Features: ` Current-Bias/Current-Sense Architecture
` Fabricated Using LinIMPACT-C™ BiCMOS Technology
` Operates From a Single 5-V Supply (±10%)
` Low-Power Idle Mode
` Single-Ended Input to Reader With One Side Grounded
` True Differential Read Output
` Wide Magnetoresistive (MR) Resistor
[R(MR)] Range From 10 to 40
` MR-Head Bias Current [II(BIAS)]
Programmable From 7 mA to 17 mA
` Buffered-Head-Voltage [V(BH)] Monitor
` Gain: 230 V/V at R(MR) = 20
` Bandwidth:
65 MHz at 1 dB [R(MR) = 20 ]
140 MHz at 3 dB [R(MR) = 20 ]
` Equivalent Input Noise = 0.55 nV/Hz at R(MR) = 20
` Write-Head Current Programmable From 10 mA to 35 mA (Base to Peak)
` Write-Current Rise/Fall Time = 3.7 ns
LI(TF) (Head Only) = 180 nH
RI(TF) = 15 , L(lead) = 50 nH
II(W) = 25 mA
` Fast Recovery Times:
Write to Read = 0.8 s (BHV/IBON = L)
Read to Write = 50 ns
` Output Capacitance = 8.5 pF for Write
` Multichannel Servo Write:
Upper or Lower Half Channels
Every Two Channels
All Channels
` Read-Fault (RUS), Write-Fault (WUS), and Idle-Fault (IUS) Detection
` MR-Head Open Protection and MR-Head
Short Detection Available (Metal Option, Disabled)
` Thermal-Asperity Detection Available (Metal Option, Disabled)
` Pseudo-ECL (PECL) Differential-Write-Data (WDX and WDY) Inputs
` Write Data Divided-by-2 (FF) Circuit Available (Metal Option, Disabled)
` Channel Separation 70 dBa at f = 25 MHz
` Power-Supply Rejection Ratio (PSRR)
50 dB at 25 MHz (Input Referred)
` MR Bias On During Write Mode; Otherwise,Programmable On/Off
` Input Control Lines:
Head Select HS (2 Channel) or HS0 HS2 (6 Channel) With Internal Pullup Resistors
R/W With Internal Pullup Resistor
CS With Internal Pullup Resistor
BHV/IBON With Internal Pulldown Resistor
` Packaged in 30-Pin (2 Channel) and 38-Pin
(6 Channel) Plastic TSSOP Packages
` Optimized for Package-On-Arm ApplicationsPinout
SpecificationsSupply voltage range, VCC (see Note 1) . . . . . . . . . . . . . . . .. . 0.3 V to 6 V
Input voltage range, VI: Digital . . . . . . . . . . . . . . . .. . 0.3 V to VCC + 0.3 V
FLT/SE . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to 8 V
MR head . . . . . . . . . . . . . . . . . . . . . 0.3 V to 1.5 V
Write-head output voltage range, VO . . . . . . . . . . . . . 0.3 V to VCC + 0.3 V
Write current, II(W), base to peak . . . . . . . . . . . . . . . . . . . . . .. . . . . . 60 mA
MR-head-bias current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 35 mA
Low-level output current, IOL, at RDX or RDY . . . . . . . . . . . . . .. .. . .. 10 mA
High-level output current, IOH, at FLT/SE . . . . . . . . . . . . . . . . .. . . . . . 12 mA
Continuous total dissipation . . . . . . . . . . . . . . See Dissipation Rating Table
Operating free-air temperature range, TA . . . . . . . . . . .. . . . . . . 0°C to 70°C
Storage temperature range, Tstg . . . . . . . . . . . . . . . . .. . . . 55°C to 150°C
Operating virtual junction temperature, TJ . . . . . . .. . . . . . . . . . . . . . . 150°C
† Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTE 1: All voltage values are with respect to GND.
DescriptionThe TLS24302 and TLS24306 are read/write BiCMOS preamplifiers designed for use with magnetoresistive (MR)/thin- ilm (TF) recording heads. The MR element is used for reading and the inductive thin-film section of the head is used or writing. The TLS24302 and TLS24306 preamplifiers implement a current-bias/current-sense architecture. Both have a single-ended read nput with a fully differential read (RDX, RDY) output that operates from a single 5-V supply.
The write-head current II(W) and MR-head bias current II(BIAS) are programmable using external resistors. Recovery time is reduced by holding BHV/IBON low during the write mode. Multichannel servo write is achieved by taking FLT/SE higher than VCC by at least 1.2 V. An optional booster circuit of TLS24302 and TLS24306 can be used to achieve higher operating frequencies.
A fault terminal (FLT/SE) goes low when the WDX/WDY input frequency is low, a head is shorted or open, there is no write current (Ix or Iy), or if VCC is low. Additionally, the TLS24302 and TLS24306 preamplifiers provide an optional thermal-asperity detection circuit that can be enabled by using an optional metal mask during the fabrication process.Table 1 lists the functions that can be changed by a custom metal mask during the fabrication process. Contact your local Texas Instruments (TI) sales office or representative for further information.The standard device and optional functions are defined as follows:
TLS24302 Data Sheet
