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Unformatted text preview: ion that must be
taken into account when designing an H-bridge circuit.
All MOSFETs must be biased to off when the inputs to
the circuit are unpredictable (like when the microcontroller is starting up). This will ensure that the
MOSFETs on each half-bridge of the H-bridge will
never be turned on at the same time. Turning
MOSFETs on that are located on the same half-bridge
will cause a short across the power supply, ultimately
damaging the MOSFETs and rendering the circuit
inoperable. Pull-down resistors at each of the MOSFET
driver inputs will accomplish this functionality (for the
configuration shown in Figure 8). H-BRIDGE MODES OF
(CTRL1) (CTRL2) (CTRL3) (CTRL4) Forward on off off on Reverse off on on off Coast off off off off Brake off on off on DS00905B-page 4 2010 Microchip Technology Inc. AN905
The speed of a BDC motor is proportional to the voltage
applied to the motor. When using digital control, a
pulse-width modulated (PWM) signal is used to generate an average voltage. The motor winding ac...
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This note was uploaded on 01/29/2014 for the course AA AA taught by Professor Aa during the Winter '10 term at ENS Cachan.
- Winter '10