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TELCOM SEMICONDUCTOR, INC.

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PRECISION ANALOG FRONT ENDS

TC500

TC500A

TC510

TC514

USING THE TC510/514

Negative Supply Voltage Converter (TC510, TC514)

A capacitive charge pump is employed to invert the

voltage is also available on the V

–

bias elsewhere in the system. Two external capacitors are

required to perform the conversion.

Timing is generated by an internal state machine driven

from an on-board oscillator. During the first phase, capacitor

+

This charge is transferred to capacitor C

–

second phase. The oscillator normally runs at 100kHz to

ensure minimum output ripple. This frequency can be re-

ship between the capacitor value is shown in the typical

characteristics curves at the end of this data sheet.

Analog Input Multiplexer (TC514)

The TC514 is equipped with a four input differential

analog multiplexer. Input channels are selected using select

inputs (A1, A0). These are high-true control signals

(i.e., channel 0 is selected when (A1, A0 = 00).

EVALUATION KIT (TC500EV)

The TC500EV consists of a pre-assembled, 4 inch by 6

inch printed circuit board that connects to the serial port of

any PC or dumb terminal. Design software is also included.

TC500EV helps reduce design time and optimize converter

performance. Please contact your local TelCom representa-

tive for more information.

Design Example

Given:

Required Resolution:

16 Bits (65,536 counts).

±2V

Power Supply Voltage: +5V

60Hz System

line frequency:

1/60Hz = 16.6msec. Use 4x line frequency = 66msec

output swing:

= .32

µF (use closest value: 0.33µF)

NOTE: TelCom recommended capacitor:

WIMA p/n: MK12 .33/63/10

Conversions/sec

= 1/(66msec + 66msec +132msec+2msec)

= 3.7 conversions/sec

NOTE: TelCom recommended capacitor:

WIMA p/n: MK12 .22/63/10

= (4.1) (0.33 x 10

= 1.025V