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Details, datasheet, quote on part number:3197
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| Part: | 3197 |
| Category: | Sensors => Hall Effect Sensors |
| Description: | Protected, High-temperature, Open-collector Hall-effect Latch |
| Company: | Allegro Micro Systems, Inc. |
| Datasheet: | Download 3197 datasheet File size : 167 kB |
| Request For quote: | Find where to buy 3197
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Datasheet text preview:
3197
PROTECTED, HIGH-TEMPERATURE, OPEN-COLLECTOR HALL-EFFECT LATCH
These open-collector Hall-effect latches are capable of sensing magnetic fields while using an unprotected power supply. The A3197LLT and A3197LU can provide position and speed information by providing a digital output for magnetic fields that exceed their predefined switch points. These devices operate down to zero speed and have switch points that are designed to be extremely stable over a wide operating temperature and voltage range. The latching characteristics make them ideal for use in pulse counting applications when used with a multi-pole ring magnet. Thermal and output short-circuit protection allow an increased wiring harness fault tolerance. The temperature compensated switch points, the wide operating voltage range, and the integrated protection make these devices ideal for use in automotive applications such as transmission speed sensors and integrated wheel bearing speed sensors.
3
Data Sheet 27609.10A*
X
PTCT
V
CC
1
2
Dwg. PH-003-2
Each monolithic device contains an integrated Hall-effect transducer, a temperature-compensated comparator, a voltage regulator, and a buffered 35 mA output sink stage. Supply protection is made possible by the integration of overvoltage and undervoltage shutdown circuitry that monitor supply fault conditions and shut down the IC. Noise shutdown circuitry (patent applied for) prevents the propagation of supply transients to the logic load. Output protection circuitry includes a current limit loop that limits the maximum output sink current, and thermal protection circuitry that shuts down the device during an over-heating condition such as with a shorted load. The A3197LLT and A3197LU are rated for operation over an extended temperature range of -40°C to +150°C. They are supplied in a three-lead SIP (suffix `U') or a surface-mount SOT-89 (suffix `LT').
GROUND
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, VCC (100 ms) .. 115 V* (continuous) ....... 28 V* Reverse Battery Voltage, VRCC (100 ms) .. -100 V (continuous) ....... -35 V Magnetic Flux Density, B .......... Unlimited Output OFF Voltage, VOUT ........ 26 V Reverse Output Voltage VOUT ......... -0.5 V Continuous Output Current, IOUT ......... 35 mA* Reverse Output Current, IOUT ....... -100 mA Package Power Dissipation, PD ...... See Graph Junction Temperature, TJ ........ 170°C Operating Temperature Range, TA ......... -40°C to +150°C Storage Temperature, TS ......... 170°C
*Fault condition, internal overvoltage shutdown above 28 V; output current limited above 35 mA.
OUTPUT
SUPPLY
FEATURES
s s s s s s s s s s Internal Protection For Automotive (ISO/DIN) Transients Operation From Unregulated Supply Reverse Battery Protection Undervoltage Lockout Supply Noise-Suppression Circuitry Output Short-Circuit Protection Output Zener Clamp Thermal Protection Symmetrical Latching Switch Points Operable with Multipole Ring Magnets
Always order by complete part number, e.g., A3197LU .
3197 PROTECTED, HIGH-TEMP., OPEN-COLLECTOR HALL-EFFECT LATCH
FUNCTIONAL BLOCK DIAGRAM
1 VCC
OVERVOLT. LOCKOUT REG.
POWER UP & TRANSIENT PROTECTION
3
OUTPUT
CONTROL
X
THERMAL SHUTDOWN CURRENT LIMIT <1
2 GROUND
Dwg. FH-012A
800
ALLOWABLE PACKAGE POWER DISSIPATION IN MILLIWATTS
700 Suffix "LT" RJA = 180°C/W 600 Suffix "U" RJA = 183°C/W 500
400
300
200
Suffix "E"
NOTE Permitted duty cycle will be less than 100% at maximum ambient temperature with high supply voltages, i.e., TA 140°C, VCC 12 V, and the "LT" package. The thermal shutdown circuitry does not protect the device from these stresses (see Internal Protective Features).
Suffix "L"
100
0
20
40
60
80
100
120
140
160
180
AMBIENT TEMPERATURE IN °C
Dwg. GH-054B
2
115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 Copyright © 1995, 2002 Allegro MicroSystems, Inc.
3197 PROTECTED, HIGH-TEMP., OPEN-COLLECTOR HALL-EFFECT LATCH
ELECTRICAL CHARACTERISTICS over operating voltage and temperature range (unless otherwise specified).
Limits Characteristic Supply Voltage Overvoltage Shutdown* Undervoltage Shutdown* Output Voltage, On Output Leakage Current Output Clamp Voltage Output Current Limit Supply Current Symbol V CC VC C ( O V ) VC C ( U V ) V OUT(SAT) IO F F VO U T ( C L M P ) IO U T M A X IC C Test Conditions Operating (but VCC x ICC vs TA limited) B > BOP B > BOP B > BOP, IOUT = 30 mA, VCC = 16 V VOUT = 26 V B BOP, VOUT = 12 V B BOP, VCC = 24 V, IOUT = 20 mA VCC = +115 V* VRCC = -35 V* VRCC = -100 V* CL = 20 pF, RL = 330 , VBB = 12 V CL = 20 pF, RL = 330 , VBB = 12 V Min. VC C ( U V ) 28 3.7 -- -- 28 35 -- -- -- -- -- -- -- 165 "LT" Package "U" Package -- -- Typ. 12 -- -- 0.2 -- 32 50 5.2 7.8 8.0 -0.5 -2.0 0.05 0.30 -- 258 183 Max. 26 55 4.5 0.5 5.0 40 70 9.0 12 17 -5.0 -10 2.0 5.0 190 -- -- Units V V V V µA V mA mA mA mA mA mA µs µs °C °C/W °C/W
Reverse Battery Current* Output Rise Time Output Fall Time Thermal Shutdown Temp.* Package Thermal Resist.
IR C C tr tf TJ RJA
MAGNETIC CHARACTERISTICS over operating voltage range (unless otherwise specified).
Limits Characteristic Operate Point Symbol BOP Test Conditions TA = -40°C TA = +25°C TA = +150°C TA = -40°C TA = +25°C TA = +150°C TA = -40°C TA = +25°C TA = +150°C Min. 60 50 40 -200 -160 -150 150 130 110 Typ. 130 110 105 -140 -120 -100 270 230 205 Max. 200 160 150 -60 -50 -40 -- -- -- Units G G G G G G G G G
Release Point
BR P
Hysteresis ( BOP - BRP )
Bhys
NOTES: BOP = magnetic operate point (output turns ON); BRP = magnetic release point (output turns OFF). As used here, negative flux densities are defined as less than zero (algebraic convention). Typical values are at TA = +25°C and VCC = 12 V (unless otherwise specified). * Fault condition. Device is shut down and operation is not possible.
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3197 PROTECTED, HIGH-TEMP., OPEN-COLLECTOR HALL-EFFECT LATCH
TYPICAL OPERATING CHARACTERISTICS
Switch Points
200
Output Saturation Voltage
500
OPERATE POINT
400
SATURATION VOLTAGE IN mV
VCC = 12 V
B BOP
100
SWITCH POINTS IN GAUSS
300
0
VCC = 5 V24 V
200
IOUT = 30 mA
-100 RELEASE POINT
100 I OUT = 5 mA
-200 -50
-25
0
25
50
75
100
125
150
0 -50
-25
0
25
50
75
100
125
150
AMBIENT TEMPERATURE IN ° C
Dwg. GH-052-2
AMBIENT TEMPERATURE IN °C
Dwg. GH-040-3
Supply Current
8.0 B BOP
SUPPLY CURRENT IN mA
VCC = 24 V
7.0
VCC = 5 V
6.0
VCC = 24 V 5.0 BBP R VCC = 5 V 4.0 -50 -25 0 25 50 75 100 125 150
AMBIENT TEMPERATURE IN °C
Dwg. GH-028-3
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115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
3197 PROTECTED, HIGH-TEMP., OPEN-COLLECTOR HALL-EFFECT LATCH
OPERATION
In operation, the output transistor is OFF until the strength of the magnetic field perpendicular to the surface of the chip exceeds the threshold or operate point (BOP). When the field strength exceeds BOP, the output transistor switches ON (a logic low) and is capable of sinking 35 mA of current. The output transistor switches OFF (a logic high) when magnetic field reversal results in a magnetic flux density below the OFF threshold (BRP). This is illustrated in the transfer characteristics graph. Note that the device latches; that is, a south pole of sufficient strength will turn the device ON. Removal of the south pole will leave the device ON. The presence of a north pole of sufficient strength is required to turn the device OFF. The switch points increase in sensitivity with increasing temperature to compensate for the typical ferrite magnet temperature characteristic. The simplest form of magnet that will operate these devices is a ring magnet. Other methods of operation are possible.
TEST CIRCUIT AND TYPICAL APPLICATION
VCC(UV) TO 26 V WITH TRANSIENTS VCC
1
REGULATED < 26 V VBB
RL
3
TO µP
CBYPASS
X
CL
2
Dwg. EH-006A
26 V MAX
VBB
OUTPUT VOLTAGE IN VOLTS
B RP
B OP
VOUT(SAT)
0 -B 0 FLUX DENSITY +B
Dwg. GH-034-2A
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