Tiny converter drives four white LEDs

25 September 2002 Opto-Electronics

Linear Technology's LT1937 is an 84% efficient, constant current white LED driver packaged in an SC-70 or a ThinSOT (profile under 1 mm). 1,2 MHz switching frequency enables extremely small externals, namely a 22 µH inductor and 0,22 µF output capacitor. The LT1937 has been optimised to drive up to four white LEDs on 3,2 V supply (6 LEDs from 5 V supply). Efficiency and <1 mA shutdown current provide optimal battery time, while input voltage range 2,5 V to 5,5 V makes it ideal for use in single cell Li-Ion and multicell Alk/NiMH battery devices. 1,2 MHz constant switching architecture minimises both input and output noise. The device delivers constant current to series-connected LEDs, ensuring uniform brightness. High accuracy feedback voltage (95 mV+ 9 mV) contributes to high efficiency and provides good brightness control even when partially dimmed to current levels of 6-8 mA.

Further reading:

PhotoMOS relays
Future Electronics Opto-Electronics
The AQY221R2SX and AQY221R2S PhotoMOS from Panasonic Industry ensures excellent characteristics and high-speed switching performance.

Read more...

---

Mouser now shipping onsemi’s image sensors
TRX Electronics Opto-Electronics
The AR0145CS is a 1/4,3-inch CMOS digital image sensor with a 1280 (H) x 800 (V) active-pixel array that can capture both continuous video and single frames.

Read more...

---

Adaptive optics’ power solution
Altron Arrow Opto-Electronics
Vicor power-dense adaptive optical modules enable colossal telescopes to look into the past for deep space discoveries.

Read more...

---

Ultra-high speed photo detection
Opto-Electronics
TDK Corporation has announced a photo-spintronic conversion element combining optical, electronic, and magnetic elements that can respond at an ultra-high speed of 20 picoseconds.

Read more...

---

High-speed lasers
RFiber Solutions Opto-Electronics
Macom are a high-volume manufacturer of lasers, deploying more than 100 million devices with a reliability of less than 50 FIT and greater than 100 years of wear-out lifetime

Read more...

---

High-performance optical interconnect
Opto-Electronics
STMicroelectronics has unveiled its next generation of proprietary technologies for higher-performing optical interconnect in datacentres and AI clusters.

Read more...

---

Halo mid-board optical transceiver
Spectrum Concepts Opto-Electronics
The Samtec Halo mid-board transceiver has been designed for next-generation embedded applications that require 56 and 112 Gbps PAM4 performance in low profile and ruggedised form factors.

Read more...

---

New generation of Ethernet media converters
IOT Electronics Opto-Electronics
Phoenix Contact is introducing three new families of media converters to the market, each designed for specific industrial environments and challenges.

Read more...

---

PIN photodiode with integrated lens
RFiber Solutions Opto-Electronics
The MARP-BP112 from Macom is a backside-illuminated PIN photodiode, usable from 1200 nm to 1650 nm, that is optimised for use in 112 GBaud PAM4 applications.

Read more...

---

RGBIR sensor with I2C interface
Electrocomp Opto-Electronics
Available in a miniature opaque 2,67 x 2,45 mm package, Vishay’s VEML6046X00 includes high-sensitivity photodiodes, a low noise amplifier, and a 16-bit analogue to digital converter.

Read more...

---