The CMKTC825A temperature-compensated Zener diode from Central Semiconductor is packaged in a space-saving SOT-363 surface-mount case. This diode provides a highly stable reference voltage of 6.2 V with only a small voltage change of less than 0.28 mV/°C over the temperature range of -55°C to +100°C. In addition, the CMKTC825A occupies 4.2 mm2 of circuit-board space and has a low profile of 1 mm.
The CMKTC825A is ideal for use in high-stability oscillators, digital volt/frequency meters, analog-to-digital converters and precision dc power supplies. The CMKTC825A is available in bulk or tape and reel and starts at $0.36 each for 3000 pieces on a 7-in. reel.
Li-Ion Battery Charger
Texas Instruments' 1-A, bq24060 single-cell Li-ion linear charger has enhanced thermal fold-back regulation and low-dropout power management. The device will enable personal digital assistants, cell phones, digital cameras and wireless headsets to charge more safely and efficiently from a battery-charge cradle or ac adapter.
The battery charger can withstand an input voltage of up to 26 V. The device charges the battery in the three phases required by battery cell manufacturers, including precharge conditioning, constant or thermally regulated current, and accurate constant voltage. The charger's algorithm reduces charge times, maximizes total charge, and protects the battery from thermal and electrical dangers. It restarts the charge when the battery voltage falls below an internal threshold, and it enters a low-power sleep mode when the external input supply is removed.
The bq24060 charger comes in a 10-pin, 3-mm × 3-mm MLP package and costs $1.20 each in quantities of 1000.
Half-Bridge DC-DC Controller
Vishay Intertechnology's Si9122A half-bridge controller and SiP11203/11204 secondary synchronous-rectifier driver offer greater than 90% dc-dc conversion efficiency — even for output voltages below 3.3 V. The 500-kHz half-bridge dc-dc controller and synchronous rectifier driver work together as a chipset to enable more efficient 25-W to 300-W telecom and computer power supplies.
Designed to operate within the telecom voltage range of 36 V to 75 V and withstand 100-V, 100-ms transients, the Si9122A is capable of controlling and driving both the low- and high-side switching devices of a half-bridge circuit and also the synchronous rectifier MOSFETs on the secondary side of the bridge.
The SiP11203/11204 drivers are rated for a 5.5-V to 13-V operating range, feature a regulated internal logic voltage of 5 V, and provide a 2.2-A source and 4-A sink drive capability. Both drivers integrate seven functions: the synchronous rectifier drivers, the error amplifier, the precision voltage reference, the optoisolator driver, control of the startup, control of the shutdown and overvoltage protection.
The Si9122A is available in TSSOP-20 or MLP65-20 packages, and the SiP11203 and SiP11204 come in a compact MLP44-16 package. Pricing in quantities of 10,000 is $1.95 each for the Si9122A and $1.55 each for the SiP11203 or SiP11204.
Online Design Services
International Rectifier has expanded its myPOWER online design services with the introduction of the POWIR+ chipset reference designs and enhanced online design services to simplify and accelerate power-management circuit design.
The first series of POWIR+ chipsets brings together the IR3637SPbF and IR3637ASPbF application-tuned PWM control ICs and their companion HEXFET MOSFETs for single-phase synchronous buck applications in computing and high-end consumer applications. The IRPP3637-06A, IRPP3637-12A and IRPP3637-18A reference designs accelerate the design process while eliminating unnecessary design iterations.
In addition to the three reference designs, users can create custom circuits by modifying any of the standard designs online at http://powirplus.irf.com.
The first series of standard POWIR+ chipset reference designs is available immediately. Customized reference designs are available in one to two weeks ordered through the POWIR+ chipset online design tool.
Pricing for each standard IRPP3637-xxA reference design is $150 in single-unit quantities. Pricing for each customized IRPP3637-xxA reference design is $250 in single-unit quantities.
El Segundo, Calif.
Switching Voltage Regulator
The ST1S06 from STMicroelectronics is a high-frequency stepdown dc-dc converter. An evolutionary advance over the previous ST1S03 and ST1S03A switching voltage regulators, the ST1S06 includes a synchronous rectification block to avoid the use of an external Schottky diode while improving the device's efficiency up to 95%. Other key features include an output current capability of 1.5 A maximum over all operating conditions, a high switching frequency of 1.5 MHz and great stability, allowing a drastic reduction in pc board area. In fact, the ST1S06 requires only a few external components to operate: the small inductor, two capacitors and, for the adjustable version, two resistors.
In production now, the ST1S06 price ranges from $0.35 each to $0.45 each in high volumes.
The CL6 and CL7 from Supertex are linear, constant-current LED drivers with fixed output currents of 100 mA. The devices are ideally suited for applications using 24-V/48-V inputs.
Both ICs feature built-in reverse polarity protection and overtemperature protection. With maximum ratings of 90 V, the ICs are able to withstand transients without any additional transient protection circuitry when used as recommended.
The CL7 also features an active low enable input pin that allows logic-level control of the LED for on/off or PWM dimming control.
The CL6 is available in DPAK and three lead TO-220 packages. The CL7 is available in a power SO-8 package. They are all Green and RoHS compliant. In 1000-unit quantities, the CL6 costs $0.93 each in the DPAK package or $0.99 each in the TO-220 packages and the CL7 costs $1.12 each.
Dual Buck Controller
Requiring no sense resistors, the ADP1823 dual buck controller from Analog Devices generates two independent outputs as low as 0.6 V from an input of 3 V to 20 V. The controller switches at a pin-selectable 300 kHz or 600 kHz, or can be synchronized to an external 300-kHz to 1-MHz clock. Output voltages are accurate to ±0.85% from 0°C to 70°C.
Other features include individual “power-good” pins for the two outputs; overcurrent, thermal overload and reverse-current-limit protection; output voltage tracking; and soft-start. Available now, the ADP1823 is priced at $2.10 per unit in 1000-piece quantities and comes in a 5-mm × 5-mm, 32-pin LFCSP.