LB1921 Sanyo Semiconductor Corporation, LB1921 Datasheet
LB1921
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LB1921 Summary of contents
Page 1
... Applications • Paper feed and drum motor drivers in FAX and PPC units Functions and Features • The LB1921 is an improved output current version of the LB1824. • Three-phase bipolar brushless motor driver • Digital speed control circuit • Thermal shutdown circuit • ...
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... Input voltage high low V SHL [Oscillator] Output high-level voltage V OH (CR) Output low-level voltage V OL (CR) Oscillator frequency f (CR) Amplitude V (CR) LB1921 Symbol Conditions V max CC V max M T ≤ 100 ms I max O Pd max1 Independent IC Pd max2 With an arbitrarily large heat sink Topr ...
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... Input high-level voltage V IH (S/S) Input low-level voltage V IL (S/S) Pull-down resistor R D (S/S) [Reversing Pin] Input high-level voltage V IH (F/R) Input low-level voltage V IL (F/R) ∆V Hysteresis IN Pull-down resistor R D (F/R) LB1921 Conditions Design target value I = – Gain: 100 kHz (FG (FGS ) ...
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... This pin goes low when the motor speed is within the lock range (±6.25%). Speed discriminator output D 24 OUT Over speed INT 25 Integrator input IN INT 26 Integrator output (speed control) OUT P 27 PLL output OUT FGS 28 FG amplifier output (after the Schmitt trigger circuit) OUT LB1921 Function high . CC No. 5439-4/10 ...
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... Note: Input high refers to the state where IN > IN The formula below gives the relationship between the oscillator frequency (f f (servo /(ECL divisor (16) number of counts) FC OSC = f /8192 OSC Crystal Oscillator External Circuit Equivalent Circuit Block Diagram LB1921 R/R = high IN2 IN3 IN1 IN2 IN3 ...
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... Sample Application Circuit AC Test Circuit Diagram LB1921 Unit (resistance: , capacitance: F) Unit (capacitance: F) No. 5439-6/10 ...
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... The speed lock range is ±6.25% of the fixed speed and the LD pin goes low when the motor is in the lock range. (This pin is an open-collector output.) When the motor speed goes out of the lock range, the LB1921 changes the motor drive output on duty according to the speed error to control the motor speed to be within the lock range. ...
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... PWM drive scheme and switches large currents in the output, noise can occur easily. Thus the power supply must be adequately stabilized so that this noise does not cause the IC to operate incorrectly. C1, C2 and C3 must be connected as close as possible to GND1. In particular, C1’s characteristics are easily influenced and thus require caution. LB1921 = 10 mA mA) ...
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... Previously, when this was a problem, additional capacitors were used to resolve the problem. However, since the LB1921 resolves this problem at the circuit level, no additional external components are required. During switching, whiskers of less than about 10 ns may be observed on the RF voltage waveform, but these are not a problem ...
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... SANYO believes information herein is accurate and reliable, but no guarantees are made or implied regarding its use or any infringements of intellectual property rights or other rights of third parties. This catalog provides information as of July, 1998. Specifications and information herein are subject to change without notice. LB1921 PS No. 5439-10/10 ...