Agamem AA51882A Servo motor controller Datasheet

Agamem Microelectronics Inc.
PRELIMINARY
AA51882
SERVO MOTOR CONTROLLER
■ DESCRIPTION
The AA51882 is an integrated circuit to be applied on servo motor of radio controlled operation.
It provides some flexible functions to tune the servo. External H-Bridge driver will be chosen for
large servo motor application.
■ FEATURES
• Built-in voltage regulator.
• 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.
• 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
AA51882
SERVO MOTOR CONTROLLER
■ PIN DESCRIPTION
PIN NO.
PIN NAME
FUNCTION
1
VREG
Constant output voltage of 2.5V (typical). Make
connections from this pin to a potentiometer or
pulse stretcher resistor.
2
CST
Connect the capacitor and resistor of the pulse
stretcher section.
3
CDB
Dead band setting by connecting a capacitor.
4
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.
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.
6
CT
Local pulse setting, connect a capacitor that will
generate a triangular wave by constant current
charging.
7
MOT1
5
©Copyright Agamem Microelectronics Inc.
Output Driver 1 (connect to motor)
2
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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
AA51882
SERVO MOTOR CONTROLLER
PIN NO.
PIN NAME
FUNCTION
8
POT
Servo position voltage from the potentiometer
connected to the servo's drive shaft.
9
GND
Ground pin
10
OUT1
Connect to the (Q4) base of the external NPN
transistor
11
OUT2
Connect to the (Q1) base of the external PNP
transistor
12
OUT3
Connect to the (Q3) base of the external NPN
transistor
13
OUT4
Connect to the (Q2) base of the external PNP
transistor
14
MOT2
Output Driver 2 (connect to motor)
15
VCC
Power supply pin
16
CFP
Fixed driving pulse setting
■ ABSOLUTE MAXIMUM RATINGS
Ta=25℃
SYMBOL PARAMETER
RATINGS
UNIT
VCC
Supply voltage
3~9
V
IO
Output current
70
mA
PD
Power dissipation
500
mW
-40~+125
℃
TSTG
Storage temperature range
©Copyright Agamem Microelectronics Inc.
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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
AA51882
SERVO MOTOR CONTROLLER
■ ELECTRICAL CHARACTERISTICS
Ta=25℃, Vcc=5V
SYMBOL
PARAMETER
VCC
Supply voltage
ICC
Operating current
TEST CONDITIONS
LIMITS
UNIT
MIN TYP MAX
3.0
5
7.5
V
When output is OFF
---
5
8
mA
When output is ON
---
6
11
mA
2.35
2.5
2.65
V
VREG
Regulator output voltage
Load capacitor 0.1uF
IREF
Reference current
RT = 18 kΩ, Pin 5
current value
80
100
120
uA
VINH
High input voltage
Pin4
3.0
---
Vcc
V
WSL
Standard local pulse width
RT = 18 kΩ, CT = 0.1 uF 1.4
1.5
1.6
ms
WDB1
Minimum dead bandwidth
CFP = 0.01uF, Not
connect CDB
---
---
1.0
us
WDB2
Standard driving band width
Not connect CFP and
CDB
---
2.5
6.0
us
ASTR
Pulse Stretcher gain
RT=18 kΩ, RST=120
kΩ, CST=0.1 uF
---
100
---
times
WFP
Fixed driving pulse width
CFP = 0.01uF, Not
connect CDB
0.7
1.0
1.3
ms
Standard driving pulse width
Not connect CFP and
CDB
0.3
0.5
0.8
ms
WOP
Output pulse width
CST = 0.1 uF, RST =
120 kΩ, Pulse width
100uS (3pin)
8.0
10.0
12.0
ms
VSAT
Output pin saturation voltage ISINK = 20 mA
---
0.2
0.4
V
WSDP
©Copyright Agamem Microelectronics Inc.
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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
AA51882
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) 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 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 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.
©Copyright Agamem Microelectronics Inc.
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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
AA51882
SERVO MOTOR CONTROLLER
(7) Output driver
The output driver controls the servo current direction. For heavy load application, the OUT2
and OUT4 pin will be connected to the base of the external PNP transistors and the OUT1and
OUT3 pin will be connected to the base of the external NPN transistors. MOT1 and MOT2 pins
are connected to PIN1 by 18kΩ resistor internally. They can be connected to both side of servo
to get the better performance when servo is to be stopped.
■ TYPICAL APPLICATION EXAMPLE
A. H-Bridge TRANSISTOR Driver
©Copyright Agamem Microelectronics Inc.
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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
AA51882
SERVO MOTOR CONTROLLER
B. H-Bridge MOSFET Driver
VS
C9
0.01uF
16
15
CFP
VCC
OUT4 13
VS
MOT1 7
C8 103pF
OUT2 11
VIN 4
Q1
Q2
M VR1
MOT2 14
5KΩ
R7
1KΩ
Q3
OUT3 12
Q4
OUT1 10
RT
CT
POT
5
6
8
RX 1KΩ
CDB CST GND VREG 1
3
2
R1
470KΩ
9
R9
1MΩ
R2
18KΩ
C3
0.1uF
C1
0.1uF
C10
C2 0.001uF
0.1uF
R4 150KΩ
C4
0.22uF
C5
4.7uF
* When the servo is about to reach the target position, the servo maybe overshoot for speed issue.
There are two ways to suppress such dispensable action.
If MOT1 and MOT2 pins are connected to both side of servo (R9 is no need), you can try to reduce the
value of R1 to let servo make an instant stop on the target position. If MOT1 and MOT2 are floating for
PCB layout issue, R9 can be plugged and tuned to get the same efforts described before.
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.
Please select low threshold voltage (Vt) MOSFET driver for the maximum driving capacity. If Vt is
higher, you should provide higher power supply voltage in order to turn on the MOSFET fully.
■ ORDERING INFORMATION
ORDER NO.
PACKAGE
PACKING
Q’TY
AA51882A
TSSOP 16L
TAPE & REEL
2,500ea
©Copyright Agamem Microelectronics Inc.
7
MARK CHART
AA51882
XXXX
A
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
AA51882
SERVO MOTOR CONTROLLER
■ PACKAGE DIMENSIONS
■ 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.
©Copyright Agamem Microelectronics Inc.
8
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.
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