DRV11873 Datasheet, PDF (8/16 Pages) Texas Instruments – 12-V, 3-PHASE, SENSORLESS BLDC MOTOR DRIVER

DRV11873
SLWS237 – NOVEMBER 2012
www.ti.com
REVERSE SPIN CONTROL FR
DRV11873 has an FR pin to set the motor for a forward spin or reverse spin. During DRV11873 power up, FR
status will be set. During normal operation, the spin direction of the motor will not be changed when the FR
status is changed. The FR status can be reset after the next PWM rising edge if PWM_IN was pulled low for 300
µs (when the FS status is high) or 600 µs (when the FS status is low).
5-V LDO
DRV11873 has a built-in 5-V LDO which can output a 20-mA load current. It can provide 5-V bias voltage for
external use. A 2.2-µF ceramic capacitor is recommend to connect closely on the PCB layout between V-5 pin
and ground.
OVER CURRENT PROTECTION
DRV11873 can adjust over current point through the external resistor connected to CS pin and ground. Without
using external current sense resistor, DRV11873 senses the current through power MOSFET. Therefore there is
no power loss during the current sensing. This current sense architecture improves the system efficiency. Short
CS pin to ground will disable over current protection. During over current protection, DRV11873 will only limit the
current to the motor and it will not shut down the operation. The over current threshold can be set by the value of
current sensing resistor through Equation 2.
I (A) = ⁶⁶⁰⁰
R_CS (W)
(2)
UVLO
DRV11873 has a built-in UVLO function block. The hysteresis of UVLO threshold is 200 mV. The device will be
locked out when V_CC reaches 4.1 V and woke up at 4.3 V.
THERMAL SHUTDOWN
DRV11873 has a built in thermal shunt down function, which will shut down the device when the junction
temperature is over 160°C and will resume operating when the junction temperature drops back to 150°C.
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