AA51890

Agamem Microelectronics Inc. PRELIMINARY ■ DESCRIPTION AA51890 SERVO MOTOR CONTROLLER The AA51890 is a BJT integrated circuit for servo motor control applications. It has the feature of internal circuit of maintaining constant voltage which helps stabilizing from fluctuation caused by voltage source and the ambient temperature. It can control external H-Bridge driver for large servo motor application. ■ FEATURES • Built-in voltage regulator. • Adjustable dead band range control. • Setting up the dead band by the internal constant. • Incorporates a protection circuit for "H-Bridge" driving configuration. • Small outline package – TSSOP16L. ■ APPLICATIONS • Servo motor control. • Radio controlled car, boat, and airplane. • IA products (such as air-condition). • Remote positioning. ■ BLOCK DIAGRAM ©Copyright Agamem Microelectronics Inc. 1 www.agamem.com.tw 2008/5/5 AGAMEM MICROELECTRONICS INCOPERATION RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. AGAMEM DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCTS OR CIRCUIT DESRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. Agamem Microelectronics Inc. PRELIMINARY ■ PIN DESCRIPTION ○ AA51890 SERVO MOTOR CONTROLLER RT EXTP2 EXTN2 GND EXTN1 EXTP1 CST OUT1 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 CT POT VIN OUT2 GND RDB VCC VREG TOP VIEW PIN NO. 1 2 3 4 5 6 7 8 9 10 11 12 13 PIN NAME RT EXTP2 EXTN2 GND EXTN1 EXTP1 CST OUT1 VREG VCC RDB GND OUT2 FUNCTION Timing Resistor Connect to the base of the external PNP transistor Connect to the base of the external NPN transistor Ground pin Connect to the base of the external NPN transistor Connect to the base of the external PNP transistor Stretcher capacitor Output Driver 1 (connect to motor) Regulated Voltage output Power supply pin Error pulse output Ground pin Output Driver 2 (connect to motor) 2 ©Copyright Agamem Microelectronics Inc. www.agamem.com.tw 2008/5/5 AGAMEM MICROELECTRONICS INCOPERATION RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. AGAMEM DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCTS OR CIRCUIT DESRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. Agamem Microelectronics Inc. PRELIMINARY PIN NO. 14 15 16 PIN NAME VIN POT CT FUNCTION Input signal Servo position voltage Timing Capacitor AA51890 SERVO MOTOR CONTROLLER ■ ABSOLUTE MAXIMUM RATINGS Ta=25℃ SYMBOL PARAMETER VCC IO PD TSTG Supply voltage Output current Power dissipation Storage temperature range RATINGS 3.2~7.5 40 300 —25~+125 UNIT V mA mW ℃ ■ ELECTRICAL CHARACTERISTICS Ta=25℃, Vcc=5V SYMBOL VCC ICC IOUT VREG IREG PARAMETER Supply voltage Operating current Output current Regulator output voltage Regulator output current TEST CONDITIONS LIMITS UNIT MIN TYP MAX 3.2 5 7 V ------5 7 30 2.5 --7 10 36 2.65 --mA mA mA V mA When output is OFF When output is ON Load capacitor 0.1uF Load resistor 500Ω 2.35 4 ©Copyright Agamem Microelectronics Inc. 3 www.agamem.com.tw 2008/5/5 AGAMEM MICROELECTRONICS INCOPERATION RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. AGAMEM DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCTS OR CIRCUIT DESRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. Agamem Microelectronics Inc. PRELIMINARY ■ FUNCTIONAL DESCRIPTION (1) Voltage Regulator AA51890 SERVO MOTOR CONTROLLER This circuit is composed of a band gap circuit, and outputs a 2.5-volt temperature compensated reference voltage. This reference voltage is stabilized when the supply voltage is variable. (2) Sawtooth wave & One-Shot Generator Connect a capacitor to CT pin will generate a triangular wave by constant current charging. A typical value is 0.1uF. The constant current is determined by a resistor connected to RT pin. A typical capacitor of approximately 0.1uF should be connected in parallel with the resistor to increase stability. (3) Servo Position & Over-Time logic This circuitry consists of a pulse width comparator, which compares the servo position detection signal (POT pin) from the one-shot timer (CT pin) whose period depends on the resistance of a potentiometer connected to the servo's drive shaft. This feedback is what provides the stability for the control circuitry. (4) Pulse Stretcher The difference between the servo control signal and the feedback signal is the error signal. This error signal is used to toggle the direction the current flows through the servo. The function of this pulse stretcher is to “stretch” the small error signal long enough and increases the duty cycle to the motor for it can maintain sufficient holding force. The circuit also implements a “dead band” function that prevents servo jitter and hunting. This is a range over which differences between the input and reference signals will not cause servo operation. When the signal differences exceed this “dead band” range, drive to the motor occurs. Servo’s drive shaft. The dead band will change according to the value of resistor connected to the RDB pin. (5) Directional Logic Control The comparator circuit compares pulses from the servo control input (VIN pin) and the voltage controlled pulse generator and provides either a positive or a negative output depending on whether the signal pulse width is larger or smaller than the position generator’s output pulse (POT pin). Application of this error voltage to the motor driver circuit causes the motor to turn in a direction that will minimize the error until both pulse widths are the same. (6) PWM Control This signal generated by directional logic control block is used to control a flip-flop that toggles the direction the current flows through the motor. The outputs of the flip-flop drive an external H-Bridge output driver that handles the high current going through the motor. This output of this block will be turned on or off with each input pulse based on the status of the directional ©Copyright Agamem Microelectronics Inc. 4 www.agamem.com.tw 2008/5/5 AGAMEM MICROELECTRONICS INCOPERATION RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. AGAMEM DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCTS OR CIRCUIT DESRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. Agamem Microelectronics Inc. PRELIMINARY AA51890 SERVO MOTOR CONTROLLER logic. The PWM drive techniques provide the benefits of reduced power dissipation, improved servo motor performance and positively affect system efficiency. (7) Output driver The output driver controls the servo current direction. For heavy load application, the EXTP1 and EXTP2 pin will be connected to the base of the external PNP transistors and the EXTN1 and EXTN2 pin will be connected to the base of the external NPN transistors. ■ TYPICAL APPLICATION EXAMPLE A. H-Bridge TRANSISTOR Driver ©Copyright Agamem Microelectronics Inc. 5 www.agamem.com.tw 2008/5/5 AGAMEM MICROELECTRONICS INCOPERATION RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. AGAMEM DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCTS OR CIRCUIT DESRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. Agamem Microelectronics Inc. PRELIMINARY B. H-Bridge MOSFET Driver AA51890 SERVO MOTOR CONTROLLER ■ ORDERING INFORMATION ORDER NO. AA51890A PACKAGE TSSOP 16L PACKING TAPE & REEL Q’TY 2,500ea MARK CHART AA51890 XXXX A ©Copyright Agamem Microelectronics Inc. 6 www.agamem.com.tw 2008/5/5 AGAMEM MICROELECTRONICS INCOPERATION RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. AGAMEM DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCTS OR CIRCUIT DESRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. Agamem Microelectronics Inc. PRELIMINARY ■ PACKAGE DIMENSIONS AA51890 SERVO MOTOR CONTROLLER ■ NOTES ON USE • The specifications for the product described in this document are for reference only. Upon actual use, therefore, please request that specifications to be separately delivered. • The application circuit examples explain typical applications of the products, and do not guarantee the success of any specific mass-production design. • Application circuit diagrams and circuit constants contained herein are shown as examples of standard use and operation. Please pay careful attention to the peripheral conditions when designing circuits and deciding upon circuit constants in the set. • Take account of common impedance when designing the earth line on a printed wiring board. ©Copyright Agamem Microelectronics Inc. 7 www.agamem.com.tw 2008/5/5 AGAMEM MICROELECTRONICS INCOPERATION RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. AGAMEM DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCTS OR CIRCUIT DESRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.