Diodes Enables Cost-Effective Headset Detection with Low Power IC in Miniature Package

September 24 2015, 03:00

Discrete, logic and analog semiconductor specialist Diodes has introduced a raft of new ICs for consumer electronics and networks, together with new voltage converters and regulators targeting a range of interesting applications for the audio industry. The new AZV5001 headset detection IC is particularly interesting.

Diodes introduced the AZV5001, an headset detection IC targeted at cost- and power-sensitive consumer electronics such as mobile phones, tablet computers and media players. The integration of a comparator, OR gate and N-channel MOSFET into a miniature package enables the connection of a headset with microphone to be quickly and simply detected.

The AZV5001 has two detect inputs that together determine when a headset has been inserted into the equipment’s audio jack. The presence of a left audio signal drives the internal comparator output low, which when logically OR’ed with a ground connection from the jack will result in a low output from the IC, indicating the headset is properly connected. Internal pull-up resistors on both detect inputs ensure that connection is not indicated when either signal is absent. When a headphone is not detected, an on-chip N-channel MOSFET is enabled, which can be used to mute the microphone input to the equipment’s audio codec.

A miniature 6-pin 1.2mm x 1.0mm x 0.4mm DFN1210H4-6 package helps the AZV5001 reduce board space. A low supply current, typically 7.5μA when operating from a 1.8V supply, reduces system power consumption while low voltage operation, down to 1.6V, is also supported.

100V MOSFET Optimized for PoE Applications
Diodes also introduced the DMN10H120SFG MOSFET, designed as a switch for IEEE 802.3 compliant 48V Power-over-Ethernet (PoE) systems. This switch enables the delivery of power through the Ethernet cable to end-applications such as wireless access points, VoIP phones, point-of-sale terminals, call systems, IP security cameras and building management devices.

In power-sourcing equipment such as LAN routers and midspans, this 100V N-channel MOSFET switches power to the CAT5 (or CAT6) network cable. The cable then provides both power and data, which reduces system costs by eliminating the power supply in the end-equipment. It also protects end-users because PoE operates between 44V to 57V, which meets the 60V Safety Extra Low Voltage (SELV) rating, which removes the need for rigorous isolation and certification of end-equipment while also easing system maintenance. I2R losses are minimized when operating at these voltage levels and this helps maximize power delivery to the end-equipment and improve efficiency.

With a 100V BVDSS rating the DMN10H120SFG MOSFET provides plenty of headroom for 48V PoE operation. The DMN10H120SFG also offers an extended safe-operating-area (SOA) that can withstand the power dissipation due to short-circuit fault conditions, such as an Ethernet cable breaking, until the PSE controller detects the fault and switches off. During this fault condition the MOSFET goes into linear mode and needs to dissipate 30W for at least 20ms, which is achieved even with a +60°C elevated operating temperature.

The DMN10H120SFG is offered in the space-saving PowerDI3333 package. Within its extensive 100V DMN10H family, Diodes also offers SOT23, SOT223 and TO252 (DPAK) packages. The avalanche-rugged DMN10H099SK3, for example, in TO252 is 100% unclamped-inductive-switch (UIS) tested to ensure it can withstand the energy pulse in switching inductive loads such as coils, motors and relays.

New DC-DC Buck Converters
Another range of interesting new component from Diodes are the recently introduced AP3402, AP3419 and AP3429 DC-DC step-down converters, which operate from inputs of 2.7V to 5.5V to supply loads up to 2A, with great efficiency under both light and heavy load conditions. A high switching frequency of 1MHz reduces the size of external components; this, combined with tiny TSOT25 or TSOT26 packages, ensures a small circuit-board footprint in end-equipment such as TVs, monitors, set-top boxes, routers, notebook PCs and security systems.

A 100% duty cycle allows the devices to work with the lowest VIN and a low quiescent current of just 90μA helps conserve the life of battery-powered equipment. The devices also feature an integrated soft-start that prevents damage as the output switches turn on while integrated over-current and over-temperature protection (OCP and OTP) protect both the system and the IC from damage under fault conditions.

Diodes also introduced the 1.5A AP65101 and 2A AP65201 synchronous DC-DC buck converters. These devices combine efficient operation with the standard pinout, space-saving TSOT26 package and are targeted toward consumer electronics, such as TVs, set-top boxes, computer monitors and home audio. These buck converters achieve maximum continuous current efficiencies up to 97%, with improved efficiency at lower loads ensured by an automatic light-load algorithm.

The AP65101 and AP65201 are designed for low-voltage regulation, especially in distributed power architectures, and operate from 4.5V to 16V inputs while delivering adjustable output voltage from 0.8V up to 80% of VIN. A low quiescent supply current and integrated high- and low-side switches with low RDS(ON) both help to reduce power loss. Protection features, including under-voltage lockout, over-current, over-voltage and over-temperature, help prevent damage to downstream components and stress-induced premature component failure. The device enable pin also has a high voltage tolerance of up to 6V.

The high level of integration and minimal need for external components combined with the small-footprint TSOT26 package provide valuable cost and circuit board space savings. Current-mode operation enables fast transient response and easy loop stabilization, while other features like programmable soft-start and a 500kHz switching frequency contribute to ease of use.
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