ADP2138ACBZ-1.5-R7

Both the ADP2138 and ADP2139 are high-efficiency, geoquicentric, synchronous step-down DC-DC converters. ADP2139 additionally added an internal discharge switch. The entire solution requires only three small external components. When the MODE pin is set to high, the buck regulator will operate in forced PWM mode, providing low peak-to-peak ripple for power supply noise-sensitive loads at the expense of light-load efficiency. When the MODE pin is set to low, the buck regulator automatically switches the operating mode based on the load current level. When the output load is high, the buck regulator operates in PWM mode. When the load current drops below a predefined threshold, the regulator operates in power saving mode (PSM) to improve light load efficiency.

The ADP2138/ADP2139 operates from a 2.3 V to 5.5 V input voltage and can be powered by a single lithium or lithium polymer battery, multiple alkaline or NiMH batteries, PCMCIA, USB, and other standard power supplies. A maximum load current of 800mA is achieved over the entire input voltage range.

The ADP2138/ADP2139 is available in 3.3 V, 3.0 V, 2.8 V, 2.5 V, 1.8 V, 1.5 V, 1.2 V, 1.0 V, and 0.8 V fixed output voltages. All models have built-in power switches and synchronous rectifiers to reduce the number of external components and increase efficiency. ADP2138/ADP2139 has a built-in soft-start function with an internal compensation mechanism. During logic-controlled shutdown, the input is disconnected from the output and ADP2138/ADP2139 draws 0.2 μA (typical) from the input source.

Other important features include undervoltage latching to prevent deep battery discharge and soft start to prevent overshoot of input current during start-up. ADP2138/ADP2139 in a 6-pin wafer-scale chip-scale package (WLCSP).

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