Wednesday, July 05, 2017

MAX1910 White LED Charge Pumps - Maxim IC

Drives LEDs with a regulated output voltage or current (up to 120mA) from an unregulated input supply (2.7V to 5.3V). These are complete DC-DC converters requiring only four small ceramic capacitors and no inductors. 200mV Current-Sense Threshold Reduces Power Loss.

MAX1910 White LED Charge Pumps - Maxim IC

The MAX1910/MAX1912 are complete charge-pump boost converters requiring only four small ceramic capacitors. They employ a 750kHz fixed-frequency 50% duty-cycle clock.

MAX1910 White LED Charge Pumps - Maxim IC

Figure 4’s circuit improves LED current matching by raising the ballast resistance while maintaining a 200mV VSET. The increased ballast resistance tolerates wider LED mismatch, but reduces efficiency and raises the minimum input voltage required for regulation.

Yet another method of biasing LEDs is shown in Figure 5. In this case, the current through the complete parallel combination of LEDs is set by R5. R1–R4 are only used to compensate for LED variations. This method of biasing is useful for parallel LED arrays that do not allow connection to individual LEDs.

Tuesday, July 04, 2017

MAX1561 - 26V Step-Up Converters - Maxim IC

The MAX1561 and MAX1599 include an internal, high-voltage, low-RDS(ON) N-channel MOSFET switch for high efficiency and maximum battery life. A single DualMode input provides a simple means of brightness adjustment and on/off control.

MAX1561 - 26V Step-Up Converters - Maxim IC

"High-Efficiency, 26V Step-Up Converters for Two to Six White LEDs"

MAX1561 - 26V Step-Up Converters - Maxim IC

Fast 1MHz (500kHz for the MAX1599) current-mode, pulse-width modulated (PWM) operation allows for small input and output capacitors and a small inductor while minimizing ripple on the input supply/battery. Programmable soft-start eliminates inrush current during startup.

Some Features -
  • Accurate Current Regulation for Uniform Illumination
  • High Efficiency Up to 87%
  • 2.6V to 5.5V Input Range
  • 0.3µA Shutdown Current
  • 26V (max) Output with Overvoltage Protection
  • Up to 900mW Output Power with Internal 30V MOSFET Switch
Why Drive White LEDs with Constant Current? - Maxim

Here you can understand how to drive white LED' s for flashlight or Internal lamp. I have tried substituting for tubelights and bulbs. These LED's are amazing. The amount of light at even 100mW is phenomenal. The future is indeed LED Lights. But more Amber component is required in LED to give the warm feeling of an Edison Lamp.

Sunday, July 02, 2017

Cirrus Logic - Analog and Mixed-signal

Cirrus Logic is recognized worldwide for its expertise in developing high-precision analog and mixed-signal integrated circuits (ICs) for a broad range of consumer and industrial markets.

Cirrus Logic - Analog and Mixed-signal

The most respected brands in the audio and industrial markets such as Bose, Harman International, IO, Onkyo, Marantz, Panasonic, Philips, Pioneer, Samsung and Sony rely on Cirrus Logic technology.

Founded in 1984 with headquarters in Austin, Texas, Cirrus Logic is fabless.

CDB5484/80/90 Evaluation Boards

Cirrus Logic - Analog and Mixed-signal

The CDB5484/80/90U boards are designed to evaluate the functionality and performance of the CS5484/80/90 energy measurement IC family. Shunt resistors, current transformers or Rogowski coils can be connected to the analog inputs. Intuitive GUI software provides easy and full access to the on-board CS5484/80/90 device and MCU.

On-board LEDs and LCD displays enable stand alone operation for extended testing. These CDBs enable fast and easy preliminary evaluation of Cirrus Logic's AFE products.

Cirrus Logic, Inc.
800 West 6th Street, Austin, Texas 78701, United States