Click here to ask about the production status of specific part numbers. Evaluates: MAX22203 MAX22203 Evaluation Kit General Description Features The MAX22203 evaluation kit (EV kit) provides a proven Easy Evaluation of the MAX22203 design to evaluate the +65V, 3.8A Dual H-Bridge MAX22203 Adjustable t Time Using an On-Board OFF motor driver. The MAX22203 can drive two brushed Potentiometer DC motors or single stepper motor. The MAX22203 IC Configurable Current Drive Regulation (CDR) integrates very low impedance FETs in a dual H-Bridge configuration with a typical RON (high side + low side) of On-board +3.3V Regulator to Drive MAX22203 Logic 0.3. The EV kit features headers, test points, and termi- Inputs nal blocks to provide an interface to the MAX22203 motor Test Points and Headers to Interface with MAX22203 driver. The MAX22203 integrated current-sense output Logic Inputs and Current-Sense Outputs ISENA and ISENB can be monitored using test points or can be connected to an external ADC using header J4. Fully Assembled and Tested The MAX22203 features embedded current-drive regula- Proven PCB Layout tion (CDR) with adjustable chopping current (I ) and TRIP adjustable current-limit off-time (t ). The MAX22203 OFF EV kit operates from an input voltage of +4.5V to +65V (V ). An on board +3.3V regulator U2 (MAX6765TTSD2+) M provides a regulated +3.3V to drive the MAX22203 logic Ordering Information appears at end of data sheet. inputs. Terminal blocks J1 and J6 are installed to provide an interface for the high voltage, high current VM inputs and motor driver outputs OUT1 and OUT2 . MAX22203 EV Kit Board 319-100754 Rev 0 4/21Evaluates: MAX22203 MAX22203 Evaluation Kit On-Board +3.3V Control Quick Start The MAX22203 features an on-board +3.3V LDO that Required Equipment operates from +4.5V to +65V. The input voltage to the MAX22203 EV kit LDO is supplied by the VM voltage. To provide 3.3V to +65V DC, 3.8A power supply the MAX22203 logic pins from the LDO, install a shunt in position 23 of header J18. An external +3.3V supply can 100kHz square-wave generator (optional) be used, which can be connected to TP3, and in this case, Brushed DC motor or load a shunt should be installed in position 12 of header J18. Procedure PWM Controls The EV kit is fully assembled and tested. Follow the steps Each MAX22203 H-Bridge can be individually PWM con- below to verify board operation. trolled by two logic inputs (DIN1 , DIN2 ) applied to either 1) As with all motor drive applications, stopping or brak- headers J4 or J9 to J14, or test points TP5 to TP10. Table ing the motor can cause a back EMF (BEMF) current 1 below describes the behavior of the full H-Bridge output and voltage spike. At high supply voltages (+65V), pins OUT1 and OUT2 with respect to the input signals this can cause the supply to rise above the absolute EN, DIN1 , and DIN2 . PWM techniques can be used to maximum allowable voltage to the supply pins of a control the output duty cycle and implement motor speed motor drive IC. It is highly recommended that the control. power supply be clamped appropriately to avoid Current Regulation Controls damage to the motor driver IC. The MAX22203 features embedded current drive regulation 2) Verify that shunts are installed in the default position. (CDR). The bridge current is sensed by a non-dissipative 3) Connect a +65V supply to VM and adjust the VM integrated current-sensing circuit (ICS) and it is then com- voltage to the desired operating voltage. pared with the threshold current (I ). As soon as the TRIP 4) Adjust the I chopping current according to the bridge current exceeds the threshold, the device enforces TRIP position of shunts on headers J2 and J3 to accom- the decay for a fixed OFF-time (t ). Once t has OFF OFF modate the load requirement. elapsed, the driver is re-enabled for the next PWM cycle. t can be adjusted by connecting a resistor (R ) 5) Adjust the t time using potentiometer R9 if the OFF ROFF OFF from the ROFF pin to GND. Potentiometer R9 and resistor off-time is being observed. R2 can be used to adjust the R resistance from 15k ROFF 6) Apply a PWM signal to the DIN1 /DIN2 inputs as to 215k and hence the t time. The following equation OFF desired to drive the load. For example, a +3.3V to shows the relationship between t and R : OFF ROFF 0V, 20kHz PWM signal with a 20% duty cycle can be t = R x K used to drive a 24V or 48V brushed DC motor con- OFF ROFF TOFF nected to output A. To drive load with current flowing Where K is 0.667s/k and t can be pro- TOFF OFF from OUT2A to OUT1A, DIN1A would be driven to grammed in a range from 10s to 80s. logic LOW (GND) and the PWM signal would be ap- The chopping current threshold (I ) can be config- TRIP plied to DIN2A. ured by connecting a resistor between the REF pins and GND. The MAX22203 EV kit has two 20k resistors Detailed Description of Hardware installed in series from each of the REF pins (R3 and R5 Enable Controls for REFA, and R4 and R6 for REFB) to GND. Shunts can be installed on headers J2 or J3 to short one of the 20k The MAX22203 enable pins (ENA and ENB) are controlled series resistors to reduce the resistance from each REF by installing shunts on headers J13 and J14 or the pins can pin to GND from 40k to 20k. be connected to a microcontroller using header J4. Table 1. Full Bridge EN , DIN1 , DIN2 , OUT1 , OUT2 Truth Table EN DIN1 DIN2 OUT1 OUT2 DESCRIPTION 0 X X High-Z High-Z H-bridge disabled. High impedance (High-Z) 1 0 0 L L Brake Low Slow decay 1 1 0 H L Forward (Current from OUT1 to OUT2 ) 1 0 1 L H Reverse (Current from OUT2 to OUT1 ) 1 1 1 H H Brake High Slow decay Maxim Integrated 2 www.maximintegrated.com