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TELCOM SEMICONDUCTOR, INC.

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5V PRECISION DATA ACQUISITION

SUBSYSTEMS

TC530

TC534

verter input. A0 is the least significant address bit (i.e.,

channel 1 is selected when A0 = 1 and A1 = 0). The

multiplexer is designed to be operated in a differential mode.

under selection must be connected to the ground reference

associated with the input signal.

EOC

R/W

RESET

1

1001111

AZ

AZ

LOAD VALUE

MSB

LSB

INT

DINT

IZ

AZ…

Conversion

Phase

Timing

Status

Converter held in AZ

state due to RESET = 1

Write LOAD VALUE to Serial Port

Power-up RESET

Undefined

Converter in Normal Service

R/W brought LOW during AZ

for serial port write cycle

R/W = HIGH strobes

LOAD VALUE into

timebase and starts

conversion

Continuous Conversions

Figure 4. TC530/534 Initialization and Load Value Write Cycle

EOC

OVR POL MSB

LSB

R/W

Figure 5. Serial Port Data Read Cycle

DC/DC Converter

An on-board, TC7660H-type charge pump supplies

negative bias to the converter circuitry, as well as to external

devices. The charge pump develops a negative output

voltage by moving charge from the power supply to the

The charge pump clock operates at a typical frequency

of 100kHz. If lower quiescent current is desired, the charge

pump clock can be slowed by connecting an external ca-

teristics curves.

APPLICATIONS

Design Example

Figure 6 shows a typical TC534 interrupt-driven applica-

tion. Timing and component values are calculated from

equations and recommendations made in the Dual Slope

Integrating Converter and Programming the TC530/534

sections of this document. The EOC connection to the

processor INT input is for interrupt-driven applications only.

GIVEN

REQUIRED RESOLUTION:

16 Bits (65,536 counts.)

±2V

POWER SUPPLY VOLTAGE: +5V

60Hz SYSTEM

66msec

2. Estimate crystal frequency

(use 2MHz)