Circuit with Manual Reset Functional Block Diagram
MR
VCC
Reset Generator + Timer
RESET (RESET)
Oscillator VREF
GND
Functional Description
General
During start-up, the reset pin on a microprocessor ensures that it is fully reset and starts up in a known condition. The AAT3526/7/8 series of microprocessor reset devices monitor the supply voltage to a
microprocessor and assert a reset signal whenever the VCC voltage falls below a factory programmed threshold. This threshold is accurate within +/-1.5% at 25C and within +/- 2.5% over the entire operating temperature range. The reset signal remains asserted for a minimum of 150ms after VCC has risen above the threshold as shown in Figure 1.
VTH VCC
VTH
VTH
tRDY
tRDY
Figure 1: Reset Timing Diagram
6
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AAT3526/7/8
MicroPower Supervisory Circuit with Manual Reset Applications Information
Reset Output Options
The AAT3528 has an active low open drain output and the AAT3526/7 have a push-pull output. The AAT3528 may be used in multiple voltage systems, with an external pull-up resistor. This allows the AAT3528 to interface to microprocessors with higher supply voltages up to 5.5V (Figure 2). In the event of a power down or brown-out condition the reset signal remains valid until the VCC drops below 1.2V. To ensure validity down to ground an external 100k resistor should be connected between the RESET output and GND. input is internally debounced which allows use of a mechanical switch. It should be a normally-open momentary switch connected from MR to GND. Additionally, the MR pin can be driven from TTL, CMOS, or open drain logic outputs.
Supply Voltage Transient Behavior
In some cases fast negative transients of short duration can appear on the VCC power supply. The AAT3526/7/8 series devices provide some immunity to line transients which can generate invalid reset pulses. Figure 1 shows typical behavior to short duration pulses verses RESET comparator overdrive. As shown in the Maximum Transient Duration vs. Reset Threshold Overdrive graph, when the transient voltage becomes larger, the time allowed before asserting a reset becomes shorter. e.g. typically a transient of 100mV below the reset threshold would have to present for more than 50s to cause a reset. Immunity can be increased by the addition of a small by-pass capacitor of 0.1F connected as close to the VCC pin as possible.
Manual Reset Input
A logic low signal on MR asserts a reset condition. Reset continues to be asserted as long as MR is low and for a minimum of 150ms after MR returns high. This input is internally pulled up to VCC via a 20k resistor, so leaving the pin unconnected is acceptable if manual reset function is not needed. The MR
+3.3V
+5.0V
VCC
100k
VCC
AAT3528
MR RESET RESET INPUT
5V System
GND
GND
Figure 2: Using AAT3528 Open Drain Output with Multiple Supplies
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AAT3526/7/8
MicroPower Supervisory Circuit with Manual Reset Factory Trimmed Reset Thresholds* and Ordering Information Table 1
Ordering Part Number
AAT3526ICX-2.32-200-T1 AAT3527ICX-2.32-200-T1 AAT3528ICX-2.32-200-T1 AAT3526ICX-2.63-200-T1 AAT3527ICX-2.63-200-T1 AAT3528ICX-2.63-200-T1 AAT3526ICX-2.93-200-T1 AAT3527ICX-2.93-200-T1 AAT3528ICX-2.93-200-T1 AAT3526ICX-3.08-200-T1 AAT3527ICX-3.08-200-T1 AAT3528ICX-3.08-200-T1 AAT3526ICX-4.38-200-T1 AAT3527ICX-4.38-200-T1 AAT3528ICX-4.38-200-T1 AAT3526ICX-4.63-200-T1 AAT3527ICX-4.63-200-T1 AAT3528ICX-4.63-200-T1
*Contact Local Sales Office for custom trimmed options
Marking
Reset Threshold Voltage, VTH (V) TA = 40 to 85C TA = 25C Min Typ Max Min Max
2.285 2.320 2.355 2.262 2.378
2.591
2.630
2.669
2.564
2.696
2.886
2.930
2.974
2.857
3.003
3.034
3.080
3.126
3.003
3.157
4.314
4.380
4.446
4.271
4.490
4.561
4.630
4.699
4.514
4.746
8
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AAT3526/7/8
MicroPower Supervisory Circuit with Manual Reset Package Information
SOT143
B e1 CL CL E H
PIN 1
S
Dim A A1 B B1 C D E E1 E2 H I S
C CL I
e2 B1
D A CL
Millimeters Min Max 0.787 1.194 0.025 1.027 0.356 0.559 0.762 0.965 0.086 0.152 2.667 3.048 1.194 1.397 1.803 2.007 0.200 BSC 2.083 2.489 0.102 0.305 0.450 0.600 0 8
Inches Min Max 0.031 0.047 0.001 0.005 0.014 0.022 0.030 0.038 0.0034 0.006 0.105 0.120 0.047 0.055 0.071 0.079 0.008 BSC 0.082 0.098 0.004 0.012 0.018 0.024 0 8
A1
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AAT3526/7/8
MicroPower Supervisory Circuit with Manual Reset
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Advanced Analogic Technologies, Inc.
1250 Oakmead Parkway, Suite 310, Sunnyvale, CA 94086 Phone (408) 524-9684 Fax (408) 524-9689 10
3526.2002.1.0.62

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