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NJU7333 Single-phaseDC Brushless Motor Driver IC
s GENERAL DESCRIPTION s PACKAGE OUTLINE The NJU7333 is a single-phase DC brushless motor driver IC for small fan-motor and high power applications. It features MOS-FET driver circuit for better saturation characteristics. Slew late of amplifiers and feedback resistors are optimized to achieve low-noise motor operation. Maximum output current is 500mA. The NJU7333 includes. frequency generator (FG) output, lock detect (with auto recovery circuit) ,and a thermal shutdown circuit . NJU7333R s FEATURES * Operating Voltage VDD=2.4 5.5V * FG Output * Internal Lock Detect / Auto Recovery Circuit * Internal Thermal Shutdown Circuit * Low Operating Current IDD=3mA (Typ.) * Low Saturation Output Voltage Vsat=0.35V @Io=500mA * C-MOS Technology * Package Outline VSP10 s BLOCK DIAGLAM s PIN FUNCTION 1:Ct 2: FG 3: Vdd 4: OUT B 5: Vss 6: Vss 7: OUT A 8: Vdd 9: IN10: IN+
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NJU7333
Preliminary s ABSOLUTE MAXIMUM RATINGS PARAMETER Supply Voltage Input Voltage Output Current (Peak) Operating Temperature Range Storage Temperature Range Power Dissipation RATINGS +7.0 -0.3 VDD+0.3 1.0 -40 +85 -50 +150 400 SYMBOL (unit) VDD (V) VID(V) IO PEAK (A) Topr (C) Tstg (C) PD (mW) (Ta=25C) NOTE
Device itself
s RECOMMENDED OPERATING CONDITIONS PARAMETER SYMBOL Supply Voltage Operating Temperature Range Input Common Mode Voltage Range Output Current VDD Tj VICM Io
CONDITION -
MIN. 2.4 -40 0.4 -
(VDD=5V, Ta=25C) TYP. MAX. UNIT 5.0 5.5 V 85 4.0 0.5 C V A
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NJU7333
Preliminary s ELECTRICAL CHARACTERISTICS PARAMETER SYMBOL General Operating Current Thermal Shutdown Temperature Thermal Shutdown Hysteresis Hall Amplifier Input Offset Voltage Feedback Resistance
Open loop gain
CONDITION -
MIN. -
(VDD=5V, Ta=25C) TYP. MAX. UNIT 3.0 180 50 4.0 mA C C
IDD TTSD THYS
VIO RF AV VICM
-
-7 22.0 0.44.0
27.5 80 -
7 33.0 -
mV k dB V
Input Common Mode Voltage Range Outputs Maximum Output Voltage Range Output Resistance FG L Output Voltage FG H Leak Current Lock Detect Circuits Lock Protect Operating Voltage Lock Detect Discharge Current Lock Detect Discharge Current Clamp Voltage Detect Voltage
VOH VOL RONH RONL VFG IFG - LEAK
Io=+350mA Io= -350mA Io=+500mA Io= -500mA 4pin=5V,3pin=0V, RP=10k 4pin=0V,3pin=5V, RP=10k
4.65 -
4.75 0.25 0.5 0.5 -
V 0.35 0.3 1.0 V A
VLOP IDCHG IDCHG VCL VID
-
4.0 -
1.5 0.5 2.6 0.6
-
V A A V V
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NJU7333
Preliminary s APPLICATION NOTE The NJU7333 is a single-phase DC brushless motor driver IC featuring CMOS process. It is suitable for fan motor drivers for a small equipment such as the note personal computers.
[Application Circuit Example]
V+ D1 GND R3 R1 VDD Hall element IN+ INR2 Ct C2 VSS FG FG out OUTB OUTA Motor C1
NJU7333
[Design Notes] Above application example is designed for 5V operation with motor current of 500mA. It uses the following components: Hall Elements: HW101A (AKE)
1. Selection of C1 and D1: C1 is used for a noise reduction purpose. A typical value is 0.1uF. Optimize the value in actual operating conditions if necessary. D1 is a diode for protection against reverse voltage supply. Silicon rectifier diode (WO3C, 10D1 and equivalent) is appropriate. 2. Lock Protection Function (Design of C2 value): Lock Protection Function, consists of Motor Lock Detection and Auto Resume Function, is a safety feature to protect a motor and a driver circuit from fatal destruction in case of motor halt. Motor Lock Detection detects motor halt due to irregular load conditions and then cuts motor driving current f or safety operation. A value of C2 determines Lock detection time (Ton) and Auto Resume Time (Toff).
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NJU7333
Preliminary
Lock detection time (Ton) is given by:
TON = C 2
VCL - VID [sec] ICHG
Where C2 is 0.47uF:
TON = 0.47 x 10 - 6 x
2 .6 - 0 . 6 = 0.62[sec ] 1.5 x 10 - 6
Auto Resume Time (Toff) is given by:
TOFF = C 2
VCL - VID [sec] IDCHG
Where C2 is 0.47uF:
TOFF = 0.47 x 10 - 6 x
2.6 - 0.6 = 1.88[sec ] 0.5 x 10 - 6
In actual application, Lock detection time (Ton) is affected by the mechanical time constant of a motor. Therefore, constant start up must be confirmed in actual evaluation taking operating variations (i.e.Temperature, Voltage change and so on) in consideration. A typical value of C2 is either 0.47uF or 1uF depending on a motor.
Hall input Motor output
Ct Terminal voltage
Toff
Ton
Motor Lock protection period Motor Locked
Returns to normal operation
3. Design of hall element bias resistance (R1 and R2) Hall amplifier is a differential amplifier with hysteresis characteristics (24mV typical). The common-mode input voltage is between 0.4V and VDD-1V and the input signal must be within the range.Non-excitation hall bias voltage is to be set at a half of VDD for effective use of common-mode input voltage range. Therefore the same value of hall bias resistors is selected for R1 and R2.
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NJU7333
Preliminary
Given that the bias current is set to be 5mA by HW101A datasheet, R1 and R2 can be determined as follows:
R1 + R 2 + Rin = R1 = R 2 = 300
VDD 5 = = 1k Ihbias 5 x 10 -3
The output voltage of hall elements is influenced by the bias current and magnetic flux density of hall elements. The optimum input voltage of NJU7333 is 100mVp-p and higher. With such input voltage, the highest efficiency can be obtained. 4. Design of FG output resistsnce (R3) FG Out(FG:Pin2) is a open drain output and R3 is a pull up register. A typical value of R3 is 10k. The timing chart of FG Out is as follows.
Hall input IN+
FG Terminal voltage
The specifications on this data book are only given for information, without any guarantee as regards either mistakes or omissions. The application circuit in this data book are described only to show representative usages of the product and not intended for the guarantee or permission of any right including the industrial rights.
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