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A1172 Micropower Ultra-Sensitive Hall-Effect Switch
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Features and Benefits
▪ Micropower operation ▪ Operation with either north or south pole— no magnetic orientation required during assembly ▪ 1.65 to 3.5 V battery operation ▪ Chopper stabilization ▫ Superior temperature stability ▫ Extremely low switchpoint drift ▫ Insensitive to physical stress ▪ Solid state reliability ▪ Small size: WLCSP (≈ 1 mm × 1 mm × 0.5 mm) ▪ Complementary, push-pull outputs eliminate need for pull-up resistor
Description
The A1172 is an ultra-sensitive, pole-independent Hall-effect switch with a latched digital output. It features operation at low supply currents and voltages, making it ideal for batteryoperated electronics. The 1.65 to 3.5 V operating supply voltage and unique clocking algorithm reduce the average operating power requirements to less than 15 μW with a 2.75 V supply. The A1172 has two push-pull output structures. Omnipolar activation for the output function is available on each output structure. As such, either a north or south pole of sufficient strength turns the available outputs off or on. The A1172 contains two complementary outputs. Therefore, for a fixed magnetic field, one output will be in a high voltage state and one output will be in a low voltage state. Improved stability is made possible through dynamic offset cancellation using chopper stabilization, which reduces the residual offset voltage normally caused by device overmolding, temperature dependencies, and thermal stress. This device
Package: 4 pin WLCSP (suffix CG)
Not to scale
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Engineering samples available on a limited basis. Contact your local sales or applications support office for additional information.
Functional Block Diagram
VDD
Clock / Logic Sample and Hold Dynamic Offset Cancellation Latch Low-Pass Filter
VOUTPS
Amp
Latch
VOUTPN
GND
1172-DS
A1172
Description (continued)
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Micropower Ultra-Sensitive Hall-Effect Switch
includes, on a single silicon chip, a Hall-voltage generator, a smallsignal amplifier, chopper stabilization, a latch, and a MOSFET output. The A1172 device offers magnetically optimized solutions, suitable for most applications. The wafer level chip scale package (WLCSP) is approximately only 1 mm by 1 mm by 0.5 mm. This package is smaller than most plastic packages and reduces the printed circuit board area consumed by micropower Hall-effect switches. Selection Guide
Part Number
A1172ECGLT
Package
Pb-free
Pb-free chip with high-temperature solder balls (RoHS compliant)
Packing*
4000 pieces per reel
4 bumped wafer-level chip-scale package (WLCSP) *Contact Allegro for additional packing options.
Absolute Maximum Ratings
Characteristic Supply Voltage Reverse Supply Voltage Output Off Voltage Reverse Output Voltage Output Current Magnetic Flux Density Operating Ambient Temperature Maximum Junction Temperature Storage Temperature Symbol VDD VRDD VOUTx VROUTx IOUTx(Sink) IOUTx(Sou.