NJM37770 New Japan Radio Co., Ltd., NJM37770 Datasheet
NJM37770
Related parts for NJM37770
NJM37770 Summary of contents
Page 1
... GENERAL DESCRIPTION NJM37770 is a stepper motor driver, which consists of a LS-TTL compatible logic input stage, a current sensor, a monostable multivibrator and a high power H-bridge output stage. The NJM37770 is a high power version and pin- compatible with the NJM37717and also NJM37770 is a high voltage version with NJM3770A. Two NJM37770 and a small number of external components form a complete control and drive unit stepper motor systems ...
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... RC Network. Reference voltage. Controls the threshold voltage of the comparator and hence the output current. Input resistance: typically 6.8 k Motor output A, Motor current flows from M Common emitter. Connect the Sense resistor between this pin and ground. NJM37770 to M when Phase is high ...
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... FUNCTIONAL DESCRIPTION The NJM37770 is intended to drive a bipolar constant current through one winding of a 2-phase stepper motor. Current control is achieved through switched-mode regulation, see figure 3 and 4. Three different current levels and zero current can be selected by the input logic. The circuit contains the following functional blocks: • ...
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... R off , it is ignored. off , as an analog voltage. This voltage is fed S NJM37770 together with the R , and compared S and ...
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... 7,8 10, °C Symbol Min V 4. -1300 NJM37770 Min Max Unit - -1500 +1500 -40 +150 °C -55 +150 °C Typ Max Unit 5 5 ...
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... I = HIGH +25° µs off MM on Symbol Conditions Rth DIP package. J-GND Rth DIP package. Note 2. J-A 2 PCB copper area with free air convection Ta=+25°C NJM37770 = 820 pF Min Typ - ...
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... The choice of motor may then require other values on the R to obtain a switching frequency above the audible range. Switching frequencies above 40 kHz are not recom- mended because the current regulation can be affected. Figure 7. Typical stepper motor driver application with NJM37770 and ground. MM and circuit GND should be kept as short as possible ...
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... V used for maximum performance and reliability. Figure 8. Copper foil used as a heatsink input, limited microstepping can 5V. R voltage. Ultra-fast recovery diodes should be MM Figure 9. Principal operating sequence. NJM37770 1 good . The anodes shall MM ...
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... The junction temperature of the chip highly effects the lifetime of the circuit. In high-current applications, the heatsinking must be carefully considered. The Rth of the NJM37770 can be reduced by soldering the ground pins to a suitable copper ground plane on j-a the printed circuit board (see figure applying an external heatsink type V7 or V8, see figure 10. ...
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... Figure 14. Typical power dissipation vs. motor current Figure 12. Typical lower diode voltage drop vs. recirculating current Figure 15. Allowable power dissipation vs. ambient temperature NJM37770 igure 13. Typical sink saturation F vs. output current The specifications on this databook are only given for information , without any guarantee as regards either mistakes or omissions. ...