FEATURES * * * * * * * DELIVERS UP TO 5A CONTINUOUS OUTPUT OPERATES AT SUPPLY VOLTAGES UP TO 55V TTL AND CMOS COMPATIBLE INPUTS NO "SHOOT-THROUGH" CURRENT THERMAL SHUTDOWN (OUTPUTS OFF) AT 160C INTERNAL CLAMP DIODES SHORTED LOAD PROTECTION (to VS or PGND or SHORTED LOAD) * NO BOOTSTRAP CAPACITORS REQUIRED * 100KHZ ONBOARD PWM 23 PIN SIP PACKAGE STYLE EX APPLICATIONS * * * * * * DC AND STEPPER MOTOR DRIVES POSITION AND VELOCITY SERVOMECHANISMS FACTORY AUTOMATION ROBOTS NUMERICALLY CONTROLLED MACHINERY COMPUTER PRINTERS AND PLOTTERS AUDIO AMPLIFICATION FIGURE 1. BLOCK DIAGRAM L E P R M I Y The SA56 is a 5A PWM Amplifier designed for motion control applications. The device is built using a multi-technology process which combines bipolar and CMOS control circuitry with DMOS power devices in the same monolithic structure. Ideal for driving DC and stepper motors; the SA56 accommodates peak output currents up to 10A. An innovative circuit which facilitates low-loss sensing of the output current has been implemented. On board PWM oscillator and comparator are used to convert an analog signal into PWM direction and magnitude for motor control applications, or to amplify audio signals using class D amplification. N I DESCRIPTION A R APEX MICROTECHNOLOGY CORPORATION * TELEPHONE (520) 690-8600 * FAX (520) 888-3329 * ORDERS (520) 690-8601 * EMAIL prodlit@apexmicrotech.com 1 SA56 ABSOLUTE MAXIMUM RATINGS ABSOLUTE MAXIMUM RATINGS SPECIFICATIONS SUPPLY VOLTAGE, VCC SUPPLY VOLTAGE, VS PEAK OUTPUT CURRENT (200mS) CONTINUOUS OUTPUT CURRENT POWER DISSIPATION POWER DISSIPATION (TA = 25C, Free Air) JUNCTION TEMPERATURE, TJ(MAX) ESD SUSCEPTIBILITY STORAGE TEMPERATURE, TSTG LEAD TEMPERATURE (Soldering, 10 sec.) JUNCTION TEMPERATURE, TJ 6V 55V 10A 5A 25W 3W 150C 1500V -40C to +150C 300C -40C to +150C SPECIFICATIONS PARAMETER VS Vcc SWITCH ON RESISTANCE, RDS(ON) CLAMP DIODE FORWARD DROP, VCLAMP LOGIC LOW INPUT VOLTAGE, VIL TEST CONDITIONS Output Current = 5A Clamp Current = 5A MIN 12 4.5 -0.5 LOGIC LOW INPUT CURRENT, IIL LOGIC HIGH INPUT VOLTAGE, VIH VIN = -0.1V -10 2 LOGIC HIGH INPUT CURRENT, IIH CURRENT SENSE OUTPUT VIN = 5.5V IOUT = 1A IOUT = 5A 1A IOUT 5A -10 CURRENT SENSE LINEARITY SHUTDOWN TEMPERATURE, TJSD QUIESCENT SUPPLY CURRENT, IS Icc OUTPUT TURN-ON DELAY TIME, tDon OUTPUT TURN-ON SWITCHING TIME, ton OUTPUT TURN-OFF DELAY TIMES, tDoff OUTPUT TURN-OFF SWITCHING TIME, toff MINIMUM INPUT PULSE WIDTH, tp Outputs Turn OFF All Logic Inputs Low TYP 0.33 2.4 200 1 2 160 13 13 300 300 100 80 200 200 75 70 1 Sourcing Outputs, IOUT = 1A Sinking Outputs, IOUT = 1A Sourcing Outputs, IOUT = 1A Sinking Outputs, IOUT = 1A Sourcing Outputs, IOUT = 1A Sinking Outputs, IOUT = 1A Sourcing Outputs, IOUT = 1A Sinking Outputs, IOUT = 1A APWM FREQUENCY (DIGITAL MODE) MAX UNITS 60 5.5 0.6 3.0 0.8 V V V V +10 Vcc A V 10 250 1.2 5 A A MA % 175 25 25 C mA mA ns ns ns ns ns ns ns ns s 500 Kc 4.1 V 1 Ref Voltage mA V 1000 ns REFERENCE VOLTAGE 3.8 4 Vref OUTPUT CURRENT (Vref 4V) ANALOG INPUT RANGE FOR FULL MODULATION Load Current = 400A HIGH CURRENT SHUTDOWN RESPONSE Output shorted 1 400 500 NOTE: These specifications apply for VS = 50V and Vcc = 5V at 25C, unless otherwise specified. APEX MICROTECHNOLOGY CORPORATION * 5980 NORTH SHANNON ROAD * TUCSON, ARIZONA 85741 * USA * APPLICATIONS HOTLINE: 1 (800) 546-2739 2 SA56 OPERATING CONSIDERATIONS GENERAL Please read Application Note 1 "General Operating Considerations" which covers stability, power supplies, heat sinking, mounting, and specification interpretation. Visit www.apexmicrotech.com for design tools that help automate tasks such as calculations for stability, internal power dissipation, current limit, heat sink selection, Apex's complete Application Notes library, Technical Seminar Workbook and Evaluation Kits. GROUND PINS The main ground for the SA56 is the package tab. In addition, there are 3 GND pins. Pin 12 is for input signal GND and pins 1 and 23 are provided for production test only. The package TAB should be connected so the load current flows through the TAB. POWER SUPPLY BYPASSING Bypass capacitors to power supply terminals Vs and Vcc must be connected physically close to the pins to prevent erratic, low efficiency operation and excessive ringing at the outputs. Electrolytic capacitors, at least 10F per output amp, are required for suppressing Vs to PGND noise. High quality ceramic capacitors (X7R) 1F or greater should also be used. Only capacitors rated for switching applications should be considered. The bypass capacitors must located as close to the power supply pins as possible (due to the very fast switching times of the outputs, the inductance of 1 inch of circuit trace could cause noticeable degradation in performance). The bypassing requirements of Vcc are less stringent, but still necessary. A 0.1F to 0.47F capacitor connected directly between the Vcc and GND (SIG) pins will suffice. PIN DESCRIPTIONS Insert pin numbers and arrange in proper order later Vs: High voltage supply Aout, Bout: Half bridge outputs PGND: Power ground, high current ground return path of the motor. SC: Short circuit detect logic output, CMOS, typically connected to SCin. Will be "HIGH" when output current exceeds the internal current threshold. SCin: Short circuit detect input, CMOS, typically connected to SC. SCin has a 100K resistor that pulls the input low when not driven. This input pin can be left open when Short Circuit Protection is not used. TLIM: Temperature limit output, CMOS, typically connected to TLIMin. Will be "HIGH" when output MOSFET temperature exceeds the internal temperature threshold. TLIMin: Temperature limit in, input CMOS. Typically connected to TLIMout. TLIMin has a 100K resistor that pulls the input low when not driven. This input pin can be left open when not used. Vcc: 5V supply for input logic and analog circuitry. DIR: Direction logic input, CMOS/TTL. Determines the active output MOSFETs in 2 quadrant digital control mode. DIS: Disable logic input, CMOS/TTL. Disables all four output MOSFETs. Also resets a latched fault condition caused by short circuit or over temperature. FAULT: Protection circuit flag output, CMOS. Goes "HIGH" when the output MOSFETs have been automatically latched "OFF" because of short circuit or excessive temperature. APWM: Digital or analog duty cycle input, CMOS/TTL or 14V analog. VREF: 4V reference voltage. Can be used at low current for biasing analog loop circuits. Internally used for generating the ramp signal in analog input mode. CPWM: PWM timing capacitor connection in analog mode. Set below 1V for digital input mode. GND (SIG): Analog ground connection for all internal low current circuitry. Iout: Analog output representing the forward output current. Typically connected to ISEN and a resistor to ground. ISEN: Analog voltage input used for programmable current limit. Typically connected to Iout and a resistor to program the current limit. MODES OF OPERATION The following chart shows the four modes of operation. Mode CPWM PWM DIR Aout Bout 2 Quad Digital GND Modulation In High High PWM 2 Quad Digital GND Modulation In Low PWM High 4 Quad Digital GND High Modulated In DIR DIR 4 Add Drive Quad Cap. to with Analog set analog Fresignal quency Not used but GND Greater Greater than 50% than 50% high for a high for a positive negative input input ANALOG INPUT OPERATION The SA56 can operate with analog or digital inputs. In the analog mode, the capacitor from CPWM to GND (SIG) sets the frequency of an internal triangular ramp signal. An analog input at the APWM pin is compared to the ramp to generate the duty cycle of the output. In Analog mode, the digital input on the DIR pin is ignored, though this pin should never be left floating. APEX MICROTECHNOLOGY CORPORATION * TELEPHONE (520) 690-8600 * FAX (520) 888-3329 * ORDERS (520) 690-8601 * EMAIL prodlit@apexmicrotech.com 3 SA56 OPERATING CONSIDERATIONS OPERATING WITH DIGITAL INPUTS A braking function can be achieved by holding the PWM input "LOW", which will turn both of the upper MOSFETs on, rapidly reducing the circulating current of the motor winding. 4 QUADRANT DIGITAL MODE During 4 quadrant operation a single digital PWM input includes magnitude and direction information. The digital PWM input signal is applied to the DIR pin and the PWM/INPUT pin is tied to "HIGH". Both pairs of output MOSFETs will switch in a locked anti-phase fashion from 0-100% duty cycle. With a 50% duty cycle the average voltage of each output will be half of Vs, and the differential voltage applied to the load will be zero. Four quadrant operation allows smooth transitions through zero current for position servos and low speed applications. Power dissipation is slightly higher since all four output MOSFETs switch every cycle. Two and 4 quadrant operation are possible with the SA56 when driven with a digital PWM signal from a microcontroller or DSP. When using a digital modulation signal, tie the CPWM pin to GND to disable the internal oscillator and ramp generator. When operating in the digital mode, pulse widths should be no less than 100ns and the switching frequency should remain less than 500KHz. This will allow enough time for the output MOSFETs to reach their full on/off state before receiving a command to reverse state. 2 QUADRANT DIGITAL MODE For sign/magnitude (2 quadrant) operation, two digital input signals are required. A digital PWM signal to the APWM pin can control the output duty cycle at one output pin with the other output pin held "HIGH". The digital input on the DIR pin will control direction by selecting the outputs that switch according to the APWM input. If DIR is a logic "HIGH", the A output will be held high and the B output will be switched as the inverse of the PWM input signal and the average output of A will always be greater than B. If DIR is logic "LOW", the B output will be held "HIGH" and the A output will be switched. Operating in 2 quadrant mode reduces switching noise and power dissipation, but limits the control of the motor at very low speed. PROTECTION CIRCUITS Thermal and short circuit protection are included in the SA56 to prevent damage during fault conditions. High current protection circuits will sense a direct short from either output to GND or Vs as well as across the load. The thermal protection will engage when the temperature of the MOSFETs reach approximately 160C. The FAULT output pin will latch "HIGH" if either protection circuits engages and will place all MOSFETs in the "OFF" state (high impedance output). The SC or TLIM output will also go "HIGH" though not be latched, to indicate which of the protection features has been triggered. If the TLIMIN is connected to TLIM and SSIN is tied to SSOUT the fault output will latch high whenever either SC or TLIM go high. The fault going high tristates the 4 output transistors. To reset the tristate condition, cycle the Vcc power or bring the DISABLE pin "HIGH" then "LOW". The most severe condition for any power device is a direct, hard-wired ("screwdriver") short from an output to ground. While the short circuit protection will latch the output MOSFETs within 500ns (typical) the die and package may be required to dissipate up to 500 Watts of power until the protection is engaged. This energy can be destructive, particularly at higher operating voltages, so good thermal design is critical if such APEX MICROTECHNOLOGY CORPORATION * 5980 NORTH SHANNON ROAD * TUCSON, ARIZONA 85741 * USA * APPLICATIONS HOTLINE: 1 (800) 546-2739 4 SA56 OPERATING CONSIDERATIONS fault tolerance is required of the system. The Vs and PGND pins may become very hot during this period of high current. PROGRAMMABLE CURRENT LIMIT The ISEN pin sources a current proportional to the forward output current of the active P channel output MOSFET. The proportionality is 200A (nom) per ampere of output current. The ISEN output is blocked during the switching transitions when current spikes can be significant. To create a programmable current limit, connect a resistor from ISEN out to GND. When the voltage across this resistor exceeds internally generated 2.75V threshold, all 4 output MOSFETs will be turned off for the remainder of the switching cycle. A 2.75K resistor will set the current limit to approximately 5 Amps. The ISEN output can also be used for maintaining a current control loop in torque motor applications. APEX MICROTECHNOLOGY * TELEPHONE (520) 690-8600 * FAX (520) 888-3329 ORDERS (520) 690-8601 * EMAILare prodlit@apexmicrotech.com This data sheet has been carefullyCORPORATION checked and is believed to be reliable, however, no responsibility is assumed for possible* inaccuracies or omissions. All specifications subject to change without notice. SA56U REV 6 DECEMBER 2004 (c) 2004 Apex Microtechnology Corp. 5