NEW PRODUCT RELEASE
September 2008
LED drivers bring smaller footprint and energy savings to lighting applications
Diodes Incorporated has extended its series of USB power switches with the introduction of 12 new parts, providing a cost effective and small form
fit for USB ports in a wide range of consumer electronics. Offering designers 0.75A, 1.5A and 2.1A current limiting options and a choice of active-high
and active-low enable, the AP21XX optimizes port protection in a host of different systems.
The AP21XX high-side power switch range has been created for USB port applications requiring fast response, high accuracy over-current and over-
temperature protection, such as HD televisions, set top boxes and PCs. Both single and dual channel power switches are available, with all devices
being optimized for self-powered and bus-powered USB applications and fully compliant with all USB standards.
The power switches include an internal sensing FET which monitors for over-current conditions, without increasing series resistance in the current
path, and an over-temperature sensor. If either over-current or over temperature conditions are sensed, the device switches into its current limiting
mode. To prevent unwanted tripping when a high capacitive load is connected to the device output, a 7ms deglitch timeout has also been included in
the AP21XX’s design.
The USB power switch family is provided in small footprint SOT25, SOP-8L and MSOP-8L-EP packages. All of which are direct replacements for
existing industry standard parts. Device operating ambient temperature range is -40 to 85oC.
LED drivers bring smaller footprint and energy savings to lighting applications
Diodes Incorporated (NASDAQ:DIOD), a leading global manufacturer and supplier of application specific standard products within the broad discrete
and analog semiconductor markets, today announced that it has further extended its Zetex LED driver series with the introduction of three new
miniature LED drivers offering improved accuracy and thermal performance. Provided in TSOT23-5 and thermally enhanced DFN6, the highly integrated
ZXLD-1352, -1356 and –1366 deliver adjustable output currents of 350mA, 550mA and 1A, respectively, and suit a broad range of automotive,
architectural and industrial lighting applications.
With an output current accuracy of typically better than 1%, the ZXLD1356 and ZXLD1366 provide users with highly accurate current matching at
working voltages up to 60V. Capable of producing output powers of 30W and 48W respectively, these TSOT23-5 and 3mm x 3mm DFN6 packaged
drivers will support up to 15 LEDs in an array of applications requiring minimum footprint and maximum efficiency.
Operating from a 7V to 30V supply and capable of producing an output current of up to 350mA, the 2.8mm x 2.9mm TSOT23-5 packaged ZXLD1352
can provide up to 8W of power for driving chains of up to 10 LEDs. With a large PWM dimming ratio of 1000:1, the driver offers highly flexible
brightness control and accurate color mixing.
TContinuous mode inductive step-down converters, specifically designed for driving single or multiple high brightness LEDs, the ZXLD drivers are
characterized by their ease of configuration and operation. Nominal output current, set by a resistor is easily adjusted by applying a PWM or DC
voltage control signal to precisely match brightness requirements; a low level control signal turns the output off and puts the driver into standby. The
drivers need the support of just three discrete external components.
July 2008 Diodes Incorporated Qualifies Power Management ICs for Automotive Markets
Diodes Incorporated (Nasdaq: DIOD), a leading global manufacturer and supplier of high-quality application specific standard products within the
broad discrete and analog semiconductor markets, today announced the qualification of a series of its popular Zetex power management ICs to
the AEC-Q100 automotive quality specification. The newly qualified products include monitors, regulators and references, which meet the
requirements of AEC-Q100 Grade 1 for operation in automotive environments at temperatures up to 125ºC. As previously announced, Diodes
closed the acquisition of United Kingdom-based Zetex plc on June 9, 2008.
The ZXCT1008 and ZXCT1080 current and voltage output current monitors, the ZTL431 and TLV431 shunt regulators, and the LM4040 precision
micropower voltage reference devices support measurement and protection duties in a wide range of reliability-critical subsystems, including window
motor control, air conditioning and courtesy lighting.
"Qualifying these very popular devices at such a stringent automotive quality specification provides automobile manufacturers the benefit of more
precise power management coupled with significantly increased reliability," said Mark King, Diodes’ Senior Vice President of Sales and Marketing.
"From a business perspective, this step is a natural progression for our Company. The Zetex range of high efficiency bipolars and MOSFETs has long
been qualified to the AEC-Q101 specification for discrete parts. Our AEC-Q100 compliant monitors, regulators and references are a perfect
complement, which substantially increases the value proposition we offer to the automotive sector."
Published by the Automotive Electronic Committee (AEC), the AEC-Q100 quality specification details the environmental and endurance tests and
conditions that electronic components need to satisfy before automotive qualification can be declared.
May 2008
Rectifier controller optimises flyback converter design
Zetex Semiconductors has introduced a dedicated rectifier controller for driving MOSFETs so that they perform as ‘ideal diodes’ in synchronous
flyback converters ranging from 50 to 150W. The ZXGD3101 enables designers to replace lossy Schottky diodes, with surface mount MOSFETs
to achieve higher efficiency, less heat generation, a reduction in power supply size and weight and a simplification of overall circuit design.
Called a ‘zero point detector driver’ (ZPDD) since it accurately senses the point at which secondary current reaches zero, the ZXGD3101 ensures
that a MOSFET performs the same function of the diode it replaces while significantly improving power supply efficiency. In a 60W notebook adapter
for example, the losses are reduced by typically 20%.
Simpler and more robust than competing synchronous controller ICs, the driver needs the support of just three external passive components and
produces source and sink currents of up to 2.5A. Since no timing information needs to be transferred from the primary side and no timing components
are needed on the secondary side, the ZXGD3101 is very simple to implement.
The ZPDD incorporates a high voltage differential amplifier stage and a high current driver in the compact SM8 package. It monitors MOSFET
Drain-Source reverse voltage and when body diode conduction occurs, produces a positive gate voltage to turn the MOSFET on. Being proportional
to the MOSFET Drain-Source reverse voltage, the drive voltage to the gate is progressively backed off, thereby ensuring rapid MOSFET turn-off at
the zero voltage switching point. This ensures that reverse conduction does not occur.
May 2008
Driver family meets demands of next generation LEDs
Zetex has introduced a family of three flexible LED drivers, providing designers with the performance needed for the next generation of high
brightness LEDs. The ZXLD132X inductive DC-DC converter series drive single or multiple LEDs with currents from 700mA through to 1.5A, in buck,
boost and buck/boost configurations. Housed in a tiny 3mm x 4mm DFN package, the drivers can reduce the circuit footprint of existing solutions
by up to 50%.
Employing an innovative variable 'on' and 'off' time control scheme with an adjustable peak switch current limit, the chips are significantly simpler
to control than alternative PFM solutions. The drivers also enable both LED current and peak inductor current to be set accurately and
independently.To read the full press release and to view the datasheets, click here.
Part number |
Description |
Input
voltage range
V |
Max output
voltage
A |
Quiescent
current
µA |
Max switch
current
mA |
Package |
ZXLD1320 |
1.5A LED driver with internal switch |
4 to 18 |
1.8 |
12 |
2000 |
TDFN1443 |
ZXLD1321 |
1A LED driver with internal switch |
1.2 to 12 |
1.8 |
12 |
2000 |
TDFN1443 |
ZXLD1322 |
0.7A LED driver with internal switch |
2.5 to 15 |
1.8 |
12 |
2000 |
DFN1443 |
April 2008
Gate drivers switch power MOSFETs and IGBTs faster than IC alternatives
Zetex Semiconductors has announced a series of bipolar gate drivers for switching MOSFETs and IGBTs in power supplies and motor drives.
Capable of sinking currents up to 9A, the low cost ZXGD3000 series enables faster charging and discharging of gate capacitances than is possible
with gate driver ICs, resulting in more rapid switching times and greater circuit efficiency.
There are four high-speed non-inverting gate drivers in the series, covering a supply voltage range of 12V to 40V. Their fast switching emitter-follower
configuration achieves propagation delays less than 2ns and rise/fall times of the order of 10ns, giving improved control of the MOSFET switching
performance. The ZXGD3000s prevent latch-up and eliminate shoot-through, so helping to improve circuit reliability and improve EMI performance.
Available in the 6-leaded SOT23 package, the ZXGD3000 series gate drivers enable component count to be reduced and power densities to be
increased. The devices’ high current gain and low input current requirement allows direct interface with low power controller ICs, so removing the
need for additional buffer circuitry.
Independent source and sink output pins provides designers with the flexibility to separately control gate rise and fall times. To greatly simplify pcb
layout and to help minimise trace inductance, the SOT23-6 package pin-out has been optimised, with a flow-through design approach putting inputs
and outputs on opposite sides of the device.
February 2008
Leadless MOSFET reduces footprint by 50%
Zetex Semiconductors has announced its first MOSFET to be packaged in the leadless 2mm x 2mm DFN package.
With a PCB footprint 50% smaller than industry standard SOT23 packaged devices and an off-board height of just 0.85mm, the ZXMN2F34MA will
benefit a range of space-starved switching and power management applications, such as external switches in buck/boost PoL converters, where
PCB footprint, thermal performance and low threshold voltage are of prime importance.
Key advantages
* Offers a superior thermal performance – improved power density
* A footprint half that of SOT23 - space and potential cost saving due to reduced PCB area
* Thin package - suitable for portable and height contained applications
The ZXMN2F34MA is one of a series of six N-channel MOSFETs packaged in a variety of SMD packages to be introduced by Zetex in February 2008.
*Driver family meets demands of next generation LEDs*
A family of three flexible LED Drivers from Zetex Semiconductors provides designers with the performance needed by the next generation of high
brightness LEDs. The ZXLD132X inductive DC-DC converter series drive single or multiple LEDs with currents from 700mA through to 1.5A, in buck,
boost and buck/boost configurations. Housed in a tiny 3mm x 4mm DFN package, the drivers can reduce the circuit footprint of existing solutions
by up to 50%.
Employing an innovative variable 'on' and 'off' time control scheme with an adjustable peak switch current limit, the chips are significantly simpler to
control than alternative PFM solutions. The drivers also enable both LED current and peak inductor current to be set accurately and independently.
The ZXLD132X feedback control circuit ensures excellent load and current regulation, resulting in LED current stability of typically +/-3% throughout
the useful life of the battery and over the extended operating temperature range of –40ºC to 125ºC. LED current can be adjusted from 100% down to
10% of preset value by applying a DC voltage signal and down to 2% using a PWM input.
The highly integrated ZXLD132X LED driver family also features a thermal control circuit that monitors an external thermistor in order to linearly reduce
output current once temperature exceeds a predetermined threshold. The device can also be shut down by applying a low-level DC voltage signal.
Chris Jolly, VP Marketing, Zetex Semiconductors said, "By combining the DC-DC converter, a current monitor for accurately stabilising the output
current, the thermal control circuitry and a powerful 2A NPN switching transistor into a tiny DFN package, we have enabled our customers to
maximise the Lumen output they get from the latest LED technology."
At the head of the product family, the ZXLD1320 buck mode driver will deliver up to 1.5A continuous LED current for an input voltage range of 4V to
18V. Providing up to a maximum of 24W of power, depending on supply voltage and external component selection, the device will suit halogen lamp
replacement and battery driven applications.
The ZXLD1321 is a boost mode driver operating with an input voltage range of 1V to 12V and delivers an LED current of 1A, while the ZXLD1322 is a
buck/boost mode driver producing 700mA for an input voltage of 2.5V to 15V. Both devices suit high power LED flashlight, LED back-up lighting and
general LED driving applications
December 2007
*Current monitor simplifies high voltage circuit protection*
With its extended common-mode sensing voltage range of 3V to 60V, the ZXCT1080 current monitor from Zetex Semiconductors provides a simple
solution for high side current sensing in a wide range of high voltage circuit protection duties in automotive, industrial motor control and power supply
applications.
By integrating a gain setting resistor, providing a fixed voltage gain of 10, the current monitor also reduces the number of external resistors needed to
measure current to just one. The reduction in circuit complexity, combined with the monitor’s SOT23-5 package, means savings in solution cost and
footprint can be achieved.
Working off a separate 4.5V to 12V supply voltage, the ZXCT1080 current monitor enables its ground referred output voltage to be closely matched
with A-D converters and microcontrollers and to be protected against harmful over-voltage conditions.
This device is also characterised by a low quiescent current – typically 80µA - which serves to reduce the error incurred in translating the actual
current being measured into the input sense current required and the overall power consumption.
September 2007
*High performance transistors set new performance standards in portable applications*
Zetex Semiconductors has added a pair of low voltage PNP transistors to its low saturation high current SOT23FF transistor range. With the
footprint of the standard SOT23 package but with a reduced off board height of less than 1mm, the ZXTP25020CFF and ZXTP19020DFF will suit a
range of slimline portable product designs.
Helping to reduce component counts and increase power density, the devices serve as cost effective switchers in a variety of portable applications,
including linear charging and high side load switching circuits.
By guaranteeing a reverse blocking capability of 7 volts, the ZXTP25020CFF removes the need for a series connected Schottky diode in linear
chargers. This saves up to 50% PCB area compared with similar footprint P-channel MOSFETs, which due to their inherent drain-source body diode,
require a series Schottky diode.
The SOT23FF package offers an improved thermal resistance of 158ºC/W giving a power rating of 0.8W from a 15mm x 15mm PCB area, thereby
substantially increasing power density when compared to standard SOT23 solutions. Power dissipation can rise to 1.96W for applications where the
equivalent PCB space of 50 x 50mm is available.
In high side switching and load or disconnect switches, the ZXTP19020DFF reduces the voltage drop to just 70mV at 1A and a base drive of 20mA
or 160mV at 2A for a 40mA base drive, which can be equated to an equivalent resistance of 70m? - in a PCB footprint of 2.5mm x 3mm.
*Versatile monitor provides accurate current measurement at low cost*
Zetex Semiconductors has introduced a low cost current monitor producing a current output signal with an accuracy as high as 1%. Housed in the
5-pin SOT23 package and with a wide, 2.5V to 20V, common mode voltage range, the ZXCT1020 provides a versatile current measurement solution
or a wide range of applications from low voltage portables through to automotive circuitry.
Converting the voltage developed across a sense resistor into a ground referenced current output this high side current monitor is simply configured
using low cost external resistors. As a result, the device output can be scaled independently of the sense resistor, using one resistor to set the
transconductance and another to set the overall gain and output impedance.
The ZXCT1020’s verimprovement in performance for very small sense voltages at high current levels. For such conditions, accuracy is further
enhanced
by the device’s very low minimum operating current consumption,
typically 25µA.
The current monitor’s improved temperature drift characteristics helps reduce calibration requirements by maintaining accuracy over a wide
temperature
range - its ambient temperature range of -40ºC to 85ºC making it suitable for the most arduous industrial operating conditions.
The ZXCT1020 will also
serve as a precision programmable current source in a range of applications including high linearity oscillators and F/V
converters.
August 2007
*High performance transistors increase power supply power density*
Zetex Semiconductors has introduced a series of miniature NPN and PNP transistors for MOSFET gate driving in latest generation power supplies.
The first bipolars to be provided in the SOT23FF package, with a footprint of 2.5mm x 3mm and an off-board height of just 1mm, the ZXTN and ZXTP
transistors offer a lower saturation voltage and higher current gain hold up, leading to improved circuit efficiency and cooler running.
Covering the operating voltage range from 20V through to 100V the Zetex bipolar transistors are able to drive MOSFET gates faster and more
efficiently than CMOS IC alternatives and being immune to latch-up, they offer an improvement in overall system reliability. The use of the SOT23FF
package also allows the devices to sit as close as possible to the MOSFET, helping to minimise track inductance and ringing effects.
The 20 volt ZXTN19020CFF and ZXTP19020CFF have guaranteed gains of 100 at 7A and 110 at 5A respectively. When connected in a common
emitter configuration they provide extremely fast switching, with propagation times less than 2ns and rise and fall times between 10 and 20nsecs.
With a peak current performance up to 15A, they offer a highly cost effective alternative to dedicated gate driver ICs.
In saturated switch applications based on the Royer and push pull topologies used in POL DC-DC modules and emergency lighting, the transistors’
low saturation voltage capability provides a significant advantage. As an illustration, the 60V rated ZXTN19060CFF NPN has a saturation voltage of
just 150mV at 1A with a base drive of 10mA, or 135mV at 2A and a base drive of 40mA.
June 2007
*Monitor provides accurate short circuit current measurement*
A wide common mode input voltage range, from ground to within 2V of the supply voltage, ensures that the ZXCT1050 current monitor from Zetex
Semiconductors will continue to provide accurate current measurement even if the load is short circuited. Its current output topology and very low
offset voltage increases its versatility and allows it to be optimised for low in-line voltage drop.
Able to operate on both high and low sides of the load, the monitor will support dynamic output current limitation circuits in a broad range of
applications, from power supply bricks to motor control circuits.
The ZXCT1050 translates the voltage across an external sense resistor into an accurate proportional output current. Since the monitor’s voltage
gain is programmable – accurately set using two external resistors – designers can select the sense resistor value to achieve the
best compromise
between accuracy and power dissipation.
At 50µA, the current monitor’s quiescent current is also 10 times less than that of larger packaged alternatives, providing an improvement in
overall power efficiency. The monitor is offered in the compact SOT23-5 format and will operate over an extended industrial temperature range from
–40ºC to 125ºC.
To simplify thermal control, the input resistance of the chip’s adjust pin has been set at 50k? in order to be compatible with common thermistor
values. The chip’s compact design and ability to comfortably withstand high-voltage transients, means it will also appeal to space-starved automotive
and industrial applications.
May 2007
*Miniature LED driver tackles higher power tasks*
Miniature LED driver tackles higher power tasks Operating from a 6V to 60V input supply and achieving up to 95% efficiency, the ZXLD1362 from
Zetex Semiconductors can drive up to 16 high power LEDs with an adjustable output current of up to 1A. Provided in the tiny TSOT23-5 package,
this LED driver is the smallest of its kind in its current rating, with a maximum footprint of 2.8mm x 2.9mm and off-board height of 1mm.
Simple to use and requiring just four external components, this highly integrated chip supports a range of flexible LED brightness and thermal
management schemes. Output current can be adjusted by applying either PWM or DC voltage control signals to the adjust pin. Application of a low
voltage signal turns the output off and puts the device into a low current standby mode.
Supporting an operating frequency of up to 1MHz, the ZXLD1362 is able to offer highly sensitive and accurate LED brightness control, with a typical
dimming ratio of 1000:1 cited at 300Hz. A soft-start feature can also be achieved by the addition of an external capacitor.
Integrating a 60V MOS switch and a high-side output current sensing circuit, which uses an external resistor to set the nominal output current, the
chip enables high power LEDs to benefit from ground referenced return paths, of particular importance in architectural lighting applications.
To simplify thermal control, the input resistance of the chip's adjust pin has been set at 50k? in order to be compatible with common thermistor
values. The chip's compact design and ability to comfortably withstand high-voltage transients, means it will also appeal to space-starved automotive
and industrial applications.
*Zetex expands cost effective shunt regulators*
Zetex has used its experience in micro-power references to expand its range of cost effective shunt regulators.
ZTL431 is available in SOT23, SOT23F and now SC70-6 for space constrained applications. The ZTL431AH6TA is Zetex’ first shunt regulator in
the SC70 package.
The ZTL432 is available in SOT23 and the low profile SOT23F package.
The ZTL431/432 are available in the extended industrial temperature as standard and matches all TL431/2 specs except maximum operating voltage
(20V),
Zetex also offers the ZTLV431: a 1.24V shunt regulator used in isolated low voltage (<3V) power supplies; extended industrial temperature range as
standard.
The ZTL431/2 Knowhow (URL Link to follow) guide contains more information about the competitive edge of this product
April 2007
*LED lighting driver increases power density*
Providing an adjustable output current of 1A from a SOT23 package, the ZXLD1360 LED driver from Zetex Semiconductors offers higher power
density than alternative and much larger SO8 devices. A buck regulator device, it operates over a supply range of 7V to 30V and is capable of
handling
up to 24W of output power in a wide range of high power LED illumination applications.
Achieving up to 95% efficiency, this LED driver’s thermally enhanced construction combines with a high level of component integration to
create compact LED lighting solutions which are low in part count and simple to configure. The ZXLD1360 integrates a 30V NDMOS switch and
a high-side current sensing circuit, which sets the average output current in relation to an external sense resistor.
Where LED brightness control is required, the output current can be adjusted above or below the set value by applying an external DC voltage or
PWM control signal to the ADJ pin. The driver’s in-built PWM filter also provides a soft-start capability by controlling the rise of input/output
current. Soft start time can be further increased using an external capacitor. Applying a low voltage to the ADJ pin turns the output off and puts
the device into a low current standby mode.
Designed to be used in LED-based automotive, industrial, emergency and architectural lighting circutits and in general illumination applications,
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Zetex Semiconductors Plc