The LT1120 is a combination micropower positive regulator and free collector comparator on a single monolithic chip. With only 40µA supply current, the LT1120 can supply over 125mA of output current. Input voltage range is from 4.5V to 36V and dropout voltage is 0.6V at 125mA. Dropout voltage decreases with lower load currents. Also included on the chip is a class B output 2.5V reference that can either source or sink current. A shutdown pin allows logic shutdown of the output. The comparator can be used for system or battery monitoring. For example, the comparator can be used to warn of low system voltage. Frequency compensation of the comparator for amplifier applications can be obtained by adding external output capacitance. The 2.5V reference will source or sink current. This allows it to be used as a supply splitter or auxiliary output.
The LT1120 combines a micropower positive regulator and an open‑collector comparator on a single chip. It operates from 4.5 V to 36 V, draws only 40 µA supply current, and can supply over 125 mA of output current. The integrated 2.5 V reference can both source and sink current, and a shutdown pin allows logic control of the output.
Typical applications include battery‑backup systems, portable instruments, and low‑power voltage monitoring. The device offers overload protection, frequency compensation for amplifier use, and is available in several 8‑lead packages such as DIP, SQ, H, N8, and S8.
| Supply Current | 40 µA |
|---|---|
| Output Current | 125 mA |
| Dropout Voltage | 0.2 V |
| Reference Voltage | 2.5 V |
| Input Voltage Range | 4.5 V – 36 V |
| Reference Output Source/Sink | 2 mA source, 2 mA sink |
The shutdown pin (SHDN) disables the main regulator when driven high; noise or leakage on this pin can affect the output voltage.
The dropout voltage is about 0.6 V when delivering 125 mA.
It includes a trimmed 2.5 V class‑B output reference that can both source and sink current.
The device is offered in 8‑lead DIP, SQ, H, N8, S8, and plastic small‑outline packages.