HT82K629A-40DIPLF HOLTEK, HT82K629A-40DIPLF Datasheet - Page 21

• Manufacturer Part Number: HT82K629A-40DIPLF
• Description: IC, USB/PS2 CONT, WIN 2000 KEYBOARD
• Manufacturer: HOLTEK

Specifications of HT82K629A-40DIPLF

• Usb Type: Keyboard Encoder
• Usb Version: 1.1
• Supply Voltage Range: 4.4V To 5.5V
• Operating Temperature Range: 0°C To +70°C
• Digital Ic Case Style: DIP
• No. Of Pins: 40
• Operating Temperature Max: 70°C
• Base Number: 82
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Application Circuits
Note:
Rev. 1.40
For single side PCB, the GND should be routed first. Avoid routing the GND line and VDD line with jumping
wires.
The GND and VDD lines should be as wide as possible, also it is recommended that the GND and VDD lines
are placed in an empty area, in order to increase their area. Wherever possible the GND plane should surround
pins such as OSCI, OSCO, VDD, V330, RESET etc and other related circuits to minimize the noise effects.
The GND/VDD loop area should be minimized. Try to keep GND and VDD lines parallel.
The external 22 resistor and 0.01 F capacitor connected to the VDD pin should be placed as close as possi-
ble to the VDD pin.
Allow room in the layout for the 0.1 F capacitor that is connected to the VDD pin. This capacitor should be con-
nected as close as possible to the VDD pin. The function of this capacitor is to filter out high frequency noise.
The lines connecting the OSCI and OSCO pins to the crystal must be kept as short as possible to minimize any
cross coupling of noise from these pins.
The 0.1 F capacitor connected to the RESET pin should be placed as close as possible to the RESET pin. The
function of this capacitor is to filter out high frequency noise to minimize the possibility of a glitch on this line
causing a false reset.
The 0.1 F capacitor connected to the V33O pin should be placed as close as possible to the V33O pin.
The USBD+ and USBD- lines to the USB connector should be kept as short as possible and should not be
placed close to the other lines to reduce the possibility of noise coupling into other lines. The externally con-
nected 1.5k resistor connected to the USBD- pin should be placed as close to as possible the USBD- pin.
The USB cable should preferably have proper shielding.
21
September 15, 2004
HT82K629A