SLVS561L December 2004 – October 2014 TLV1117
The TLV1117 device is a positive low-dropout voltage regulator designed to provide up to 800 mA of output current. The device is available in 1.5-V, 1.8-V, 2.5-V, 3.3-V, 5-V, and adjustable-output voltage options. All internal circuitry is designed to operate down to 1-V input-to-output differential. Dropout voltage is specified at a maximum of 1.3 V at 800 mA, decreasing at lower load currents.
The TLV1117 device is designed to be stable with tantalum and aluminum electrolytic output capacitors having an ESR between 0.2 Ω and 10 Ω.
Unlike pnp-type regulators, in which up to 10% of the output current is wasted as quiescent current, the quiescent current of the TLV1117 device flows into the load, increasing efficiency.
The TLV1117C device is characterized for operation over the virtual junction temperature range of 0°C to 125°C, and the TLV1117I device is characterized for operation over the virtual junction temperature range of –40°C to 125°C.
NPN output topology provides lower output impedance than most LDOs. However, an output capacitor is required. To support maximum current and lowest temperature, 1.4-V headroom is recommended (less for lower currents) (VI – VO).
Current limiting and over temperature shutdown protects against overload or under heat sinking.
Op amp with 1.25-V offset input at the ADJUST pin provides easy output voltage programming. For current regulation applications, a single resistor whose resistance value is 1.25 V / IOUT and power rating is greater than (1.25 V)2 / R should be used. For voltage regulation applications, two resistors set the output voltage.
The device OUTPUT pin will source current necessary to make OUTPUT pin 1.25 V greater than ADJUST terminal to provide output regulation.
The adjustable version of the device requires 1-V headroom (VI – VO) to operate in regulation. With less headroom, the device may drop out and OUTPUT voltage will be INPUT voltage minus drop out voltage.
The device passes its bias current to the OUTPUT pin. The load or feedback must consume this minimum current for regulation or the output may be too high.
When an overload occurs the device will shut down the output stage or reduce the output current to prevent device damage. The device will automatically reset from the overload. The output may be reduced or alternate between on and off until the overload is removed.