CXA3188N 2ch. Read/Write Amplifier for Thin Film Head of Hard Disk Drive For the availability of this product, please contact the sales office. Description The CXA3188N is a Read/Write Amplifier for the thin film head of hard disk drive and designed to handle up to 2 channel heads. Features • Operate on single +5 V power supply • Low power consumption Read : 90 mW Write : 115 mW + IW × 5 Idle : 8 mW • Designed for two terminal thin-film or MIG heads. • Read amplifier emitter follower output featuring 200 times gain(typ). • Differential input capacitance for Read : 6pF (typ) • Input noise : 0.47 nV / √ Hz (typ) • Write current range : 10 to 20 mA • Differential Head voltage swing : 9 Vp-p (typ) • Differential P-ECL write data input. • Built-in write unsafe detection circuit. • Built-in Servo write function. • Read data outputs are high impedance in write mode. • Unselected head voltage is high impedance. • Self switching damping resistor 380 Ω. • Built-in supply voltage monitor circuit prohibits incorrect write during power on or abnormal voltage. 16 pin SSOP (Plastic) Absolute Maximum Ratings (Ta=25 °C) • Supply voltage VCC 6 V • Operating temperature Topr –20 to +70 °C • Storage temperature Tstg –55 to +150 °C • Allowable power dissipation (on board) PD 760 mW • Write current IW 22 mA • WUS/SE pin input current ISEH 15 mA Operating Conditions Supply voltage VCC 5±0.5 V Function Read, Write and Write unsafe detection for HDD, power supply ON/OFF detection. Structure Bipolar silicon monolithic IC 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— E98128-TE CXA3188N Block Diagram and Pin Configuration GND 16 XCS 1 MODE CONTROL H0X 2 H0Y 3 H1X 4 DRIVER WRITE CURRENT SOURCE AMP 15 R/W 14 WC 13 RDY DRIVER AMP H1Y VCC 5 AMP 12 RDX HEAD SELECT 6 11 HS POWER ON/OFF DETECTOR NC 10 WDX 7 WD BUF WUS/SE 8 WRITE UNSAFE DETECTOR 9 —2— WDY CXA3188N Pin Description No. Symbol 1 GND Description Equivalent circuit VCC 2 3 4 5 H0X H0Y H1X H1Y 2 2k 2k 4 Head. 2 channels provided. 3 5 100k GND 6 7 VCC NC 5 V power supply. VCC 8 Write unsafe detection output / Servo Enable signal input. 8 WUS/SE GND VCC 9 10 WDY WDX 9 Differential P-ECL write data input. 10 GND —3— CXA3188N No. Symbol Description Equivalent circuit VCC 11 HS Head select signal input. At “Low” : Head0 at “High” : Head1 11 2.1V 180k GND VCC 12 13 12 RDY RDX Read amplifier output. 13 GND VCC 14 A setting resistor for the write current value is connected between this pin and GND. WC 14 2.5V GND VCC Read/Write signal input. At “High” : Read at “Low” : Write 180k 15 R/W 15 2.1V GND VCC 16 XCS Power save signal input At “High” : Power saving. 16 2.1V 100k GND —4— CXA3188N Electrical Characteristics Item (Unless otherwise specified, VCC=5 V, Ta=25 °C, Write current IW=20 mA) Symbol Current consumption for read ICCR Current consumption for write ICCW Current consumption for idle ICCI Digital input “Low” input voltage Digital input “High” input voltage Digital input “Low” input current Digital input “High” input current Write data input current Test condition IW=20 mA Min. Typ. Max. Unit. 11 18 25 mA 14 +IW 23 33 +IW +IW 1.1 1.6 2.1 mA 0.8 V VIL VIH IIL IIH “H” applied voltage: 5 V “L” applied voltage: 0 V mA 2.0 V –100 µA IWD 100 µA 50 µA Write data input voltage range VWDV VCC–2.5 VCC V WD input amplitude VWDA 0.3 1 V VTH 3.4 4.3 V IW 10 20 mAo-p Write current voltage VWC 2.25 2.5 2.75 V Write current gain AW IW=AW • VWC/RWC 18 20 22 mA/mA Write current setting constant KW When write current is “Iw[mA]”, IW=KW/RWC. (RWC=3.3 kΩ) 46 51 56 Power supply ON/OFF detector threshold voltage Write current setting range Write unsafe output leak current Write unsafe output Low voltage IWUS 3.9 50 µA 0.5 V VWUSL Output current: 1 mA WUS/SE input current ISEH Servo write Enabled 5 14 mA WUS/SE High input voltage VSEH Servo write Enabled VCC +1.5 VCC +1.6 V —5— CXA3188N Item Read amplifier differential voltage gain Symbol AV BW1 Frequency band width BW 2 Input referred noise voltage EN Common mode rejection ratio CMRR Supply voltage rejection ratio PSRR Channel Separation Read data output offset voltage for Read RDX, RDY common mode output voltage difference between modes RDX, RDY common mode output voltage for Read CS Test condition Input voltage:1 mVp-p,300 kHz load resistor: (RDX, RDY) 1 kΩ Frequency at which Av lower by 1dB Frequency at which Av lower by 3dB Typ. Max. Unit. 170 200 230 V/V 35 60 MHz 75 120 MHz Head impedance: 0 Ω Common input voltage: 100 mVp-p, 20 MHz Ripple voltage: 100 mVp-p, 20 MHz Selected head input voltage: 0 mVp-p Unselected head input voltage: 100 mVp-p, 20 MHz VOFF Vdiff Min. CRD=0.1 µ 0.47 —6— nV √ Hz 50 dB 50 dB 50 dB –300 300 mV –300 300 mV VCC –2.3 VRD 0.65 V CXA3188N Unless otherwise specified, VCC=5 V, Ta=25 °C, fWD (Write data frequency) =5 MHz, IW=15 mA, LH (Head inductance) =1 µH, RH (Head DC resistance value) =30 Ω Item Head differential voltage amplitude Mode switching time Read to Write Symbol Measurement conditions VSW Differential voltage between HX pin and HY pin at switching of Write current Typ. Max. 9 Unit. Vp-p TRW is the time required for Write current to turn TRW TWR1 Mode switching time Write to Read TWR2 Mode switching time Power saving to Read TIR Mode switching time safe to unsafe TSA1 Mode switching time unsafe to safe TSA2 Head switching time TH Write current propagation delay time TPD Write current rise/fall time Min. TR/TF to 90 % after Pin 15 changes from “High” to “Low”. TWR1 is the time required for the Read amplifier output∗ to turn to 90 % after Pin 15 changes from “Low” to “High”. TWR2 is the time required for Write current to decreases to 10 % after Pin 15 changes from “Low” to “High”. TIR is the time required for the Read amplifier output∗ to turn to 90 % after Pin 16 changes from “High” to “Low”. TSA1 is the time required for Pin 8 to turn “High” after the last transition of Write data when Write data is stopped in Write mode. TSA2 is the time required for Pin 8 to turn “Low” after the first transition of Write data in Write mode. TH is the time required for the Read amplifier output∗ to reach 90 % when the selected head switched in Read mode. 1.0 0.13 0.3 µs 0.2 0.3 µs 0.1 0.3 µs 1 µs 3.0 µs 0.6 µs 0.6 µs 2.3 TPD is the time required for Write current to reach 90 % after the Write data falling edge. 2 7 ns TR is the time required for Write current to reach 90 % from 10 %; TF is the same time required to reach 10 % from 90 %. LH=0 µH, RH=0 Ω 1 3 ns ∗Read amplifier output 100 mVp-p 10 MHz —7— CXA3188N Test Circuit 1 V 1k 1k 1µ 1µ V V ×100 LPF to 15MHz AMP ×1 PG AMP V 5V PG a b a b c a b a b A A 16 15 14 13 1 2 3 4 3V a b PG 4V a b c a b c A A A 12 11 10 9 5 6 7 8 2.7k A a b a b a b a b V a a b c d e 5.1k a b c d e A b 0.1µ a 6V b 33 0.1µ A VCC 5V 0.1µ 1µ Fig. 1 Test Circuit 2 1k 1k 1µ 1µ ×1 AMP PG PG 16 15 14 13 1 2 3 4 PG PG PG 12 11 10 9 5 6 7 8 RWC 2.7k 5.1k LH 1µH LH 1µH Fig. 2 —8— 5V 1µ VCC 5V CXA3188N Timing Chart 1 WDX WDY R/W 50% 50% 50% PS TRW TWR 2 90% 90% IWX IWY 10% 10% TWR1 TIR 90% RDX RDY 90% Fig. 3 Timing Chart 2 WDX WDY TPD IWX IWY 90% 90% 10% 10% TR WUS 90% TF 50% TSA1 50% TSA2 Fig. 4 —9— CXA3188N Description of Functions Read amplifier This is a low noise amplifier for amplifying the signals from the heads with an emitter follower output. The RDX and RDY are the outputs of the differential amplifier, the X side of the head input and RDX pin and the Y side of the head inputs and RDY pin have the same polarity. Write circuit The Write data input to WDX pin and WDY pin passes through the buffer amp. It drives the Write switch circuit which supplies the Write current to the heads. The Write current flows into the X side when WDX is “Low” and WDY is “High”. Mode control The mode are set as shown Table 1 by R/W and WUS/SE. CS R/W WUS/SE L L X L H X L L ∗∗ H X X Table 1. Mode selection Mode Write Read Servo Write Power Save Servo write mode ∗∗ This mode allows for writing to multiple channels at once. In this mode the write driver will drive all channels simultaneously. To enable servo write mode follow these steps: (1) Place the device in the Read mode. (2) Set WUS/SE to VSEH volts, or input ISEH to WUS/SE. (3) Initiate the write operation by setting R/W Low. Write unsafe detection circuit This circuit detects write errors. In normal Write mode, the WUS output is low; in the conditions listed below, it is high. • Head input is open (under the condition which RH=∞ and Write data frequency is ≤ 10 MHz) • Head input is shorted to GND or VCC. • Write data frequency is abnormally low. • No Write current. • In read mode. • Supply voltage is abnormal (see “power supply ON/OFF detection”). Power supply ON/OFF detection This circuit monitors VCC to detect erroneous Writes. The error status is established when VCC falls below the threshold voltage (VTH) of the power supply ON/OFF detector, in which case the recording and playback functions are prohibited. When VCC rises above, VTH, the prohibition of these functions is released. —10— CXA3188N Application Circuit RWC 2.7k 1µ 1µ 16 15 14 13 12 11 10 9 1 2 3 4 5 6 7 8 5.1k LH LH 1µ 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. —11— CXA3188N Notes on operation • This device handles high frequency and high gain signals. Please note the following; ♦ Connect VCC decoupling capacitor of approximately 1000 pF near the device. ♦ Make the GND area as large as possible. • The WC pin is a constant voltage pin. When noise affects this pin, it creates noise in Write current. Therefore, locate RWC as close to the device as possible. • Write unsafe detection circuit This circuit uses the voltage waveforms of the head pins for detection. Wave form of write data Voltage waveform of head pins (HX, HY) VFB VTH=1.4V VTH GND ♦ VFB must be more than 2 V. When VFB < 2 V, it is possible that Write unsafe detection maximum frequency becomes more than 1 MHz. ♦ The normal operating area of write unsafe detection circuit is changed by head inductance, head DC resistance, write current and other. —12— CXA3188N Application Notes Use the following characteristics for reference VCC=5 V, Ta=25 °C Item Symbol Differential output capacitance Differential output resistance Differential input capacitance Read mode Differential input resistance Output resistance Unselected head differential current at write mode CO RD CI RI RRD Write current symmetry TASY Write mode Condition Between head input pins Between head input pins f=5MHz RDX or RDY, f=5MHz LH=2 µH, RH=30 Ω IW=15 mA LH=0 µH, RH=0 Ω IW=15 mA IUS Min. Typ. Max. Unit 4.5 380 6 1.2 45 pF Ω pF kΩ Ω 250 0.4 6 490 10 60 0.2 mAp-p –0.5 0.5 ∗TAS=T1–T2 IWX+IWY 50% T1 50% 50% T2 Setting of Write current Write current can be set with resistor RWC (kΩ) at Pin 14. IW=K/RWC (mA) Refer to Fig. 5. Write current setting constant vs. Write current Write current setting constant kw Write current vs. RWC Write current IW (mA) 20 10 5 2 5 10 VCC=5V Ta=25°C 55 52.5 50 47.5 45 10m 20 15m Write current IW (mA) RWC (kΩ) Fig. 5 Fig. 6 —13— 20m ns CXA3188N Normalized read amplifier voltage gain vs. Supply voltage Ta=25°C 1.04 1.02 1 0.98 0.96 1.02 1 0.98 0.96 4.0 4.5 5.0 5.5 6.0 –25 0 25 50 Supply voltage VCC (V) Ambient temperature Ta (°C) Normalized write current vs. Supply voltage Normalized write current vs. Ambient temperature Ta=25°C RWC=24k Ω 1.04 1.02 1 0.98 0.96 75 VCC=5V RWC=2.4k Ω 1.02 IW/IW (Ta=25°C) IW/IW (VCC=5V) VCC=5V 1.04 AV/AV (Ta=25°C) AV/AV (Ta=25°C) Normalized read amplifier voltage gain vs. Ambient temperature 1 0.98 4.0 4.5 5.0 5.5 6.0 –25 Supply voltage VCC (V) 0 25 50 Ambient temperature Ta (°C) —14— 75 CXA3188N Input referred noise voltage vs. Supply voltage Input referred noise voltage vs. Ambient temperature VCC=5V Ta=25°C 0.55 EN (VCC=5V) (mV/ Hz) EN (Ta=25°C) (mV/ Hz) 0.49 0.47 0.45 0.45 0.4 4.0 4.5 5.0 5.5 6.0 –25 Supply voltage VCC (V) 4.0 OFF → ON 3.9 ON → OFF 3.8 –25 0 25 50 0 25 50 Ambient temperature Ta (°C) Power supply ON/OFF detector threshold voltage vs. Ambient temperature Power supply ON/OFF detector Threshold Voltage (V) 0.5 75 Ambient temperature Ta (°C) —15— 75 CXA3188N Package Outline Unit : mm 16PIN SSOP (PLASTIC) + 0.2 1.25 – 0.1 ∗5.0 ± 0.1 0.1 16 9 1 6.4 ± 0.2 ∗4.4 ± 0.1 A 8 + 0.05 0.15 – 0.02 0.65 + 0.1 0.22 – 0.05 0.13 M 0.5 ± 0.2 0.1 ± 0.1 0° to 10° DETAIL A NOTE: Dimension “∗” does not include mold protrusion. PACKAGE STRUCTURE PACKAGE MATERIAL EPOXY RESIN SONY CODE SSOP-16P-L01 LEAD TREATMENT SOLDER / PALLADIUM PLATING EIAJ CODE SSOP016-P-0044 LEAD MATERIAL 42/COPPER ALLOY PACKAGE MASS 0.1g JEDEC CODE NOTE : PALLADIUM PLATING This product uses S-PdPPF (Sony Spec.-Palladium Pre-Plated Lead Frame). —16—