CXA1597P

CXA1597M/P Recording Equalizer Amplifier for Stereo Cassette Decks Description The CXA1597M/P is a bipolar IC developed for recording equalizer amplifier in analog cassette decks. It is suited specifically for double cassette decks. Incorporating the filter circuit greatly reduces the external parts. Features • Built-in filter required for recording equalizer amplifiers • Inductor (coil) is unnecessary • Low frequency boost is possible with an external capacitor • Built-in recording mute function (requiring only an external time constant circuit to implement soft mute) • Fade in/out DC controllable • NORM/CrO2/METAL tape mode switching function • NORM/HIGH tape speed recording switching function • DC controllable for recording level calibration (approximately ±6dB variable) • DC controllable for high frequency equalizer amplifier gain (approximately ±4dB variable) • Built-in 2 channels • Small package Applications Recording equalizer amplifier for stereo analog cassette decks (Supports ALPS ELECTRIC CO., LTD. HADKH55-series heads) Block Diagram and Pin Configuration REC MUTE REC OUT2 9 8 CXA1597M 16 pin SOP (Plastic) CXA1597P 16 pin DIP (Plastic) Structure Bipolar silicon monolithic IC Absolute Maximum Ratings • Supply voltage VCC 17 V • Operating temperature Topr –20 to +75 °C • Storage temperature Tstg –65 to +150 °C • Allowable power dissipation PD (CXA1597M) 500 mW (CXA1597P) 900 mW Operating Conditions Supply voltage Dual power supplies (VCC – VEE) ±5.0 to 8.0 V Single power supply (VCC) 10.0 to 16.0 V REC CAL Gp CAL REC IN2 IREF BOOST2 16 15 14 13 12 11 10 BIAS REC EQ 2 CONTROL CXA1597M/P REC EQ 1 VG 1 2 3 4 5 6 TAPE EQ VEE VCC 7 Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits. –1– REC OUT1 SPEED DGND GND BOOST1 REC IN1 E95127-ST CXA1597M/P Pin Description Pin No. Symbol Typical pin voltage DC AC I/O Z (in) (Ta = 25°C, VCC = 7.0V, VEE = –7.0V, DVCC = 5.0V) Equivalent circuit Description 10k 1 SPEED — — I — 1 DGND Tape speed switching pin. ∗ Normal/Double speed switching. High = Double speed Low = Normal speed 2 TAPE EQ 2.5V — I — 50k 2 5k 5k DGND Tape equalizer amplifier switching ∗ (NORM/CrO2/ METAL switching) pin. High = REC EQ METAL Medium = REC EQ CrO2 Low = REC EQ NORM Connect to GND. 3 DGND 0.0V — I — GND 50k 4 13 REC IN1 REC IN2 0.0V –18dBv I 50kΩ 4 13 Recording equalizer amplifier input pin. 30k 5 GND 5 GND (VG) 0.0V — I 15kΩ 30k Connect to GND for positive/ negative dual power supplies. Vcc/2 (center potential) for a single power supply. (Connect a capacitor of 10µF or more) –2– CXA1597M/P Pin No. Symbol Typical pin voltage DC AC I/O Z (in) Equivalent circuit Description Connection pin of an external capacitor for low frequency boost. ∗ When low frequency boost is unnecessary, connect to GND for positive/ negative dual power supplies; connect a capacitor (3.3µF or more) for a single power supply. Connect to the negative power supply for positive/negative dual power supplies. Connect to GND for a single power supply. 280 6 11 BOOST1 BOOST2 0.0V — I 9.5kΩ 4.8k 5.5k 6 11 34k 35.5k 280 GND 7 VEE –7.0V — I — 200 8 9 REC OUT1 REC OUT2 0.0V –3dBv O 50kΩ 50k 8 9 200 Recording equalizer amplifier output pin. 10 VCC 7.0V — I — Positive power supply connection pin. Reference current setting pin for monolithic filter. ∗ The reference current can be set by attaching a resistor between this pin and the VEE pin. 200 12 IREF VEE + 1.2V — O — 12 6k –3– CXA1597M/P Pin No. Symbol Typical pin voltage DC AC I/O Z (in) Equivalent circuit Description ∗ Recording level calibration pin. High = Recording level gain increased Low = Recording level gain reduced ∗ Leave this pin open when not using the recording level calibration function. Recording mute ON/OFF selection pin. ∗ Recording mute is controlled with DC voltages of 0 to 5V. High = Recording mute OFF Low = Recording mute ON ∗ Soft mute and fader can be switched over by changing the time constant of the external time constant circuit. High frequency calibration pin. ∗ Controlled with DC voltages of 0 to 5V High = High frequency level gain increased Low = High frequency level gain reduced ∗ Leave this pin open when not using the high frequency calibration function. 54k 14 REC CAL 2.5V — I 54k 14 2.5V 54k DGND 30k 15 REC MUTE — — I — 15 2.5V 54k DGND 16 Gp CAL 2.5V — I 54kΩ 16 54k 2.5V 54k DGND –4– CXA1597M/P Electrical Characteristics Item Current consumption (ICC) (Ta = 25°C, VCC = 7.0V, VEE = –7.0V) Conditions Min. 8.0 ±5.0 10.0 Recording equalizer amplifier reference output level (315Hz) (This output level is the tape reference 0dB which generates magnetic flux of 250nWb/m) All of the recording equalizer amplifier blocks use this level as their reference level. Input level when the reference output level is 315Hz, –3.0dBv (For measurement, input a 315Hz, –18.5dBv signal to the REC IN pins (Pins 4 and 13) and then measure the output level.) NORM-tape, NORM-speed mode Input a 3kHz signal (–20dB level down) to the REC IN pins and then measure the relative deviation from NORM-NS, 315Hz mode. NORM-tape, NORM-speed mode Input a 8kHz signal (–20dB level down) to the REC IN pins and then measure the relative deviation from NORM-NS, 315Hz mode. NORM-tape, NORM-speed mode Input a 12kHz signal (–20dB level down) to the REC IN pins and then measure the relative deviation from NORM-NS, 315Hz mode. CrO2-tape, NORM-speed mode Input a 3kHz signal (–20dB level down) to the REC IN pins and then measure the relative deviation from NORM-NS, 315Hz mode. CrO2-tape, NORM-speed mode Input a 8kHz signal (–20dB level down) to the REC IN pins and then measure the relative deviation from NORM-NS, 315Hz mode. CrO2-tape, NORM-speed mode Input a 12kHz signal (–20dB level down) from the reference to the REC IN pins and then measure the relative deviation from NORM-NS, 315Hz mode. METAL-tape, NORM-speed mode Input a 3kHz signal (–20dB level down) to the REC IN pins and then measure the relative deviation from NORM-NS, 315Hz mode. METAL-tape, NORM-speed mode Input a 8kHz signal (–20dB level down) to the REC IN pins and then measure the relative deviation from NORM-NS, 315Hz mode. Typ. 12.0 ±7.0 14.0 Max. Unit 16.0 ±8.0 16.0 mA V V Entire LSI Operating voltage range 1 (positive/ negative dual power supplies) Operating voltage range 2 (single power supply) Recording equalizer amplifier Recording reference output level NORM-NORM mode –3.0 dBv Recording equalizer amplifier Recording reference input level NORM-NORM mode –20.0 –18.5 –17.0 dBv NORM-NORM mode REC-EQ frequency response 1 (3kHz, –20dB) NORM-NORM mode REC-EQ frequency response 2 (8kHz, –20dB) NORM-NORM mode REC-EQ frequency response 3 (12kHz, –20dB) CrO2-NORM mode REC-EQ frequency response 1 (3kHz, –20dB) CrO2-NORM mode REC-EQ frequency response 2 (8kHz, –20dB) CrO2-NORM mode REC-EQ frequency response 3 (12kHz, –20dB) METAL-NORM mode REC-EQ frequency response 1 (3kHz, –20dB) METAL-NORM mode REC-EQ frequency response 2 (8kHz, –20dB) –1.9 –0.4 1.1 dB Recording equalizer amplifier 2.5 4.5 6.5 dB 7.3 10.3 13.3 dB 2.9 4.4 5.9 dB 7.1 9.1 11.1 dB 11.3 14.3 17.3 dB 3.9 5.4 6.9 dB 7.1 9.1 11.1 dB –5– CXA1597M/P Item METAL-NORM mode REC-EQ frequency response 3 (12kHz, –20dB) NORM-HIGH mode REC-EQ frequency response 1 (5kHz, –20dB) NORM-HIGH mode REC-EQ frequency response 2 (15kHz, –20dB) NORM-HIGH mode REC-EQ frequency response 3 (20kHz, –20dB) CrO2-HIGH mode REC-EQ frequency response 1 (5kHz, –20dB) Conditions METAL-tape, NORM-speed mode Input a 12kHz signal (–20dB level down) to the REC IN pins and then measure the relative deviation from NORM-NS, 315Hz mode. NORM-tape, HIGH-speed mode Input a 5kHz signal (–20dB level down) to the REC IN pins and then measure the relative deviation from NORM-NS, 315Hz mode. NORM-tape, HIGH-speed mode Input a 15kHz signal (–20dB level down) to the REC IN pins and then measure the relative deviation from NORM-NS, 315Hz mode. NORM-tape, HIGH-speed mode Input a 20kHz signal (–20dB level down) to the REC IN pins and then measure the relative deviation from NORM-NS, 315Hz mode. CrO2-tape, HIGH-speed mode Input a 5kHz signal (–20dB level down) to the REC IN pins and then measure the relative deviation from NORM-NS, 315Hz mode. CrO2-tape, HIGH-speed mode Input a 15kHz signal (–20dB level down) to the REC IN pins and then measure the relative deviation from NORM-NS, 315Hz mode. CrO2-tape, HIGH-speed mode Input a 20kHz signal (–20dB level down) to the REC IN pins and then measure the relative deviation from NORM-NS, 315Hz mode. METAL-tape, HIGH-speed mode Input a 5kHz signal (–20dB level down) to the REC IN pins and then measure the relative deviation from NORM-NS, 315Hz mode. METAL-tape, HIGH-speed mode Input a 15kHz signal (–20dB level down) to the REC IN pins and then measure the relative deviation from NORM-NS, 315Hz mode. METAL-tape, HIGH-speed mode Input a 20kHz signal (–20dB level down) to the REC IN pins and then measure the relative deviation from NORM-NS, 315Hz mode. NORM-tape, NORM-speed mode, RL = 2.7kΩ Input a 1kHz signal and set the output so that THD (total harmonic distortion) is 1%. (Measure the distortion of a +11dB level-up signal.) Min. Typ. Max. Unit 10.4 13.4 16.4 dB –1.3 0.2 1.7 dB 4.0 6.5 9.0 dB 7.4 10.9 14.4 dB 3.9 5.4 6.9 dB Recording equalizer amplifier CrO2-HIGH mode REC-EQ frequency response 2 (15kHz, –20dB) CrO2-HIGH mode REC-EQ frequency response 3 (20kHz, –20dB) METAL-HIGH mode REC-EQ frequency response 1 (5kHz, –20dB) METAL-HIGH mode REC-EQ frequency response 2 (15kHz, –20dB) METAL-HIGH mode REC-EQ frequency response 3 (20kHz, –20dB) 8.6 11.1 13.6 dB 11.4 14.9 18.4 dB 5.9 7.4 8.9 dB 9.5 12.0 14.5 dB 11.8 15.3 18.8 dB NORM-NORM mode REC-EQ signal handling 11.0 12.0 — dB NORM-NORM mode REC-EQ total harmonic distortion (1kHz, 0.0dB, RL = 2.7kΩ) NORM-tape, NORM-speed mode, RL = 2.7kΩ Input a 1kHz, 0.0dB (reference input level) signal and measure the distortion. (Measure the distortion as THD + N.) — 0.14 0.6 % –6– CXA1597M/P Item Conditions NORM-tape, NORM-speed mode, Rg = 5.1kΩ With no signal, measure the noise using the "A"WGT filter. (The measured value is indicated as the relative value compared to the reference level.) NORM-tape, NORM-speed mode With no signal, measure the DC offset voltage of the REC OUT pin. NORM-tape, NORM-speed mode, REC-MUTE = 0.5V Input a 1kHz signal (+12dB level up) and measure the attenuation when REC MUTE is on. (Use a 1kHz BPF.) NORM-tape, NORM-speed mode, REC-MUTE = 2.5V Input a 1kHz, 0.0dB (reference level) signal and measure the attenuation characteristics curve of the soft mute function. (when REC-MUTE = 2.5V) Min. Typ. Max. Unit NORM-NORM mode REC-EQ S/N ratio 1 ("A"-WGT filter) 57 65 — dB NORM-NORM mode Output DC offset voltage (REC OUT pin) NORM-NORM mode REC-EQ mute characteristics 1 (REC-MUTE = 0.5V) –500 0.0 500 mV — –91 –80 dB Recording equalizer amplifier NORM-NORM mode REC-EQ mute characteristics 2 (REC-MUTE = 2.5V) –7.0 –5.5 –4.0 dB NORM-tape, NORM-speed mode, REC-CAL = 5.0V NORM-NORM mode Input a 315Hz signal (–20dB level down) and REC-EQ REC-CAL characteristics 1 measure the amount of change compared to (REC-CAL = 5.0V) when the REC-CAL function is at the standard setting. NORM-tape, NORM-speed mode, REC-CAL = 0.0V NORM-NORM mode Input a 315Hz signal (–20dB level down) and REC-EQ REC-CAL characteristics 2 measure the amount of change compared to (REC-CAL = 0.0V) when the REC-CAL function is at the standard setting. NORM-NORM mode REC-EQ Gp-CAL characteristics 1 (GP-CAL = 5.0V) NORM-tape, NORM-speed mode, Gp-CAL = 5.0V Input a 8kHz signal (–20dB level down) and measure the amount of change compared to when the Gp-CAL function is at the standard setting. NORM-tape, NORM-speed mode, Gp-CAL = 0.0V Input a 8kHz signal (–20dB level down) and measure the amount of change compared to when the Gp-CAL function is at the standard setting. TAPE EQ control pin voltage TAPE EQ control pin voltage TAPE EQ control pin voltage SPEED control pin voltage SPEED control pin voltage 4.1 6.1 8.1 dB –8.9 –6.9 –4.9 dB 3.9 5.9 7.9 dB NORM-NORM mode REC-EQ Gp-CAL characteristics 2 (GP-CAL = 0.0V) Mode control Control circuit high level Mode control Control circuit medium level Mode control Control circuit low level Mode control Control circuit high level Mode control Control circuit low level –5.9 –3.9 –1.9 dB 4.2 2.2 0.0 3.5 0.0 — — — — — VCC 2.8 0.5 VCC 0.5 V V V V V Control circuit Binary switching Ternary switching –7– Electrical Characteristics Measurement Circuit C1 100µ 25V REC CAL 50k ON SW5 OFF CAL ON/OFF SW15 "A" WTG SW16 DIN Audio SW8 SW10 1kHz BPF SW12 2ch 1ch Noise Filter IN AC Voltmeter C15 4.7µ 50V ∗R17 2.7k R19 100 R15 10k 16 11 15 10 14 13 12 9 OUT SW14 Filter C6 10µ SW6 C8 2.2µ ∗R12 5.1k ∗R13 27k C2 1µ 25V ∗R2 18k ∗R4 27k ∗R6 2k ∗R3 27k ∗R1 2k ∗R5 18k DC 5V Supply C3 1µ 25V 0.5V 2.5V 4.0V 5.0V GP CAL 50k A DC Ammeter OFF ∗R7 620 R10 10k Gp CAL REC IN2 IREF REC MUTE REC CAL GND CXA1597M/P BOOST2 ON SW1 REC MUTE VCC Power Supply ∗C11 0.47µ C13 100µ SW17 Power Supply 1 2 3 SW7 ∗R11 5.1k SW9 C7 2.2µ C9 10µ 4 R9 10k R8 10k C4 10µ C5 10µ 5 SW2 SPEED HIGH 6 SPEED TAPE EQ DGND REC IN1 GND (VG) BOOST1 VEE REC OUT1 REC OUT2 METAL 120µs SW3 SW4 METAL ∗C10 0.47µ –8– 7 8 C14 4.7µ 50V C12 100µ 25V ∗R16 2.7k Distortion Analyzer Oscilloscope SW13 2ch R14 10k 1ch R18 100 SW11 Note 1. Resistor tolerance ∗: 2. Capacitor tolerance ∗: Coupling Capacitor ±5% ±1% ±5% ±2% ±10% DC Voltmeter NORM METAL A 70µs DC Ammeter CXA1597M/P Audio SG Application Circuit (Positive/Negative Dual Power Supplies) REC CAL (DC control) R2 10k LINE IN2 REC Mute (Soft Mute/Fader) C10 150p L2 27mH R7 12k C12 75p C2 3.3µ 50V R3 27k C8 3.3µ 50V 10 9 C4 0.47µ 35V GND RV2 10k VEE R5 5.6k GND VCC C6 100µ 25V GND Gp CAL (DC control) REC OUT2 (to HEAD) 16 11 15 14 13 12 Gp CAL REC IN2 IREF REC CAL BOOST2 VCC REC MUTE CXA1597M/P DGND SPEED REC IN1 VEE TAPE EQ GND (VG) 1 2 3 4 5 BOOST1 6 7 REC OUT1 8 C7 3.3µ 50V R6 12k REC OUT2 VEE TAPE EQ (METAL/CrO2/NORMAL) RV1 10k GND R1 10k GND GND GND CXA1597M/P Application circuits shown are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits or for any infringement of third party patent and other right due to same. LINE IN1 VEE –9– C1 3.3µ 50V R4 5.6k C3 0.47µ 35V C5 100µ 25V C11 75p Tape Speed (NORM/HIGH) C9 150p L1 27mH REC OUT1 (to HEAD) GND CXA1597M/P Description of Operation 1. Recording equalizer amplifier The primary features of the CXA1597 recording equalizer amplifier are that by taking full advantage of monolithic filter technology, an LC resonance circuit consisting of a coil and capacitor normally required for high frequency compensation is dispensed with and medium and low-frequency sensitivity compensation is performed with its internal filter alone. This IC has the circuit configuration shown in Fig. 1 to provide the optimum frequency response required for recording equalizer amplifiers. GND C1 0.47µ BOOST R8 4.8k –7dBv Gm2 Bias OSC R11 –7dBv 40k Gm5 C7 75p REC OUT –3dBv OP4 C5 3.3µ R13 50k ×1 C4 100p GND R5 20k –6dBv CONTROL GND ×1 C3 100p IfQ R14 12k L1 27mH C6 150p GND GND REC HEAD GND IfM C2 200p ×1 REC IN –18.5dBv R1 50k VGS OP2 R4 0dBv 5.5k R3 35k R7 34k GND VGS IGH GND GND VEE GND VEE VCC VCC VEE BIAS GND IGL VGS VGS GND (VG) R1 27k IREF DGND –6dBv OP3 R6 20k Gm3 R2 5k If/Q REC MUTE SPEED to Control IC GND VGS TAPE EQ Gm4 +6dBv R10 8k R9 24k DVCC IGP REC CAL CALIBRATION Gp CAL R15 50k R16 50k GND Fig. 1. CXA1597 functional circuit block diagram The symbols (Gm2, Gm3, Gm4, Gm5) shown in Fig. 1 denote "voltage → current converter circuits" and "multiplier circuits." The "voltage → current converter circuits" convert the voltage between the positive and negative input pins into current by using the IC's internal resistance. The "multiplier circuits" multiply the current generated by the "voltage → current converter circuits" with a coefficient. The recording equalizer amplifier requires the six parameters shown in Fig. 2 (GL, GH, GP, fM, fP, and Q) to implement its frequency response. These parameters are controlled by each control current shown in Fig. 1 (IGL, IGH, IGP, IfM, If/Q, and IfQ). Therefore, the CXA1597 reduces fluctuations caused by the temperature characteristics and unevenness of its internal resistance by using currents which are independent of the internal resistance (currents which depend on external resistance) and those which are dependent on the internal resistance. This IC uses currents dependent on the internal resistance where equalizer amplifier gain is determined and currents dependent on external resistance where the filter time constant is determined. This is because the generatrix of the coefficient for the "multiplier circuits" is generated in the IC so that it depends on the internal resistance. Consequently, the gain relationship of GL, GH and GP is such that because the current obtained by the "voltage → current converter circuits" is converted into voltage by the I-V amplifier in the final stage of Fig. 1, the control currents are controlled by currents dependent on the internal resistance. In this way, the coefficients for conversion [voltage → current → voltage] all become ratios to the internal resistance, so that the fluctuations of temperature characteristics and unevenness are reduced. – 10 – CXA1597M/P Also, the relationship of time constants fM, fP and Q is configured by the product of the current obtained with the "voltage → current converter circuits" and the IC's internal capacitance connected to the output of each "multiplier circuit". By using the currents determined by the CXA1597 external resistance which are not dependent on the internal resistance for control, the coefficients for voltage → current conversion become certain ratios to the internal resistance; therefore, the frequency response does not depend on the internal resistance. GP Low frequency boost Q Gain [dB] GH GL fM Frequency [Hz] fP Fig. 2. Conceptual diagram of CXA1597 frequency response 2. Low frequency boost The CXA1597 implements low frequency boost simply by attaching an external capacitor. As shown in Fig. 1, this IC contains a resistance-based attenuation circuit after the input amplifier, with one of the resistors connected to the BOOST pins (Pins 6 and 11). When a capacitor is connected to these BOOST pins (Pins 6 and 11), the following transfer function is obtained. GBOOST (s) = s • C1 • R7 • R8 + R7 s • C1 • (R4 • R7 + R7 • R8 + R8 • R4) + (R4 + R7) (s = jω) From the above, items f1, f2, A1, and A2 in Fig. 3 are transformed into the following: f1 = R4 + R7 2π • C1 • (R4 • R7 + R7 • R8 + R8 • R4) 1 2π • C1 • R8 R7 R4 + R7 R7 • R8 = R4 • R7 + R7 • R8 + R8 • R4 R7 • R8 R7 + R8 R4 + R7 • R8 R7 + R8 = 2π • C1 • 1 ( R4 • R7 + R8 R4 + R7 ) f2 = A1 = A2 = – 11 – CXA1597M/P Here, R4 = 5.5kΩ, R7 = 34kΩ, and R8 = 4.8kΩ. Therefore, A1 and A2 take on the following values. A1 = 0.861 (times) = –1.30 (dB); A2 = 0.433 (times) = –7.26 (dB) The difference between A1 and A2 is approximately 6 dB, so that 6 dB boost can be applied for low frequency boost. The boost frequency response can be freely set with the value of the external C1 capacitor. A1 Gain [dB] 6dB A2 oct f1 Frequency [Hz] f2 Fig. 3. CXA1597 low frequency boost frequency response 3. Recording mute function The CXA1597 recording mute function is implemented by using a built-in recording mute circuit which varies the recording equalizer amplifier gain according to the magnitude of the DC voltage applied to the REC MUTE pin (Pin 15) just like an electronic volume control. For this reason, any desired soft mute (gradual signal attenuation without distortion) or fader (fade in/out) can be freely set depending on momentary changes in the DC voltage applied to the REC MUTE pin (Pin 15). The CXA1597 recording mute circuit operation is such that the reference voltage source used to generate the control currents (IGL, IGH, and IGP) to control each gain (GL, GH, and GP) shown in Fig. 1 is varied by the voltage input to the REC MUTE pin (Pin 15), so that the recording signal is attenuated while maintaining the respective gain ratios. Eventually, when the recording signal is completely muted, only the I-V amplifier in the final stage is connected to the output pin (REC OUT). Therefore, the noise of the monolithic filter consisting of each "voltage → current converter circuit" and "multiplier circuit" is attenuated simultaneously with the recording signal. At this point in time, the I-V amplifier in the final stage is functioning almost as a buffer, providing a significant amount of mute. Fig. 4 illustrates the recording mute waveforms. Fig. 4. Recording mute waveform – 12 – CXA1597M/P 4. Recording level calibration function The CXA1597 allows the recording level to be finely adjusted with a DC voltage. The recording equalizer amplifier gain can be varied by approximately ±6dB simply by applying DC voltage to the REC CAL pin (Pin 14). Circuit operation for this function is such that each gain (GL, GH, and GP) is varied relative to the reference voltage source which controls currents (IGL, IGH, and IGP) by varying its voltage as in the case of the recording mute circuit. The input resistance of the REC CAL pin (Pin 14) is 54kΩ as described in the Pin Description, which is equivalent to the internal resistance. This means the voltage converted into current by the internal resistance is the difference between the DC voltage applied to the REC CAL pin (Pin 14) and the internal reference voltage (2.5V), so that all coefficients become ratios to the internal resistance. Recording level can be finely adjusted independent of the temperature characteristics and unevenness inherent in the IC. This recording calibration function performs in all modes (NORM/CrO2/Metal tape, NORM/HIGH speeds, as well as the recording mute mode). When not using the recording level calibration function, simply leave the REC CAL pin (Pin 14) open, and the voltage on the REC CAL pin (Pin 14) is matched to the internal reference voltage (2.5V), with the recording level set for the standard output gain. 5. High frequency equalizer amplifier calibration function In addition to the recording level calibration function, the CXA1597 allows high frequency equalizer amplifier characteristics to be controlled with DC voltage. By simply applying DC voltage to the GP CAL pin (Pin 16) as in the case of the recording level calibration function, the recording equalizer amplifier gain (only the GP gain) can be varied by approximately ±4dB. This function also relatively varies the GP gain when the recording level calibration function is activated. Circuit operation for this function is such that the voltage applied to the pin is converted into current by the internal resistance as in the case of recording level calibration, and that the "multiplier circuits" provide a coefficient to the control current according to the value of the GP gain control current (IGP) for the mode currently set. Therefore, the calibration of high frequency equalizer amplifier characteristics is independent of the temperature characteristics and unevenness inherent in the IC, as in the case of recording level calibration. This function, too, operates in all modes. When not using the high frequency equalizer amplifier calibration function, simply leave the GP CAL pin (Pin 16) open, and the high frequency equalizer amplifier characteristics are set for standard output gain. Fig. 5 schematically shows the recording level/high frequency equalizer amplifier calibration functions. GP CAL REC CAL Gain [dB] REC CAL REC CAL fM Frequency [Hz] fP Fig. 5. Conceptual diagram of recording level/high frequency equalizer amplifier calibration functions The noise level of the recording equalizer amplifier is relatively changed by varying its frequency characteristics. – 13 – CXA1597M/P 6. Temperature characteristics and accuracy of the recording equalizer amplifier The temperature characteristics of the built-in monolithic filter and the filter cut-off frequency depend on the 27kΩ external resistance connected to the IREF pin (Pin 12). For low frequency boost, however, the cut-off frequency becomes uneven depending on the temperature characteristics or unevenness of the internal resistance since its time constant is configured by the product of an external capacitor and the internal resistance. Also, the recording equalizer frequency response depends on unevenness in the absolute, as well as relative values of the internal capacitance. Furthermore, the high frequency response indicates a high element sensitivity at the filter because the band-pass filter Q is high. Compared to low frequency, although the unevenness inherent in the IC is more likely to occur, this occurs relatively, and not individually for channels 1 and 2. – 14 – CXA1597M/P Notes on Operation 1. Power supply The CXA1597 is designed basically for positive/negative dual power supplies, and can also operate with a single power supply. Connect the power supplies for each case as shown below: VCC (Pin 10) Positive/negative dual power supplies Single power supply Positive power supply Power supply VEE (Pin 7) Negative power supply GND GND (Pin 5) DGND (Pin 3) GND ∗ GND GND ∗ For a single power supply, connect a decoupling capacitor (10µF or more) to the GND (VG) pin (Pin 5). The ripple rejection ratio depends on the capacitance of this capacitor. 2. Operation mode control (NORM/CrO2/METAL tape, NORM/HIGH speed) The CXA1597 incorporates an electronic switch and its operation is controlled by the DC voltage applied to the two mode control pins - TAPE EQ pin (Pin 3) and SPEED pin (Pin 1). The mode control voltages are as follows Control voltage High level 3-state Medium level Low level 2-state High level Low level Min. 4.2 2.2 0.0 3.5 0.0 Max. VCC 2.8 0.5 VCC 0.5 The voltages in the table to the left are the values relative to DGND. Operation mode control table Pin No. 1 2 Pin name SPEED TAPE EQ Pin voltage H HIGH SPEED METAL TAPE CrO2 TAPE M L NORMAL SPEED NORMAL TAPE Remarks 2-state 3-state Note: Pin voltage = Medium when the 3-state input pin is open. If the switching click noise presents a problem, add time constant circuits of 0.1 to 1s to the mode control pins. Since the mode control circuit has a linear region of approximately ±300mV, this time constant circuit may effectively reduce the switching click noise. – 15 – CXA1597M/P 3. Recording mute function (soft mute, fade in/out) As described in Description of Operation, the CXA1597 recording mute function is implemented by using a built-in recording mute circuit which varies the recording equalizer amplifier gain according to the magnitude of the DC voltage applied to the REC MUTE pin (Pin 15) just like an electronic volume control. Consequently, the muting time can be varied according to momentary changes of the DC voltage applied to the REC MUTE pin (Pin 15) and, furthermore, the recording signal can be gradually attenuated without causing distortion. The table below shows the relationship between the DC voltage applied to the REC MUTE pin (Pin 15) and the attenuation. Control voltage Positive/negative dual power supplies Single power supply ∗ Referenced to the DGND pin (Pin 3). Recording mute ON DGND to 0.5V DGND to 0.5V Attenuation –6.6dB 2.5V 2.5V Recording mute OFF 4.0V to VCC 4.0V to VCC 4. Low frequency boost (low frequency compensation) The CXA1597 low frequency boost function can be implemented simply by connecting a capacitor to the BOOST pins (Pins 6 and 11) as described in Description of Operation. Although the boost is fixed to 6dB, the time constant which determines the cut-off frequency can be set to any desired value depending on the capacitance of the external capacitor. The pole (f1) and zero (f2) shown in Fig. 3. Low frequency boost frequency response can be expressed, with the external capacitor assumed to be CB, as follows: f1 = 1 2π • CB • (9.53kΩ) (Hz), f2 = 1 2π • CB • (4.8kΩ) (Hz) Based on the above equation, determine the best low frequency response. However, the resistance which determines the time constant along with the external capacitor is the internal resistance, so that the cut-off frequency tends to fluctuate depending on the unevenness and temperature characteristics inherent in the IC. Note that the unevenness and the temperature characteristics of the internal resistance that determines the low frequency boost frequency response are approximately ±20% and +2500 ppm/°C, respectively. When not using low frequency boost, follow the procedure described below. a) For positive/negative dual power supplies Connect the BOOST pins (Pins 6 and 11) to GND. b) For single power supply Connect a fairly large capacitor (3.3µF or more) to the BOOST pins (Pins 6 and 11) or simply leave the BOOST pins open. If the BOOST pins are left open, note that the output level increases by 6dB, so the input reference should be set 6dB down. The CXA1597 is basically designed for positive/negative dual power supplies and the BOOST pins cannot be easily connected to GND as in the case of positive/negative dual power supplies. – 16 – CXA1597M/P 5. Recording level calibration The CXA1597 allows the recording level to be finely adjusted with a DC voltage as described in Description of Operation. Therefore, the recording level can be varied by approximately ±6dB simply by applying DC voltages of 0 to 5V (for positive/negative dual power supplies) to the REC CAL pin (Pin 14). The table below shows the input range regulation of control voltages with the power supplies used.∗1, ∗2 Up Positive/negative dual power supplies Single power supply 2.5V to VCC 2.5V to VCC Typ. 2.5V 2.5V Down DGND to 2.5V DGND to 2.5V ∗1 Although the above range of voltages can be input to the control pin, the controllable input voltage range is as follows: 2.5V < Vup ≤ 5.0V DGND ≤ Vdown < 2.5V ∗2 Control voltages for this IC are referenced to the DGND pin (Pin 3). Also note that when not using this recording calibration function, simply leave the REC CAL pin (Pin 14) open, so that the voltage on the REC CAL pin is matched to the internal reference voltage (2.5V), with the recording level set for the standard gain. 6. High frequency calibration The CXA1597 allows the high frequency equalizer amplifier characteristics to be finely adjusted with a DC voltage as described in Description of Operation. Therefore, the recording level in high frequencies (peak) can be varied by approximately ±4dB simply by applying DC voltages of 0 to 5V (for positive/negative dual power supplies) to the GP CAL pin (Pin 16). The table below shows the input range regulation of control voltages with the power supplies used. ∗3, ∗4 Up Positive/negative dual power supplies Single power supply 2.5V to VCC 2.5V to VCC Typ. 2.5V 2.5V Down DGND to 2.5V DGND to 2.5V ∗3 Although the above range of voltages can be input to the control pin, the controllable input voltage range is as follows: 2.5V < Vup ≤ 5.0V DGND ≤ Vdown < 2.5V ∗4 Control voltages for this IC are referenced to the DGND pin (Pin 3). Also note that when not using this high frequency calibration function, simply leave the GP CAL pin (Pin 16) open, so that the voltage on the GP CAL pin is matched to the internal reference voltage (2.5V), with the high frequency equalizer amplifier characteristics set for the standard gain. 7. Monolithic filter (the resistance connected to the IREF pin) To increase the accuracy of the frequency response of its internal monolithic filter, the CXA1597 entrusts the control current that determines the filter time constant to an external resistance. Specifically, this resistance is the 27kΩ external resistor connected to the IREF pin (Pin 12). This means that the accuracy of the recording equalizer amplifier frequency response is determined by the resistance connected to the IREF pin. Therefore, the resistor used for this purpose must be free of unevenness and have excellent temperature characteristics (e.g., a metallic film resistor). Also note that the recording equalizer amplifier frequency response can be shifted as desired by altering the value of the resistance connected to the IREF pin. For example, when the resistance value is reduced, the frequency response is shifted to the high-frequency side, and when the resistance value is increased, the frequency response is shifted to the low-frequency side. – 17 – CXA1597M/P Example of Representative Characteristics Frequency response (NORMAL speed) 30.0 VCC, VEE = ±7.0V 0dB = NORM-NORM, 315H, –23dBv (–20dB) (Tape) (Speed) NORM -NORM CrO2 -NORM METAL-NORM Output response [dB] 20.0 10.0 0.0 –10.0 10 100 1k Frequency [Hz] 10k 100k Frequency response (HIGH speed) 30.0 VCC, VEE = ±7.0V 0dB = NORM-NORM, 315H, –23dBv (–20dB) (Tape) (Speed) NORM -HIGH CrO2 -HIGH METAL-HIGH Output response [dB] 20.0 10.0 0.0 –10.0 10 100 1k Frequency [Hz] 10k 100k Load characteristics 14 12 Maximum output level [dB] 10 8 6 4 2 0 VCC, VEE = ±7.0V MODE: NORM-NORM (Tape) (Speed) 0dB = –3dBv (REC OUT pin) THD + N = 1% 315Hz 1kHz 100 1k RL – Load resistance [Ω] 10k – 18 – CXA1597M/P Total harmonic distortion 10 100 VCC, VEE = ±7.0V 0dB = –3dBv, RL = 2.7k MODE: NORM-NORM (Tape) (Speed) 315Hz 1kHz 3kHz 6.3kHz 10kHz 15kHz Output level vs. Mute voltage 80 T. H. D + N [%] Output level [%] 60 1.0 40 20 0.1 –10 0 10 20 VCC, VEE = ±7.0V MODE: NORM-NORM (Tape) (Speed) 100% = 1kHz, + 12dB (at 315Hz, –3dBv) f = 1kHz 0 –1.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 Output level [dB] REC MUTE pin voltage [V] Output level vs. Mute voltage 0 0 Output level vs. Mute voltage –20 –20 Output level [dB] –40 –60 Output level [dB] VCC, VEE = ±7.0V MODE: NORM-NORM (Tape) (Speed) 0dB = 1kHz, + 12dB (at 315Hz, –3dBv) f = 1kHz –40 –80 –60 –100 0.0 1.0 2.0 3.0 4.0 5.0 6.0 –80 0.5 REC MUTE pin voltage [V] 1.0 VCC, VEE = ±7.0V MODE: NORM-NORM (Tape) (Speed) 0dB = 1kHz, + 12dB (at 315Hz, –3dBv) f = 1kHz 5.0 REC MUTE pin voltage [V] – 19 – CXA1597M/P Output level vs. REC CAL voltage 10 Output level [dB] 0 VCC, VEE = ±7.0V MODE: NORM-NORM Gp CAL = Open (Tape) (Speed) 0dB = REC CAL pin and Gp CAL pin Open –20dB (at 315Hz, –3dBv) 315Hz 3kHz 8kHz 12kHz –2.0 –1.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 –10 REC CAL pin voltage [V] Output level vs. Gp CAL voltage 5 Output level [dB] 0 VCC, VEE = +7.0V MODE: NORM-NORM REC CAL = Open (Tape) (Speed) 0dB = Gp CAL pin and REC CAL pin Open –20dB (at 315Hz, –3dBv) 315Hz 3kHz 8kHz 12kHz –2.0 –1.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 –5 Gp CAL pin voltage [V] REC CAL and Gp CAL frequency response 40.0 VCC, VEE = ±7.0V 0dB = NORM-NORM, 315Hz, –23dBv (–20dB) REC CAL & Gp CAL Open 30.0 (Tape) (Speed) Gp CAL = 5.0V Gp CAL = 2.5V Gp CAL = 0.0V 20.0 Output response [dB] 10.0 REC CAL = 5.0V REC CAL = 2.5V 0.0 REC CAL = 0.0V –10.0 10 100 1k Frequency [Hz] 10k 100k – 20 – CXA1597M/P Supply voltage vs. Current consumption 13 ICC – Current consumption [mA] 12 11 10 5 6 7 8 VCC – Supply voltage [V] – 21 – CXA1597M/P Package Outline CXA1597M Unit: mm 16PIN SOP (PLASTIC) 300mil + 0.4 9.9 – 0.1 + 0.4 1.85 – 0.15 16 9 0.15 + 0.2 0.1 – 0.05 + 0.3 5.3 – 0.1 7.9 ± 0.4 0.45 ± 0.1 1.27 + 0.1 0.2 – 0.05 ± 0.12 M PACKAGE STRUCTURE PACKAGE MATERIAL SONY CODE EIAJ CODE JEDEC CODE PACKAGE WEIGHT SOP-16P-L01 ∗SOP016-P-0300-A LEAD TREATMENT LEAD MATERIAL EPOXY RESIN SOLDER PLATING COPPER ALLOY 0.2g CXA1597P 16PIN DIP (PLASTIC) 300mil 16 9 7.62 + 0.3 6.4 – 0.1 + 0.4 19.2 – 0.1 + 0.1 0.05 0.25 – 0° to 15° EPOXY RESIN SOLDER PLATING COPPER 1.0 g 1 2.54 8 0.5 ± 0.1 1.2 ± 0.15 3.0 MIN + 0.4 3.7 – 0.1 0.5 MIN PACKAGE STRUCTURE PACKAGE MATERIAL SONY CODE EIAJ CODE JEDEC CODE DIP-16P-01 ∗DIP016-P-0300-A Similar to MO-001-AE LEAD TREATMENT LEAD MATERIAL PACKAGE WEIGHT – 22 – 0.5 ± 0.2 1 8 6.9