Highest Current, 1.2A, Charge Pumps Enable Brightest WLED Flashes in Camera Phones, Even with Low-Battery Input Voltage
The MAX1577Y/MAX1577Z charge pumps drive white LEDs, including camera strobes, with regulated current up to 1.2A (guaranteed to 800mA). The very low openloop output resistance allows high flash brightness, even from a low battery input voltage. The adaptive 1x/2x regulating charge-pump operation provides high efficiency (up to 92%) while in movie mode or backlighting. Fast (1MHz) switching allows the use of tiny external components. The MAX1577Y/MAX1577Z use an external resistor to set the full-scale LED current. Two enable inputs (EN1 and EN2) provide simple on/off control and LED current of 20%, 33%, or 100% full scale. If there is less than 24mV across the external resistor, the output voltage is regulated. The MAX1577Z has fixed 5.1V output-voltage regulation, while the MAX1577Y has logic-controlled output voltage of 3.4V, 4.6V, or 5.1V for backlighting, keyboard, and RGB applications. The MAX1577Y/MAX1577Z are available in an 8-pin, 3mm x 3mm TDFN package (0.8mm max height).
Title | Download file |
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MAX1577-MAX1577Z Data Sheet | MAX1577-MAX1577Z.pdf |
Part Number | Battery Input | Regulation Topology | Max. No. of LEDs | LED Channels | LED Configuration | ILED per Channel (A) | PWM Dimming Freq. (kHz) | Dimming Ratio | Dimming Control | POUT (W) | VIN (V) | VIN (V) | ICC (mA) | LED String Volt. (V) | Oper. Freq. (kHz) | Package/Pins |
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max | max | max | min | max | max | max | ||||||||||
MAX1577 | 1-Cell Li+ | Charge Pump | 1 | 1 | Parallel | 1.2 | 5 | 5 | Digital PWM | 5 | 2.7 | 5.5 | 5 | 5.1 | 1000 | See Data Sheet |
Part Number | Status | Recommended Replacement | Package | Temp | RoHS |
---|---|---|---|---|---|
MAX1577ZETA+ | Active | TDFN-EP,;8 pin;9.6 mm² | -40°C to +85°C | Lead Free | |
MAX1577ZETA+T | Active | TDFN-EP,;8 pin;9.6 mm² | -40°C to +85°C | Lead Free | |
MAX1577ZETA-T | No Longer Available | MAX1577ZETA+T | TDFN-EP,;8 pin;9.6 mm² | -40°C to +85°C | No |