Each month we’re compiling a list of part searches from Findchips.com & Parts.io, taken from Supplyframe’s ranked search feed. From that list we’ve stripped out the standard fare (e.g. discrete resistors & capacitors in chip packages – 0402, 0603, 0805, etc) and what’s left is a snapshot of what you and others are searching for and our comments on some of the items we found curious.
Category: Microcontroller IC
In the number 10 spot for January is the (Dallas) Maxim DS80C400-FNY 8-bit MCU and in a world seemingly dominated by ARM, this device proves that not only is the 8051 alive and well, but it continues to be popular enough to rank amongst our top search results. Sadly…this little device is OBSOLETE as of April of 2014 and the numbers this month appear like a mad dash for inventory as folks gear up to get their last orders in before the product’s ‘last delivery date’, scheduled for October 2015. Judging by the lack of inventory already, it seems true the early birds are going to force some redesign work for the rest of us (though it may be time, no?).
And where ARM may offer better MIPS-per watt-per dollar performance (amongst a range of other performance plusses), this little device has a not-so-shabby set of on-board peripherals including a 10/100 Ethernet MAC, CAN 2.0, 1-Wire Master, and 3 full-duplex HW serial ports. A total of 64 GPIO pins are avail. It also includes a full IPv4/v6 TCP/IP stack and OS included in ROM and supports up to 32 simultaneous TCP connections with a maximum 5Mb/s performance thru the MAC. The firmware ‘implements UDP, TCP, DHCP, ICMP, and IGMP’. Worth noting also are the 5V tolerant inputs. Replacement suggestions are welcome in the comments!
Category: Bus Controller IC
Weighing in at number 9 is the CP2102-GM from the folks over at Silicon Labs and don’t let the categorization fool you, this little micro is really a USB-to-UART. What stood out to us was that this device showed up in the ranked search feed above the FT232 (from FTDI) and though we might have expected FTDI to top the list (though nothing scientific about this assumption aside from a cursory glance at the dev kits I have laying around), closer inspection reveals that both the SiLabs device and the FT232 are pretty closely matched.
Firstly, both were close to the same price though the CP2012-GM was consistently about $0.20 cheaper than the FT232 and though both come in a 5x5mm QFN package, the FT232 comes in a variety of other packaging options (some of which will dwarf your micro if you don’t watch out!). Both support Full Speed USB2.0 (not high speed and not USB3.0) and both provide drivers via their respective manufacturer websites. On-board ROM will enable either device to be programmed with a unique VID, PID, description, etc. though so far as we can tell, only FTDI has released a driver that “bricked” device clones flooding the market.
Category: Optocoupler Output IC
Number 8 is the 6N137 single-channel optocoupler with open-collector, schottky-clamped output. This little device comes in DIP and SOIC packages that’ll no doubt dwarf many of your other components, but provides the sought-after isolation and the right performance (10MBd) for a huge range of applications. We especially like that it supports up-thru TTL levels, so it’s fine to drive this from between 2 to 5.5V and thus it’s pretty versatile, even for use with older CPUs (cough…Arduino…cough :).
Category: Switching Regulator IC
Number 7 this month is the LTM4644IY DC-DC (Buck) converter from Linear Technology and as excited as we are for anything capable of 4x independent output rails, each configured with a single resistor and each capable of up to 4A of output current *per channel* (5A peak); the price <cough> leaves something to be desired, at least if you’re not a part of the target demographic (>$40USD is not uncommon for this device…and no, that’s not a typo). Nevertheless, this little device is super cool for what it does and it’s worth mentioning as it just might replace a much larger and massively more complex power supply system.
By the numbers the LTM4644 accepts a 4-14V input and can regulate that to between 0.6 and 5.5V on each of the 4 output channels and with a maximum output current of up to 4A per channel! (Even at 90+% efficiency, I would be sure and watch how hot this gets…time to finally break out your Flir One and watch the mini-meltdown live!) And while that alone makes it cool, the real kicker is that each output is configured using a single resistor (!). FETs and inductors are all on-board and each output has it’s own independent output enable. This little device also has internal PLLs to synchronize the outputs or they can operate asynchronously.
Clearly the target application is FPGAs with their myriad power requirements, though we got to thinking that a few serial programmable digital potentiometers could make this an awesome and totally versatile benchtop power supply.
Category: Linear Regulator IC
Number 6 is the LM317 linear regulator – brainchild of analog legends Bob Widlar and Robert Dobkin (at the time working for National Semiconductor) – and still in production some 45 years later (!) by just about everyone with a stake in power . And though it might crimp your snowflake-style to admit that you too are using this little adjustable wonder, let’s not forget just how versatile and practical this device was/is and just how much history was made on the backs of these two guys’ design, which dates back to 1970! (…the patent having been issued in 1971)
Firstly the LM317 supports a massive 3-40V input range and will regulate that to between 1V2 and 37V output by way of a simple, two-resistor voltage divider network. And as far as current is concerned, this little gem supports up to 1.5A of output current (you left room for the heatsinks, no?). What’s more, they are about as cheap as they come ($0.15-0.25 USD).
And about the heat? Well, umm…yeah…about that. Hey, as linear regulators go, what goes in goes out, or it goes up. So heatsinks are required and efficiency as you’d expect is a function of that delta between input and output voltages and the total current thru the device. But alas, this hasn’t prevented a device old enough to have kids who have kids from ranking amongst our top search results. For more history, have a look at the following video interview with Bob Dobkin…truly a historic figure in the history of analog and power.
Category: Switch/Digital Output Temperature Sensor
Slipping into the top 5 this month is Maxim’s DS18B20 One-Wire temperature sensor. And though at first glance this component seems pricey – and let’s face it, it is – there are some nice features to such a simple device that it had us thinking about creative ways to use this in our own designs. Firstly, the numbers:
The DS18B20 has user-programmable resolution to between 9 & 12 bits celsius temperature measurements and a supported range of -55°C to +125°C with ±0.5°C accuracy from -10°C to +85°C . The supply voltage can range from +3.0 to +5.5V making this useful in a wider range of applications. It also includes user programmable temperature alarms for both low and high temps.
Some additional features that caught our eye included for example, so-called “Parasite Power” mode in which the device is powered from the data line. Likewise, each device is given a unique 64-bit ID (to enable multiple devices to run on the same one-wire bus, this is part and parcel of one wire devices) and this raised some interesting questions on our end about just “how unique?” and whether or not we could use these uniquely identify parts of our systems (always nice to have a bit of non-volatile storage with an ID in it to know what boards might be plugged into a multi-board assembly or what products you have connected to a larger system).
Category: Operational Amplifier IC
Number 4 on the list is also made by just about everyone with an analog division but that’s largely because it’s a sort of Swiss Army knife for amplifier designs and it’s the LM324N Quad OpAmp. This little device has 4 amplifiers and requires only a single source. So no mucking around with +/- 12V rails (unless you *must*) the LM324 can operate with a single supply input of from 3 V to 32 V (if you choose to use a dual supply, voltages range from ±1.5 V to ±16 V). Low input bias and offset parameters such as a 3mV input offset voltage and 2nA typical input offset current, along with a 20nA bias current make this device one that’s hard to put to bed.
Category: Pressure Sensor
Bottoming out the top three for January was the MPL3115A2 I2C precision altimeter / barometric pressure sensor from Freescale Semiconductor. In an 8-pin LGA package measuring only 5x3mm, this device is ultra-compact targeting mobile phones, GPS devices, laptops, and tablets, amongst others. In addtion to pressure and altitude, this device also includes an on-board temperature sensor so all-up, providing 20-bit barometric pressure resolution, 20-bit altitude resolution, and 12-bit temperature resolution in a single device accessible over I2c, with only limited processor pins required and priced to sell at comfortably below $3 USD.
Category: Operational Amplifier IC
‘And for the Silver?’ January’s silver medal goes to the high-precision MC33078DR Operational Amplifier from our friends at TI. This device has “cool audio applications” written all over it, with a low-low 0.002% total harmonic distortion and ‘excellent phase and gain margins, large output voltage swing with no deadband crossover distortion, and symmetrical sink/source performance.’ A nice little device that makes us want to run out and build ‘something audio’ this weekend, just for kicks.
Regarding the numbers, the MC33078DR supports dual-supply operation powered from ±5 V to ±18 V with a large output voltage swing of 14.1V to -14.6V a high slew rate of 7 V/µs, high gain bandwidth of 16MHz, a low 0.15mV input offset voltage and low noise voltage of 4.5 nV/√Hz.
For the record at least one of us has built a headphone amplifier, though using the TI OPA2132 and it still sounds genius, despite a less-than-our-best effort semi-professional construction effort.
Category: Small Signal FET
Again this month is topped out by something hardly sexy, but no less useful: the BSS138 N-Channel FET which like so many other popular parts, has a place in just about every manufacturer’s product portfolio.
This little device may not be the grunty power MOSFET you’ll use to drive big machines, but rather finds it’s sweet spot driving low power servos and other low-power switching applications. Ultra low Rds(on)of 3.5Ω @ VGS = 10 V, or 6.0Ω @ VGS = 4.5 V means a more efficient device and ultra small packaging and low cost make this a no-brainer for applications calling for FETs.
That’s it for the top ten for January! Please leave comments below and let us know what you think!