
S1C62740 TECHNICAL HARDWARE
EPSON
I-101
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (General-purpose Operation Amplifier)
General-purpose Operation Amplifier (AMP)
4.13
Configuration of
AMP circuit
The S1C62740 has an MOS input general-purpose operation
amplifier built into two channels (AMP0 and AMP1). The respective
AMP, which has two differential input terminals (inverted input
terminal AIM, noninverted input terminal AIP) and output terminal
(AOUT), can be used for general purposes.
When using this circuit as a general-purpose operational amplifier,
make sure that the output voltage does not exceed VDDA. In
addition, use within the permitted range of the operating
conditions on page I-128.
Figure 4.13.1 shows the configuration of the AMP circuit.
Operation of AMP
circuit
(1) AMP circuit ON/OFF control
The AMP circuit AMP0 and AMP1 ON/OFF are controlled by
register AMPON0 and AMPON1, respectively. Writing "1" to the
register turns ON the AMP circuit, and writing "0" turns OFF
the circuit. Because the power current consumption of the IC
becomes big when the AMP circuit is turned ON, set the AMP
circuit to OFF unless otherwise necessary.
A waiting time of at least 3 msec is required for the AMP circuit
to become stable after its power is turned ON.
(2) AMP output
The outputs of AMP0 and AMP1 are output to outside through
AOUT0 and AOUT1 terminals, respectively. When the AMP
circuit is used in such a way that the comparator output takes
binary form ("0" or "1"), the output data can be read through
register AMPDT0 (AMP0 output data) or AMPDT1 (AMP1 output
data).
When the AMP circuit is OFF (when AMPON0 or AMPON1 is set
to "0"), AOUT0/AOUT1 shift into a high-impedance status and
the read data AMPDT0/AMPDT1 goes "0".
Address
AMPON0(1)
Power
control
Input
control
Data
bus
AIP0(1)
AIM0(1)
VDDA
AMPDT0(1)
AOUT0(1)
VSSA
+
-
Fig. 4.13.1
Configuration of AMP circuit