L272Figure 12 : Motor Current Control Circuit. Note : The input voltage level is compatible with L291 (5-BIT D/A converter). Figure 13 : Bidirectional Speed Control of DC Motors. 2R3 ° R1 For circuit stability ens ure that RX > where RM = internal resistance of motor. RM Vs 2R ° R1 The voltage available at the terminals of the motor is VM = 2 (Vi ⋅ ) + Ro ⋅ ΙM where Ro = 2 RX and IM is the motor current. 6/10