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.