AA51883 Agamem Microelectronics Inc. PRELIMINARY SERVO MOTOR CONTROLLER ■ DESCRIPTION The AA51883 is an integrated circuit to be applied on servo motor of radio controlled operation. It provides some flexible functions to tune the servo. External PNP driver will be chosen for servo motor application. ■ FEATURES • Internal output NPN power transistor. • Adjustable dead band range control by external capacitor. • Fixed pulse width setting to provide start-up power and speed control • Incorporates a protection circuit for "H-Bridge" driving configuration ■ APPLICATIONS • Servo motor control. • Radio controlled car, boat, and airplane. • IA products (such as air-condition). • Remote positioning. ■ BLOCK DIAGRAM VIN VCC 2 3 1 Directional Logic Control 8 CFP PWM Control Output Driver EXP1 16 OUT1 13 OUT2 12 Servo Position & Over-Time Logic Sawtooth Wave & One Shot Generator Pulse Stretcher Voltage Regulator 9 10 11 7 6 15 RT CT POT CDB CST GND ©Copyright Agamem Microelectronics Inc. 1 EXP2 5 VREG www.agamem.com.tw 2008/4/9 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. AA51883 Agamem Microelectronics Inc. PRELIMINARY SERVO MOTOR CONTROLLER ■ PIN DESCRIPTION EXP1 CFP VCC N.C. VREG 1 2 3 4 5 CST CDB VIN 6 7 8 ○ 16 15 OUT1 GND 14 13 12 N.C. OUT2 11 10 9 POT CT EXP2 RT TOP VIEW PIN NO. PIN NAME PIN FUNCTION 1 EXP1 Connect to the (Q1) base of the external PNP transistor 2 CFP Fixed driving pulse setting 3 VCC Power supply pin 5 VREG Constant output voltage of 2.5V (typical). Make connections from this pin to a potentiometer or pulse stretcher resistor. 6 CST Connect the capacitor and resistor of the pulse stretcher section. 7 CDB Dead band setting by connecting a capacitor. 8 VIN Input signal, an adjustable pulse of 20ms cycle and 1.0-2.0ms pulse-width, operate with a positive pulse of peak value 3V or greater. 9 RT Timing Resistor, connect a resistor that will determine the value of the constant current of this pin. A resistor of 18kΩ will yield a current of 1.0mA. 10 CT Local pulse setting, connect a capacitor that will generate a triangular wave by constant current charging. 11 POT Servo position voltage from the potentiometer connected to the servo's drive shaft. 12 EXP2 Connect to the (Q2) base of the external PNP transistor 13 OUT2 Output Driver 2 (connect to motor) 15 GND Ground pin 16 OUT1 Output Driver 1 (connect to motor) ©Copyright Agamem Microelectronics Inc. 2 www.agamem.com.tw 2008/4/9 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. AA51883 Agamem Microelectronics Inc. PRELIMINARY SERVO MOTOR CONTROLLER ■ ABSOLUTE MAXIMUM RATINGS ℃ Ta=25 SYMBOL PARAMETER RATINGS UNIT Vcc Supply voltage 9 V IO Output current 50 mA Pd Power dissipation 500 mW —40~125 ℃ Tstg Storage temperature range ■ ELECTRICAL CHARACTERISTICS ℃ and Vcc=5V Ta=25 Vcc Supply voltage ICC Operating current When output is OFF When output is ON LIMITS UNIT MIN TYP MAX 3.0 5 7.5 V --5 8 mA --6 11 mA VREG Regulator output voltage Load capacitor 0.1uF 2.35 2.5 2.65 V 80 100 120 uA 3.0 --- Vcc V 1.4 1.5 1.6 ms --- --- 1.0 us --- 2.5 6.0 us --- 100 --- times 0.7 1.0 1.3 ms 0.3 0.5 0.8 ms 8.0 10.0 12.0 ms --- 0.2 0.4 V SYMBOL IREF VinH W SL W db1 W db2 ASTR W FP W SDP Wop Vsat PARAMETER CONDITIONS RT = 18 kΩ, Pin 5 current value High input voltage Pin4 Standard local RT = 18 kΩ, CT = 0.1 uF pulse width Minimum dead CFP = 0.01uF, Not connect bandwidth CDB Standard driving Not connect CFP and CDB band width Pulse Stretcher RT=18 kΩ, RST=120 kΩ, gain CST=0.1 uF Fixed driving pulse CFP = 0.01uF, Not connect width CDB Standard driving Not connect CFP and CDB pulse width CST = 0.1 uF, RST = 120 Output pulse width kΩ, Pulse width 100uS (3pin) Output pin I = 20 mA saturation voltage SINK Reference current ©Copyright Agamem Microelectronics Inc. 3 www.agamem.com.tw 2008/4/9 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. AA51883 Agamem Microelectronics Inc. PRELIMINARY SERVO MOTOR CONTROLLER ■ APPLICATION CIRCUIT C9 0.01uF 2 3 CFP VCC EXP1 1 VS OUT1 16 Q2 EXP2 12 VIN 8 AA51883 Q1 C8 103pF M VR1 OUT2 13 5K Ω Ω R7 1K RX 1KΩ RT CT POT CDB 9 10 11 7 CST GND VREG 5 6 15 R1 470K Ω R2 18K C3 0.1uF C2 C1 0.1uF 0.1uF C10 0.001uF R4 150K C4 0.22uF Ω Ω C5 4.7uF Half H-Bridge application using two external PNPs When the servo is about to reach the target position, the servo maybe overshoot for speed issue. OUT1 and OUT2 pins are connected to both side of servo, you can try to reduce the value of R1 to let servo make an instant stop on the target position. The application circuit is for reference only. The value of resistor and capacitor needs to be changed and gets the best performance in various servos. ©Copyright Agamem Microelectronics Inc. 4 www.agamem.com.tw 2008/4/9 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. AA51883 Agamem Microelectronics Inc. PRELIMINARY SERVO MOTOR CONTROLLER ■ FUNCTIONAL DESCRIPTION (1) Voltage Regulator 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) Saw tooth 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 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 of 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, the servo will start to shift. The dead band will change according to the value of capacitor connected to the CDB pin. (5) Directional Logic Control The comparator circuit compares pulses from the servo control input (VIN pin) and the voltage controlled pulse generator. It 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 ©Copyright Agamem Microelectronics Inc. 5 www.agamem.com.tw 2008/4/9 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. AA51883 Agamem Microelectronics Inc. PRELIMINARY SERVO MOTOR CONTROLLER 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 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 light load application, the servo can be connected with OUT1 and OUT2 pin only. For heavy load application, the EXP1 and EXP2 pin will be connected to the base of the external PNP transistor. It drives in an H-bridge configuration (The sink NPN drivers are built inside the chip). ■ 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. ■ ORDERING INFORMATION ORDER NO. PACKAGE PACKING Q’TY AA51883A TSSOP 16L TAPE & REEL 2,500ea ©Copyright Agamem Microelectronics Inc. 6 MARK CHART AA51883 XXXX A www.agamem.com.tw 2008/4/9 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. AA51883 Agamem Microelectronics Inc. PRELIMINARY SERVO MOTOR CONTROLLER ■PACKAGE DIMENSIONS TSSOP 16L E1 E L C 12°(4X) A1 A A2 theta D SYMBOLS A A1 A2 b C D E E1 e L y theta DIMENSIONS IN MILLIMETERS MIN NOM MAX --0.05 0.80 0.19 0.09 4.90 6.20 4.30 --0.45 --0° ----1.00 ----5.00 6.40 4.40 0.65 0.60 ----- 1.20 0.15 1.05 0.30 0.20 5.10 6.60 4.50 --0.75 0.10 8° e b DIMENSIONS IN INCHES MIN NOM MAX --0.002 0.031 0.007 0.004 0.193 0.244 0.169 --0.018 --0° ----0.039 ----0.197 0.252 0.173 0.026 0.024 ----- 0.048 0.006 0.041 0.012 0.008 0.201 0.260 0.177 --0.030 0.004 8° NOTE 1. PACKAGE BODY SIZES EXCLUDE MOLD FLASH PROTRUSIONSOR GATE BURRS 2. TOLERANCE +/- 0.1 mm UNLESS OTHERWISE SPECIFIED 3. COPLANARITY : 0.1 mm 4. CONTROLLING DIMENSION IS MILLIMETER. CONVERTEDINCH DIMENSIONS ARE NOT NECESSARILY EXACT. 5. FOLLOWED FROM JEDEC MO-153 ©Copyright Agamem Microelectronics Inc. 7 www.agamem.com.tw 2008/4/9 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.