Common Datasheets
Here are some datasheets that students tend to use a lot. NOTE: For more datasheets of "jellybean" (i.e., 74XX) devices, have a look at [http://www.fairchildsemi.com Fairchild].
Check out the [http://www.datasheetarchive.com Data Sheet Archive] for datasheets of obsolete devices. Also check out TI's [http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/UnderstandingLogicDataSheets.pdf Understanding and Interpreting Standard-Logic Data Sheets] application note for a guide to understanding these documents.
74XX Series
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74AC00.pdf 7400]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74HCT04.pdf 7404]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74LS05.pdf 7405]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74AC08.pdf 7408]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74LS14.pdf 7414]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74ACT32.pdf 7432]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74ALS74.pdf 7474]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74ALS86.pdf 7486]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74ls138.pdf 74138]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74LS148.pdf 74148]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74LS151.pdf 74151]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74LS155.pdf 74155]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74LS161A.pdf 74161A]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74LS162.pdf 74162]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74ALS162.pdf 74162]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74AC163.pdf 74163]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74LS164.pdf 74164]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74HC165.pdf 74165]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74LS166.pdf 74166]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74AS181A.pdf 74181A]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74LS191.pdf 74191]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74ACT191.pdf 74191]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74LS192.pdf 74192]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74ABT240.pdf 74240]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74ACT244.pdf 74244]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74FR245.pdf 74245]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74LS273.pdf 74273]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74AHC573.pdf 74573]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74HCT374.pdf 74374]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74HC4040.pdf 744040]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/74HC4511.pdf 744511]
Discrete Components
Diodes
Bipolar Transistors
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/2N3904.pdf 2N3904 NPN transistor]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/2N2222A.pdf 2N2222A NPN transistor]. NOTE: ON Semiconductor published a datasheet for this a while ago with a reversed pinout! The 2N2222 should have the same pinout as a 2N3904.
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/2n4410.pdf 2N4410 NPN transistor]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/MMBTA06.pdf MMBTA06 NPN SMT transistor]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/2N3906.pdf 2N3906 PNP transistor]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/mpsa56.pdf MPSA56 PNP transistor]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/MMBT2907A.pdf MMBT2907A PNP SMT transistor]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/TIP31_A_B_C.pdf TIP31 power NPN transistor]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/TIP32_A_B_C.pdf TIP32 power PNP transistor]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/TIP120_121_122.pdf TIP122 NPN Darlington transistor]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/TIP125_126_127.pdf TIP125 PNP Darlington transistor]
MOSFET's
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/NDP6030PL.pdf NDP6030PL P-channel logic-level MOSFET]
[http://rocky.digikey.com/WebLib/Fairchild/Web%20Data/RFD14N05L,05LSM_RFP14N05L.pdf RFD14N05L N-channel logic-level MOSFET]
[http://rocky.digikey.com/WebLib/On-Semi/Web%20Data/2N7000-D.pdf 2N7000 N-channel digital interface logic-level MOSFET]. Also see the 2N7002 surface-mount version, and the [http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/FDV301N.pdf FDV301N]/[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/FDV303N.pdf FDV303N] N-channel digital MOSFET's, and their P-channel counterparts, the FDV302P/FDV304P.
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/2n3819.pdf 2N3819 N-channel JFET]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/irl2703.pdf IRL2703 N-channel MOSFET]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/irfp450x.pdf IRFP450 N-channel MOSFET]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/irf520.pdf IRF520 N-channel MOSFET]
Timers/Oscillators
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/LMC555.pdf LMC555 timer]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/MXO45,45T,45HS,45HST.pdf MXO45 oscillator]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/LTC6900.pdf LTC6900] (up to 20 MHz), [http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/LTC1799.pdf LTC1799] (up to 33 MHz), and [http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/LTC6905.pdf LTC6905] (up to 170 MHz) SOT-23 silicon oscillators programmable with one resistor
Linear Devices
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/LM311.pdf LM311 comparator]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/tlv2371.pdf TLV2371/2/4 rail-to-rail op-amp] (single, dual, quad)
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/LMV821.pdf LMV821/2/4 rail-to-rail op-amp] (single, dual, quad)
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/lm741.pdf LM741 op-amp]
[http://rocky.digikey.com/WebLib/Linear%20Tech%20Web%20Data/LT1638,%20LT1639.pdf LT1638 dual rail-to-rail op-amp]
[http://www.national.com/ds/LM/LM1458.pdf LM1458 dual op-amp]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/OPA227.pdf OPA227 high-precision op-amp]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/PGA2311.pdf PGA2311] and [http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/PGA4311.pdf PGA4311] digitally-programmable-gain audio amplifiers
Linear Regulators
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/7805.pdf 7805 +5V regulator]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/7905.pdf 7905 -5V regulator]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/LM317.pdf LM317 adjustable 1.5A positive regulator]
[http://rocky.digikey.com/WebLib/Fairchild/Web%20Data/LM350.pdf LM350 adjustable 3A positive regulator]
[http://rocky.digikey.com/WebLib/Texas%20Instruments/Web%20data/LM237,337.pdf LM337 adjustable 1.5A negative regulator]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/LM340.pdf LM340 +5V regulator]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/lm2940.pdf LM2940 LDO]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/lm1117.pdf LM1117 LDO]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/LP2975.pdf LP2975 ultra-low current LDO using an external MOSFET]
Interface Devices
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/ADM232L.pdf ADM232L RS232 interface]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/ADM233.pdf ADM233 RS232 interface (no capacitors)]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/MC1489.pdf MC1489 RS232 receiver]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/MC1488.pdf MC1488/SN75188 RS232 driver]
EEPROM
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/25LC040.pdf 25LC040 4K SPI EEPROM]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/93AA46.pdf 93AA46 1K serial EEPROM]
Digital Potentiometers
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/AD8400.pdf AD8400]
[http://rocky.digikey.com/WebLib/Microchip/Web%20Data/MCP41XXX_42XXX.pdf MCP41010 single 10k potentiometer]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/MCP42100.pdf MCP42100 dual 100k potentiometer]
A/D Converters
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/ADC0831.pdf ADC0831 8-bit serial A/D]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/TLC548CP.pdf TLC548CP 8-bit serial A/D]
D/A Converters
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/LTC1661.pdf LTC1661 10-bit dual D/A]
Analog Switch
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/SN74HC4066.pdf 74HC4066 quad analog switch]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/MAX4677-MAX4679.pdf MAX4677/8/9 analog switches with 2-Ohm on-resistance]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/TLP227Gn.pdf TLP227 optically-isolated analog switch]
Current Sense
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/ZXCT1010.pdf ZXCT1010 high-side current monitor]
Voltage Converters
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/NJU7660.pdf NJU7660 voltage doubler/inverter]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/NKASeriesDCDCConverters.pdf NKA Series isolated 1W DC/DC converters]
Programmable Logic
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/ATF16V8.pdf ATF16V8]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/ATF22V10CQZ.pdf ATF22V10CQZ]
Motor Control/Interface
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/L293.pdf L293 dual H-bridge] (outdated...use 754410)
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/SN754410.pdf 754410 dual H-bridge]
Miscellaneous Drivers
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/A6276.pdf A6276 16-channel serial-input LED driver]
Memory
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/AT45DB321B.pdf AT45DB321B 4 megabyte SPI-serial FLASH memory]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/CY7C1019B.pdf CY7C1019B 128Kx8 SRAM]
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/CY7C109B,CY7C1009B.pdf CY7C109B 128Kx8 SRAM], comparable to the CY7C1019B but lower power.
Optoisolators
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/HCPL-7510.pdf HCPL-7510] linear optocoupler (think optoisolator for analog voltages instead of digital signals). The HCPL-7800 is more accurate, the HCPL-7520 slightly less accurate. Price varies accordingly.
Microchip PIC
Atmel AVR
Microcontroller Supervisors
[http://claymore.engineer.gvsu.edu/~steriana/courses/Downloads/datasheets/MCP130.pdf MCP130 reset supervisor]