3195

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

The A3195 latch has been optimized for use in automotive ring magnet sensing applications.  Such applications include transmission speed sensors, motor position encoders, and wheel bearing speed sensors. Special care has been taken to optimize the operation of these devices in automotive subsystems that require ISO DP9637 protection but NOT operation.  Short-circuit protection is included to prevent damage caused by pinched wiring harnesses.  An on-chip pull-down resistor is provided to allow device testing without the connection of the control module.

A typical application consists of a ferrite ring magnet located on a rotating shaft.  Typically, this shaft is at-tached to the transmission, the sensor is mounted on a board, with care being taken to keep a tight tolerance on the air gap between the package face and the magnet. The device will provide a change in digital state at the transition of every magnetic pole and, thus, give an indication of the transmission speed.  The high magnetic hysteresis allows the device to be immune to vibration of the magnet shaft and relatively good duty cycles can be
obtained.

Hall effect applications information is also available in the Allegro Integrated and Discrete Semiconductors Data Book or Application Note 27701.

Supply Voltage, V_CC (100 ms).......... ......... 115 V*
       (continuous).......................................... 26 V
Reverse Battery Voltage,
       V_RCC  (100 ms)..................................  -100 V
       (continuous)........................................  -30 V
Magnetic Flux Density, B.......................  Unlimited
Reverse Output Voltage, V_OUT .................  -0.5 V
Continuous Output Current,
       I_OUT...................................Internally Limited
Package Power Dissipation,
       P_D................................................ See Graph
Junction Temperature, TJ ........................ 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