DA6502.008

29 November 2012

9 (20)

TEST AND TRIM CONTROL REGISTER

Pins

TE1

(output),

TE2

(input)

and

TE3

(input/output) are used for testing purposes. In

normal use these pins are left floating.

TE2=0: normal operation, (pull down resistor on

chip). TE1 is driven high.

TE2=1: the converter is in continuous integration

mode. The sigma - delta modulator latch output is

connected to the TE1 pin and TE1 is also

connected to the on-chip decimator input. This way

an external decimator can use the TE1 pin signal

and the results from the external and the on-chip

decimator can be compared.

(MEASOSC) turns the oscillator on and connects

the oscillator output to the TE3 pin for frequency

measurement.

oscillator trimming. When set to 1, the six least

adjust the oscillator frequency (see table 4). When

the right frequency is obtained the trim value can be

nominal frequency, 200kHz, is designed to occur

for internal oscillator trimming since this is

done during wafer level testing.

If

TRIMALLREG=0 then data from

EEPROM

set to 1 the internal oscillator is turned off and an

external clock signal can be connected to the TE3

pin. This enables the use of an external conversion

clock.

clock division, forcing the A/D conversion to run at

half the speed. Clock division is also used when an

external clock is used (EXTCLK bit is set).

refreshing sensor sample only at every fourth clock

cycle for additional power saving but with increased

sampling noise level.

Bit Number

Bit Name

Description

Value

Function

7…5

X

-

4

ICLKDIV

Additional clock

division

0

1

100kHz/50kHz to SDM

50kHz/25kHz to SDM

3

ISAMPL

Sample refresh

mode selection

0

1

Refresh at every clock cycle

Refresh at fourth clock cycle

2

TRIMALLREG

Trim bits from

register

0

1

Normal operation

OSC trim register in use

1

EXTCLK

External clock mode

0

1

Normal operation

External clock from TE3

0

MEASOSC

Oscillator test mode

0

1

Normal operation

OSC output to TE3

X = Don’t care, SDM = Sigma delta modulator

Bit Number

Bit Name

Description

Value

Function

7…6

X

-

5…0

OSCF

11111

…

00000

200kHz oscillator frequency

trimming value

X = Don’t care

Note: It is recommended to not change oscillator frequency trimming value since trimming is done during wafer level testing.