A3175 and A3177
Hall Effect Latches
Discontinued Product
These parts are no longer in production The device should not be
purchased for new design applications. Samples are no longer available.
Date of status change: October 31, 2005
Recommended Substitutions:
For new customers and applications:
• for the A3175, refer to the
A1211
• for the A3177, refer to the
A1210
NOTE: For detailed information on purchasing options, contact your
local Allegro field applications engineer or sales representative.
Allegro MicroSystems, Inc. reserves the right to make, from time to time, revisions to the anticipated product life cycle plan for a
product to accommodate changes in production capabilities, alternative product availabilities, or market demand. 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 which may result from its use.
3175
AND
3177
HALL-EFFECT LATCHES
These Hall-effect latches are temperature-stable and stress-resistant
sensor ICs especially suited for electronic commutation in brushless dc
motors using multipole ring magnets. Each device includes a voltage
regulator, quadratic Hall voltage generator, temperature compensation
circuit, signal amplifier, Schmitt trigger, and an open-collector output on
a single silicon chip. The on-board regulator permits operation with
supply voltages of 4.5 volts to 18 volts. The switch output can sink
10 mA. With suitable output pull up, they can be used directly with
bipolar or MOS logic circuits.
The three package styles available provide a magnetically optimized
package for most applications. Suffix ‘LT’ is a surface-mount SOT89/
TO-243AA package; suffixe ‘UA’ features wire leads for through-hole
mounting.
Data Sheet
27609.4d
V
X
CC
1
2
3
GROUND
OUTPUT
SUPPLY
FEATURES
■
Symmetrical Response
■
4.5 V to 18 V Operation
■
Open-Collector Output
■
Reverse Battery Protection
■
Activate With Small, Commercially Available Permanent Magnets
■
Solid-State Reliability
■
Small Size
■
Superior Temperature Stability
■
Resistant to Physical Stress
Dwg. PH-003A
Pinning is shown viewed from branded side.
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, V
CC
. . . . . . . . . . . . .
18 V
Reverse Battery Voltage, V
RCC
. . . .
-18 V
Magnetic Flux Density, B . . . .
Unlimited
Output OFF Voltage, V
OUT
. . . . . . . .
18 V
Continuous Output Current, I
OUT
.
15 mA
Operating Temperature Range,
T
A
. . . . . . . . . . . . . . .
-20
°
C to +85
°
C
Storage Temperature Range,
T
S
. . . . . . . . . . . . . . .
-65
°
C to +150
°
C
Always order by complete part number, e.g.,
UGN3175LT
.
See Magnetic Characteristics table for differences between devices.
3175
AND
3177
HALL-EFFECT
LATCHES
FUNCTIONAL BLOCK DIAGRAM
1
V
CC
REG.
X
3
OUTPUT
GROUND
2
Dwg. FH-005-2
ELECTRICAL CHARACTERISTICS at T
A
= +25
°
C, V
CC
= 4.5 V to 18 V (unless otherwise noted).
Limits
Characteristic
Supply Voltage
Output Saturation Voltage
Output Leakage Current
Supply Current
Output Rise Time
Output Fall Time
Symbol
V
CC
V
OUT(SAT)
I
OFF
I
CC
t
r
t
f
Test Conditions
Operating
V
CC
= 18 V, I
OUT
= 10 mA, B > B
OP
V
OUT
= 18 V, B < B
RP
V
CC
= 4.5 V, B < B
RP
(Output OFF)
V
CC
= 12 V, R
L
= 1.1 kΩ, C
L
= 20 pF
V
CC
= 12 V, R
L
= 1.1 kΩ, C
L
= 20 pF
Min.
4.5
—
—
—
—
—
Typ.
—
200
0.05
5.0
0.04
0.18
Max.
18
300
5.0
10
2.0
2.0
Units
V
mV
µA
mA
µs
µs
MAGNETIC CHARACTERISTICS in gauss; V
CC
= 4.5 V to 18 V.
Characteristic
Operate Point, B
OP
Part
Number*
UGN3175
UGN3177
Release Point, B
RP
UGN3175
UGN3177
Hysteresis, B
hys
UGN3175
UGN3177
T
A
= +25
°
C
Min.
25
50
-170
-150
100
100
Typ.
—
—
—
—
200
200
Max.
170
150
-25
-50
—
—
Min.
15
25
-180
-150
80
50
T
A
= -20
°
C to +85
°
C
Typ.
—
—
—
—
180
180
Max.
180
150
-15
-25
—
—
NOTE: As used here, negative flux densities are defined as less than zero (algebraic convention).
Complete part number includes a suffix denoting package type (LT or UA).
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1991, 2002 Allegro MicroSystems, Inc.
3175
AND
3177
HALL-EFFECT
LATCHES
ELEMENT LOCATIONS
Suffix “LT”
ACTIVE AREA DEPTH
0.0305"
0.775 mm
NOM
0.090"
2.30 mm
0.045"
1.15 mm
SWITCH POINT IN GAUSS
(±0.005” [0.13mm] die placement)
TYPICAL OPERATING CHARACTERISTICS
200
100
OPERATE POINT
0
V
CC
= 14 V
A
1
2
3
-100
RELEASE POINT
-200
Dwg. MH-008-1C
-30
-10
10
30
50
70
90
AMBIENT TEMPERATURE IN
°
C
Suffix “UA”
ACTIVE AREA DEPTH
0.0195"
0.50 mm
NOM
0.083"
2.12 mm
Dwg. GH-020
A
BRANDED
SURFACE
1
2
3
0.055"
1.39 mm
Dwg. MH-011C
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 responsi-
bility for its use; nor for any infringements of patents or other rights of
third parties that may result from its use.
www.allegromicro.com
3175
AND
3177
HALL-EFFECT
LATCHES
PACKAGE DESIGNATOR ‘LT’
(SOT89/TO-243AA)
Dimensions in Inches
(for reference only)
Dimensions in Millimeters
(controlling dimensions)
0.181
0.173
0.072
0.064
0.167
0.155
0.102
0.090
0.063
0.055
0.0173
0.0138
4.60
4.40
1.83
1.62
4.25
3.94
2.60
2.29
1.60
1.40
0.44
0.35
1
2
3
0.090
0.084
1
2
3
2.29
2.13
0.047
0.035
0.059
BSC
0.0189
0.0142
0.0221
0.0173
0.118
BSC
Dwg. MA-009-3A in
1.20
0.89
1.50
BSC
0.48
0.36
0.56
0.44
3.00
BSC
Dwg. MA-009-3A mm
0.098
0.079
B
A
0.031
0.102
0.181
3 0.047
0.031
TYP
2.5
2.0
B
A
0.8
2.6
4.6
1.2
0.8
TYP
1
0.028
TYP
2
1
0.7
TYP
2
3
Pads 1, 2, 3, and A — Standard SOT89 Layout
Pads 1, 2, 3, and B — Low-Stress Version
Pads 1, 2, and 3 only — Lowest Stress, But Not Self Aligning
Dwg. MA-012-3 in
Pads 1, 2, 3, and A — Standard SOT89 Layout
Pads 1, 2, 3, and B — Low-Stress Version
Pads 1, 2, and 3 only — Lowest Stress, But Not Self Aligning
Dwg. MA-012-3 mm
NOTES: 1. Exact body and lead configuration at vendor’s option within limits shown.
2. Supplied in bulk pack (500 pieces per bag) or add "TR" to part number for tape and reel.
3. Only low-temperature (≤240°C) reflow-soldering techniques are recommended for SOT89 devices.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000