Low US4881
CMOS Voltage High Sensitivity Latch Preliminary Datasheet
Features and Benefits
Chopper stabilized amplifier stage Optimized for BDC motor applications New miniature package / thin, high reliability package Operation down to 2.2V CMOS for optimum stability, quality, and cost Low IDD current
Applications
Solid state switch Brushless DC motor commutation Speed sensing
Ordering Information
Part No. US4881 US4881
Temperature Suffix Package Temperature Range E SO or UA -40 to 85oC Extended L SO or UA -40 to 150oC Automotive Contact factory or sales representative for legacy temperature code options
ry a in im l re P
Functional Diagram
Description
The US4881 is a bipolar Hall effect sensor IC fabricated from mixed signal CMOS technology. It incorporates advanced chopper stabilization techniques to provide accurate and stable magnetic switch points. There are many applications for this HED in addition to those listed above. The design specifications and performance have been optimized for commutation applications in brushless DC motors and automotive speed sensing. The output transistor will be latched on (BOP) in the presence of a sufficiently s trong South pole magnetic field facing the marked side of the package. Similarly, the output will be latched off (BRP) in the presence of a North field.
SO Package Pin 1 - VD D Pin 2 - Output Pin 3 - GND
V DD
Output
Voltage Regulator
Chopper
GND UA Package Pin 1 - V D D Pin 2 - GND Pin 3 - Output
The SOT-23 device is reversed from the UA package. The SOT-23 output transistor will be latched on (BOP) in the presence of a sufficiently strong North pole magnetic field subjected to the marked face.
Note: Static sensitive device; please observe ESD precautions. Re verse VDD protection is not included. For reverse voltage protec tion, a 100 resistor in series with VDD is recommended. US4881 CMOS Low Voltage High Sensitivity Latch 3901004881 Rev 1.5 24/July/01 Page 1
US4881
CMOS Low Voltage High Sensitivity Latch
US4881 Electrical Specifications
DC operating parameters: TA = 25oC, VDD = 12VDC (unless otherwise specified). Parameter Supply Voltage Supply Current Saturation Voltage Output Leakage Output Rise Time Output Fall Time Symbol Test Conditions VDD Operating IDD VDS(on) IOFF tr tf B<BOP IOUT = 20 mA, B>BOP B<BRP, VOUT = 18V VDD = 12V, RL = 1.1K, CL = 20pf VDD = 12V, RL = 1.1K, CL = 20pf Min 2.2 1.5 Typ 2.5 0.4 0.01 0.04 0.18 Max 18 4.0 0.5 5.0 Units V mA V A s s
US4881 Magnetic Specifications
DC operating parameters: TA = 25oC, VDD =12 VDC (unless otherwise specified). Parameter Operating Point Release Point Hysteresis Symbol Test Conditions BOP BRP Bhys Min 0.5 -4.5 2.0 Typ 2.0 -2.0 4.0 Max 4.5 -0.5 6.5 Units mT mT mT
Note: 1 mT = 10 Gauss.
Absolute Maximum Ratings
Supply Voltage (Operating), VDD Supply Current (Fault), IDD Output Voltage, VOUT Output Current (Fault), IOUT Power Dissipation, PD Operating Temperature Range, T A Storage Temperature Range, T S Maximum Junction Temp, TJ ESD Sensitivity (All Pins) 18V 50mA 18V 50mA 100mW -40 to 150C -65 to 150C 175C +/- 4KV
Melexis Inc. reserves the right to make changes without further notice to any products herein to improve reliability, function o r design. Melexis does not assume any liability arising from the use of any product or application of any product or circuit described herein.
US4881 CMOS Low Voltage High Sensitivity Latch
3901004881 Rev 1.5
24/July/01
Page 2
US4881
CMOS Low Voltage High Sensitivity Latch Preliminary Datasheet
Performance Graphs
Typical Magnetic Switch Points versus Supply Voltage
12.5
Typical Magnetic Switch Points versus Temperature
12 B HYS
4881
4881
7.5 BOP
7.5
Flux Density (mT)
Flux Density (mT)
B OP 2.5
2.5
-2.5
-2.5
B RP -7.5 -7.5
BRP
-12.5 0 5 10 15 20 25 30
-12.5 -40 0 40 80 120
o
160
200
Supply Voltage (V)
Temperature ( C)
Min/Max Magnetic Switch Range versus Temperature
12.5
Output Voltage versus Flux Density
4881
30
4881
7.5 B OP Max
24
Flux Density (mT)
Output Voltage (V)
V DD 18
2.5
B OP Min
B OP 12
-2.5
B RP Max
-7.5
BRP Min
6 B RP V out
-12.5 -40 0 40 80 120 160 200
0 -30 -20 -10 0 10 20 30
Temperature ( oC)
Flux Density (mT)
US4881 CMOS Low Voltage High Sensitivity Latch
3901004881 Rev 1.5
24/July/01
Page 3
US4881
CMOS Voltage Low High Sensitivity Latch
Performance Graphs
Typical Supply Current versus Supply Voltage
5
Typical Saturation Voltage versus Temperature VDD = 12 V, I OUT = 20mA
4881
500
4881
4
400 VDS(ON)
Supply Current (mA)
TA = -40 C 3 TA = 25oC 2 TA = 125oC
o
VDS(ON) (mV)
20 25 30
300
200
1
100
0 0 5 10 15
0 -40 0 40 80 120
o
160
200
Supply Voltage (V)
Temperature ( C)
Power Dissipation versus Temperature
500
Wave Soldering Parameters
All Devices All Devices
280
Package Power Dissipation (mW)
400
260
300
Solder Temperature (oC)
200
UA Package R JA =206oC/W
240
200
220
100 SO Package RJA =575oC/W 0 -40 0 40 80 120 160
200
0
5
10
15
20
25
30
Temperature ( oC)
Time in Wave Solder (Seconds)
US4881 CMOS Low Voltage High Sensitivity Latch
3901004881 Rev 1.5
24/July/01
Page 4
US4881
CMOS Low Voltage High Sensitivity Latch Preliminary Datasheet
Unique Features
CMOS Hall IC Technology
The chopper stabilized amplifier uses switched capacitor techniques to eliminate the amplifier offset voltage, which, in bipolar devices, is a major source of temperature sensitive drift. CMOS makes this advanced technique possible. The CMOS chip is also much smaller than a bipolar chip, allowing very sophisticated circuitry to be placed in less space. The small chip size also contributes to lower physical stress and less power consumption.
Application Comments
If reverse supply protection is desired, use a resistor in series with the VDD pin. The resistor will limit the Supply Current(Fault), IDD, to 50 mA. For severe EMC conditions, use the application circuit below.
Installation Comments
Consider temperature coefficients of Hall IC and magnetics, as well as air gap and life time variations. Observe temperature limits during wave soldering.
Applications Examples
Automotive and Severe Environment Protection Circuit
R1 100 VDD D1 Z1 C1 4.7n F
Two Wire Optional Current Biasing Circuit V
RL IDD Iout
DD
IIN
RL 1.2 K OUT C2 4.7n F
Supply Voltage
Hall IC
VSS
Rb
Hall IC
The resistors R b and R L can be used to bias the input current, Iin. Refer to the part specification for limiting values. This circuit will help in getting the precise ON and OFF currents desired. B RP = Ioff = (V DD / Rb + I DD ) B OP = Ion = (Ioff + VDD / R L )
US4881 CMOS Low Voltage High Sensitivity Latch
3901004881 Rev 1.5
24/July/01
Page 5
US4881
CMOS Low Voltage High Sensitivity Latch
Physical Characteristics
1.60 1.40 4.30 3.90 2.64 2.34 45o Typical
UA Package Dimensions
5o Typical
UA Hall Plate / Chip Location
2.13 1.87 0....