AN3370K PANASONIC | Alldatasheet

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Technical content

The AN3370K can amplify high-frequency current gen- erated by the built-in oscillator and drive the Flying-erase head. This IC also allows to set an oscillation frequency and an output current optionally with external constants according to the erase head. n Features

  • Built-in high-accuracy, stable oscillator.
  • Capable of varying output current value and an oscilla- tion frequency with external constants. AN3370K Flying-Erase IC n Block Diagram 1.1–0.25 1.65–0.25 0.25 3.0–0.3 3.5–0.25 0.5 1.11.778+ 0.1 – 0.05 Unit : mm 10-Pin Shrunk SIL Plastic Package (10-SSIP) 6.0–0.3 (12.0) 18.24–0.3 1 2 3 4 5 6 7 8 9 10 V CC GND Output Driver OSC

V 1= 5V, RL= 300Ω V 1= 5V, RL= 300Ω Supply current Oscillation output amplitude Oscillation frequency 11.55 12.1 V PP MHz Parameter min Condition typ max UnitSymbol V O2 V 1= 0V, RL= 300ΩOscillation output amplitude 10 mV PP V 1HFlying ON 3.5 V V 1LFlying OFF 0.8 V ICC V 1= 5V 20 28 36 mA n Electrical Characteristics (VCC =12V, Ta=25˚C) 1 2 3 4 5 6 8 107 1.8kΩ 0.01µF V CC =12V 0.01 µF 4µH 68pF68pF56pF 100µF 4.7µH 33pF 0.01µF 5.1kΩ Output Driver OSC Flying Control Voltage Note) Do not apply a voltage (0V included) to the Pin2 from the external. Parameter Symbol Rating Unit V CC PD Topr Tstg Power dissipation Supply voltage Operating ambient temperature Storage temperature 12.6 500 – 20 to + 70 – 55 to +150 V mW n Absolute Maximum Ratings (Ta=25˚C) Parameter Symbol Range Operating supply voltage range V CC 10.5V to 12.5V n Recommended Operating Range (Ta = 25˚C) n Application Circuit

Pin No. Pin name Description I/O impedance Equivalent circuitTyp. waveform Power supply Output pin GND Oscillation input pin Reference voltage pin Oscillation feedback pin Oscillation output pin High-frequency current 3M Ω 60kΩ 10kΩ NPN T r emitter NPN T r emitter 3kΩ 6.2kΩ 3.4V 30kΩ 30kΩ 30kΩ 30kΩ 5 3 10kΩ 10kΩ 6V 8 93kΩ 106.2kΩ Flying erase control pin Flying erase ON/OFF control pin. ON when 3.5V or more is applied, and OFF when 0.8V or less is applied. Feedback pin to obtain a DC volt- age by filtering an output signal via an external capacitor Do not apply a voltage from the external. Power supply pin. Apply 12V typically from the external. Generates a reference voltage of 1/2 V CC (approx. 6V) A signal from Pin10 oscillation output is divided by the capacitor and is fed back. Oscillates at the frequency deter- mined by L, C of the Pins8, 9, 10 It is possible to change the current which can be taken out of an out- put, by varying the resistor between this pin and GND. Feedback pin n Pin Descriptions

0.01µF V CC =12V V H = 5V 0.01µF 100µF 4.7µH C 1 C 2 R X 0.01µF LX C X1 C X2 AN3370K Flying EraseH Erase Head L n Supplementary Explanation

  • Characteristic Curve 1) Internal Oscillation Frequency An internal oscillation frequency is determined by the fol- lowing expression. Set C X1 , CX2 , and LX according to a fre- quency. In order to obtain stable oscillation, set CX1 /CX2 near 1 and absolute value of CX1 , CX2 to such a considerable extent that an internal IC capacitance (approx. 5pF) and an external PCB capacitance can be ignored. 2) R X Output current amplitude from the IC is determined by the external resistor RX of the Pin7 ; it is approximately as shown in Fig. 1. Therefore, use within the following range. I 5=20mA pp to 65mApp. 3) Do not apply the Pin1 voltage when VCC is off. Use the Pin2 voltage open. 4) Output Dynamic Range Since the output pin (5) dynamic range of the AN3370K is 8V PP (at VCC =12V), set a combination of C1, C2, and erase head inductance (L) so that the following will be ensured. I5 (mApp) · load impedance < 8VPP. 5) Serial and Parallel Resonance Points
  • Serial resonance frequency Since Pin5 amplitude is minimized at a point of f 1, set f1 so that it will almost coincide with fOSC .
  • Parallel resonance frequency Suppose the internal capacitance of the Pin5 is C 5, then parallel resonance frequency is Although an erase head current is maximized at this point, set f2/fOSC = 1.25 to 1.4 fOSC = 1 Lx·C X1 · CX2 C X1 + CX22p f1 = 1 L (C1 + C2)2p (2) f2 = L C 5 + C1 C 2 + Fig. 1. I5–R X I5 (mAPP) R X (kΩ ) 0 5 10 15 20 25 100 V CC =12V LX = 5.6µH C X1 = CX2 = 68pF fosc=10.8MHz I 50Ω R X 0.047µF 5 7