The MAX1945R/MAX1945S high-efficiency pulse-width modulation (PWM) switching regulators deliver up to 6A of output current. The devices operate from an input supply range of 2.6V to 5.5V and provide selectable output voltages of 1.8V, 2.5V, and adjustable output voltages from 0.8V to 85% of the supply voltage. With VCC at 3.3V/5V, the input voltage can be as low as 2.25V. The MAX1945R/MAX1945S are ideal for on-board post-regulation applications. Total output voltage error is less than ±1% over load, line, and temperature. The MAX1945R/MAX1945S operate at a selectable fixed frequency (500kHz or 1MHz) or can be synchronized to an external clock (400kHz to 1.2MHz). The high operating frequency minimizes the size of external components. The high bandwidth of the internal error amplifier provides excellent transient response. The MAX1945R/MAX1945S have internal dual N-channel MOSFETs to lower heat dissipation at heavy loads. Two MAX1945R/MAX1945Ss can operate 180 degrees out-of-phase of each other to minimize input capacitance. The devices provide output voltage margining for board-level testing. The MAX1945R provides a ±4% voltage margining. The MAX1945S provides a ±9% voltage margining. The MAX1945R/MAX1945S are available in 28-pin TSSOP-EP packages and are specified over the -40°C to +85°C industrial temperature range. An evaluation kit is available to speed designs.
The MAX1945R and MAX1945S are high‑efficiency PWM step‑down regulators that deliver up to 6 A of output current. They operate from an input supply range of 2.6 V to 5.5 V and offer selectable output voltages of 1.8 V, 2.5 V, or an adjustable range from 0.8 V to 85 % of the input voltage.\n\nBoth devices are available in a 28‑pin TSSOP‑EP package and are specified for an industrial temperature range of –40 °C to +85 °C. They support a fixed switching frequency of 500 kHz or 1 MHz (or external clock synchronization) and provide voltage margining of ±4 % (MAX1945R) or ±9 % (MAX1945S).
| Input voltage range | 2.6 V – 5.5 V |
|---|---|
| Maximum output current | 6 A |
| Efficiency | up to 95 % |
| Output voltage options | 1.8 V, 2.5 V, or 0.8 V‑85 % of VIN |
| Package | 28‑pin TSSOP‑EP |
| Operating temperature range | -40 °C to +85 °C |
| Switching frequency | 500 kHz or 1 MHz (selectable) |
| Voltage margining (MAX1945R) | ±4 % |
| Voltage margining (MAX1945S) | ±9 % |
The devices can deliver up to 6 A of output current.
It operates from 2.6 V to 5.5 V input.
Fixed 1.8 V or 2.5 V can be chosen via FBSEL, or an adjustable voltage from 0.8 V to 85 % of the input voltage is available.
A fixed frequency of 500 kHz or 1 MHz can be selected, or an external clock from 400 kHz to 1.2 MHz may be used.