MAX1678EUA+, DC/DC преобразователь (повышающий) [uMAX-8]
The MAX1678EUA+ is a 1 cell to 2 cell, low noise, high efficiency, step up DC to DC converter in 8 pin µMAX package. It is a high efficiency, low voltage, synchronous- rectified, step up DC to DC converter intended for use in devices powered by 1 to 3 cell alkaline, NiMH or NiCd batteries or a 1 cell lithium battery. It has a 0.87V start-up voltage and features a low 37µA quiescent supply current. The device includes a 1ohm, N-channel MOSFET power switch, a synchronous rectifier that acts as the catch diode, a reference, pulse-frequency-modulation (PFM) control circuitry and circuitry to reduce inductor ringing all in an ultra-small, 1.1mm high µMAX package. The output voltage is preset to 3.3V or can be adjusted from +2V to +5.5V using only two resistors. Efficiencies up to 90% are achieved for loads up to 50mA. The device also features an independent undervoltage comparator (PFI/PFO) and a logic-controlled 2µA shutdown mode.
• Supply voltage range is 0.7V to 5.5V
• Operating temperature range from -40°C to 85°C
• Built-in synchronous rectifier (no external diode)
• Power-fail detector
• Output current is 45mA at 3.3V for 1 cell input and output current is 90mA at 3.3V for 2 cell input
• Inductor damping switch suppresses EMI