Features: ` Controlled Baseline
− One Assembly/Test Site, One Fabrication Site
` Extended Temperature Performance of
−40°C to 125°C
` Enhanced Diminishing Manufacturing
Sources (DMS) Support
` Enhanced Product Change Notification
`Qualification Pedigree†
`Power-On Reset Generator
` Automatic Reset Generation After
Voltage Drop
` Precision Voltage Sensor
` Temperature-Compensated Voltage
Reference
` Programmable Delay Time by External
Capacitor
` Supply Voltage Range . . . 2 V to 6 V
`Defined RESET Output from VDD 1 V
` Power-Down Control Support for Static
RAM With Battery Backup
` Maximum Supply Current of 16 A
` Power Saving Totem-Pole OutputsSpecificationsSupply voltage, VDD (see Note 1) ..............................................................................................7 V
Input voltage range, CONTROL, RESIN, SENSE (see Note 1) ..................................... −0.3 V to 7 V
Maximum low output current, IOL ..........................................................................................10 mA
Maximum high output current, IOH ..................................................................................... −10 mA
Input clamp current, IIK (VI < 0 or VI > VDD) ..................................................................... ±10 mA
Output clamp current, IOK (VO < 0 or VO > VDD) ................................................................ ±10 mA
Continuous total power dissipation ....................................................See Dissipation Rating Table
Operating free-air temperature range, TA: TL77xxQ ................................................ −40 to 125
Storage temperature range, Tstg ................................................................................... −65 to
† 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 TLC7705-EP family of micropower supply voltage supervisors provide reset control, primarily in microcomputer and microprocessor systems. During power-on, RESET is asserted when VDD reaches 1 V. After minimum VDD ( 2 V) is established, the circuit monitors SENSE voltage and keeps the reset outputs active as long as SENSE voltage (VI(SENSE)) remains below the threshold voltage. An internal timer delays return of the output to the inactive state to ensure proper system reset. The delay time, td, is determined by an external capacitor:
td = 2.1 * 104 * CT
Where
CT is in farads
td is in seconds
Except for the TLC7705-EP, which can be customized with two external resistors, each supervisor has a fixed SENSE threshold voltage set by an internal voltage divider. When SENSE voltage drops below the threshold voltage, the outputs become active and stay in that state until SENSE voltage returns above threshold voltage and the delay time, td, has expired. In addition to the power-on-reset and undervoltage-supervisor function, the TLC7705-EP adds power-down control support for static RAM. When CONTROL is tied to GND, RESET will act as active high. The voltage monitor contains additional logic intended for control of static memories with battery backup during power failure. By driving the chip select (CS) of the memory circuit with the RESET output of the TLC7705-EP and with the CONTROL driven by the memory bank select signal (CSH1) of the microprocessor (see Figure 10), the memory circuit is automatically disabled during a power loss. (In this application the TLC77xx power has to be supplied by the battery.)
TLC7705-EP Data Sheet
