Data Sheet
27633b
3235
2
3
4
GROUND
1
OUTPUT2
V CC
Each device includes a Hall voltage generator, two Schmitt
triggers, a voltage regulator, output transistors, and on-board reverse
polarity protection. The regulator enables these devices to operate
from voltages ranging between 4.5 V and 24 V. On-chip compensation
circuitry stabilizes the switch points over temperature.
OUTPUT1
Type UGN3235K Hall-effect sensor ICs are bipolar integrated circuits
designed for commutation of brushless dc motors, and other rotary
encoding applications using multi-pole ring magnets. The device
features two outputs which are independently activated by magnetic
fields of opposite polarity.
SUPPLY
X
DUAL-OUTPUT
HALL-EFFECT SWITCH
T
C
U
D
O
R
y
l
P On
Each open-collector output is independently operated by the
proper amount and polarity of incident magnetic flux. Output 1 responds only to the positive flux from the south pole of a magnet,
Output 2 to the negative flux from the north pole of a magnet. When
the IC experiences the field of a south magnetic pole greater than
the maximum operate point of Output 1, that output switches to the
LOW state and Output 2 is unaffected. When the incident flux falls
below the minimum release point for Output 1, that output returns to
the HIGH state and Output 2 remains unchanged.
D
e
E
c
U
n
e
N er
I
T
f
e
N
R
O
r
C
o
F
S
I
D
Dwg. PH-007
Pinning is shown viewed from branded side.
Output 2 independently responds in the same manner to the
negative flux from the north magnetic pole of a magnet. Figure 1
shows a zone in the region of 0 G, tH, where both outputs are in the
HIGH or OFF state. This constitutes a delay that is independent of
rate of change of the incident magnetic field and ensures that both
outputs are never ON simultaneously. This is an essential feature for
driving brushless dc motors with a minimum of reactive transient
currents.
The UGN3235K is supplied in a four-pin plastic single in-line
package (SIP).
ABSOLUTE MAXIMUM RATINGS
at TA = +25°C
Power Supply, VCC . . . . . . . . . . . . . . . . 25 V
Reverse Battery Voltage, VRCC . . . . . -30 V
Magnetic Flux Density, B . . . . . . Unlimited
Output OFF Voltage, VOUT . . . . . . . . . . 25 V
Output ON Current, IOUT . . . . . . . . . . 50 mA
Operating Temperature Range,
TA . . . . . . . . . . . . . . . . -20°C to + 85°C
Storage Temperature Range
TS . . . . . . . . . . . . . . . . -65°C to +150°C
FEATURES
■ Reliable and Rugged Magnetic Sensing Switch
■ Two Outputs Independently Switched by North and South Poles
■ Independent Actuation of Outputs Minimizes Inductive-Load
Reactive Transient
■ Built-in Hysteresis Minimizes Interference from Stray Fields
■ Operates from 4.5 V to 24 V
■ Outputs Compatible with All Logic Levels
■ On-Board Reverse Polarity Protection
■ Open-Collector, Active-Low Outputs
Always order by complete part number: UGN3235K .
3235
DUAL-OUTPUT
HALL-EFFECT SWITCH
FUNCTIONAL BLOCK DIAGRAM
1
VCC
2
OUTPUT
1
3
OUTPUT 2
4
GROUND
REG.
X
Dwg. FH-003A
ELECTRICAL CHARACTERISTICS at TA = +25°C (unless otherwise noted).
Characteristic
Symbol
Supply Voltage
VCC
Output Saturation Voltage
Test Conditions
Min.
Typ.
Max.
Units
4.5
—
24
V
VOUT(SAT)
VCC = 24 V, IOUT = 20 mA
—
160
400
mV
Output Leakage Current
IOFF
VOUT = 24 V, VCC = 24 V
—
—
1.0
µA
Supply Current
ICC
VCC = 24 V, Output Open
—
6.0
8.0
mA
Output Rise Time
tr
VCC = 14 V, RL = 820 Ω, CL = 20 pF
—
0.04
0.4
µs
Output Fall Time
tf
VCC = 14 V, RL = 820 Ω, CL = 20 pF
—
0.18
0.4
µs
MAGNETIC CHARACTERISTICS at VCC = 4.5 V to 24 V
Characteristic
Operate Point, BOP
Release Point, BRP
Hysteresis, Bhys
Test Conditions
Output
Min.
Max.
Units
TA = +25°C
Q1
Q2
50
-175
175
-50
G
G
TA = -20°C to +85°C
Q1
Q2
35
-200
200
-35
G
G
TA = +25°C
Q1
Q2
25
-160
160
-25
G
G
TA = -20°C to +85°C
Q1
Q2
15
-190
190
-15
G
G
TA = +25°C
Q1 & Q2
15
100
G
TA = -20°C to +85°C
Q1 & Q2
15
110
G
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1989, 2003 Allegro MicroSystems, Inc.
3235
DUAL-OUTPUT
HALL-EFFECT SWITCH
SWITCH POINTS vs. TEMPERATURE
TRANSFER CHARACTERISTICS
150
BOPS
V OUT(OFF)
25 V
MAX
BRPS
50
0
BRPN
-50
B OP1
B OP2
OUTPUT VOLTAGE
SWITCH POINT IN GAUSS
100
BOPN
-100
BRP1
BRP2
VOUT(SAT)
0
-150
-50
-25
0
50
25
75
100
125
AMBIENT TEMPERATURE IN °C
150
0
-B
+B
MAGNETIC FLUX
Dwg. GH-027-1
Dwg. GH-043A
APPLICATIONS
+B (SOUTH)
B OP1
MAGNETIC FLUX
Figure 1 illustrates a method of sensing the presence
of either a north or south magnetic pole. Because the
UGN3235K is an open-collector device, it is possible to
directly connect (wired OR) the two outputs. This causes
the output to go LOW when either a north pole or south
pole of sufficient magnitude is sensed. The device
connected in this manner suits many applications, ranging
from doubling the resolution of a ring-magnet encoder, to
zero-crossing detection.
B RP2
OUTPUTS
Q1
20 mA
1
B OP2
ON
DEAD
TIME
OFF
DEAD
TIME
ON
Q2
OFF
ON
OFF
2
VCC
0
–B (NORTH)
VCC
4.5 V to 24 V
X
BRP1
4
3
Dwg. WH-009-1
SIGNAL
OUTPUT
Figure 2
Zero-crossing detection
Dwg. EH-010
Figure 1
Omnipolar detector
Figure 2 shows that there is a “dead time” approximately centered around 0 G. Thus, by sensing the HIGH
portion of the UGN3235K wired-OR output, the zerocrossing can be detected.
Figure 3 shows that the UGN3235K makes it possible
to implement a very efficient brushless dc motor control
using a minimum number of components. Referring again
to Figure 1, the dead time (where both drivers are OFF)
allows the motor coil field to decay sufficiently. This
avoids both excessive reactive voltages and the magnetic
drag resulting from the motor coils working in opposition
to each other.
3235
DUAL-OUTPUT
HALL-EFFECT SWITCH
VCC
5 V to 24 V
2N4356
1 kΩ
1 kΩ
4
3
2N4356
2
X
1
VCC
0.1 µF
Dwg. EH-009
Figure 3
Motor driver
GUIDE TO INSTALLATION
ELEMENT LOCATION
ACTIVE AREA DEPTH
0.0165"
0.42 mm
NOM
0.106"
2.70 mm
0.058"
1.47 mm
A
BRANDED
SURFACE
TEMPERATURE IN °C
280
260
240
220
200
1
2
3
4
Dwg. MH-001-1C
0
5
10
TIME IN SECONDS
15
20
Dwg. GA-001
All Hall-effect integrated circuits are susceptible to mechanical stress effects. Caution
should be exercised to minimize the application of stress to the leads or the epoxy
package. Use of epoxy glue is recommended. Other types may deform the epoxy
package.
To prevent permanent damage to the Hall cell, heat-sink the leads during hand
soldering. Recommended maximum conditions for wave soldering are shown in the
graph above.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
3235
DUAL-OUTPUT
HALL-EFFECT SWITCH
Dimensions in Inches
(controlling dimensions)
Dimensions in Millimeters
(for reference only)
5.28
5.16
0.208
0.203
0.063
0.059
45°
1.60
1.50
45°
3.51
3.38
0.138
0.133
45°
45°
0.085
1
2
3
0.033
4
2.16
1
2
3
0.84
4
MAX
MAX
0.0173
0.0138
0.600
0.560
0.44
0.35
15.24
14.23
SEE NOTE
SEE NOTE
0.0189
0.0142
0.48
0.36
0.050
BSC
1.27
BSC
Dwg. MH-009D mm
Dwg. MH-009D in
Surface-Mount Lead Form (Suffix -TL)
2.41
0.095
±0.13
±0.005
0.004
MAX
0.002
0.051
MAX
MAX
0°–8°
0.10
0.020
MIN
FLAT
MAX
Dwg. MH-015 in
0°–8°
0.51
MIN
FLAT
Dwg. MH-015 mm
NOTES: 1. Tolerances on package height and width represent allowable mold offsets. Dimensions given are measured at the widest point (parting
line).
2. Exact body and lead configuration at vendor’s option within limits shown.
3. Height does not include mold gate flash.
4. Recommended minimum PWB hole diameter to clear transition area is 0.035” (0.89 mm).
5. Where no tolerance is specified, dimension is nominal.
6. Supplied in bulk pack (500 pieces per bag).
3235
DUAL-OUTPUT
HALL-EFFECT SWITCH
The products described herein are manufactured under one or
more of the following U.S. patents: 5,045,920; 5,264,783; 5,442,283;
5,389,889; 5,581,179; 5,517,112; 5,619,137; 5,621,319; 5,650,719;
5,686,894; 5,694,038; 5,729,130; 5,917,320; and other patents
pending.
Allegro MicroSystems, Inc. reserves the right to make, from time to
time, such departures from the detail specifications as may be
required to permit improvements in the performance, reliability, or
manufacturability of its products. Before placing an order, the user is
cautioned to verify that the information being relied upon is current.
Allegro products are not authorized for use as critical components
in life-support appliances, devices, or systems without express written
approval.
The information included herein is believed to be accurate and
reliable. However, Allegro MicroSystems, Inc. assumes no responsibility for its use; nor for any infringements of patents or other rights of
third parties that may result from its use.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000