LD3301-X 1 and 2-Channel 5V or 3.3V GMR Head Preamplifier GMR resistor range: 25Ω to 65Ω Programmable 5 bit GMR head bias current: Ib = 2mA-9.75mA Programmable gain control: 130V/V & 200V/V @ Rmr = 35Ω, Ib = 6mA Wide bandwidth: BW = 250 MHz at -1dB @ Rmr = 35Ω Programmable booster for wide bandwidth Equivalent input noise: Vn = 0.8nV/√Hz @ Rmr = 35Ω Impedance matched differential inputs for WDX and WDY Programmable 5 bit write head current: Iw = 15 mA to 60 mA Servo Bank Write Mode Rise/Fall Time: 1ns@5V / [email protected] Typical (Iw = 40mA (0-p), Ltf = 50nH, Rtf = 15Ω) Fast recovery times: W/R = 200ns @ 5V supply, W/R= 400ns @ 3.3V supply Programmable write current overshoot control Read fault and Write fault detection Rmr value measurement mode GMR Head Open/Short and TF Head Protection Programmable (7 bits) thermal asperity detection threshold control and programmable thermal asperity compensation Serial port read back capability GMR ESD protection diodes on reader Internal capacitor DESCRIPTION The LD3301-1, LD3301-2 are BiCMOS devices that support a 1-channel (2-channel) GMR Preamplifier. They are designed for use with 4-terminal magnetoresistive recording heads, providing a low noise GMR head amplifier, GMR bias current control, thin film write driver, write current control, thermal asperity detection and correction. Fast recovery mode can be also programmed to put the chip faster in read mode from any other existing modes. The device is programmable for read gain, GMR resistance measurement, and thermal asperity threshold level. The device allows multiple channel write functions for servo writing. Half or all of the heads can be simultaneously selected in the servo write mode. Features and thresholds are controlled through a serial port interface. This product requires +3.3V or +5V supply voltage. Available in flip-chip or TSSOP packages. FEATURES Current Bias/Current Sense Architecture +5V or +3.3V Supply 3.3V CMOS compatible Logic Interface Power Management Integrated reference resistor Single ended input to reader with one side grounded externally Differential read output GND RGND VCC RREF SDEN SCLK SDATA RBW MRRB SERIAL PORT AND DATA REGISTER HEAD SELECT LOW VOLTAGE FAULT RDY WDX WDY READ BIAS CONTROL MR BIAS CURRENT 5-BIT DAC WRITE CURRENT 5-BIT DAC TA DETECTION THRESHOLD 7-BIT DAC MODE CONTROL POWER MANAGEMENT RDX 2K THERMAL ASPERITY DETECTION AND CORRECTION READ OUTPUT BUFFER DUMMY HEAD W0X W0Y R0 MRGND PREAMPS AND WRITE DRIVERS PECL INPUT BUFFER HEAD VOLTAGE MEASUREMENT HEAD UNSAFE DETECT FLT LDIC Confidential 1 version 1.6.2