Hall-Effect Digital Latches

The Hall-effect digital latches will always switch on with a south magnetic of sufficient strength and switch off with a north magnetic field of sufficient strength. The output will not change if the magnetic field is removed. To change the output state, the opposite magnetic field polarity must be applied. Allegro offers a variety of latching Hall-effect switches each with a different operate threshold (Bop) with respect to the south pole of a magnet and an release threshold (Brp) with the opposite value in respect to the north pole of a magnet.

Hall-Effect Digital Latches
Part Number	Operate Point (G)	Release Point (G)	Hysteresis (G)	Temperature Ranges	Packages	Output	Replaces	Comments
A1210	25 to 150	-150 to -25	>50 (typ 180)	E, L	LH, UA	Open Collector	UGN3177
A1211	15 to 180	-180 to -15	>80 (typ 180)	L	UA	Open Collector	UGN3175
A1212	50 to 175	-175 to -50	100 to 350	L	LH, UA	Open Collector	A3187
A1213	80 to 200	-200 to -80	160 to 400	L	LH, UA	Open Collector	A3188, A3189
A1214	140 to 300	-300 to -140	280 to 600	L	LH, UA	Open Collector	A3185
A1220	5 to 40	-40 to -5	Typ 45	E, L	LH, UA	Open Collector	A3280	Supply voltage 3 to 24 V, Chopper-Stabilized
A1221	15 to 90	-90 to -15	Typ 100	E, L	LH, UA	Open Collector	A3281	Supply voltage 3 to 24 V, Chopper-Stabilized
A1222	70 to 150	-150 to -70	Typ 220	E, L	LH, UA	Open Collector		Supply voltage 3 to 24 V, Chopper-Stabilized
A1223	100 to 180	-180 to -100	Typ 300	E, L	LH, UA	Open Collector		Supply voltage 3 to 24 V, Chopper-Stabilized
A1225	140 to 300	-300 to -140	340 to 540	L	LT, UA	Open Collector		Supply voltage 3 to 24 V, Chopper-Stabilized
A1227	50 to 175	-175 to -50	100 to 350	L	LT, UA	Open Collector		Supply voltage 3 to 24 V, Chopper-Stabilized
A1229	80 to 200	-80 to -200	160 to 400	L	LT, UA	Open Collector		Supply voltage 3 to 24 V, Chopper-Stabilized
A1242	5 to 80	-80 to -5	40 to 110	E, L	LH, UA	Current Source		Two-wire operation
A3290	5 to 50	-50 to -5	10 to 100	K	LH, UA	Open Collector		Chopper-stabilized
A3291	10 to 100	-100 to -10	20 to 100	K	LH, UH	Open Collector		Chopper-stabilized
Temperature range codes: S = -20°C to 85°C, E = -40°C to 85°C, K = -40°C to 125°C, L = -40°C to 150°C

Application Note: Latching Switch Hall-Effect IC Basics