LB11600JV_11 Datasheet, PDF (28/30 Pages) Sanyo Semicon Device – Brushless Motor Predriver IC for Automotive Applications

LB11600JV
CSD voltage rise time (during motor rotation): Tchg ≈ Cc × Rc × ln((V1 - Ic × Rc) / (V2 - Ic × Rc)) (s)
Cc:
CSD pin external capacitor (connected between VCC and CSD)
Rc:
CSD pin external resistor (connected between the CSD pin and ground)
Ic:
CSD pin transistor current (3.5mA maximum (design target value))
V1:
CSD pin initial voltage
V2:
CSD pin voltage (when the transistor is in the on state): 4.9V (typical)
<Constraint Time Setting Example>
When VCC = 5V, to set the motor constraint time to 3 seconds:
Use a 10µF capacitor for the CSD pin capacitor Cc and a 130kΩ resistor for Rc.
Motor constraint time: Tcsd = 1n (5 / (0.6 – 130kΩ × 1μA) × 10μF × 130kΩ
= 2.36 × 10μF × 130kΩ = 3.068 (s)
The discharge time for the capacitor specified above will be the motor constraint time.
The pulse signal that detects whether or not the motor is turning is set by the CSET pin capacitor.
If a 0.022 µF capacitor is used as the CSET pin capacitor Cs:
Rotation pulse signal detection time: Tps = 0.022μF × 0.7/50μA = 308μs
Note that care is required in setting these values since the amplitude of the rotation pulse detection signal is influenced by
the motor speed, and the CSD capacitance.
If the rotation pulse detection signal time is too short, the IC will not be able to raise the CSD potential to the high level.
Also, if the CSD pin capacitor value is too small and the discharge time too short, the rotation detection pulse signal will
not be issued for the motor rotation period at the start of motor rotation (when the motor is turning slowly), and the
constraint protection circuit may latch. For example, since at speeds under 100rpm the UH output period will be 300ms,
the motor constraint time must be set to a time of at least 600ms.
8. Overcurrent Protection Circuit
The overcurrent protection circuit limits the output current to be a
To the RF pin
maximum of I = VRF/Rf (where VRF = 0.24V typical, and RF is the
current detection resistor). The current limiter circuit detects the reverse
recovery current in the output diodes due to PWM operation and includes
Current
detection
resistor
a built-in filter circuit to prevent incorrect operation. While this internal filter circuit is adequate for most applications, if
the circuit is observed to operate incorrectly (for example, in cases where the diode reverse recovery current flows for
over 3 µs), an external filter circuit (such as a passive low-pass filter circuit) must be added.
9. Thermal Protection Circuit
The thermal protection circuit turns off one side of the output (UH, VH, and WH) if the IC junction temperature (Tj)
exceeds the stipulated temperature (TSD = 170°C, typical).
10. Direction Reversal
Do not reverse motor direction while the motor is turning. To reverse directions, first stop the motor (set PWMIN high or
set the S/S pin high) and then startup again with the desired direction.
11. HP Output
The Hall signal created from the IN3 pin Hall amplifier input signal is inverted and output from the HP pin. Since the HP
pin is an open-collector output, a pull-up resistor must be inserted between VCC and the HP pin.
Hall amplifier input conditions: IN3-: fixed potential, HP pin: pulled up to VCC.
IN3+ input
IN3-
HP pin
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