HT45R2K-C Datasheet, PDF (66/105 Pages) Holtek Semiconductor Inc – Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale

HT45R2K-C/-B/-A
Dual Slope 16K/8K/4K ASSP MCU for Body Fat Scale
DO PAP
IA
DO PAN
O P 5N
O P 5P
R v f1
V IN T
VDSO
PW R
C o n tro l
VO REG
ADPW REN
M
PG A
U
A D IS
( G a in = 2 ,4 )
X
M UX
fro m
DCHOP
fro m
T H /L B
PG AG
R v f2
+
-
In te g ra to r
R v f3
V CMP _-
+ _{C o m p a ra to r}
ADCM PO
O n C h ip
O ff C h ip
DO PAO
DCHOP
T H /L B
DSRR _DSRC
R F C _{( A D in p u t fo r e x te r n a l}
th e r m a l/lo w b a tte r y d e te c tio n
o r o th e r u s a g e )
DSCC
N o te : V IN T , V C M P s ig n a l c a n c o m e fr o m d iffe r e n t R g r o u p s w h ic h a r e s e le c te d b y s o ftw a r e r e g is te r s .
Dual Slope ADC Structure
A D D IS C H 0
A D D IS C H 1
An instrumentation amplifier is included to provide a high CMRR amplifying interface to differential
signals from external sensors. With a standard instrumentation amplifier setup of three operational
amplifiers and a DAC for offset calibration, this structure provides a low noise sensor interface.
Two registers are used for overall control of the instrumentation amplifier and a single register for
DAC control. If these functions are not used they should be disabled using the register bits to reduce
power consumption.
DOPAN
+
OP5N
0.22uF
102
OP3
-
10k
100pF
RA_String
Bridge
Sensor
47uF
16V
0.1uF
102
DOPAP
Gain = 1/2/4/8/16/32
-
OP4
+
10k
OP5P
100pF
-
OP5
+
RSEN
82k
DOPAO
Vout
Gain = 4/5/6/7/8/9
RB_String
DCHOP
105
6 bits
DAC
RSEN
Instrumentation Amplifier
Rev. 1.20
66
May 30, 2013