SS49E linear Hall sensor: specs and pinout
A low-cost linear Hall-effect sensor IC in a flat TO-92-style package with an analog, current-sourcing output that follows the magnetic field.
Specs
| Spec | Value | Source |
|---|---|---|
| Supply voltage | 2.7 V to 6.5 V DC | source Table 1 Operating Characteristics, Vs = 5.0 V (p.3) |
| Supply current (at Vs = 5.0 V) | 6 mA typ, 10 mA max at 25 degC | source Table 1 Operating Characteristics, Vs = 5.0 V (p.3) |
| Sensitivity (at Vs = 5.0 V) | 1.0 to 1.75 mV/Gauss, 1.4 typ at 25 degC | source Table 1 Operating Characteristics, Vs = 5.0 V (p.3) |
| Null output at 0 Gauss (at Vs = 5.0 V) | 2.25 V to 2.75 V, 2.50 V typ at 25 degC | source Table 1 Operating Characteristics, Vs = 5.0 V (p.3) |
| Output voltage span (at Vs = 5.0 V) | 1.05 V to (Vs - 1.05) min; 0.95 V to (Vs - 0.95) typ | source Table 1 Operating Characteristics, Vs = 5.0 V (p.3) |
| Magnetic range (at Vs = 5.0 V) | +/-650 Gauss min, +/-1000 Gauss typ | source Table 1 Operating Characteristics, Vs = 5.0 V (p.3) |
| Output current (at Vs = 5.0 V) | 1.5 mA (Vs above 3.0 V) | source Table 1 Operating Characteristics, Vs = 5.0 V (p.3) |
| Response time (at Vs = 5.0 V) | 3 us typ | source Table 1 Operating Characteristics, Vs = 5.0 V (p.3) |
| Operating temperature | -40 degC to 100 degC | source Table 1 Operating Characteristics, Vs = 5.0 V (p.3) |
| Absolute maximum supply | -5.0 V DC to 8.0 V DC | source Table 2 Absolute Maximum Ratings (p.3) |
Power
| Value | Source | |
|---|---|---|
| Supply | 2.7 V to 6.5 V DC | source Table 1 Operating Characteristics, Vs = 5.0 V (p.3) |
| Current | 6 mA typ, 10 mA max at 25 degC | source Table 1 Operating Characteristics, Vs = 5.0 V (p.3) |
Chip pins
These are the pins of the chip on the module, from the chip datasheet. The module's own header may label or expose them differently.
Lead order is from Figure 4 on p.6 of the Honeywell sheet: the leads are marked "+" (Vs), "-" (V-) and "0" (OUTPUT), left to right in the front view drawn there. That is the bare SS49E package; the stocked part can be a different lead form (the sheet also lists SS49E-L and SS49E-F), so check the listing photo before wiring.
| Pin | Function | Voltage | Notes | Source |
|---|---|---|---|---|
| Vs (+) | Supply | 2.7-6.5 V DC | Lead marked "+" in Figure 4 (p.6), left to right in the front view of the drawing | source Figure 4 Mounting Dimensions (continued), p.6; names from the block diagram |
| V- (-) | Ground | Lead marked "-" in Figure 4 (p.6), left to right in the front view of the drawing | source Figure 4 Mounting Dimensions (continued), p.6; names from the block diagram | |
| OUTPUT (O) | Analog output, current sourcing | Null 2.50 V typ at Vs = 5.0 V | Lead marked "0" in Figure 4 (p.6), left to right in the front view of the drawing | source Figure 4 Mounting Dimensions (continued), p.6; names from the block diagram |
Build with it
Project ideas for the SS49E linear Hall sensor. Each link opens Soldr with the prompt filled in; Soldr assigns the pins, checks power and shows how to wire every part.
- Magnet field readout: Powered from the Uno's 5 V, the output sits near 2.5 V with no magnet, which the Uno ADC reads.
- Wheel rotation counter: The sensor has a 3 us response time and a 2.7-6.5 V supply, so 3.3 V from the ESP32 works. The sheet values for null (2.50 V) and sensitivity are at Vs = 5.0 V; at 3.3 V the null moves to about Vs/2 and sensitivity scales with the supply (sheet graph), and the output span is narrower, so calibrate against your own magnet. The output stays below its supply, within the ESP32 ADC range.
- A position sensor that tracks a magnet on a servo arm with an Arduino Uno compatible board, an SS49E and an SG90 servo: The servo needs its own 5 V supply with grounds joined; the sensor output rises and falls with magnet distance.
Common mistakes
- Expecting a switch: the output is analog, near 2.5 V at 0 Gauss with a 5.0 V supply, and moves 1.0-1.75 mV per Gauss (source)
- Putting more than 6.5 V on it: the operating range is 2.7-6.5 V and the absolute maximum is 8.0 V DC (source)
- Loading the output too hard: the output current figure is 1.5 mA, so use a high-impedance input such as an ADC pin (source)
Not covered by the official source
- Vs-dependence of null and sensitivity is only shown in graphs.
- A newer issue (4) of the sheet exists; this page uses the issue 3 copy.
- Which physical face of the package is the front view in Figure 4 is not stated in words; check the Hall element side against the drawing before wiring.
Sources
- link (Honeywell SS39ET/SS49E/SS59ET Series datasheet, issue 3)