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180mA, 1x/2x, White LED Charge Pump in 3mm x 3mm TDFN

White LED Charge Pump in 3mm x 3mm TDFN Achieves 83% Average Efficiency

Product Details

Key Features

Parametric specs for LED Drivers
VIN (V) (min) 2.7
VIN (V) (max) 5.5
Max. No. of LEDs 3
# LED Channels 3
Regulation Topology Charge Pump
Battery Input 1-Cell Li+
LED Configuration Parallel
ILED per Channel (A) (max) 0.06
Dimming Ratio (max) 20
Dimming Control Serial Pulse
POUT (W) 0.75
ICC (mA) (max) 2
LED String Volt. (V) (max) 5
Switching Frequency (kHz) 1000
Package/Pins TDFN/10
Budgetary
Price (See Notes)
1.88
View Less

Simplified Block Diagram

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Sampling:
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Parameters

Parametric specs for LED Drivers
VIN (V) (min) 2.7
VIN (V) (max) 5.5
Max. No. of LEDs 3
# LED Channels 3
Regulation Topology Charge Pump
Battery Input 1-Cell Li+
LED Configuration Parallel
ILED per Channel (A) (max) 0.06
Dimming Ratio (max) 20
Dimming Control Serial Pulse
POUT (W) 0.75
ICC (mA) (max) 2
LED String Volt. (V) (max) 5
Switching Frequency (kHz) 1000
Package/Pins TDFN/10
Budgetary
Price (See Notes)
1.88

Key Features

  • Up to 180mA (60mA/LED) Drive Capability
  • 83% Average Efficiency (PLED / PBATT) Over Li+ Battery Discharge
  • 0.5% (typ) LED Current Matching
  • Adaptive 1x/2x Mode Switchover
  • Low Input Ripple and EMI
  • 5% to 100% Dimming Through Single-Wire Serial Pulse Interface
  • Low 0.1µA Shutdown Current
  • 2.7V to 5.5V Supply Voltage Range
  • Soft-Start Limits Inrush Current
  • Output Overvoltage Protection
  • Thermal-Shutdown Protection
  • 10-Pin 3mm x 3mm TDFN Package

Applications/Uses

  • Camera Strobes/Flashes and Movie Lights
  • Cell Phones/Smartphones
  • LCD Backlights
  • PDAs, Digital Cameras, and Camcorders

Description

The MAX1574 charge pump drives up to three white LEDs with regulated constant current for uniform intensity. By utilizing adaptive 1x/2x charge-pump modes and very-low-dropout current regulators, it achieves 180mA output drive capability and high efficiency over the 1-cell lithium-battery input voltage range. Fixed-frequency (1MHz) switching allows for tiny external components, and the regulation scheme is optimized to ensure low EMI and low input ripple.

The MAX1574 uses an external resistor to set the fullscale 100% LED current. An enable input (EN) is used for simple on/off control or can be pulsed repeatedly to set lower LED current in multiple steps down to 5%. Once the desired brightness is set, the MAX1574 maintains constant LED current as long as EN is kept high. If EN is kept low for more than 2ms, the MAX1574 enters shutdown. The MAX1574 is available in a 10-pin 3mm x 3mm TDFN package (0.8mm max height).

Simplified Block Diagram

MAX1574: Typical Operating Circuit MAX1574: Typical Operating Circuit Zoom icon

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .

Sampling:
Selecting the Sample button above will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.