DB74HU

DB74HU DB74HU DB74HU SA57- Demonstration Board for the SA57 INTRODUCTION The DB74HU is designed to demonstrate the capabilities of the SA57 DC brush motor driver IC. This fully assembled demonstration allows the user to directly control the speed and direction of the motor. An onboard circuit controls the direction and provides four quadrant PWM signals to control the power outputs of the SA57. LEDs provide visual feedback for motor control status and fault indications. Provisions on the DB74HU allow the user to bypass the onboard control circuit and directly interface with the SA57 motor driver. The DB74HU demonstrates proper layout techniques for the SA57 high current switching amplifier. The economical construction uses only a two-sided PCB and allows the SA57 to deliver peak power of over 1kW. THERMAL CONSIDERATIONS: The SA57 is available in a surface mount package which can deliver peak power of over 1kW. This presents an obvious and significant thermal challenge. The DB74HU offers a compact design which can deliver 17A peak current and dissipate approximately 20W in still air at 25ºC ambient temperature. To use the DB74HU in higher power applications, use a fan or mount a heatsink with larger thermal mass. Although the SA57 is rated for operation from -25 to +85ºC, the other components on the DB74HU are limited to 0 to 70ºC ambient temperature. CIRCUIT OPERATION The DB74HU control circuit receives power via two terminal block connections. The Vs connection supplies power to drive the motor and must be above the undervoltage lockout threshold of the SA57, approximately 8.3V. The Figure control circuit requires 12V for proper operation. A regulator on the DB74HU provides the 5V logic supply for the SA57. There are no special considerations for sequencing the two supplies. Figure 2 (next page) shows the user control features of the DB74HU. The PWM duty cycle is controlled with the potentiometer. LED5 will illuminate when the 12V supply is connected. The DB74HU will power up with the SA57 disabled. The enable button will toggle the SA57 on and off with LED2 illuminating to indicate the enable status. Direction of the motor is similarly controlled with the button and is indicated by the LED. The DB74HU monitors the Temperature warning status pin of the SA57. If this pin goes high LED4 illuminates and the enable circuit is forced to a disable status. The temperature LED is not latched and may stay illuminated only briefly while the temperature of the SA57 is above 135ºC. The temperature decrease rapidly via the heatsink once the SA57 is disabled. The SA57 current limit feature is set to limit at approximately 15A to provide a demonstration of the full capabilities of the SA57. LED3 will illuminate if the SA57 cycle-by-cycle current limit circuit engages. The thermal and current limit features are robust, but will not protect the SA57 in all circumstances. The user must consider the worst case thermal and power dissipation conditions. Push-button switches 1 and 2 trigger latches for direction and enable control, respectively. Diodes D7 & D8 and resistors R24, 25, 29 & 30 provide a means of bypassing the DB74HU control circuit. The 5V regulator, U3, provides 5V to the SA57, the latches and the status LEDs. www.apexanalog.com DB74HUU Copyright © Apex Microtechnology, Inc. 2012 (All Rights Reserved) 1 – User Control Features OCT 2012 1 DB74HUU REVC DB74HU 2B 2T +12V J4 1 2 3 4 5 6 C7 1 GND 2 C8 3 R7 0.1uF 24.9K GND C12 4 C13 1% 5 33pF X7R 6 2200pF C17 7 X7R 8 GND 2200pF 9 10 +12V +5V GND 3 CW 13 C14 2 14 0.1uF 1 GND 1 2 3 4 5 6 12 R8 20K J5 11 U2 GND VDD VREF AHI TACH_OUTALOW R_TACH BHI C_TACH BLOW CT CHI SYNCH CLOW -IN DIR_IN SNS_NI QUAD SNS_I BRAKE I_OUT COAST OC_REF HALLC PWM_I HALLB PWM_NI HALLA 28 R9 27 26 4.99K R10 1% 4.99K 1% 25 24 R16 23 R17 4.99K 1% 22 4.99K 1% 21 20 +12V +5V 19 C16 18 16 3 4 GND 6.8K 5 TP1 R24 6 R11 1% +12V GND +5REG 0.1uF 1N4148WS-V-GS08 2 3 3 1 +5REG 4 D PRE Q 15 +5REG 1.0K 5% GND 11 1 SW2 ENABLE 4 2 3 13 10 +5REG LED3 CLK CLR PRE Q Q 9 8 R20 1.0K 5% GND 2.0K 20 +5V GND 21 22 R26 MMBT3904LT1 Q1 MMBT3904LT1 LED2 18 19 LED4 D 16 17 R19 1.0K 5% R27 10K 1% R30 3.30K 1% TP6 R13 R18 1.0K 5% TP3 R25 +5REG R31 24.9K 1% GND 7 TP4 14 LED1 R21 6 U4-B 12 10 11 6.8K 1% D8 GND GND 5 +5V 1N4148WS-V-GS08 9 12 GND R22 4.99K 1% 8 13 Q CLK CLR GND 7 U4-A GND 2 TP8 2.0K VCC 14 D7 TP5 R29 3.30K 1% C15 +5V R32 1.0K U1 2 15 UCC3626PW GND LED5 C1 X7R 1UF GND GND SW1 1 DIRECTION 4 1 OUT GND 1 TP2 R23 4.99K 1% IN 0.1uF 17 +5REG U3 8 2 3 6 7 0.1uF +5V 1B 1T Figure 2 – Schematic C18 X7R 1UF 10K 1% 5% GND NC PGND/SLUG NC NC NC PGND2 NC PGND2 2B NC 2T OUT2 I2 OUT2 SC NC SGND VS2 ILIM/DIS1 VS2 SGND NC SGND NC SGND PGND1 1B PGND1 1T NC VDD OUT1 I1 OUT1 DIS2 NC TEMP VS1 NC VS1 NC NC NC PGND/SLUG SA57HU_LB 44 43 GND 42 41 40 GND D1 PDS5100 39 38 37 +VS D2 PDS5100 +VS OSTTA054163 36 5 35 C3 C6 34 1.0nF 150uF 33 GND GND 4 3 GND 1 31 28 27 26 25 24 23 OUT1 TB1 30 29 OUT2 2 32 GND D5 PDS5100 +VS D6 PDS5100 C2 1.0nF GND C5 150uF GND GND D9 Q2 1N4148WS-V-GS08 GND GND GND ENHANCING & BYPASSING THE DB74HU CONTROL CIRCUIT: Connector J5 allows the user to bypass many of the manual control features of the DB74HU. A signal generator can control the duty cycle with a 2.5 to 7.5V signal, overriding the control potentiometer. A rising 5V edge on pin 3 or 4 of connector J5 will toggle the Direction or Enable latches, respectively. By jumping resistors R24 & R25, the latches are bypassed completely and the logic signals on pins 3 & 4 will directly control the direction and enable functions of the DB74HU. With these resistors jumped, the direction and enable LEDs will not represent the states of the DB74HU and the pushbuttons will have no effect on the operation. The Temperature disable feature of the DB74HU will also not function, although LED4 will continue to provide over-temperature status. Connector J4 is connected directly to the PWM input pins of the SA57. This connector may be used to monitor the signals or to bypass the control IC on the DB74HU. The enable function is not controlled via these pins, although pulling all four input pins low provides the same effect. The Enable pushbutton and the connection via J5 are also effective as previously described. The circuit shown in figure 3 in the dashed box is a simple circuit that allows the user to monitor and control the enable or direction status remotely. Either feature can be toggled on the falling edge of the signal at the node labeled TOGGLE. LAYOUT CONSIDERATIONS A simple two layer construction is sufficient because of the convenient pinout of the SA57 input signals are routed into one side of the package and high power output signals are routed from the other side in 2 ounce copper. This eliminates the need to route control signals near motor connections where noise may corrupt the signals. Filling top and bottom layers with copper reduces inductive coupling from the high current outputs. 1nF capacitors with excellent high frequency characteristics bypass the Vs motor supplies on each phase. Two 150μF electrolytic capacitors provide a local, low inductance source to accommodate surge currents up to 17A. Six 100V Schottky 2 DB74HUU DB74HU diodes conduct the commutation current via low forward voltage paths which reduces the power dissipation in the SA57. These diodes are rated for 5A continuous and are mounted close to the SA57 to reduce inductance in the commutating current loop. For applications with continuous currents less than 5A, the Schottky diodes may not be necessary if the higher forward voltage internal body diodes and the associated power dissipation are manageable during commutation cycles. Figure 3 shows the top and bottom layouts of the DB74HU. Gerber files for the circuit board are available upon request. Figure 3 – PCB Layout (not to scale) 3.50” 3.00” TOP SIDE DB74HUU BOTTOM SIDE 3 DB74HU BILL OF MATERIALS Designation Description C1,C18 CAP, 1.0uF, 16V C13 CAP, 33pF, 50V C2,C3 CAP, 1.0nF,100V C5,C6 CAP, 150uF, 100V C7,C8,C14,C15,C16 CAP, 0.1uF,16V C12,C17 CAP, 2.2nF,50V D1,D2,D5,D6 Diode, 5A Schottky D7,D8,D9 IN4148 J4, J5 Conn, 6 pin .100 ctrs LED1, LED2, LED3, LED4, LED, Red LED5, Q1,Q2 XTR, NPN R11,R13 RES 2.0K, 1% R24,R25 RES, 6.8K R26,R27 RES, 10K R29,R30 RES, 3.3K R18,R19,R20,R21,R32 RES, 1.0K, 5% R7,R31 RES, 24.9K,1/10W, 1% R8 POT, 20K R9,R10,R16,R17,R22,R23 RES, 4.99K SW1,SW2 Pushbutton, SPST-NO TB1 Terminal Block, 5 pos, 5mm U1 SA57-HU-FH U2 UCC3626 U3 LM78L05 U4 74AC74 Heatsink PCB, 3.00” x 3.50” Screw, #4-40 x 1/2” Gap Pad, Thermal Interface, 40 mils thick, 1ºC/W 4 P/N Kemet, C0805C105K4RAC Kemet, C0603C330J5GACTU Kemet,C0805C102J1GACTU Panasonic, EEVFK2A151M GRM188F51C104ZA01D GRM188R71H222KA01D Diodes Inc., DS5100 Vishay, 1N4148WS-V-GS08 Samtec, TSM-106-01-T-SV Lite-On, LTST-C190CKT MMBT3904 Vishay,CRCW06032K00FKEA Vishay,CRCW06036K80FKEA Vishay,CRCW060310K0FKEA Vishay,CRCW06033K30FKEA RK73B1JTTD102J RK73H1JTTD2492F muRata, PVG3A203C01 CRCW06034K99FKEA Panasonic, EVQ-Q2B01W On Shore Tech, OSTTA0S4163 Apex Microtechnology, SA57-HU-FH Texas Instruments, UCC3626PW National Semiconductor, LM78L05ACMX/NOPB Texas Instruments, SN74AC74PW Apex Microtechnology, HS36, 2.8º/W Apex Microtechnology, EVAL74 18-8 SS Pan Head Phillips Screw, 91772A110 GP5000S3S-0.040-02-43-NA DB74HUU DB74HU DB74HU QUICK START GUIDE 1. Connect the following: Connection Location Vs TB1 Ground TB1 Vctrl J5-6 Motor Phase A TB1 Motor Phase B TB1 Indicator Comment 9-60V LED 2 12V 2. Apply 12V to Vctrl. LED 5 should light. 3. Apply voltage to Vs based on rated motor voltage, normally 12-48V. 4. Press ENABLE switch 3. LED 2 will light and motor should start. ORDERING INFORMATION DB74HU Demonstration Board includes one populated EVAL74 PCB and one SA57-HU-FH sample. NEED TECHNICAL HELP? CONTACT APEX SUPPORT! For all Apex Microtechnology product questions and inquiries, call toll free 800-546-2739 in North America. For inquiries via email, please contact apex.support@apexanalog.com. International customers can also request support by contacting their local Apex Microtechnology Sales Representative. To find the one nearest to you, go to www.apexanalog.com IMPORTANT NOTICE Apex Microtechnology, Inc. has made every effort to insure the accuracy of the content contained in this document. However, the information is subject to change without notice and is provided "AS IS" without warranty of any kind (expressed or implied). Apex Microtechnology reserves the right to make changes without further notice to any specifications or products mentioned herein to improve reliability. This document is the property of Apex Microtechnology and by furnishing this information, Apex Microtechnology grants no license, expressed or implied under any patents, mask work rights, copyrights, trademarks, trade secrets or other intellectual property rights. Apex Microtechnology owns the copyrights associated with the information contained herein and gives consent for copies to be made of the information only for use within your organization with respect to Apex Microtechnology integrated circuits or other products of Apex Microtechnology. This consent does not extend to other copying such as copying for general distribution, advertising or promotional purposes, or for creating any work for resale. APEX MICROTECHNOLOGY PRODUCTS ARE NOT DESIGNED, AUTHORIZED OR WARRANTED TO BE SUITABLE FOR USE IN PRODUCTS USED FOR LIFE SUPPORT, AUTOMOTIVE SAFETY, SECURITY DEVICES, OR OTHER CRITICAL APPLICATIONS. PRODUCTS IN SUCH APPLICATIONS ARE UNDERSTOOD TO BE FULLY AT THE CUSTOMER OR THE CUSTOMER’S RISK. Apex Microtechnology, Apex and Apex Precision Power are trademarks of Apex Microtechnolgy, Inc. All other corporate names noted herein may be trademarks of their respective holders. DB74HUU www.apexanalog.com Copyright © Apex Microtechnology, Inc. 2012 (All Rights Reserved) OCT 2012 5 DB74HUU REVC