TC815

DS21474B-page 12

© 2002 Microchip Technology Inc.

5.0

MANUAL RANGE SELECTION

The TC815 voltage and resistance auto-ranging fea-

ture can be disabled by momentarily bringing RANGE

(Pin 59) to digital ground potential (Pin 58). When the

change from auto-to-manual ranging occurs, the first

manual range selected is the last range in the Auto-

Ranging mode.

The TC815 power-up circuit selects auto-range opera-

tion initially. Once the manual range option is entered,

range changes are made by momentarily grounding

the RANGE control input. The TC815 remains in the

Manual Range mode until the measurement function

(voltage or resistance), or measurement option (AC/

DC,

Ω/LOΩ) changes. This causes the TC815 to return

to auto-ranging operation.

The “Auto” LCD annunciator driver is active only in the

Auto-Range mode. Table 5-1 shows typical operation,

where the manual range selection option is used. Also

shown is the extended resolution display format.

Also see Figure 5-1 through Figure 5-3.

Note

1: A flashing MSD is shown as a “1”. A flashing MSD indicates the TC815 is over-ranging if all other digits are zero.

2: The first manual range selected is the last range in the Auto-Ranging mode.

3: A flashing MSD with a non-zero display indicates the TC815 has entered the Extended Resolution Operating mode. An

additional 1000 counts of resolution is available. This extended operation is available only in manual operation for voltage,

resistance and current measurements.

4:

= Momentary ground connection.

TABLE 5-1:

MANUAL RANGE OPERATION

Input

DC Volts

AC Volts

Ohm

LO Ohm

23.5V

18.2V

18.2k

Ω

2.35M

Ω

Range

Display

Range

Range

Display

Range

Range

Display

Power-on

Auto-Range

Operation

200mV

“1”00.0V

2V

“1”000V

200

Ω

“1”00.0

Ω

2k

Ω

“1”.000k

Ω

2V

1.000V

20V

18.20V

2k

Ω

“1”.000k

Ω

10k

Ω

“1”.0.00k

Ω

20V

“1”0.00V

—

—

20k

Ω

18.20

Ω

200k

Ω

“1”.00.0k

Ω

200V

23.5V

—

—

—

—

2000k

Ω

“1”350k

Ω

Manual Operation

Input

DC Volts

AC Volts

Ohm

LO Ohm

23.5V

18.2V

18.2k

Ω

2.35M

Ω

# of Range

Changes

(See Note 4

)

Range

Display

Range

Range

Display

Range

Range

Display

1

200V

23.5V

20V

18.20V

20k

Ω

18.20V

2000k

Ω

“1”350k

Ω

2

200mV

“1”00.0V

2V

“1”.000V

200

Ω

“1”00.0

ΩkΩ

2k

Ω

“1”.000k

Ω

3

2V

1.000V

20V

18.20V

2k

Ω

“1”000k

Ω

20k

Ω

“1”0.00k

Ω

4

20V

“1”3.50V

20V

18.2V

20k

Ω

18.20k

Ω

200k

Ω

“1”00.0k

Ω

5

200V

23.5V

600V

19V

200k

Ω

18.2k

Ω

2000k

Ω

“1”350k

Ω

6

1000V

24V

2V

“1”.000V

2000k

Ω

19k

Ω

2k

Ω

“1”.000k

Ω

7

200mV

“1”00.0mV

20V

18.20V

200k

Ω

“1”00.0

Ω

20k

Ω

“1”0.00k

Ω

8

2V

“1”.000V

200V

18.2V

2k

Ω

“1”.000k

Ω

200k

Ω

“1”00.0k

Ω