A3212LLHLT

A3212 MICROPOWER, ULTRA-SENSITIVE HALL-EFFECT SWITCH The A3212 integrated circuit is an ultra-sensitive, pole independent Hall-effect switch with a latched digital output. This sensor is especially suited for operation in battery-operated, hand-held equipment such as cellular and cordless telephones, pagers, and palmtop computers. A 2.5 volt to 3.5 volt operation and a unique clocking scheme reduce the average operating power requirements to less than 15 µW with a 2.75 volt supply. Unlike other Hall-effect switches, either a north or south pole of sufficient strength will turn the output on; in the absence of a magnetic field, the output is off. The polarity independence and minimal power requirement allow these devices to easily replace reed switches for superior reliability and ease of manufacturing, while eliminating the requirement for signal conditioning. Improved stability is made possible through chopper stabilization (dynamic offset cancellation), which reduces the residual offset voltage normally caused by device overmolding, temperature dependencies, and thermal stress. This device includes on a single silicon chip a Hall-voltage generator, small-signal amplifier, chopper stabilization, a latch, and a MOSFET output. Advanced BiCMOS processing is used to take advantage of low-voltage and low-power requirements, component matching, very low input-offset errors, and small component geometries. Four package styles provide magnetically optimized solutions for most applications. Miniature low-profile surface-mount package types EH and EL (0.75 and 0.50 mm nominal height) are leadless, LH is a leaded low-profile SMD, and UA is a three-lead SIP for through-hole mounting. Each package is available in a lead (Pb) free version (suffix, –T) with 100% matte tin plated leadframe. EL package for limited release, engineering samples available. FEATURES ■ ■ ■ ■ Micropower Operation Operation with North or South Pole 2.5 V to 3.5 V Battery Operation Chopper Stabilized Superior Temperature Stability Extremely Low Switch-Point Drift Insensitive to Physical Stress ESD Protected to 5 kV Solid-State Reliability Small Size Easily Manufacturable with Magnet Pole Independence Data Sheet 27622.61G 2 x 2 mm MLPD Package A3212EELLT-T Approximate actual size ABSOLUTE MAXIMUM RATINGS Supply Voltage, VDD .............................. 5 V Magnetic Flux Density, B .......... Unlimited Output Off Voltage, VOUT ...................... 5 V Output Current, IOUT ........................... 1 mA Junction Temperature, TJ ................ +170°C Operating Temperature, TA Range 'E-' .................... -40°C to +85°C Range 'L-' .................. -40°C to +150°C Storage Temperature Range, TS .............................. -65°C to +170°C Caution: These CMOS devices have input static protection (Class 3) but are still susceptible to damage if exposed to extremely high static electrical charges. ■ ■ ■ ■ A3212 MICROPOWER, ULTRA-SENSITIVE HALL-EFFECT SWITCH Product Selection Guide Use complete part numbers when ordering Part Number A3212EEHLT A3212EEHLT–T A3212EELLT–T A3212ELHLT A3212ELHLT–T A3212EUA A3212EUA–T A3212LLHLT A3212LLHLT–T A3212LUA A3212LUA–T Pb-free – Yes Yes – Yes – Yes – Yes – Yes Packing* (Units/Pack) Tape and Reel (3000) Tape and Reel (3000) Tape and Reel (2000) Tape and Reel (3000) Tape and Reel (3000) Bulk Pack (500) Bulk Pack (500) Tape and Reel (3000) Tape and Reel (3000) Bulk Pack (500) Bulk Pack (500) 3-Pin Surface Mount SIP-3 Through Hole, Straight Lead 3-Pin Surface Mount –40 to 150 SIP-3 Through Hole, Straight Lead –40 to 85 Leadless Surface Mount Package Ambient Temperature TA (°C) *Contact Allegro for additional packaging and handling options. FUNCTIONAL BLOCK DIAGRAM SUPPLY SWITCH TIMING LOGIC DYNAMIC OFFSET CANCELLATION OUTPUT SAMPLE & HOLD LATCH X GROUND Dwg. FH-020-5 2 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 3212 MICROPOWER, ULTRA-SENSITIVE HALL-EFFECT SWITCH Package Suffix ‘EH’ Pinning (Leadless Chip Carrier) NO CONNECTION Dwg. PH-016-2 Package Suffix ‘EL’ Pinning (Leadless Chip Carrier) GROUND SUPPLY 6 VDD 5 4 3 X V 1 OUTPUT DD 2 NO CONNECTION 3 GROUND 1 2 GROUND Dwg. PH-016-1 Package Suffix ‘LH’ Pinning (SOT23W) Package Suffix ‘UA’ Pinning (SIP) 3 X V DD V DD 1 2 1 2 3 GROUND OUTPUT SUPPLY GROUND Dwg. PH-016-1 Dwg. PH-016 Pinning is shown viewed from branded side. www.allegromicro.com Copyright © 2002, 2003 Allegro MicroSystems, Inc. OUTPUT SUPPLY OUTPUT SUPPLY 3 A3212 MICROPOWER, ULTRA-SENSITIVE HALL-EFFECT SWITCH ELECTRICAL CHARACTERISTICS over operating voltage and temperature range (unless otherwise specified). Limits Characteristic Supply Voltage Range Output Leakage Current Output On Voltage Awake Time Period Duty Cycle Chopping Frequency Supply Current Symbol VDD IOFF VOUT tawake tperiod d.c. fC IDD(EN) IDD(DIS) IDD(AVG) Chip awake (enabled) Chip asleep (disabled) VDD = 2.75 V VDD = 3.5 V Test Conditions Operating1 VOUT = 3.5 V, BRPN < B < BRPS IOUT = 1 mA, VDD = 2.75 V Min. 2.5 – – – – – – – – – – Typ. 2.75