US651661 Preliminary Datasheet old 692 DownloadLink 5258

US651 / US661
Two-Coil Low Noise Fan Driver
Features and Benefits
Soft Switching for low noise applications
Slope control setting by dedicated pin
One-chip solution (Hall + Drivers)
Advanced Protection (enhanced locked rotor,
reverse voltage, thermal, output clamping)
Integrated tachometer (US651) or
alarm (US661) signal output
Application Examples
5V/12V DC brushless motors
Continuous output current up to 350mA
Low noise brushless cooling fans
PC, server, laptop cooling fan
Power supply cooling fan
Large and small fan size
Ordering Information
Part No.
US651
US661
Temperature Code
E (-40°C to 85°C)
E (-40°C to 85°C)
1 Functional Diagram
Package Code
DC (8-pin narrow SOIC8)
DC (8-pin narrow SOIC8)
2 General Description
The US651/661 is a one-chip solution for driving
two-coil brushless DC fan and motors. It is
especially suitable for relatively high-current rated
operation as it can drive up to 350mA continuous
output current.
The use of Melexis Soft Switching concept lowers
the acoustic and electrical motor noise and
provides smoother operation. This efficient
solution is combined with an innovative slope
control design controllable via a dedicated pin.
The device includes reverse voltage protection,
locked rotor protection and thermal protection.
Therefore, the IC robustness perfectly suits for
consumer and automotive-on-board applications.
Tachometer (FG) or Alarm (RD) open-drain output
is available. It makes the connectivity with external
interface such as hardware monitoring or Super
I/O IC easier.
The device is delivered in RoHS compliant DC
package (SMD) for automatic soldering
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Preliminary Datasheet
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US651 / US661
Two-Coil Low Noise Fan Driver
Table of Contents
1 Functional Diagram ........................................................................................................ 1
2 General Description........................................................................................................ 1
3 Glossary of Terms .......................................................................................................... 3
4 Absolute maximum ratings ............................................................................................ 3
5 Pin definitions and descriptions.................................................................................... 3
6 General Electrical Specifications .................................................................................. 4
7 Magnetic Specifications ................................................................................................. 4
8 Output Behaviour vs Magnetic Pole.............................................................................. 5
9 Detailed General Description ......................................................................................... 5
10 Unique Features............................................................................................................ 6
10.1 Soft Switching & Slope setting.................................................................................................................6
10.2 Enhanced Locked Rotor Protection.........................................................................................................7
11 Performance Graphs .................................................................................................... 7
11.1 RDSON vs TJ ...............................................................................................................................................7
11.2 RDSON vs VDD ............................................................................................................................................7
11.3 IDD vs TJ....................................................................................................................................................7
11.4 IDD vs VDD .................................................................................................................................................7
11.5 Internal Slope Duration vs VDD ................................................................................................................8
11.6 Slope Duration vs VDD..............................................................................................................................8
11.7 VOL vs. TJ .................................................................................................................................................8
11.8 ILEAK vs. TJ ................................................................................................................................................8
11.9 IFGLIM vs. VDD ............................................................................................................................................8
11.10 PDmax vs. TA ............................................................................................................................................8
12 Application Information................................................................................................ 9
13 Application Comments ................................................................................................. 9
14 Standard information regarding manufacturability of Melexis products with
different soldering processes......................................................................................... 10
15 ESD Precautions ......................................................................................................... 10
16 DC Package Information (8-pin narrow SOIC) .......................................................... 11
17 Disclaimer.................................................................................................................... 12
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US651 / US661
Two-Coil Low Noise Fan Driver
3 Glossary of Terms
Two-coil fan
MilliTesla (mT), Gauss
Peak output current
Continuous output current
Locked rotor
FG
RD
A fan with two-coil windings where current alternates from 1 coil to the other
depending on the direction of the magnetic field.
Units of magnetic flux density :
1mT = 10 Gauss
The current flowing in the coil at start-up, only limited by the coil resistance
RCOIL and the output driver resistance RDSON.
Average absolute value of the output current when the fan is spinning.
The state when the fan stopped spinning due to mechanical blockage.
Frequency generator or tachometer output
Rotation detection or alarm output
4 Absolute maximum ratings
Parameter
Symbol
Supply Voltage
VDD
FG / RD voltage
VFG (VRD)
Voltage on pin SLOPE
VSLOPE
Peak output current
IOUTp
Continuous output current
IOUTc
Operating Temperature Range
TA
Junction temperature
TJ
Storage Temperature Range
TS
Magnetic flux density
B
Table 1: Absolute maximum ratings
Value
-12 to 18
-7 to 18
-0.5 to 18
700
350
-40 to 85
125
-55 to 150
Unlimited
Units
V
V
V
mA
mA
°C
°C
°C
mT
Exceeding the absolute maximum ratings may cause permanent damage. Exposure to absolute-maximumrated conditions for extended periods may affect device reliability.
5 Pin definitions and descriptions
Pin Name Function
FG (RD)
Tachometer (Alarm) open-drain output
VDD
Power Supply pin
SLOPE
Slope Control pin
OUT1
Open Drain Coil Driver 1
GND
Ground pin
OUT2
Open Drain Coil Driver 2
NC
Not connected
NC
Not connected
Table 2: Pin definitions and descriptions
Pin number (DC)
1
2
3
4
5
6
7
8
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Two-Coil Low Noise Fan Driver
6 General Electrical Specifications
o
DC Operating Parameters TJ = 25 C, VDD = 12V (unless otherwise specified)
Parameter.
Supply Voltage
Supply Current
OUT1, OUT2 ON Resistance
OUT1, OUT2 Clamp Voltage
FG / RD Output Low Voltage
FG / RD Output Clamp Voltage
FG / RD Output Leakage Current
FG / RD Output Current Limit
Symbol
VDD
IDD
RDSON 1,2
VOUT 1,2
VOL
VCLMP
ILEAK
IFGLIM
Test Conditions
Operating
Min
3
Typ
12
3
3
Max
18
5
5
0.35
0.5
Output Switching Slope Duration (1)
TSW
VDD = 12V,
pin SLOPE left open
40
70
160
µs
Output Switching Slope Duration (1)
TSW
VDD = 12V,
RSLOPE =100k
87
120
189
µs
Output Switching Slope Duration (1)
TSW
VDD = 5V,
pin SLOPE left open
73
126
250
µs
Output Switching Slope Duration (1)
TSW
Locked Rotor Period
Locked Rotor Period
Locked Rotor Period
36
IOL = 4mA
18
VFG (VRD) = 5V
VFG (VRD) = 12V
10
20
Units
V
mA
Ω
V
V
V
µA
mA
87
120
189
µs
TON
TOFF
TON
VDD = 5V,
RSLOPE =100k
VDD = 12V
VDD = 12V
VDD = 5V
0.24
1.44
0.48
0.29
1.5
0.6
0.39
2.34
0.89
s
s
s
Locked Rotor Period
TOFF
VDD = 5V
2.88
3.65
5.34
s
Thermal Protection Shutdown
TSD
Note 2
160
oC
Thermal Protection Release
TREL
Note 2
130
oC
Single layer PCB
150
oC/Watt
DC Package Thermal Resistance
RTH
Table 3: Electrical specifications
Note 1: Measured with active load connected to the output, from 10% to 90% of the VDD voltage.
Note 2: Guarantied by design
7 Magnetic Specifications
o
DC Operating Parameters TJ = 25 C, VDD = 12V (unless otherwise specified)
Parameter.
Symbol
Test Conditions
Operate point
BOP
Release point
BRP
Hysteresis
BHYST
Table 4: Magnetic specifications
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Min
-6
2
Typ
3
-3
6
Max
6
Units
mT
mT
mT
Preliminary Datasheet
Mar/07
US651 / US661
Two-Coil Low Noise Fan Driver
8 Output Behaviour vs Magnetic Pole
Parameter
Test Conditions
North pole
B < Brp
South pole
B > Bop
Table 5: Driver output vs magnetic pole
OUT1
Low
High
OUT2
High
Low
FG
Low
High
Note : The magnetic pole is applied facing the branded side of the package
9 Detailed General Description
The US651/661 is a one-chip solution for driving two-coil brushless DC fans. Based on CMOS process, the
chip contains a Hall-effect sensor with dynamic offset correction, logic control and two low-ohmic open-drain
output drivers.
The output drivers OUT1 and OUT2 are fully protected against switching transients. So there is no need of
external zener diode to cut the high voltage spikes induced by the fan coils.
In case the junction temperature TJ exceeds TSD, the thermal protection stops the current flowing through the
full bridge by setting the outputs OUT1 and OUT2 low and setting the output FG (RD) high.
The IC stays in this state until the junction temperature decreases below TREL.
Reverse voltage protection is integrated on the VDD pin.
The FG/RD open drain output has an internal current limit which protects the driver in case of accidentally big
current flow through the logic driver. It could occur if a low-ohmic pull-up resistor is used or if the FG/RD
output is directly short connected to a supply voltage.
The US651 has an open-drain tachometer FG output that follows the Hall signal, thus enabling to determine
the rotation speed of the fan.
In the US661, the open-drain alarm output RD is a safety signal which allows detecting if the fan rotates or
not. It is active low during normal spinning of the motor. It goes high when the magnetic flux switching
frequency drops below nearly:
- 2Hz for 12V application (60RPM for 2 pole-pair fan)
- 1Hz for 5V application (30RPM for 2 pole-pair fan)
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US651 / US661
Two-Coil Low Noise Fan Driver
10 Unique Features
10.1 Soft Switching & Slope setting
The US651/661 provides an efficient solution for low noise application with internal slope control circuit,
controllable via a dedicated pin.
In Two-coil fan driver, the predominant source of electrical noise is when the output driver is switched off.
Due to the electromotive force of the fan coil, the output voltage sharply increases but is internally clamped
by the fan driver. This effect lasts until the energy in the coil is dissipated, then the output voltages decreases
to a normal value, equal to the sum of the fan supply voltage plus the back EMF of the fan in rotation.
The resulting swift change in the coil current increases the overall acoustic noise.
(a) – General view
(b) – Enlarged view on output switching
Figure 1 – Output voltage without slope control (RSLOPE = 0оhm)
In the above Fig.1a is observed the US651/661 output voltage with traditional driving technique, also referred
as “hard switching”. In this case, the output driver is directly switched on and off which results in large voltage
spikes, clamped at the output clamping voltage value (Fig.1b).
(a) – General view
(b) – Enlarged view on output switching
Figure 2 – Output voltage with internal slope control (RSLOPE not connected, SLOPE pin left open)
When the SLOPE pin is left open (not connected), the US651/661 provides internally defined output slope
duration. In contrast with the “hard switching”, the “soft switching” technique controls the output voltage at the
switching event and a rise/fall time is implemented to the driving signal. On Fig.2b, the output clamping
voltage is even not reached, result of a smoother recirculation of the fan coil current.
(a) – General view
(b) – Enlarged view on output switching
Figure 3 – Output voltage with long output slope duration (RSLOPE = 500k)
When a simple resistor is connected between the SLOPE pin the ground, the US651/661 modifies the output
slope duration in relation with the value of the resistor RSLOPE. The output slope duration can be increased so
that the output voltages spikes from Fig.1 are totally removed on Fig.3.
For most of the application, the internal soft switching mode from the Fig.2 represents the simplest solution
and most adequate balance between low fan acoustic noise and IC power dissipation.
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US651 / US661
Two-Coil Low Noise Fan Driver
It is also possible to run into the 3 different modes as “hard switching”, “internal soft switching” and “external
soft switching”, giving the possibility to adapt the fan design to stringent requirements. For example, high
speed fan generally requires longer output slope compared to usual middle or low speed fan.
Increasing the output slope duration inevitably leads to high power dissipation of the IC itself. However, the
device is well protected against over power dissipation thanks to the integrated thermal shutdown.
10.2 Enhanced Locked Rotor Protection
Specially designed for driving large fans, the Locked Rotor Protection is optimised for low start-up voltage.
At low voltage, fans inevitably starts rotating slower than at higher voltage. Big fans with large inertia have
slow start-up causing a longer first output pulse after power-on. If this pulse duration is longer than the LRP
TON period, the fan may falsely enter locked rotor condition.
The US651/661 provides an adequate and simple solution to prevent this by automatically increasing the
locked rotor protection period at low voltage. The device internally compares the supply voltage applied on
the VDD and automatically double the LRP periods at 5V (0.6s, 3.65s) compared than 12V (0.29s, 1.5s).
This facilitates driving heavier fans and motors with large inertia without any external component (TON/TOFF is
increased or decreased depending on the fan supply voltage VDD).
11 Performance Graphs
11.2 RDSON vs VDD
11.1 RDSON vs TJ
10
10
VDD = 5V
9
VDD = 12V
Tj = -40°C
8
8
7
7
6
6
Ron (ohms)
Ron (ohms)
9
5
4
Tj = 25°C
Tj = 85°C
Tj = 125°C
5
4
3
3
2
2
1
1
0
0
-40
-20
0
20
40
60
80
100
120
3
4
5
6
7
8
9
Tj (°C)
11.3 IDD vs TJ
11
12
13
14
15
16
17
18
11.4 IDD vs VDD
5
5
4
4
3
3
IDD (mA)
IDD (mA)
10
VDD (Volts)
2
Tj = -40°C
2
Tj = 25°C
Tj = 85°C
VDD = 5V
1
Tj = 125°C
1
VDD = 12V
0
0
-40
-20
0
20
40
60
80
100
120
3
Tj (°C)
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4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
VDD (Volts)
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Two-Coil Low Noise Fan Driver
11.5 Internal Slope Duration vs VDD
11.6 Slope Duration vs VDD
200
1200
180
1100
R = 700k
R = 500k
R = 300k
R = 100k
R = 50k
1000
160
900
Output Slope (us)
Output Slope (us)
140
Tj = 25°C
120
100
80
60
800
700
600
500
400
300
40
200
20
100
0
0
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
3
4
5
6
7
8
9
VDD (Volts)
10
11
12
13
14
15
16
17
18
VDD (Volts)
11.8 ILEAK vs. TJ
11.7 VOL vs. TJ
0.5
100
Tj = -40°C
80
Tj = 25°C
0.3
Leakage Current (uA)
FG/RD Output Saturation Voltage (V)
90
0.4
VDD=5V ; Iol=4mA
VDD=12V ; Iol=4mA
0.2
70
Tj = 125°C
60
50
40
30
20
0.1
10
0
0
-40
-20
0
20
40
60
80
100
3
120
4
5
6
7
8
9
10
11.9 IFGLIM vs. VDD
12
13
14
15
16
17
18
11.10 PDmax vs. TA
50
0.8
45
Single Layer PCB
Pmax = 666mW
0.7
35
Allowable Power Dissipation (W)
40
Current limit (mA)
11
VDD (Volts)
Tj (°C)
Tj = 25°C
Tj = 125°C
30
25
20
15
TA = 25°C
0.6
RTH 1S = 150°C/W
0.5
0.4
TA max = 85°C
0.3
0.2
10
0.1
5
0
TJ max = 125°C
0
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
-40
VDD (Volts)
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0
20
40
60
80
100
120
140
Ta (°C)
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Two-Coil Low Noise Fan Driver
12 Application Information
Typical computer fan application circuit
13 Application Comments
During fan rotation, the coils may affect the stability of the VDD voltage. To filter eventual spikes, it is
recommended to add a 100nF decoupling capacitor between VDD pin and GND, closer to the chip.
If the FG/RD pull-up resistor is connected to VDD, a diode should be connected between the fan supply
voltage and the common point of the fan coils to avoid parasitic effects on FG/RD output.
The voltage VDD and VPU can be physically the same voltage source. However, the pull-up voltage VPU is
generally connected to a different digital power source at 5V as it feeds the FG or RD signal to an IC
interface.
When the default slope is sufficient, the pin SLOPE may just be left open.
For slope adjustment, it is required to connect a resistor RSLOPE between the SLOPE pin to ground. The value
of the resistor modifies the output slope as shown in the performance graph.
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Two-Coil Low Noise Fan Driver
14 Standard information regarding manufacturability of Melexis
products with different soldering processes
Our products are classified and qualified regarding soldering technology, solderability and moisture sensitivity
level according to following test methods:
Reflow Soldering SMD’s (Surface Mount Devices)
•
•
IPC/JEDEC J-STD-020
Moisture/Reflow Sensitivity Classification for Nonhermetic Solid State Surface Mount Devices
(classification reflow profiles according to table 5-2)
EIA/JEDEC JESD22-A113
Preconditioning of Nonhermetic Surface Mount Devices Prior to Reliability Testing
(reflow profiles according to table 2)
Wave Soldering SMD’s (Surface Mount Devices) and THD’s (Through Hole Devices)
•
•
EN60749-20
Resistance of plastic- encapsulated SMD’s to combined effect of moisture and soldering heat
EIA/JEDEC JESD22-B106 and EN60749-15
Resistance to soldering temperature for through-hole mounted devices
Iron Soldering THD’s (Through Hole Devices)
•
EN60749-15
Resistance to soldering temperature for through-hole mounted devices
Solderability SMD’s (Surface Mount Devices) and THD’s (Through Hole Devices)
•
EIA/JEDEC JESD22-B102 and EN60749-21
Solderability
For all soldering technologies deviating from above mentioned standard conditions (regarding peak
temperature, temperature gradient, temperature profile etc) additional classification and qualification tests
have to be agreed upon with Melexis.
The application of Wave Soldering for SMD’s is allowed only after consulting Melexis regarding assurance of
adhesive strength between device and board.
Melexis is contributing to global environmental conservation by promoting lead free solutions. For more
information on qualifications of RoHS compliant products (RoHS = European directive on the Restriction Of
the use of certain Hazardous Substances) please visit the quality page on our website:
http://www.melexis.com/quality.aspx
15 ESD Precautions
Electronic semiconductor products are sensitive to Electro Static Discharge (ESD).
Always observe Electro Static Discharge control procedures whenever handling semiconductor products.
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Two-Coil Low Noise Fan Driver
16 DC Package Information (8-pin narrow SOIC)
8
7
6
5
3.81
3.99
5.80
6.20
Notes:
1. Controlling dimensions in millimeters
2. Detail of pin #1 identifier are optional but must be located
within the zone indicated.
3. Lead coplanarity should be to 0.10mm max.
0.41
1.27
1
2
3
4. All dimensions excluding mold flashes and end flash from
the package body shall not exceed 0.25mm per side.
4
DETAIL A
Pin 1 Mark
see note 2
Marking:
4.80
4.98
1.52
1.72
1.37
1.57
h x 45°
0.36
0.46
1.27 BSC
Line 1 :
US651 (US661) - Name of the Device
Line 2 :
XXXXXX - Assembly lot number (6 digits)
Line 3 :
YYWW - Assembly date
YY = year
WW = calendar week
0.19
0.25
Seating Plane
See DETAIL A
0.63
Hall plate location
Notes:
1. All dimensions are in millimeters
0.023
2. Hall plate location in X and Y relative to package center
3. Assembly tolerances +/-0.1
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17 Disclaimer
Devices sold by Melexis are covered by the warranty and patent indemnification provisions appearing in its
Term of Sale. Melexis makes no warranty, express, statutory, implied, or by description regarding the
information set forth herein or regarding the freedom of the described devices from patent infringement.
Melexis reserves the right to change specifications and prices at any time and without notice. Therefore, prior
to designing this product into a system, it is necessary to check with Melexis for current information. This
product is intended for use in normal commercial applications. Applications requiring extended temperature
range, unusual environmental requirements, or high reliability applications, such as military, medical lifesupport or life-sustaining equipment are specifically not recommended without additional processing by
Melexis for each application.
The information furnished by Melexis is believed to be correct and accurate. However, Melexis shall not be
liable to recipient or any third party for any damages, including but not limited to personal injury, property
damage, loss of profits, loss of use, interrupt of business or indirect, special incidental or consequential
damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical
data herein. No obligation or liability to recipient or any third party shall arise or flow out of Melexis’ rendering
of technical or other services.
© 2002 Melexis NV. All rights reserved.
For the latest version of this document, go to our website at
www.melexis.com
Or for additional information contact Melexis Direct:
Europe and Japan:
Phone: +32 1367 0495
E-mail: [email protected]
All other locations:
Phone: +1 603 223 2362
E-mail: [email protected]
ISO/TS 16949 and ISO14001 Certified
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