ONSEMI LB11961-TLM-H

Ordering number : EN8793B
LB11961
Monolithic Digital IC
Single-Phase Full-Wave
Fan Motor Driver
http://onsemi.com
Overview
The LB11961 is a single-phase bipolar drive motor driver that easily implements direct PWM motor drive systems with
excellent efficiency. The LB11961 is optimal for fan motor drive in personal computer power supply systems and CPU
cooling fan systems.
Features
• Single-phase full-wave drive (16V, 1.0A transistors are built in)
• Built-in variable speed function controlled by a thermistor input
The LB11961 can implement quiet, low-vibration variable speed control using externally clocked high side transistor
direct PWM drive.
• Built-in regenerative diode (Di); only requires a minimal number of external components.
• Built-in HB
• Minimum speed setting pin (allows full-speed mode operation at startup)
• Operates in full-speed mode when the thermistor is removed.
• Built-in lock protection and automatic recovery circuits
• FG (speed detection) and RD (lock detection) outputs
• Built-in thermal shutdown circuit
Semiconductor Components Industries, LLC, 2013
May, 2013
92111 SY 20110915-S00002/31407 TI PC 20070206-S00002 B8-6878 No.8793-1/7
LB11961
Specifications
Absolute Maximum Ratings at Ta = 25°C
Parameter
Symbol
VCC maximum output voltage
VCC max
OUT pin maximum output
IOUT max
Conditions
Ratings
current
OUT pin output voltage
Unit
18
V
1.0
A
VOUT max
18
V
HB maximum output current
IHB max
10
mA
VTH input pin voltage
VTH max
6
V
RD/FG output pin output voltage
VRD/FG max
18
V
RD/FG output current
IRD/FG max
10
mA
Allowable power dissipation
Pd max
When mounted on a circuit board *1
1.1
W
Operating temperature
Topr
-30 to +90
°C
Storage temperature
Tstg
-55 to +150
°C
*1 Specified circuit board : 114.3 × 76.1 × 1.6mm3, glass epoxy.
Caution 1) Absolute maximum ratings represent the value which cannot be exceeded for any length of time.
Caution 2) Even when the device is used within the range of absolute maximum ratings, as a result of continuous usage under high temperature, high current,
high voltage, or drastic temperature change, the reliability of the IC may be degraded. Please contact us for the further details.
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating
Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability.
Recommended Operating Conditions at Ta = 25°C
Parameter
VCC supply voltage
Symbol
Conditions
Ratings
VCC
Unit
4.5 to 16
V
VTH input level voltage range
VTH
0 to 9
V
Hall sensor input common-mode
VICM
0.2 to 3
V
input voltage range
Electrical Characteristics Unless otherwise specified Ta = 25°C, VCC = 12V
Parameter
Symbol
Ratings
Conditions
min
Circuit current
6VREG voltage
HB voltage
ICC1
Drive mode
ICC2
Lock protection mode
V6VREG
VHB
I6VREG = 5mA
IHB = 5mA
typ
Unit
max
12
18
24
mA
8
11
16
mA
5.8
6
6.2
V
1.10
1.25
1.40
V
CPWM high-level voltage
VCRH
3.45
3.6
3.75
V
CPWM low-level voltage
VCRL
1.95
2.05
2.15
V
CPWM oscillator frequency
FPWM
18
25
32
CT pin high-level voltage
VCTH
3.45
3.6
3.75
CT pin low-level voltage
VCTL
1.55
1.7
1.85
V
ICT charge current
ICT1
1.5
2
2.5
μA
ICT discharge current
ICT2
0.15
0.2
0.25
μA
ICT charge/discharge current
RCT
8.5
10
11.5
C = 100pF
kHz
V
ratio
OUT output low saturation
VOL
IO = 200mA
0.2
0.3
V
VOH
IO = 200mA
0.9
1.1
V
Zero peak value (including offset and
10
20
mV
0.2
0.3
V
30
μA
voltage
OUT output high saturation
voltage
Hall sensor input sensitivity
VHN
hysteresis)
RD/FG output pin low-level
VRDL/FGL
IRD/FG = 5mA
IRDL/FGL
VRD/FG = 7V
voltage
RD/FG output pin leakage
current
No.8793-2/7
LB11961
Package Dimensions
unit : mm (typ)
3313
6.5
Pd max – Ta
1.2
0.5
6.4
Allowable power dissipation, Pd max – W
8
4.4
14
1
1.3
7
0.22
0.15
0.65
0.1 (1.3)
1.5max
(2.35)
1.5
Specified circuit board : 114.3×76.1×1.6mm3
glass epoxy board
1.1
1.0
0.8
0.6
0.53
0.4
0.2
0
– 30
– 10
10
30
50
70
90
110
Ambient temperature, Ta – °C
SANYO : HSSOP14(225mil)
Truth Table
VTH
IN-
IN+
Low
High
Low
(open)
Low
High
High
Low
High
Low
High
-
High
Low
-
Low
High
CPWM
CT
High
Low
Low
-
High
OUT1
OUT2
FG
High
Low
Low
Low
High
Off
Off
Low
Low
Low
Off
Off
High
Off
Low
Off
High
Off
RD
Mode
During rotation − drive
(PWM off)
On
During rotation − regeneration
(PWM on)
Off
Lock protection
CPWM – High is the state where CPWM > VTH, and CPWM– Low is the state where CPWM < VTH.
Open : The LB11961 operates in full-speed mode when the thermistor is removed.
No.8793-3/7
LB11961
Pin Assignment
F-GND
(P-GND)
F-GND
(P-GND)
OUT2
1
14
OUT1
VCC
2
13
S-GND
RMI
3
12
CT
VTH
4
11
6VREG
CPWM
5
10
IN-
FG
6
9
HB
RD
7
8
IN+
LB11961
Top view
F-GND (P-GND) : The motor system ground and the heat sink. Since the heat generated Since the heat generated by the chip is
dissipated through F-GND, the thermal resistance is lowered by increasing the area of the copper foil and solder
surface in the printed circuit pattern.
S-GND :
Control system ground
Block Diagram
FG
RD
Thermal
protection circuit
VCC
Constant
voltage
6VREG
Delay circuit
Control
circuit
1.3V
HB
Hall
OUT2
M
IN+
Delay circuit
OUT1
IN−
Amplifier with
hysteresis
Charge/discharge
circuit
S-GND
CT
VTH
Oscillator
circuit
CPWM
P-GND
No.8793-4/7
LB11961
Application Circuit Example
*2
CM
VCC
HB
*7
IN−
H
FG
*3
IN+
6VREG
RD
*6
*5
RMI
*8
OUT1
VTH
OUT2
CPWM
CP = 100pF
*4
CT
F-GND
*1
CT = 0.47μF to 1μF
S-GND
F-GND
*1. Power supply and ground lines
P-GND is connected to the motor power supply system and S-GND is connected to the control circuit power supply system.
These two systems should be formed from separate lines and the control system external components should be connected to
S-GND.
*2. Regeneration power supply stabilization capacitor
The capacitor CM provides power supply stabilization for both PWM drive and kickback absorption. A capacitor with a value of
over 0.1µF is used for CM. A large capacitor must be used when the coil inductance is large or when the coil resistance is low.
Since this IC adopts a technique in which switching is performed by the high side transistor and regeneration is handled by the low
side transistor, the pattern connecting CM to VM and P-GND must be as wide and as short as possible.
*3. Hall sensor input
Lines that are as short as possible must be used to prevent noise from entering the system. The Hall sensor input circuit consists of
a comparator with hysteresis (20mV). We recommend that the Hall sensor input level be at least three times this hysteresis, i.e. at
least 60mVp-p.
*4. PWM oscillator frequency setting capacitor
If a value of 100pF is used for CP, the oscillator frequency will be f = 25kHz, and this will be the basic frequency of the PWM
signal.
*5. RD output
This is an open collector output. It outputs a low level when the motor is turning and a high level when it is stopped. This pin must
be left open if unused.
*6. FG output
This is an open collector output, and a rotation count detection function can be implemented using this FG output, which
corresponds to the phase switching. This pin must be left open if unused.
*7. HB pin
This pin provides a Hall effect sensor bias constant-voltage output of 1.25V.
*8. RMI pin
Connect this pin to VTH if unused. Even if unused, the IC is set internally to operate at a 10% drive duty at the voltage
corresponding to the lowest speed. (The capacitor is used to set up full-speed mode at startup.)
No.8793-5/7
LB11961
Control Timing Chart
(VCC × 28%)
Thermistor removed
Internal lowest speed setting voltage
f = 25kHz (CP=100pF)
High on duty
3.6V
(VCC × 30%)
RMI voltage
CPWM
2.0V
(VCC × 16%)
Low on duty
0V
Set minimum
speed
Full speed mode
PWM control variable speed mode
Low
temperature
High
temperature
12V
VCC
0V
FG
1. Set minimum speed mode
A VTH voltage level is generated when the thermistor detects the set temperature. At low temperatures, the fan
motor turns at the lowest speed, which is set with the RMI pin. The LB11961 compares the CPWM oscillator
voltage with the RMI pin voltage and sets the duty for the lowest drive state.
2. High speed ↔ low speed mode
The PWM signal is controlled by comparing the CPWM oscillation voltage that cycles between 1.2V and 3. 8V
and the VTH voltage.
When the VTH voltage is lower, the high and low side transistors are turned on, and when the VTH voltage is
higher, the high side transistor is turned off and the coil current is regenerated through the low side transistor.
Thus the output on duty increases as the VTH voltage becomes lower, the coil current increases, and the motor
speed increases.
Rotation speed feedback is provided by the FG output.
3. Full-speed mode
The LB11961 switches to full-speed mode above a certain temperature.
4. Thermistor removed mode
If the thermistor is removed, the VTH input voltage will rise. However, the output will go to full drive at 100%
and the motor will run at full speed.
No.8793-6/7
LB11961
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PS No.8793-7/7