Atmel ICE50, User Manual

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General Description
3-14 ICE50 User Guide
2523A–AVR–11/02
3.5.3 Analog Comparator The Analog Comparator is built around a high speed comparator and a CMOS output
buffer/voltage converter. Figure 3-20 shows the Analog Comparator block diagram. The
total propagation delay from the AIN0 and AIN1 pins to the internal ACO signal is typi-
cally 90ns, max 210ns. For parts, the total propagation delay from the AIN0 and AIN1
pins to the internal ACO signal is typically 500 ns, max 750 ns.
The comparator features an internal hysteresis of typical 1 mV, max 4 mV @ 25
°
C to
ensure clean switching.
Figure 3-20. Analog Comparator Block Diagram
3.5.4 A/D Converter The block diagram of the ICE50 AD converter is shown in Figure 3-21.
Figure 3-21. ICE50 AD Converter
ACME
ADEN
AIN1
ADC Multiplexer
Output
ACBG
1.2V
AIN0
+
-
ACD
100R
ACO
ANALOG COMPARATOR
330
Ω
330
Ω
330
Ω
330
Ω
330
Ω
330
Ω
330
Ω
330
Ω
Pos
Input
Mux
Neg
Input
Mux
ADMUX Decoder
1.2V
V
CC
V
CC
+
-
10K
10K
+
-
ref
ref
1x/10x/100x
1x/2x
ADC Multiplexer Output
10-bit ADC
Vin
Vref
330
Ω
330
Ω
Voltage
Reference
Selection
Aref Out
+
-
10K
10K
+
-
Vref
2
Q[0..9]
A/D Converter
ADC7
ADC6
ADC5
ADC4
ADC3
ADC2
ADC1
ADC0
AVCC
Aref
2.5V