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MICROSTEPPING MOTOR CONTROLLER WITH DUAL DAC
GENERAL DESCRIPTION
NJU39612 is a dual 7-bit+sign; Digital-to-Analog Converter
(DAC) developed to be used in micro stepping applications
together with the dual stepper motor driver. The NJU39612
has a set of input registers connected to an 8-bit data port for
easy interfacing directly to a microprocessor. Two registers
are used to store the data for each seven-bit DAC, the eighth
bit being a sign bit (sign/magnitude coding).
FEATURES
• Analog control voltages from 3V down to 0.0V
• High-speed microprocessor interface
• Full -scale error
• Fast conversion speed
• Matches the dual stepper motor drivers
• Package
EMP20
BLOCK DIAGRAM
WR
CS
A0
D7 - D0
RESET
Figure 1. Block Diagram
1 LSB
3 s
E1
E2
POR
PACKAGE OUTLINE
NJU39612E2
V
V
DD
Ref
NJU39612
DA- Data 1
E
C
D
R
DA- Data 2
E
C
D
R
R
V
ss
NJU39612
Sign 1
DA 1
D / A
DA
2
D / A
Sign 2
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Table of Contents
Related Manuals for JRC NJU39612
Summary of Contents for JRC NJU39612
- Page 1 NJU39612 is a dual 7-bit+sign; Digital-to-Analog Converter (DAC) developed to be used in micro stepping applications together with the dual stepper motor driver. The NJU39612 has a set of input registers connected to an 8-bit data port for easy interfacing directly to a microprocessor. Two registers are used to store the data for each seven-bit DAC, the eighth bit being a sign bit (sign/magnitude coding).
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Page 2: Pin Configuration
Sign Sign 1, TTL/CMOS level. To be connected directly to NJM377x phase input. Databit D7 is transfered non inverted from NJU39612 data input. Voltage Drain-Drain, logic supply voltage. Normally +5 V. Write, TTL/CMOS level, input for writing to internal registers. Data is clocked into flip flops on positive edge. -
Page 3: Definition Of Terms
Data Bus Interface NJU39612 is designed to be compatible with 8-bit microprocessors such as the 6800, 6801, 6803, 6808, 6809, 8051, 8085, Z80 and other popular types and their 16/32 bit counter parts in 8 bit data mode. The data bus inter- face consists of 8 data bits, write signal, chip select, and two address pins. - Page 4 Data points are exaggerated for illustra- tion purpose. TNom = code 127. Data Transfer D7 —> Sign1, (D6—D0) —> (Q61—Q01) D7 —> Sign2, (D6—D0) —> (Q62—Q02) No Transfer Figure 7. Table showing how data is transfered inside NJU39612.
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Page 5: Absolute Maximum Ratings
NJU39612 ABSOLUTE MAXIMUM RATINGS Parameter Pin no. Symbol Unit Voltage Supply Logic inputs 5-14,16 -0.3 + 0.3 Reference input -0.3 + 0.3 Current Logic inputs 5-14,16 -0.4 +0.4 Temperature Storage temperature +150 Operating ambient temperature RECOMMENDED OPERATING CONDITIONS Parameter Symbol... -
Page 6: Electrical Characteristics
NJU39612 ELECTRICAL CHARACTERISTICS Electrical characteristics over recommended operating conditions. Parameter Symbol Conditions Unit Logic Input Reset logic HIGH input voltage Reset logic LOW input voltage Logic HIGH input voltage Logic LOW input voltage Reset input current < V < V -0.01... - Page 7 NJU39612 D0-D7 Sign Figure 8. Timing Reset pres Sign Figure 9. Timing of Reset...
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Page 8: Applications Information
With a microprocessor, data is stored in ROM / RAM area or each step is successively calculated. NJU39612 is connected like any peripheral addressable device. All parts of stepping can be tailored for specific damping needs etc. - Page 9 NJU39612 Time when motor is in a compromise position. Time when micro position is correct. Write signal. Motor position. Writing to channel 1. Writing to channel 2. Time Actual data = true position Useful time = correct Double pulse write signal...
- Page 10 NJU39612 Programming NJU39612 There are basically two different ways of programming the NJU39612. They are called “single-pulse programming” and “double-pulse programming.” Writing to the device can only be accomplished by addressing one register at a time. When taking one step, at least two registers are normally updated. Accordingly there must be a certain time delay between writing to the first and the second register.
- Page 11 NJU39612 D0-D7 NJU39612 NJM3777 Counter PROM Clock Up/Dn Vref Step Voltage Control Logic Reference Direction Figure 12. Typical blockdiagram of an application without a microprocessor. (+5 V) 0.1 F 0.1 F 10 F V DD Sign Phase NJU39612 NJM3777 Sign...