HT82K628A Windows 2000 PS/2 Keyboard Encoder Features Design for Windows 95/98/NT/2000/XP 101/102/104/105/107/109 keys or other special ap- TM plication keyboard encoder Supports Windows keys 8 external hot keys Supports PC/AT and PS/2 code set 1, 2, 3 Supports Mini-keyboard and Internet/Multimedia Supports Japanese , Korean , Brazilian and keyboard European WINDOWS is a registered trademark of Microsoft RC oscillator corporation Phantom key detection 40-pin DIP package Low power consumption General Description The HT82K628A is a keyboard encoder designed for An inexpensive RC oscillator can be used for the system IBM PC/AT, IBM PS/2 and all compatible machines. clock. Simple implementation of this device is an advan- tage for high performance and low cost keyboard appli- The HT82K628A accepts keyboard inputs and provides cations. a 16-character first-in-first-out buffer in which data is stored. Pin Assignment % Rev. 1.60 1 April 16, 2004HT82K628A Pin Description Pin No. Pin Name I/O Description 10~7, 2~1, 40~39, 29~22, R0~R19 O Keyboard matrix scanning output pins 14~11 6~3, 38~35 C0~C7 I Keyboard matrix scanning input pins 15 VSS Negative power supply, ground 16 SCROLL O Scroll Lock indicator 17 NUM O Num Lock indicator 18 DATA I/O Bidirectional data transmission line 19 CLOCK I/O Synchronous clock signal. Used to clock the transmission data. 20 Fn Select I Mini-keyboard select, enables the function if connected to VSS. 21 Macro Key Select I Macro Key select, disables the function if connected to VSS. 30 CAPS O Caps Lock indicator Chip reset input. Active low. Built-in power-on reset circuit to reset the en- 31 RESET I tire chip. Chip can also be externally reset via RESET pin. 32 VDD 5.0V positive power supply 33 OSC1 I System clock input 58.3k resistor connected for RC OSC 34 NC No connection Absolute Maximum Ratings Supply Voltage ..........................V 0.3V to V +5.5V Storage Temperature ........................... 50 Cto125 C SS SS Input Voltage .............................V 0 3V to V +0.3V SS . DD Operating Temperature .......................... 25 Cto70 C Note: These are stress ratings only. Stresses exceeding the range specified under Absolute Maximum Ratings may cause substantial damage to the device. Functional operation of this device at other conditions beyond those listed in the specification is not implied and prolonged exposure to extreme conditions may affect device reliabil- ity. Electrical Characteristics Ta=25 C Test Conditions Symbol Parameter Min. Typ. Max. Unit V Conditions DD V Operating Voltage 3 5 5.25 V DD I Operating Current (RC OSC) 5V No load, f = 4MHz 2.5 5 mA DD SYS V Input Low Voltage 5V 0 1.5 V IL V Input High Voltage 5V 3.5 5V IH I Sink Current (C0~C7, R0~R19, DATA, CLOCK) 5V V = 0.5V 16 25 mA OL OL I Source Current (C0~C7, R0~R19) 5V V = 4.5V mA OH1 OH 8 16 I Source Current (Scroll, Num, Caps) 5V V = 4.5V mA OH2 OH 2.5 4 I LED Sink Current (Scroll, Num, Caps) 5V V =3.4V 10 18 24 mA LED OL R Internal Pull-high Resistance (C0~C7, R0~R19) 5V 512 20 ph k R Internal Pull-high Resistance (DATA, CLOCK) 5V 2 4.7 8 k ph1 R Internal Pull-high Resistance (RESET)5V 25 50 75 k ph2 f System Clock (RC OSC) 5V 4 MHz SYS Rev. 1.60 2 April 16, 2004