Diodes AH921 User Manual

HIGH SENSITIVITY CMOS HALL-EFFECT LATCH AH921

Data Sheet

General Description

The AH921 is a Hall-effect latch designed in mixed signal CMOS technology. It is quite suitable for use in automotive, industrial and consumer applications.

Superior high-temperature performance is made possible through dynamic offset cancellation, which reduces the residual offset voltage normally caused by device over-molding, temperature dependencies, and thermal stress. The device integrates a voltage regulator, Hall-voltage generator, small-signal amplifier, chopper stabilization, schmitt trigger, and is directly drivable by the output.

An on-board regulator permits operation with supply voltage from 3.5V to 24V.

The AH921 is available in TO-92S-3 and SOT-2 3-3 packages, which are optimized for most applications.

TO-92S-3 SOT-23-3

Features

• Wide Operating Voltage Range from 3.5 to 24V

• Symmetrical Switch Points

• Chopper-stabilized Amplifier Stage

• Superior Temperature Stability

• Compact Size

• Built-in Pull-up Resistor

• ESD Rating: 3500V (Human Body Model)

Applications

• Brushless DC Motor Commutation

• Brushless DC Fan

• Solid-state Switch

• Revolution Counting

• Speed Detection

• High Sensitivity and Unconnected Switch

Figure 1. Package Types of AH92 1

Jul. 2011 Rev. 1. 2 BCD Semiconductor Manufacturing Limited

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Data Sheet

HIGH SENSITIVITY CMOS HALL-EFFECT LATCH AH921

Pin Configuration

Z3 Package N Package

(TO-92S-3) (SOT-23-3)

3

2

1

(Front View) (Top View)

Figure 2. Pin Configuration of AH921

Pin Description

Pin Number

TO-92S-3 SOT-23-3

1 1 VCC Supply voltage

Pin Name Function

21

2 3 GND Ground pin 3 2 OUT Output pin

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Data Sheet

HIGH SENSITIVITY CMOS HALL-EFFECT LATCH AH921

Functional Block Diagram

A (B) A for TO-92S-3 B for SOT-23-3

Hall Sense

VCC

1 (1)

Reference Voltage

Chopper

Switch

2 (3)

AMP

100k

GND

Figure 3. Functional Block Diagram of AH921

OUT

3 (2)

Ordering Information

AH921 -

Circuit Type

Package Z3: TO-92S-3 N: SOT-23-3

G1: Green

TR: Tape & Reel Blank: Bulk

Package

TO-92S-3 AH921Z3-G1 921 Bulk SOT-23-3

Temperature

Range

-40 to 125°C

Part Number Marking ID Packing Type

AH921NTR-G1 GS6 Tape & Reel

BCD Semiconductor's Pb-free products, as designated with "G1" suffix in the part number, are RoHS compliant and green.

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Data Sheet

HIGH SENSITIVITY CMOS HALL-EFFECT LATCH AH921

Absolute Maximum Ratings (Note 1)

Parameter Symbol Value Unit

Supply Voltage VCC 28 V Supply Current (Fault) ICC 5 mA Output current (Continuous) I

Power Dissipation

Operating T em perature TA -50 to 150 Storage Temperature T Maximum Junction Temperature TJ (Max) 165 ESD (Human Body Model) ESD 3500 V

25 mA

OUT

P

D

-65 to 150

STG

TO-92S-3 400 SOT-23-3

230

mW

ºC ºC ºC

Note 1: Stresses greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “Recommended Operating Conditions” is not implied. Exposure to “Absolute Maximum Ratings” for extended periods may affect device reliability.

Recommended Operating Conditions

Parameter Symbol Min Max Unit

Supply Voltage V Operating Temperature TA -40 125 ºC

CC

3.5 24 V

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Data Sheet

HIGH SENSITIVITY CMOS HALL-EFFECT LATCH AH921

Electrical Characteristics

V

=12V, TA=25°C, unless otherwise specified.

CC

Parameter Symbol Conditions Min Typ Max Unit

Supply Voltage VCC Operating 3.5 12 24 V

Supply Current ICC

VCC=12V, B<BRP 3.0 5.0 mA V

=12V, B>BOP 3.0 5.0 mA

CC

Saturation Voltage V Output Leakage Current I Output Rising Time t Output Falling Time t

I

SAT

LEAKAGE

FALLING

VCC=V

CL=20pF 0.4 2

RISING

CL=20pF 0.4 2

=20mA, B>BOP 185 500 mV

OUT

=24V, B<BRP 0.1 10

OUT

μA

μs μs

Magnetic Characteristics

V

=12V, TA=25°C, unless otherwise specified.

CC

Parameter Symbol Min Typ Max Unit

Operating Point BOP 5 22 40 Gauss Releasing Point BRP -40 -22 -5 Gauss Hysteresis B

45 Gauss

HYS

Figure 4. Magnetic Flux Density of AH921

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