Evaluates: MAX14871 MAX14871 Evaluation Kit General Description Features The MAX14871 evaluation kit (EV kit) consists of a Operates From a Wide 4.5V to 36V Supply MAX14871 evaluation board. The EV kit is a fully assembled Standalone or Software-Controlled Operation and tested circuit board that evaluates the MAX14871 full- Proven PCB Layout bridge DC motor driver Fully Assembled and Tested The EV kit is designed to work as either a stand-alone board or with a software interface, demonstrating all of the major features of the device. Ordering Information appears at end of data sheet. MAX14871 EV Kit Block Diagram CIRCUITRYTO SELECT/SET MICRO- VMODEAND UPTO 36V USB VREF OPERATION ON-BOARD LDOFOR MICROCONTROLLER LOGIC-LEVEL SIGNALS ICM7556 PWMCIRCUIT MAX14871 FORLOGIC-LEVEL MOTORDRIVER PULSEGENERATION (1kHz) JUMPERSFORV , REF MODE, SNS, EN SETTINGS 19-7699 Rev 0 6/15 SOFTWARE-CONTROLLED HARDWARE-CONTROLLED OPERATION OPERATION TERMINALBLOCKCONNECTORFORMOTOR CONNECTIONEvaluates: MAX14871 MAX14871 Evaluation Kit On-Board PWM Generator Quick Start The ICM7556 (U2) general-purpose timer circuit is Recommended Equipment available to generate PWM signals for switching either MAX14871 EV kit the PWM or DIR inputs. Adjust the R1 potentiometer to User-supplied Windows XP , Windows Vista , or change the duty cycle of the output signal. Windows 7 PC with a spare USB port. The EV kit comes with the PWM frequency set up to 1kHz 24V, 1A power supply but can be adjusted up to 10kHz by changing the C3 capacitor. Set the PWM frequency using the following DC brushed motor equation: Procedure f = 1.46/ (R + 2 x R ) x C SW 29 32 3 The EV kit is fully assembled and tested. Follow the steps Motor Operation below to verify board operation before exercising the full features of the device: The MAX14871 is capable of operating in any one of three current regulation modes: fast decay, slow decay, or 1) Verify that all jumpers are in their default positions, as 25% ripple current mode. To set the mode, apply a voltage shown in Table 1. to VMODE and VREF (Table 2). 2) Connect the 24V DC power supply on the VCC and V GND connectors on the EV kit board. REF Set the V voltage to limit the motor current using the REF 3) See application note Using the MAX14871EVKIT with following equation: software to configure the board for software operation. V = I x A x R REF MOTOR V SENSE 4) Connect the DC brushed motor to the M1 and M2 V terminals in the J12 connector. For easy evaluation, J6 can be used to set the REF V voltage to 3.3V or 0V. Connect 1-2 on J6 to set REF to 5) Turn on the 24V power supply. V 3.3V. Connect 2-3 on J6 to set REF to 0V. Detailed Description of Hardware MODE The J7 jumper can be used to set the MODE voltage The MAX14871 EV kit is a fully tested circuit board demonstrating the capabilities of the MAX14871 motor high (3.3V) or low (0V). For 25% ripple mode, however, the MODE voltage must be between 0.5V and 1V. Apply driver. an external voltage to the MODE test point, or connect a Stand-Alone Operation resistor divider on the R3 and R5 resistor pads to set the Remove all of the shunts on the P2 header for stand- MODE voltage for this mode of operation. alone operation. On-board LDOs generate logic rails and Fault Indicator LED headers are included for device configuration in stand- The FAULT output is connected to the 3.3V logic supply alone mode. through R4. LED1 turns on during a fault condition. On-Board LDO The MAX15006 (U5) on-board LDO generates 3.3V for logic signals and for powering the fault LED. The 3.3V LDO also powers the on-board ICM7556 PWM signal generator. Windows Vista and Windows XP are registered trademarks and registered service marks of Microsoft Corporation. Maxim Integrated 2 www.maximintegrated.com