Adaptive Deadtime Control Technology Sets New Standard
May 25, 2004 - International Rectifier, IR® introduced the IR2161, the world's first intelligent control IC specifically designed for electronic transformers that drive low voltage halogen lamps. All necessary features are integrated into a single 8-pin DIP or SOIC, reducing parts count, simplifying circuits and increasing reliability.The new IR2161 control IC can adapt to changing supply voltage, frequency conditions, and lamp conditions enabling the introduction of highly-reliable halogen transformers while streamlining their design and manufacture.
Featuring IR's rugged high voltage IC technology, this compact 8-pin device incorporates a 600V half-bridge driver, advanced overload and short-circuit protection circuitry with high temperature shutdown and adaptive control techniques offering a reliable alternative to the traditional approach based upon self-resonating, bipolar transistor half-bridge circuits. The IR2161 also accommodates external dimming with a standard phase-cut, triac-based dimmer. Compared to similar circuits using discrete components, the IR2161 can reduce component count by 20%.
Adaptive Deadtime Control
Adaptive Deadtime Control is a key feature of the IR2161, which increases transformer reliability by continually maintaining soft switching. The IC has an active deadtime circuit that detects the point at which the DC bus voltage in the half bridge slews to 0V and sets the low-side driver (LO output) high. An internal sample and hold system allows approximately the same delay to be used to set the high-side driver (HO output) high after LO has gone low. Adaptive deadtime control reacts on a cycle-by-cycle basis of the oscillator and adjusts dead time as necessary to maintain soft switching regardless of external conditions.
IR's Enabling HVJI Technology
IR2161 is based upon International Rectifier's high-voltage junction-isolation (HVJI) IC technology. This proprietary technology allows high-voltage circuits to be isolated from low-voltage circuitry, so that both high- and low-side drive functions can be housed on a single, compact chip for controlling various switching converter topologies. Since halogen lighting requires both high- and low-voltage circuits to function, components made with IR's HVJI technology are particularly well-suited to the application.
Design Assistance
Click on any of the part numbers below for access to the IR2161 datasheet. In addition, an entire suite of application notes, technical papers, design software and reference designs are available at the IR Lighting website.
| Part Number | Package | Standard Pack Quantity | Breakdown Voltage | Drive Current | Junction Temperature |
| IR2161 | 8 Lead DIP | 50 | 600V | 250/400mA | -55C to 150C |
| IR2161S | 8 Lead SOIC | 95 | |||
| IR2161STR | 8 Lead SOIC in Tape and Reel | 2500 |
Availability and Pricing
The IR2161 converter IC is available immediately in 8-pin DIP, 8-pin SOIC, and 8-pin SOIC tape and reel. Pricing for the IR2161 begins at US $0.73 each (IR2163S) in 100,000-piece quantities.
