lb11693 Sanyo Semiconductor Corporation, lb11693 Datasheet - Page 11
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lb11693
Manufacturer Part Number
lb11693
Description
Three-phase Brushless Motor Driver For 24 V Fan Motors
Manufacturer
Sanyo Semiconductor Corporation
Datasheet
1.LB11693.pdf
(12 pages)
Available stocks
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Part Number:
lb11693H-TRM-E
Manufacturer:
ONSEMI
Quantity:
20 000
possible if the braking current is limited to be under Iomax (1.8 A) by the motor coil resistance or other factors. Also,
since a transient through current will flow at the instant the direction is switched if the direction switching operation is
performed just from the F/R pin, a period where drive is turned off must be provided when switching directions.
Through currents must be prevented by setting the IC to the stop state with the S/S pin or TOC pin to provide a drive off
period where the duty due to the PWMIN pin is set to 0% and switching the F/R pin during that period.
9. Power Saving Circuit
This IC goes to a low-power mode (power saving state) when set to the stop state with the S/S pin. In the power saving
state, the bias currents in most of the circuits are cut off. However, the 5 V regulator output is still provided in the
power saving state.
10. Notes on the PWM Frequency
The PWM frequency is determined by the capacitor C (F) connected to the PWM pin.
It is preferable to use a frequency in the range 15 kHz to 25 kHz for the PWM frequency. The connected capacitor must
be connected to the GND1 pin with a line as short as possible.
11. Control Methods
The output duty can be controlled by either of the following methods
12. Undervoltage Protection Circuit
The undervoltage protection circuit turns the low side output transistor off when
the LVS pin voltage falls below the minimum operation voltage (about 3.8 V).
The operating voltage detection level is set up for 5 V systems. The detected
voltage level can be increased by shifting the voltage by inserting a zener diode
in series with the LVS pin. The LVS influx current during detection is about
65 µA. To minimize the effect of sample-to-sample variations in the zener
voltage, the current flowing in the zener diode must be increased thus
stabilizing the rise in the zener diode voltage. If this is required, insert a resistor between the LVS pin and ground.
If the LVS pin is left open, the internal pull-down resistor will result in the IC seeing a ground level input, and the
output will be turned off. Therefore, a voltage in excess of the LVS circuit clear voltage (about 4.3 V) must be applied
to the LVS pin if the application does not use the undervoltage protection circuit. The maximum rating for the LVS pin
applied voltage is 30 V.
13. Constraint Protection Circuit
When the motor is physically constrained (held stopped), the CSD pin external capacitor is charged (to about 3.0 V) by
a constant current of about 2.4 µA and is then discharged (to about 1.0 V) by a constant current of about 0.17 µA. This
process is repeated, generating a sawtooth waveform. The constraint protection circuit turns motor drive (the low side
• Control based on comparing the TOC pin voltage to the PWM oscillator waveform
• Control based on a pulse signal input to the PWMIN pin
The low side output transistor duty is determined according to the result of comparing the TOC pin voltage to the
PWM oscillator waveform. When the TOC pin voltage is 1.3 V or lower, the duty will be 0%, and when it is 3.0 V
or higher, the duty will be 100%.
Since the TOC pin is the output of the control amplifier (CTL), a control voltage cannot be directly input to the
TOC pin. Normally, the control amplifier is used as a full feedback amplifier (with the EI– pin connected to the
TOC pin) and a DC voltage is input to the EI+ pin (the EI+ pin voltage will become equal to the TOC pin voltage).
When the EI+ pin voltage becomes higher, the output duty increases. Since the motor will be driven when the EI+
pin is in the open state, a pull-down resistor must be connected to the EI+ pin if the motor should not operate when
EI+ is open.
When TOC pin voltage control is used, a low-level input must be applied to the PWMIN pin or that pin connected
to ground.
A pulse signal with a frequency in the range 15 to 25 kHz can be input to the PWMIN pin, and the duty of the low
side output transistor can be controlled based on the duty of that input signal. Note that the output is on when a low
level is input to the PWMIN pin, and off when a high level is input. When the PWMIN pin is open it goes to the
high level input and the output is be turned off.
When controlling motor operation from the PWMIN pin, the EI– pin must be connected to ground, and the EI+ pin
must be connected to the TOC pin.
f
PWM
≈ 1/(23400 C)
LB11693
To the power supply
level to be detected
To the LVS pin
No.8095-11/12