High Capacity H-Bridge

Transcription

1 High Capacity H-Bridge Functional Specification Revision Sterling Drive Boulder, CO Page 1

2 Revision History 3 Features 3 General Description 3 Functional Block Diagram 4 Recommended and Absolute Maximum Ratings 4 Pin Descriptions 5 Control Logic 6 Current Sensing 6 Physical Pinout 7 Physical Dimensions 8 Contents Page 2

3 Revision History This document has the following revision notes: Revision Date Description 0.0 April 2, 2007 Initial Creation 0.1 April 10, 2007 Added pinout and dimension drawing 0.2 April 16, 2007 Control logic truth table. 0.3 May 9, 2007 Added dimensioned drawing and pinout. Updated operating temperature. 0.4 May 31, 2007 Updated block diagram and pin descriptions. 0.5 June 10, 2007 Combined absolue and maximum values into a single table. 1.0 August 8, 2007 Added current sense information. Features The H-Bridge has the following features: Designed for output voltages from 5.0 to 30.0 Volts PWM operation up to 100kHz Continuous Current Rating up to 15 Amps CMOS/TTL compatable inputs Low on resistance Over current protection Short circuit protection across motor leads Seperate logic and motor supply inputs Digital Status Outputs Quadrature encoder pass through with pull-up resistors Screw terminals for motor and supply wiring Solder pads with strain relief holes for input power and motor leads Conforms to the Acroname H-Bridge Standard General Description The high capacity H-Bridge is designed for use with a wide range of motor voltages and high current capacities up to 15 Amps. Conforming to the Acroname H-Bridge standard, the H-Bridge motor dirver easily connects to the Acroname BrainStem Moto 1.0 Module. Integrated encoder pass through connector are included to simplify wiring and providing motion feedback. Page 3

4 Functional Block Diagram VCC Vmotor PWM Direction Fault Control Logic Current Sense Motor+ Motor- Current Sense Ground Analog Multiplexor VCC Ground Encoder A Encoder B Encoder A Encoder B Recommended and Absolute Maximum Ratings Operation beyond these limits may damage the device. Proper device operation is guaranteed when operating within the limits specified under Recommended table values. Proper device operation is not guaranteed when exceeding Absolute Maximum table values. Recommended Absolute Maximum Motor Voltage 5.0V to 30.0V 5.0V to 35.0V Continuous Output Current 15.0 A 18.5 A Logic Supply Voltage (Vcc) 4.5V to 5.5V -0.5V to 5.5V Logic Supply Current (Icc) 20.0mA Combined MOSFET Power Dissipation 2.0W MOSFET Junction Temperature -55 to 175 ºC Storage Temperature -40 to 85 ºC Page 4

5 Operating Frequency 0.0 to 100.0kHz 100kHz Ambient Operating Temperature -40 to 85 ºC Pin Descriptions Peripherial connections. Interface Connectors for Encoder Pass-through Pin Signal Name Type Description J7 VCC Logic Power Input VCC is logic power input and is nominally 5V. J7 ENC_A Digital Input ENC_A is channel A of the quadrature encoder. When the motor spins forward, channel A should lead channel B. There is a 2.2K pull-up resistor between this signal and VCC. J7 ENC_B Digital Input ENC_B is channel B of the quadrature encoder. When the motor spins in revers, channel B should lead channel A. There is a 2.2K pull-up resistor between this signal and VCC. J7 GND Logic Ground GND is connected to logic ground (passed from the Interface Connector) and is intended to be used by the encoder. Interface connectors on the H-Bridge then conform to the Acroname H-Bridge Standard. Moto 1.0 Interface Connectors Pin Signal Name Type Description J8 STATUS Digital Output STATUS is active (logic high) when the driver is functioning properly. It wil become inactive (logic low) due to an over current condition. J8 CURRENT Analog Output CURRENT is an analog voltage signal corresponding to the amount of current flowing through the driver. J8 VCC Logic Power Input VCC is logic power input and is nominally 5V. J8 GND Logic Ground GND is the logic ground reference. J8 ENC_A Digital Input ENC_A is channel A of the quadrature encoder. When the motor spins forward, channel A should lead channel B. There is 2.2K pull-up resistor between this signal and VCC. J8 ENC_B Digital Input ENC_B is channel B of the quadrature encoder. When the motor spins in reverse, channel B should lead channel A. There is a 2.2K pull-up resistor between this signal and VCC. Page 5

6 Control Logic Control input and output truth table is a shown in the following table. Control Inputs H-Bridge State (*) Control Outputs PWM Brake Direction Fault Motor + Motor - Function Float Float Free Spin GND GND Brake GND GND Brake Vmotor GND Forward Float Float Free Spin GND GND Brake GND GND Brake GND Vmotor Reverse Float Float Free Spin Float Float Free Spin Float Float Free Spin Float Float Free Spin Float Float Free Spin Float Float Free Spin Float Float Free Spin Float Float Free Spin Note (*): The Fault state, which is linked to the Status pin on the H-Bridge connector, has a logic high value when no fault conditions are present. Only when the status pin is at logic low is when there is actually a fault condition. Current Sensing The H-Bridge contains two high side current sensing monitors that are multiplexed to the output pin based on the voltage level of the Direction pin. The output voltage is has a linear relationship throughout a current range from 0.0 to 15.0 amps. The actual functional relationship between pin voltage and current flow is as follows: Page 6

7 Physical Pinout The features of the H-Bridge are as follows: Designed to conform to the Acroname H-Bridge standard. Page 7

8 Physical Dimensions The following dimensions show the shape of the board. All dimensions are in inches. Page 8