Measure Mode

FS501 has voltage measuring and resistance measuring modes, and the modes are controlled by 00F register

MODE3:0. When MODE=0, it is in the voltage measuring mode. The measured voltage can be either directly

fed from INHMUX to ADC, or fed through the ACBUF amplifier and then fed to the ADC.

ON CHIP

OFF CHIP

OSRC

Rth

HUNK

TENM

Rref2

Rref1

OSR

OSR

OSREN

AGND

SGND

hunk<1>

OSRC

hunk<0>

tenm<0>

SDB

INL

INH

VRL

VRH

hunk<2>

tenm<1>

tenm<1>

When MODE=1, it is in the resistance measuring mode. The circuit is shown in Fig. 9. Suppose that the

Equation 3

out

VRL

VRH

INL

INH

ref

th

D

G

V

V

V

V

R

R













resistance measuring circuit is shown in Table 8.



Table 8. Setup Table of the Resistance Measuring Circuit

Range Mode

MODE3:0

HUNK

hunk2:0 tenm1:0

HUNK

1001

1

111

00

TENM

1001

0

000

11