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Details, datasheet, quote on part number:3195
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| Part: | 3195 |
| Category: | Sensors => Hall Effect Sensors |
| Description: | Protected, High-temperature, Effect Latch With Active Pull-down |
| Company: | Allegro Micro Systems, Inc. |
| Datasheet: | Download 3195 datasheet File size : 128 kB |
| Request For quote: | Find where to buy 3195
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Datasheet text preview:
3195
PROTECTED, HIGH-TEMPERATURE, HALL-EFFECT LATCH WITH ACTIVE PULL-DOWN
These Hall-effect latches are capable of sensing magnetic fields while using an unprotected power supply. The A3195 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. A 25 mA high-side driver combined with an active pull-down is especially useful for driving capacitive loads. Output short-circuit protection allows for 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. Each monolithic device contains an integrated Hall-effect transducer, a temperature-compensated comparator, a voltage regulator, and a buffered high-side driver with an active pull-down. Supply protection is made possible by the integration of overvoltage shutdown circuitry that monitors supply fault conditions. Output protection circuitry includes source and sink current current limiting for short circuits to supply or ground. The A3195E is rated for operation over a temperature range of -40°C to +85°C; the A3195L is rated for operation over an extended temperature range of -40°C to +150°C. They are supplied in a threelead SIP (suffix U) or a surface-mount SOT89 (suffix LT).
Data Sheet 27609.15
X
LATCH
VCC 1
2
3
GROUND
Dwg. PH-013
Pinning is shown viewed from branded side.
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, VCC (100 ms) .......... 115 V* (continuous) .. 26 V Reverse Battery Voltage, VRCC (100 ms) .... -100 V (continuous) ......... -30 V Magnetic Flux Density, B .. Unlimited Reverse Output Voltage, V OUT ......... -0.5 V Continuous Output Current, IOUT .......... -25 mA Package Power Dissipation, PD ....... See Graph Junction Temperature, T J ........ 170°C Operating Temperature Range, T A Suffix "E" ........... -40°C to +85°C Suffix "L" ......... -40°C to +150°C Storage Temperature, T S ........ 170°C
*Fault condition, internal overvoltage shutdown above 28 V. Internal current limiting is intended to protect the device from output short circuits.
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., A3195LU .
3195 PROTECTED, HIGH-TEMP., ACTIVE PULL-DOWN HALL-EFFECT LATCH
FUNCTIONAL BLOCK DIAGRAM
1 VCC
OVERVOLT. LOCKOUT REG.
LATCH
X
3
OUTPUT
CURRENT LIMIT
Dwg. FH-013
15k
2 GROUND
TRANSFER CHARACTERISTICS
800
ALLOWABLE PACKAGE POWER DISSIPATION IN MILLIWATTS
700 Suffix "LT" RJA = 180°C/W 600
26 V MAX
VOUT(H)
500
400
300
OUTPUT VOLTAGE IN VOLTS
Suffix "U" RJA = 183°C/W
B RP
B OP
200
Suffix "E"
100 Suffix "L"
VOUT(L)
0
0 20 40 60 80 100 120 140 160 180
-B
0 FLUX DENSITY
+B
Dwg. GH-034-3
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.
3195 PROTECTED, HIGH-TEMP., ACTIVE PULL-DOWN HALL-EFFECT LATCH
ELECTRICAL CHARACTERISTICS over operating voltage and temperature range (unless otherwise specified).
Limits Characteristic Supply Voltage Overvoltage Shutdown* Output Voltage, High (Source Voltage) Output Voltage, Low (Sink Voltage) Output Clamp Voltage Output Current Limit Supply Current Symbol VCC V CC(OV) VOUT(H) V OUT(L) V OUT(CLMP) IO U T M A X I CC Test Conditions Operating (but VCC x ICC VS TA limited) B > BO P B BOP, IOUT BOP, IOUT = 5 mA B 26 V, IOUT = 0 B BOP, VOUT BOP, VCC = 18 V, IOUT = 0 VCC= +115 V* VRCC = -35 V* VRCC = -100 V* CL = 20 pF, RL = 330 CL = 20 pF, RL = 330 "LT" Package "U" Package Min. 3.8 28 VCC -2 -- -- 15 -26 8.0 -- -- -- -- -- -- -- -- -- Typ. 12 -- -- 0.1 0.25 18 -- -- 6.0 8.0 8.0 -0.1 -0.1 0.12 0.30 258 183 Max. 26 55 VCC -0.3 0.2 0.5 21 -70 25 9.0 12 17 -5.0 -10 2.0 5.0 -- -- Units V V V V V V mA mA mA mA mA mA mA µs µs ° C/W ° C/W
Reverse Battery Current* Output Rise Time Output Fall Time Package Thermal Resist.
IR C C tr tf 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 = Maximum TA = -40°C TA = +25°C TA = Maximum TA = -40°C TA = +25°C TA = Maximum Min. 60 50 40 -200 -160 -150 150 130 110 Typ. 125 110 100 -125 -110 -100 250 220 200 Max. 200 160 150 -60 -50 -40 -- -- -- Units G G G G G G G G G
Release Point
BRP
Hysteresis ( BOP - BRP )
B hys
NOTES: Negative current is defined as coming out of (sourcing) the output. 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. 1 gauss (G) is exactly equal to 0.1 millitesla (mT). * Fault condition. Device is shut down and operation is not possible.
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3195 PROTECTED, HIGH-TEMP., ACTIVE PULL-DOWN HALL-EFFECT LATCH
TYPICAL OPERATING CHARACTERISTICS
200
Vcc
OPERATE POINT
Vcc - 1
OUTPUT VOLTAGE IN VOLTS
100
SWITCH POINTS IN GAUSS
OUTPUT HIGH, B B RP (SOURCING CURRENT) I OUT = -20 mA
Vcc - 2 VCC = 16 V 0.4 I OUT = 5 mA
0
VCC = 3.8 V26 V
-100 RELEASE POINT
0.2
OUTPUT LOW, B B OP (SINKING CURRENT) I OUT 100 µA
-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-052-1
AMBIENT TEMPERATURE IN ° C
Dwg. GH-040-2
TYPICAL OPERATING CHARACTERISTICS
Output Current Limit
20
9.0
OUTPUT LOW, B B OP (SINKING CURRENT)
0
8.0
-20
VCC = 16 V
SUPPLY CURRENT IN mA
CURRENT LIMIT IN mA
VCC = 26 V
7.0
VCC = 12 V
-40 OUTPUT HIGH, B B RP (SOURCING CURRENT) -60 -50
6.0
VCC = 3.8 V OUTPUT HIGH, B B OP OUTPUT LOW, B B RP
-25
0
25
50
75
100
125
150
5.0 -50
-25
0
25
50
75
100
125
150
AMBIENT TEMPERATURE IN ° C
Dwg. GH-004-1
AMBIENT TEMPERATURE IN °C
Dwg. GH-028-2
4
115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
3195 PROTECTED, HIGH-TEMP., ACTIVE PULL-DOWN HALL-EFFECT LATCH
3.8 V TO 26 V WITH TRANSIENTS VCC
1
C BYPASS
X
3
TO µP CL RL
2
Dwg. EH-007
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 (page 2). 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
An external 0.1 µF to 0.47 µF capacitor, with good high-frequency characteristics, should be connected between terminals 1 and 2 to bypass high-voltage noise and reduce EMI susceptibility. Internal Pull-Down Resistor. An internal pull-down resistor (nominal 15 k) is provided to allow testing of the device without the need for an external load.
20
18
PULL-DOWN RESISTANCE IN k
16
14
12
10 -50
-25
0
25
50
75
100
125
150
AMBIENT TEMPERATURE IN ° C
Dwg. GH-060
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