The OT1153 series on-chip regulators allow for efficient on-chip conversion of IO voltages to Core voltages. E.g. 3.3V to 1.2V with only one external inductor and one external capacitor. 2MHz conversion frequency is used to minimize the size of the external components. Input voltages of 2.5-5V are available and currents up to 80mA. Versions with internal or external references are available. In normal operation constant on time PWM modulation is used, with an optional low power mode in which where the synchronous rectifier is disabled.
On-Chip IO to Core Voltage Buck Regulator on UMC 55nm ULP
Overview
Key Features
- Input voltages of 2.5V, and 3.3V.
- Available output currents to 100mA.
- Available output voltages 0.91V to 1.2V.
- Works with straight-through IO pads.
- Soft startup.
- Optional frequency sync input.
- 10mVpp ripple.
- Suspend mode input lowers regulator power for light loads, by using a non-synchronous rectifier, and low frequency.
- Typical 50µH, and 1µF external components.
- -40°C to 125°C temperature operation.
- Base cell area 0.18mm2 in UMC 55nm ULP process.
- Available reference, and frequency dither cells.
Benefits
- Efficient on-chip core power generation from external IO power.
- Replacement of external buck regulator chips in low power applications.
Block Diagram

Deliverables
- GDS layout.
- LEF outline.
- Spice/CDL netlist for LVS.
- Black box timing files.
- Design review documentation.
- Integration notes.
Technical Specifications
Related IPs
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- Linear Voltage Regulator - High Input Voltage (30V), Output Load up to 5mA
- General-Purpose I/O Controller Core