Honeywell SS351AT, SS451A User Manual

DESCRIPTION

FEATURES

POTENTIAL APPLICATIONS

The SS351AT and SS451A sensors are small, versatile digital Hall-effect devices that are operated by the magnetic field from a permanent magnet or an electromagnet. They are designed to respond to a either a North pole or a South pole.

These omnipolar sensors are sensitive and flexible devices designed to meet a wide range of potential applications. The SS351AT and SS451A have a typical operating point of 85 G at 25 °C [77 °F]. Because they can be operated by a North pole or a South pole, they do not require the magnet polarity to be identified, thus making the installation easier and potentially reducing the system cost.

These sensors are available in two package styles. The SS351AT is available in the subminiature SOT-23 surface mount package; the SS451A is available in the leaded, flat TO92-style package. The SS351AT’s small size requires less PC board space, allowing it to be used in smaller assemblies. Its 3 Vdc capability allows for use in low voltage applications, promoting energy efficiency.

The SS351AT is available on tape and reel (3000 units per reel); the SS451A is available in a bulk package (1000 units per bag).

Subminiature package size (SS351AT) supplied on tape

and reel allows for a compact design with automated component placement, helping to reduce manufacturing costs

Simple activation from a North pole or a South pole and

sensitive magnetics make this omnipolar product suitable in a variety of potential motion control, lid closure detection, and displacement sensing applications

Low voltage 3 Vdc capability helps reduce power

consumption

Built-in reverse polarity protection protects the device from

potential damage during installation

Thermally balanced integrated circuit provides for stable

operation over a wide temperature range of -40° to 150 °C [-40 °F to 302 °F]

RoHS-compliant materials meet Directive 2002/95/EC

Commercial:

Speed and RPM (revolutions per minute) sensing in

fitness equipment Magnetic encoder for building access Damper or valve position control in HVAC (heating,

ventilation and air conditioning) equipment Flow rate sensing in appliances and water softeners Printer head position sensing

Industrial:

Flow rate sensing in industrial processes Robotic control (cylinder position monitoring) Float-based fluid level sensing

Medical:

Displacement sensor in hospital beds and medical

equipment Medication bin monitor on portable drug carts

Table 1. SS351AT/SS451A Specifications (At Vs=3.0 Vdc to 24 Vdc, 20 mA load, TA = -40 °C to 150 °C [-40 °F to 257 °F])

Characteristic

Condition

Minimum

Typical

Maximum

Unit

Supply voltage1:

Vdc

SS451A

-40 °C to 150 °C [-40 °F to 302 °F]

3 – 24

SS351AT

-40 °C to 125 °C [-40 °F to 257 °F]

3 – 24

SS351AT

150 °C [302 °F]

3 – 12

Supply current

Vsupply = 5 V at 25 °C [77 °F] Vsupply = 3 V at 25 °C [77 °F]

– – –

4.5

3.5 –

6 5 9 mA

Output Current

–

– – 20.0

Vsat

at 20 mA, gauss > Bop positive

or gauss < Bop negative

– – 0.4

Output leakage current

gauss > Bop+ or < Bop-

– – 10

µA

Output switching time: rise fall

Vsupply = 12 V at 25 °C [77 °F],

RL =1.6 KOhm, CL = 20 pF

– –

1.5

µs

Thermal resistance:

–

°C/W

SS451A

–

233

–

SS351AT

–

303

–

SS351AT/SS451A:

–

gauss

Operate positive

135

Operate negative

-135

-85

-35

SS351AT/SS451A:

–

gauss

Release positive

120

Release negative

-120

-50

-10

SS351AT/SS451A

gauss

Differential

–

Operating temperature

–

-40 [-40]

–

150 [302]

°C [°F]

Storage temperature

–

-40 [-40]

–

150 [302]

°C [°F]

Characteristic

Minimum

Typical

Maximum

Unit

Supply voltage

-28.0

–

28.0

Applied output voltage

-0.5 – 28.0

Output current – –

Magnetic flux – –

no limit

gauss

NOTICE

Absolute maximum ratings are the extreme limits that the device will withstand without damage to the device. However, the electrical and mechanical characteristics are not guaranteed as the maximum limits (above recommended operating conditions) are approached, nor will the device necessarily operate at absolute maximum ratings.

Figure 1. SS351AT Rated Supply Voltage

Figure 2. Current Sinking Output Block Diagram

Note 1: See Figure 1.

Table 2. SS351AT/SS451A Absolute Maximum Ratings1

Note 1: The magnetic field strength (gauss) required to cause the switch to change state (operate and release) will be as specified

in the magnetic characteristics. To test the switch against the specified magnetic characteristics, the switch must be placed in a uniform magnetic field.

2 www.honeywell.com/sensing

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